Publications by authors named "Yahsou Delmas"

60 Publications

IgA nephropathy in association with inflammatory bowel diseases: results from a national study and systematic literature review.

Nephrol Dial Transplant 2021 Jan 8. Epub 2021 Jan 8.

Département de Néphrologie et Transplantation, Centre de Référence Maladie Rare « Syndrome Néphrotique Idiopathique », Hôpital Universitaire Henri Mondor, Assistance Publique-Hôpitaux de Paris AP-HP, Créteil, France.

Background: Little is known about clinical characteristics and kidney outcome in patients with biopsy-proven immunoglobulin A nephropathy (IgAN) in a context of inflammatory bowel disease (IBD).

Methods: We conducted a retrospective multicenter study with centralized histological review, to analyze the presentation, therapeutic management and outcome of 24 patients suffering from IBD associated IgAN relative to a cohort of 134 patients with primary IgAN without IBD.

Results: Crohn's disease and ulcerative colitis accounted for 75% and 25% of IBD-associated IgAN cases, respectively. IBD was diagnosed before IgAN in 23 cases (a mean of 9 years previously) and was considered active at IgAN onset in 23.6% of patients. Hypertension was present in 41.7% of patients. Urinary protein-to-creatinine ratio exceeded 100 mg/mmol in 70.8% of patients (mean: 254 mg/mmol). Estimated glomerular filtration rate (eGFR) exceeded 60 ml/min/1.73m2 in 13/24 patients and only one patient required dialysis. In the Oxford MEST-C classification of renal biopsies, 57% were M1, 48% E1, 76% S1, 57% T1+T2 and 38% C1+C2. Steroids were administered in 50% of cases. After a mean follow-up of 7.2 years, four patients (16.7%) had a poor kidney outcome: end-stage renal disease (n = 3) or a > 50% decrease in eGFR from initial values (n = 1). A similar evolution was observed in patients with primitive IgAN.

Conclusions: This first case series suggests that IBD-associated IgAN have frequent inflammatory lesions at onset and variable long-term outcome.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1093/ndt/gfaa378DOI Listing
January 2021

Eculizumab discontinuation in children and adults with atypical haemolytic uremic syndrome: a prospective multicentric study.

Blood 2020 Dec 3. Epub 2020 Dec 3.

Assistance Publique - Hôpitaux de Paris, paris, France.

The optimal duration of eculizumab treatment in patients with atypical haemolytic uremic syndrome (aHUS) remains poorly defined. We conducted a prospective national multicentric open-label study in order to assess eculizumab discontinuation in children and adults with aHUS. Fifty-five patients (including 19 children) discontinued eculizumab (mean duration of treatment, 16.5 months). Twenty-eight (51%) patients had complement gene rare variants, mostly in MCP (n= 12, 22%), CFH (n= 6, 11%) and CFI (n=6, 10%) genes. At eculizumab discontinuation, 17 (30%) and 4 (7%) patients had chronic kidney disease stage 3 and 4, respectively. During follow-up, 13 (23%) patients (6 children and 7 adults) experienced aHUS relapse. In multivariable analysis, female gender and the presence of a rare complement gene variant were associated with an increased risk of aHUS relapse, whereas requirement for dialysis during previous episodes of acute aHUS was not. In addition, an increased soluble C5b-9 plasma level at eculizumab discontinuation was associated with a higher risk of aHUS relapse in all patients and in the subset of carriers of complement gene rare variants, in log rank test and in multivariable analysis. Among the 13 relapsing patients, who were all restarted on eculizumab, 11 regained their baseline renal function and two had a worsening of their pre-existing chronic kidney disease, including one patient who progressed to end-stage renal disease. A strategy of eculizumab discontinuation in aHUS patients based on complement genetics is reasonable and safe. It improves the management and quality of life of a sizeable proportion of aHUS patients while reducing the cost of treatment. Trail registration number: NCT02574403.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1182/blood.2020009280DOI Listing
December 2020

A regimen with caplacizumab, immunosuppression, and plasma exchange prevents unfavorable outcomes in immune-mediated TTP.

Blood 2021 Feb;137(6):733-742

Centre de Référence des Microangiopathies Thrombotiques, Assistance Publique-Hôpitaux de Paris (AP-HP), Paris, France.

The anti-von Willebrand factor nanobody caplacizumab was licensed for adults with immune-mediated thrombotic thrombocytopenic purpura (iTTP) based on prospective controlled trials. However, few data are available on postmarketing surveillance. We treated 90 iTTP patients with a compassionate frontline triplet regimen associating therapeutic plasma exchange (TPE), immunosuppression with corticosteroids and rituximab, and caplacizumab. Outcomes were compared with 180 historical patients treated with the standard frontline treatment (TPE and corticosteroids, with rituximab as salvage therapy). The primary outcome was a composite of refractoriness and death within 30 days since diagnosis. Key secondary outcomes were exacerbations, time to platelet count recovery, the number of TPE, and the volume of plasma required to achieve durable remission. The percentage of patients in the triplet regimen with the composite primary outcome was 2.2% vs 12.2% in historical patients (P = .01). One elderly patient in the triplet regimen died of pulmonary embolism. Patients from this cohort experienced less exacerbations (3.4% vs 44%, P < .01); they recovered durable platelet count 1.8 times faster than historical patients (95% confidence interval, 1.41-2.36; P < .01), with fewer TPE sessions and lower plasma volumes (P < .01 both). The number of days in hospital was 41% lower in the triplet regimen than in the historical cohort (13 vs 22 days; P < .01). Caplacizumab-related adverse events occurred in 46 patients (51%), including 13 major or clinically relevant nonmajor hemorrhagic events. Associating caplacizumab to TPE and immunosuppression, by addressing the 3 processes of iTTP pathophysiology, prevents unfavorable outcomes and alleviates the burden of care.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1182/blood.2020008021DOI Listing
February 2021

Management of thrombotic microangiopathy in pregnancy and postpartum: report from an international working group.

Blood 2020 Nov;136(19):2103-2117

Maternité Port-Royal, Hôpital Cochin, Université de Paris/AP-HP, Fighting Prematurity University Hospital Federation (FHU PREMA), INSERM UMR 1139, Paris, France.

Pregnancy and postpartum are high-risk periods for different forms of thrombotic microangiopathy (TMA). However, the management of pregnancy-associated TMA remains ill defined. This report, by an international multidisciplinary working group of obstetricians, nephrologists, hematologists, intensivists, neonatologists, and complement biologists, summarizes the current knowledge of these potentially severe disorders and proposes a practical clinical approach to diagnose and manage an episode of pregnancy-associated TMA. This approach takes into account the timing of TMA in pregnancy or postpartum, coexisting symptoms, first-line laboratory workup, and probability-based assessment of possible causes of pregnancy-associated TMA. Its aims are: to rule thrombotic thrombocytopenic purpura (TTP) in or out, with urgency, using ADAMTS13 activity testing; to consider alternative disorders with features of TMA (preeclampsia/eclampsia; hemolysis elevated liver enzymes low platelets syndrome; antiphospholipid syndrome); or, ultimately, to diagnose complement-mediated atypical hemolytic uremic syndrome (aHUS; a diagnosis of exclusion). Although they are rare, diagnosing TTP and aHUS associated with pregnancy, and postpartum, is paramount as both require urgent specific treatment.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1182/blood.2020005221DOI Listing
November 2020

Hereditary Thrombotic Thrombocytopenic Purpura.

N Engl J Med 2020 01;382(4):393-394

Bordeaux University Hospital, Bordeaux, France

View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1056/NEJMc1915670DOI Listing
January 2020

Use of Highly Individualized Complement Blockade Has Revolutionized Clinical Outcomes after Kidney Transplantation and Renal Epidemiology of Atypical Hemolytic Uremic Syndrome.

J Am Soc Nephrol 2019 12 1;30(12):2449-2463. Epub 2019 Oct 1.

French Study Group of Atypical Hemolytic Uremic Syndrome, France.

Background: Atypical hemolytic uremic syndrome (HUS) is associated with high recurrence rates after kidney transplant, with devastating outcomes. In late 2011, experts in France recommended the use of highly individualized complement blockade-based prophylaxis with eculizumab to prevent post-transplant atypical HUS recurrence throughout the country.

Methods: To evaluate this strategy's effect on kidney transplant prognosis, we conducted a retrospective multicenter study from a large French nationwide registry, enrolling all adult patients with atypical HUS who had undergone complement analysis and a kidney transplant since January 1, 2007. To assess how atypical HUS epidemiology in France in the eculizumab era evolved, we undertook a population-based cohort study that included all adult patients with atypical HUS (=397) between 2007 and 2016.

Results: The first study included 126 kidney transplants performed in 116 patients, 58.7% and 34.1% of which were considered to be at a high and moderate risk of atypical HUS recurrence, respectively. Eculizumab prophylaxis was used in 52 kidney transplants, including 39 at high risk of recurrence. Atypical HUS recurred after 43 (34.1%) of the transplants; in four cases, patients had received eculizumab prophylaxis and in 39 cases they did not. Use of prophylactic eculizumab was independently associated with a significantly reduced risk of recurrence and with significantly longer graft survival. In the second, population-based cohort study, the proportion of transplant recipients among patients with ESKD and atypical HUS sharply increased between 2012 and 2016, from 46.2% to 72.3%, and showed a close correlation with increasing eculizumab use among the transplant recipients.

Conclusions: Results from this observational study are consistent with benefit from eculizumab prophylaxis based on pretransplant risk stratification and support the need for a rigorous randomized trial.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1681/ASN.2019040331DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6900783PMC
December 2019

Immune thrombotic thrombocytopenic purpura in older patients: prognosis and long-term survival.

Blood 2019 12;134(24):2209-2217

Service d'Hématologie, AP-HP.6, Paris, France; and.

Older age is associated with increased mortality in immune thrombotic thrombocytopenic purpura (iTTP). Yet, data are scarce regarding iTTP occurring among older patients. To assess clinical features and long-term impact of iTTP on mortality in older patients (>60 years old), characteristics and prognoses of adult iTTP patients enrolled in the French Reference Center for Thrombotic Microangiopathies registry between 2000 and 2016 were described according to age (<60 years old or ≥60 years old). Long-term mortality of iTTP older survivors was compared with that of non-iTTP geriatric subjects. Comparing, respectively, older iTTP patients (N = 71) with younger patients (N = 340), time from hospital admission to diagnosis was longer (P < .0001); at diagnosis, delirium (P = .034), behavior impairment (P = .045), renal involvement (P < .0001), and elevated troponin level (P = .025) were more important whereas cytopenias were less profound (platelet count, 22 × 103/mm3 [9-57] vs 13 × 103/mm3 [9-21], respectively [P = .002]; hemoglobin level, 9 g/dL [8-11] vs 8 g/dL [7-10], respectively [P = .0007]). Short- and mid-term mortalities were higher (P < .0001) and increased for every 10 years of age range. Age ≥60 years, cardiac involvement, increased plasma creatinine level, and total plasma exchange volume were independently associated with 1-month mortality. Compared with a non-iTTP geriatric population, older survivors showed an increased long-term mortality (hazard ratio = 3.44; P < .001). In conclusion, older iTTP patients have atypical neurological presentation delaying the diagnosis. Age negatively impacts short-term but also long-term mortality.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1182/blood.2019000748DOI Listing
December 2019

Outcome of children with Shiga toxin-associated haemolytic uraemic syndrome treated with eculizumab: a matched cohort study.

Nephrol Dial Transplant 2020 12;35(12):2147-2153

Service de Pédiatrie, Unité de Néphrologie, Centre de référence Maladies Rénales Rares du Sud-ouest, Centre Hospitalier Universitaire de Bordeaux, Bordeaux, France.

Background: Treatment with eculizumab in Shiga toxin-associated haemolytic and uraemic syndrome (STEC-HUS) remains controversial despite its increasing utilization. The aim of our study was to evaluate the outcomes of children treated with eculizumab for STEC-HUS in a single-centre matched cohort study.

Methods: Data were retrospectively collected from medical records of children diagnosed with STEC-HUS. The outcomes of patients treated with eculizumab for STEC-HUS were compared with those of a control group of untreated patients matched for age, sex and severity of acute kidney injury with a 1:2 matching scheme.

Results: Eighteen children (median age 40.6 months) with STEC-HUS treated with eculizumab were compared with 36 matched control patients (median age 36.4 months) who did not receive eculizumab. All patients survived in the two groups. Within 1 month of HUS onset, the evolution of haematological and renal parameters did not differ between the two groups. At 12 months of follow-up, renal outcome was not significantly different between the two groups. At the last follow-up, the prevalence of decreased glomerular filtration rate in the eculizumab group (27%) was not statistically different from that in controls (38%), as was the prevalence of proteinuria and high blood pressure. Children who received eculizumab more often had extrarenal sequelae during follow-up. Eculizumab treatment appeared to be safe in children with STEC-HUS.

Conclusion: The benefit of eculizumab on renal and extrarenal outcomes in STEC-HUS could not be established based on our findings. However, efficacy and safety are not best assessed by the observational design and small sample size of our study. Randomized controlled trials are thus required to determine the efficacy of eculizumab in this indication.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1093/ndt/gfz158DOI Listing
December 2020

Atypical and secondary hemolytic uremic syndromes have a distinct presentation and no common genetic risk factors.

Kidney Int 2019 06 15;95(6):1443-1452. Epub 2019 Mar 15.

Centre de Recherche en Transplantation et Immunologie, UMR 1064, INSERM, Université de Nantes, Nantes, France; Institut de Transplantation Urologie Néphrologie, CHU Nantes, Nantes, France; Department of Nephrology and Immunology, Center Hospitalier Universitaire de Nantes, Nantes, France. Electronic address:

Secondary hemolytic uremic syndrome (HUS) is a heterogeneous group of thrombotic microangiopathies associated with various underlying conditions. Whether it belongs to the spectrum of complement-mediated HUS remains controversial. We analysed the presentation, outcome, and frequency of complement gene rare variants in a cohort of 110 patients with secondary HUS attributed to drugs (29%), autoimmune diseases (24%), infections (17%), malignancies (10%), glomerulopathies (9%), extra-renal organ transplantation (8%), and pancreatitis (3%). The frequency of complement gene rare variants was similar in patients with secondary HUS (5%) and in healthy individuals (6% and 8% in French and European controls, respectively). At diagnosis, 40% of patients required dialysis and 18% had neurological manifestations. Fifty percent of patients received plasmatherapy and 35% were treated with eculizumab. Haematological and complete renal remission was achieved in 80% and 24% of patients, respectively. Thirty-nine percent of patients progressed to chronic kidney disease (stages 3-4) and an additional 37% reached end-stage renal disease. Eleven percent of patients died, most often from complications of the underlying cause of HUS. Only one patient experienced an HUS relapse. Patients treated with eculizumab presented with more severe HUS and were more likely to require dialysis at the time of diagnosis as compared to patients not treated with eculizumab. Rates of hematological remission, chronic kidney disease (stages 3-4), and end-stage renal disease were similar in the two groups. Secondary HUS is an acute nonrelapsing form of HUS, not related to complement dysregulation. The efficacy of eculizumab in this setting is not yet established.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.kint.2019.01.023DOI Listing
June 2019

Eculizumab prevents thrombotic microangiopathy in patients with atypical haemolytic uraemic syndrome in a long-term observational study.

Clin Kidney J 2019 Apr 16;12(2):196-205. Epub 2018 May 16.

Emory University School of Medicine and Children's Healthcare of Atlanta, Atlanta, GA, USA.

Background: Eculizumab, a terminal complement inhibitor, is approved for atypical haemolytic uraemic syndrome (aHUS) to inhibit complement-mediated thrombotic microangiopathy (TMA).

Methods: In five parent studies, eculizumab effectively prevented TMA and improved renal and haematologic outcomes in patients with aHUS; therefore, these patients could enrol in this long-term, prospective, observational and multicentre study. The primary endpoint was the TMA manifestation rate off and on eculizumab post-parent study. analyses evaluated rates during labelled versus non-labelled dosing regimens, and in those with versus without identified complement abnormalities. Serious targeted treatment-emergent adverse events (TEAEs) were evaluated.

Results: Of 87 patients in the current study, 39 and 76 had off- and on-treatment periods, respectively; 17 (44%) with off periods reinitiated eculizumab. TMA manifestation rate per 100 patient-years was 19.9 off and 7.3 on treatment [hazard ratio (HR), 4.7; P = 0.0008]; rates were highest off treatment and lowest during labelled regimens. TMA manifestations with hospitalizations/serious AEs occurred more frequently off versus on treatment. TMA rates were higher among patients with identified complement abnormalities (HR, 4.5; P = 0.0082). Serious targeted TEAEs occurred at similar rates off and on treatment.

Conclusions: As expected, patients with aHUS have increased risk of TMA manifestations after discontinuation of eculizumab or in the setting of non-labelled eculizumab dosing. Collectively, results show that maintaining eculizumab treatment minimizes risk of TMA, particularly in patients with identified complement abnormalities. Future studies are needed to further characterize TMA and longer term outcomes on labelled or non-labelled eculizumab regimens and after discontinuation of treatment.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1093/ckj/sfy035DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6452204PMC
April 2019

Outcomes in patients with atypical hemolytic uremic syndrome treated with eculizumab in a long-term observational study.

BMC Nephrol 2019 04 10;20(1):125. Epub 2019 Apr 10.

Division of Pediatric Nephrology, Emory University School of Medicine and Children's Healthcare of Atlanta, 2015 Uppergate Drive NE, Atlanta, GA, 30322, USA.

Background: There are limited long-term outcome data in eculizumab-treated patients with atypical hemolytic uremic syndrome (aHUS). We report final results from the largest prospective, observational, multicenter study of patients with aHUS treated with eculizumab.

Methods: Patients with aHUS who participated in any of five parent eculizumab trials and received at least one eculizumab infusion were eligible for enrollment in a long-term follow-up study. Rates of thrombotic microangiopathy (TMA) manifestations off versus on eculizumab were evaluated. Additional endpoints included change from baseline estimated glomerular filtration rate (eGFR), long-term renal outcomes, and serious targeted treatment-emergent adverse events.

Results: Among 93 patients (0-80 years of age), 51 (55%) remained on eculizumab and 42 (45%) discontinued; for those who discontinued, 21 (50%) reinitiated therapy. Patients who reinitiated eculizumab had similar baseline clinical characteristics to patients who remained on eculizumab, with higher likelihood of genetic/autoimmune complement abnormalities, more prior TMAs, and longer disease course versus those who did not reinitiate. Mean eGFR improved rapidly and remained stable for up to 6 years on eculizumab. In patients who discontinued, there was a trend toward decreasing renal function over time from discontinuation. Additionally, off-treatment TMA manifestation rates were higher in those aged < 18 years at diagnosis, with identified genetic/autoimmune complement abnormalities, or history of multiple TMAs prior to eculizumab initiation. The safety profile was consistent with previous studies. Three definite and one possible meningococcal infections related to eculizumab were reported and resolved with treatment. Three deaths unrelated to eculizumab were reported.

Conclusions: The current study confirms the efficacy and safety of eculizumab in aHUS, particularly with regard to long-term renal function and TMA events. Pediatric age at disease onset and presence of genetic or autoimmune complement abnormalities are risk factors for TMA events off treatment. Overall, patients who discontinue eculizumab may be at risk for additional TMA manifestations and renal function decreases. Discontinuation of eculizumab, with careful monitoring, is an option in select patients with consideration of patient preference, organ function normalization, and risk factors for relapse, including mutational analysis, age of onset, and history of multiple TMA episodes.

Trial Registration: ClinicalTrials.gov NCT01522170 , January 31, 2012.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1186/s12882-019-1314-1DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6456946PMC
April 2019

Post-partum acute kidney injury: sorting placental and non-placental thrombotic microangiopathies using the trajectory of biomarkers.

Nephrol Dial Transplant 2020 09;35(9):1538-1546

Sorbonne Université, Urgences Néphrologiques et Transplantation Rénale, Assistance Publique-Hôpital de Paris (APHP), Hôpital Tenon, Paris, France.

Background: Among the severe complications of preeclampsia (PE), acute kidney injury (AKI) is problematic if features of thrombotic microangiopathy (TMA) are present. Although a haemolysis enzyme liver low-platelets syndrome is considerably more frequent, it is vital to rule out a flare of atypical haemolytic and uraemic syndrome (aHUS). Our objective was to improve differential diagnosis procedures in post-partum AKI.

Methods: A total of 105 cases of post-partum AKI, admitted to nine different regional French intensive care units from 2011 to 2015, were analysed. Analysis included initial and final diagnosis, renal features, haemostasis and TMA parameters, with particular focus on the dynamics of each component within the first days following delivery. A classification and regression tree (CART) was used to construct a diagnostic algorithm.

Results: AKI was attributed to severe PE (n = 40), post-partum haemorrhage (n = 33, including 13 renal cortical necrosis) and 'primary' TMA (n = 14, including 10 aHUS and 4 thrombotic thrombocytopenic purpura). Congruence between initial and final diagnosis was low (63%). The dynamics of haemoglobin, haptoglobin and liver enzymes were poorly discriminant. In contrast, the dynamic pattern of platelets was statistically different between primary TMA-related AKI and other groups. CART analysis independently highlighted the usefulness of platelet trajectory in the diagnostic algorithm. Limitations of this study include that only the most severe cases were included in this retrospective study, and the circumstantial complexity is high.

Conclusion: Trajectory of platelet count between admission and Day 3 helps to guide therapeutic decisions in cases of TMA-associated post-partum AKI. Our study also strongly suggests that during the post-partum period, there may be a risk of transient, slowly recovering TMA in cases of severe endothelial injury in women without a genetic mutation known to induce aHUS.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1093/ndt/gfz025DOI Listing
September 2020

Long-term outcome of diarrhea-associated hemolytic uremic syndrome is poorly related to markers of kidney injury at 1-year follow-up in a population-based cohort.

Pediatr Nephrol 2019 04 27;34(4):657-662. Epub 2018 Oct 27.

Service de Pédiatrie, Centre de référence Maladies Rénales Rares du Sud-ouest (SoRare), CHU de Bordeaux, Bordeaux, France.

Background: Hemolytic uremic syndrome due to Shiga toxin-producing E. coli (STEC-HUS) is the main cause of acute kidney injury in young children. Most fully recover kidney function; however, some develop long-term sequelae. We aimed to determine whether kidney injury 1 year after HUS onset is associated with long-term kidney outcome in pediatric STEC-HUS.

Methods: A retrospective population-based study of children < 15 years with STEC-HUS between 1992 and 2012 was performed. Mixed effects logistic regression was used to investigate associations between kidney injury at 1 year and long-term kidney outcome.

Results: Ninety-eight STEC-HUS cases were reported. Of 96 patients who survived acute phase, 84 were evaluated at 1-year follow-up of whom 42 (44% of survivors) showed ≥ 1 signs of kidney injury. Data from 81 patients were collected after median follow-up of 8.7 (IQR 3.5-12.7) years. At last follow-up, 42 (44% of survivors) had ≥ 1 signs of kidney injury including decreased estimated glomerular filtration rate (eGFR) < 90 mL/min/1.73 m (n = 30), proteinuria (n = 17), or hypertension (n = 5). Among 42 patients with kidney injuries at 1-year follow-up, only 22 (52%) still had kidney disease at last follow-up. Conversely, of 33 patients without kidney injury at 1-year and available long-term outcome data, 11 (33%) had proteinuria or decreased GFR at last follow-up. There was no statistically significant association between kidney injury at 1 year and long-term kidney outcome.

Conclusions: Since kidney sequelae may appear at variable time intervals after acute HUS, all patients need lifelong follow-up to detect early signs of chronic kidney disease and propose measures to slow progression.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s00467-018-4131-zDOI Listing
April 2019

Both Monoclonal and Polyclonal Immunoglobulin Contingents Mediate Complement Activation in Monoclonal Gammopathy Associated-C3 Glomerulopathy.

Front Immunol 2018 2;9:2260. Epub 2018 Oct 2.

INSERM UMRS1138, Centre de Recherche des Cordeliers, Team "Complément et Maladies", Paris, France.

C3 glomerulopathy (C3G) results from acquired or genetic abnormalities in the complement alternative pathway (AP). C3G with monoclonal immunoglobulin (MIg-C3G) was recently included in the spectrum of "monoclonal gammopathy of renal significance." However, mechanisms of complement dysregulation in MIg-C3G are not described and the pathogenic effect of the monoclonal immunoglobulin is not understood. The purpose of this study was to investigate the mechanisms of complement dysregulation in a cohort of 41 patients with MIg-C3G. Low C3 level and elevated sC5b-9, both biomarkers of C3 and C5 convertase activation, were present in 44 and 78% of patients, respectively. Rare pathogenic variants were identified in 2/28 (7%) tested patients suggesting that the disease is acquired in a large majority of patients. Anti-complement auto-antibodies were found in 20/41 (49%) patients, including anti-FH (17%), anti-CR1 (27%), anti-FI (5%) auto-antibodies, and C3 Nephritic Factor (7%) and were polyclonal in 77% of patients. Using cofactor assay, the regulation of the AP was altered in presence of purified IgG from 3/9 and 4/7 patients with anti-FH or anti-CR1 antibodies respectively. By using fluid and solid phase AP activation, we showed that total purified IgG of 22/34 (65%) MIg-C3G patients were able to enhance C3 convertase activity. In five documented cases, we showed that the C3 convertase enhancement was mostly due to the monoclonal immunoglobulin, thus paving the way for a new mechanism of complement dysregulation in C3G. All together the results highlight the contribution of both polyclonal and monoclonal Ig in MIg-C3G. They provide direct insights to treatment approaches and opened up a potential way to a personalized therapeutic strategy based on chemotherapy adapted to the B cell clone or immunosuppressive therapy.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fimmu.2018.02260DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6175995PMC
September 2019

ADAMTS13 Gene Mutations Influence ADAMTS13 Conformation and Disease Age-Onset in the French Cohort of Upshaw-Schulman Syndrome.

Thromb Haemost 2018 Nov 12;118(11):1902-1917. Epub 2018 Oct 12.

Institut Universitaire d'Hématologie, Université Paris Diderot, Hôpital Saint-Louis, Assistance Publique-Hôpitaux de Paris, Paris, France.

Background:  Congenital thrombotic thrombocytopaenic purpura (TTP) or Upshaw-Schulman syndrome (USS) is a rare, life-threatening, inherited thrombotic microangiopathy (TMA). USS is mostly due to bi-allelic recessive sequence variations of the () gene inducing a severe ADAMTS13 deficiency (activity < 10 IU/dL). In healthy individuals, ADAMTS13 circulates in a folded conformation where CUB domains interact with the spacer domain. The spacer-CUB interaction is abrogated when ADAMTS13 is conformationally activated.

Objective:  This article evaluates the influence of sequence variations on both clinical/biological phenotype and ADAMTS13 conformation in USS.

Patients And Methods:  All USS patients from the French registry for TMAs (1 January 2000 to 1 June 2017) were investigated for ADAMTS13 genotype, phenotype (activity, antigen and autoantibodies) and conformation. Clinical records were analysed (inaugural acute TTP and follow-up). Child-onset USS was compared with adult-onset USS.

Results:  Fifty-six USS patients from 51 families (34 child-onset and 22 adult-onset cases) were enrolled. Child-onset USS was characterized by a large panel of sequence variations ( = 43), spread all over gene and not correlated with either clinical features or plasmatic ADAMTS13 parameters. In contrast, adult-onset USS, consisting exclusively in pregnancy-induced TTP, included a smaller and distinct panel of sequence variations ( = 20) because of one mutation (p.Arg1060Trp) present in 82% of patients. ADAMTS13 conformation was studied in 16 USS patients (5 child-onset and 11 adult-onset USS, encompassing 16 distinct sequence variations) whose ADAMTS13 antigen levels were detectable: 14 of 16 patients (87.5%) exhibited abnormalities of ADAMTS13 conformation.

Conclusion:  In USS, age-onset defines two entities and sequence variations modify ADAMTS13 conformation.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1055/s-0038-1673686DOI Listing
November 2018

Immune-Thrombotic Thrombocytopenic Purpura is a Rare Cause of Ischemic Stroke in Young Adults: Case Reports and Literature Review.

J Stroke Cerebrovasc Dis 2018 Nov 12;27(11):3163-3171. Epub 2018 Sep 12.

Department of Neurology, CHU de Bordeaux, Bordeaux, France / Except Yahsou Delmas: Department of Nephrology, CHU de Bordeaux, Bordeaux, France.

Introduction: Immune thrombotic thrombocytopenic purpura (i-TTP), related to acquired ADAMTS-13 dysfunction, can lead to various neurological symptoms including ischemic stroke. To date the clinical, radiological, and biological characteristics of patients having a stroke as the inaugural manifestation of i-TTP are largely unknown.

Methods: Probable immune-TTP was defined by a low ADAMTS-13 activity associated with the presence of ADAMTS-13 inhibitors and/or favorable clinicobiological response under immunological treatments. The clinical, radiological, biological data and outcome under treatment are described in a cohort of 17 patients coming from 3 local cases and a literature review.

Results: Fourteen of the 17 patients were female and the mean age was 41 years. None of the patients had the classical pentad of TTP. Only 41% had a combination of thrombocythemia and hemolysis. Stroke was multifocal in 35% and included large artery strokes. No adverse event was observed following intravenous thrombolysis. Refractory and relapsing forms were observed in 47%.

Discussion: The clinical, radiological, and biological presentation of patients with stroke as the inaugural presentation of i-TTP is heterogeneous. This diagnosis should be discussed in every young adult with ischemic stroke of undetermined source.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.jstrokecerebrovasdis.2018.07.017DOI Listing
November 2018

Preemptive rituximab prevents long-term relapses in immune-mediated thrombotic thrombocytopenic purpura.

Blood 2018 11 10;132(20):2143-2153. Epub 2018 Sep 10.

Centre de Référence des Microangiopathies Thrombotiques, Hôpital Saint-Antoine, Assistance Publique-Hôpitaux de Paris, Paris, France.

Preemptive rituximab infusions prevent relapses in immune thrombotic thrombocytopenic purpura (iTTP) by maintaining normal ADAMTS13 activity. However, the long-term outcome of these patients and the potential adverse events of this strategy need to be determined. We report the long-term outcome of 92 patients with iTTP in clinical remission who received preemptive rituximab after identification of severe ADAMTS13 deficiency (activity <10%) during the follow-up. Thirty-seven patients had >1 iTTP episode, and the median cumulative relapse incidence before preemptive rituximab was 0.33 episode per year (interquartile range [IQR], 0.23-0.66). After preemptive rituximab, the median cumulative relapse incidence in the whole population decreased to 0 episodes per year (IQR, 0-1.32; < .001). After preemptive rituximab, ADAMTS13 activity recovery was sustained in 34 patients (37%) during a follow-up of 31.5 months (IQR, 18-65), and severe ADAMTS13 deficiency recurred in 45 patients (49%) after the initial improvement. ADAMTS13 activity usually improved with additional courses of preemptive rituximab. In 13 patients (14%), ADAMTS13 activity remained undetectable after the first rituximab course, but retreatment was efficient in 6 of 10 cases. In total, 14 patients (15%) clinically relapsed, and 19 patients (20.7%) experienced benign adverse effects. Preemptive rituximab treatment was associated with a change in ADAMTS13 conformation in respondent patients. Finally, in the group of 23 historical patients with iTTP and persistently undetectable ADAMTS13 activity, 74% clinically relapsed after a 7-year follow-up (IQR, 5-11). In conclusion, persistently undetectable ADAMTS13 activity in iTTP during remission is associated with a higher relapse rate. Preemptive rituximab reduces clinical relapses by maintaining a detectable ADAMTS13 activity with an advantageous risk-benefit balance.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1182/blood-2018-04-840090DOI Listing
November 2018

Cardiac Rhythm Disturbances in Hemodialysis Patients: Early Detection Using an Implantable Loop Recorder and Correlation With Biological and Dialysis Parameters.

JACC Clin Electrophysiol 2018 03 27;4(3):397-408. Epub 2017 Sep 27.

Centre Hospitalier Universitaire de Bordeaux, Bordeaux, France; Unité INSERM 1026, Universite de Bordeaux, Bordeaux, France.

Objectives: The aim of this study was to identify using implantable loop recorder (ILR) monitoring the mechanisms leading to sudden death (SD) in patients undergoing hemodialysis (HD).

Background: SD accounts for 11% to 25% of death in HD patients.

Methods: Continuous rhythm monitoring was performed using the remote monitoring capability of the ILR device in patients undergoing HD at 8 centers. Clinical, biological, and technical HD parameters were recorded and analyzed.

Results: Seventy-one patients (mean age 65 ± 9 years, 73% men) were included. Left ventricular ejection fraction was <50% in 16%. Twelve patients (17%) had histories of atrial fibrillation or flutter at inclusion. During a mean follow-up period of 21.3 ± 6.9 months, 16 patients died (14% patient-years), 7 (44%) of cardiovascular causes. Four SDs occurred, with progressive bradycardia followed by asystole. The incidence of patients presenting with significant conduction disorder and with ventricular arrhythmia was 14% and 9% patient-years, respectively. In multivariate survival frailty analyses, a higher risk for conduction disorder was associated with plasma potassium >5.0 mmol/l, bicarbonate <22 mmol/l, hemoglobin >11.5 g/dl, pre-HD systolic blood pressure >140 mm Hg, the longer interdialytic period, history of coronary artery disease, previous other arrhythmias, and diabetes mellitus. A higher risk for ventricular arrhythmia was associated with potassium <4.0 mmol/l, no antiarrhythmic drugs, and previous other arrhythmias. With ILR monitoring, de novo atrial fibrillation or flutter was diagnosed in 14 patients (20%).

Conclusions: ILR may be considered in HD patients prone to significant conduction disorders, ventricular arrhythmia, or atrial fibrillation or flutter to allow early identification and initiation of adequate treatment. Therapeutic strategies reducing serum potassium variability could decrease the rate of SD in these patients. (Implantable Loop Recorder in Hemodialysis Patients [RYTHMODIAL]; NCT01252823).
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.jacep.2017.08.002DOI Listing
March 2018

Patterns of Clinical Response to Eculizumab in Patients With C3 Glomerulopathy.

Am J Kidney Dis 2018 07 9;72(1):84-92. Epub 2018 Feb 9.

Department of Nephrology and Immunology, Centre Hospitalier Universitaire de Nantes, Nantes, France. Electronic address:

Background: Cases reports and small series of patients with C3 glomerulopathy have reported variable efficacy of eculizumab.

Study Design: Case series of C3 glomerulopathy.

Setting & Participants: Pediatric and adult patients with C3 glomerulopathy treated with eculizumab between 2010 and 2016 were identified through the C3 glomerulopathy French registry database, and a questionnaire was sent to participating French pediatric and adult nephrology centers, as well as one pediatric referral center in Québec, Canada.

Outcomes: Global or partial clinical renal response.

Measurements: Evolution of serum creatinine and proteinuria values.

Results: 26 patients (13 children/adolescents) were included. 22 (85%) patients had received steroids, plasma exchange, or immunosuppressive therapy before eculizumab, and 3 of them had rapid progression of their kidney disease despite treatment. At the initiation of eculizumab therapy, 11 (42%) patients had chronic kidney disease, 7 (27%) had rapidly progressive disease, and 3 (12%) required dialysis. After eculizumab treatment (median duration, 14 months), 6 (23%) patients had a global clinical response; 6 (23%), a partial clinical response; and 14 (54%), no response. Compared with those who had a partial clinical or no response, patients who had a global clinical response had lower estimated glomerular filtration rates, a more rapidly progressive course, and more extracapillary proliferation on kidney biopsy. Age, extent of renal fibrosis, frequency of nephrotic syndrome, low serum C3 and C3 nephritic factor and elevated soluble C5b-9 concentrations, or complement gene variants did not differ between responders and nonresponders.

Limitations: Retrospective design without a control group, relatively small number of cases, inclusion of pediatric and adult cases.

Conclusions: Eculizumab appears to be a potential treatment for patients with crescentic rapidly progressive C3 glomerulopathy. Its benefit in patients with non-rapidly progressing forms seems to be limited.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1053/j.ajkd.2017.11.019DOI Listing
July 2018

Clinical and genetic heterogeneity in familial steroid-sensitive nephrotic syndrome.

Pediatr Nephrol 2018 03 23;33(3):473-483. Epub 2017 Oct 23.

INSERM UMR1163, Laboratory of Hereditary Kidney Diseases, Imagine Institute, 24 Boulevard du Montparnasse, 75015, Paris, France.

Background: Familial steroid-sensitive nephrotic syndrome (SSNS) is a rare condition. The disease pathophysiology remains elusive. However, bi-allelic mutations in the EMP2 gene were identified, and specific variations in HLA-DQA1 were linked to a high risk of developing the disease.

Methods: Clinical data were analyzed in 59 SSNS families. EMP2 gene was sequenced in families with a potential autosomal recessive (AR) inheritance. Exome sequencing was performed in a subset of 13 families with potential AR inheritance. Two variations in HLA-DQA1 were genotyped in the whole cohort.

Results: Transmission was compatible with an AR (n = 33) or autosomal dominant (AD, n = 26) inheritance, assuming that familial SSNS is a monogenic trait. Clinical features did not differ between AR and AD groups. All patients, including primary (n = 7) and secondary steroid resistant nephrotic syndrone (SRNS), (n = 13) were sensitive to additional immunosuppressive therapy. Both HLA-DQA1 variations were found to be highly linked to the disease (OR = 4.34 and OR = 4.89; p < 0.001). Exome sequencing did not reveal any pathogenic mutation, neither did EMP2 sequencing.

Conclusions: Taken together, these results highlight the clinical and genetic heterogeneity in familial SSNS. Clinical findings sustain an immune origin in all patients, whatever the initial steroid-sensitivity. The absence of a variant shared by two families and the HLA-DQA1 variation enrichments suggest a complex mode of inheritance.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s00467-017-3819-9DOI Listing
March 2018

Hemolytic Uremic Syndrome in Pregnancy and Postpartum.

Clin J Am Soc Nephrol 2017 Aug 8;12(8):1237-1247. Epub 2017 Jun 8.

Due to the number of contributing authors, the affiliations are provided in the Supplemental Material.

Background: Pregnancy is associated with various forms of thrombotic microangiopathy, including hemolytic uremic syndrome. A previous small French study suggested that pregnancy-associated hemolytic uremic syndrome was to be included in the spectrum of atypical hemolytic uremic syndrome linked to complement alternative pathway dysregulation.

Design, Setting, Participants, & Measurements: We sought to retrospectively analyze the presentation, outcome, and frequency of complement alternative pathway gene variants in a larger international (France, United Kingdom, Italy) cohort of patients with pregnancy-associated hemolytic uremic syndrome.

Results: Eighty-seven patients with pregnancy-associated hemolytic uremic syndrome were included. Hemolytic uremic syndrome occurred mainly during the first pregnancy (58%) and in the postpartum period (76%). At diagnosis, 56 (71%) patients required dialysis. Fifty-six (78%) patients underwent plasma exchanges, 21 (41%) received plasma infusions, and four (5%) received eculizumab. During follow-up (mean duration of 7.2 years), 41 (53%) patients reached ESRD, 15 (19%) had CKD, and 18 (28%) patients experienced hemolytic uremic syndrome relapse. Twenty-four patients (27%) received a kidney transplant and a recurrence of hemolytic uremic syndrome occurred in 13 (54%) patients. Variants in complement genes were detected in 49 (56%) patients, mainly in the (30%) and genes (9%).

Conclusions: Pregnancy-associated hemolytic uremic syndrome and atypical hemolytic uremic syndrome nonrelated to pregnancy have the same severity at onset and during follow-up and the same frequency of complement gene variants.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.2215/CJN.00280117DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5544502PMC
August 2017

Predictive features of chronic kidney disease in atypical haemolytic uremic syndrome.

PLoS One 2017 18;12(5):e0177894. Epub 2017 May 18.

Centre de Reference des Microangiopathies Thrombotiques, Hôpital Saint Antoine, AP-HP, Paris, France.

Chronic kidney disease (CKD) is a frequent and serious complication of atypical haemolytic uremic syndrome (aHUS). We aimed to develop a simple accurate model to predict the risk of renal dysfunction in aHUS based on clinical and biological features available at hospital admission. Renal function at 1-year follow-up, based on an estimated glomerular filtration rate < 60mL/min/1.73m2 as assessed by the Modification of Diet in Renal Disease equation, was used as an indicator of significant CKD. Prospectively collected data from a cohort of 156 aHUS patients who did not receive eculizumab were used to identify predictors of CKD. Covariates associated with renal impairment were identified by multivariate analysis. The model performance was assessed and a scoring system for clinical practice was constructed from the regression coefficient. Multivariate analyses identified three predictors of CKD: a high serum creatinine level, a high mean arterial pressure and a mildly decreased platelet count. The prognostic model had a good discriminative ability (area under the curve = .84). The scoring system ranged from 0 to 5, with corresponding risks of CKD ranging from 18% to 100%. This model accurately predicts development of 1-year CKD in patients with aHUS using clinical and biological features available on admission. After further validation, this model may assist in clinical decision making.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0177894PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5436831PMC
September 2017

Thrombotic thrombocytopenic purpura misdiagnosed as autoimmune cytopenia: Causes of diagnostic errors and consequence on outcome. Experience of the French thrombotic microangiopathies reference centre.

Am J Hematol 2017 Apr 21;92(4):381-387. Epub 2017 Feb 21.

Service de Médecine Interne, Centre Hospitalier Universitaire Charles Nicolle, Rouen, France.

Thrombotic thrombocytopenic purpura (TTP) has a devastating prognosis without adapted management. Sources of misdiagnosis need to be identified to avoid delayed treatment. We studied 84 patients with a final diagnosis of severe (<10%) acquired ADAMTS13 deficiency-associated TTP from our National database that included 423 patients, who had an initial misdiagnosis (20% of all TTP). Main diagnostic errors were attributed to autoimmune thrombocytopenia, associated (51%) or not (37%) with autoimmune hemolytic anemia. At admission, misdiagnosed patients were more frequently females (P = .034) with a history of autoimmune disorder (P = .017) and had organ involvement in 67% of cases; they had more frequently antinuclear antibodies (P = .035), a low/undetectable schistocyte count (P = .001), a less profound anemia (P = .008), and a positive direct antiglobulin test (DAT) (P = .008). In multivariate analysis, female gender (P = .022), hemoglobin level (P = .028), a positive DAT (P = .004), and a low schistocytes count on diagnosis (P < .001) were retained as risk factors of misdiagnosis. Platelet count recovery was significantly longer in the misdiagnosed group (P = .041) without consequence on mortality, exacerbation and relapse. However, patients in the misdiagnosed group had a less severe disease than those in the accurately diagnosed group, as evidenced by less organ involvement at TTP diagnosis (P = .006). TTP is frequently misdiagnosed with autoimmune cytopenias. A low schistocyte count and a positive DAT should not systematically rule out TTP, especially when associated with organ failure.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/ajh.24665DOI Listing
April 2017

Treatment of B-cell disorder improves renal outcome of patients with monoclonal gammopathy-associated C3 glomerulopathy.

Blood 2017 03 9;129(11):1437-1447. Epub 2017 Jan 9.

Department of Nephrology, Centre Hospitalier Universitaire de Poitiers, Poitiers, France.

The high frequency of monoclonal gammopathy in adult patients with C3 glomerulopathy (C3G) emphasizes the role of monoclonal immunoglobulin (MIg) in the occurrence of renal disease and raises the issue of the therapeutic management. The aim of the study was to evaluate the effect of chemotherapy in a large cohort of patients with MIg-associated C3G. Fifty adult patients with MIg and biopsy-proven C3G were extracted from the French national database of C3G. We retrospectively compared renal outcomes in patients who either received or did not receive chemotherapy targeting the underlying B-cell clone. At diagnosis, renal disease was severe, with nephrotic-range proteinuria in 20/46 (43%) patients and chronic kidney disease stage 3 or above in 42/49 (86%) patients. Monoclonal gammopathy was of IgG type in 47 (94%) patients. Hematological diagnosis was monoclonal gammopathy of renal significance in 30 (60%), multiple myeloma in 17 (34%), and chronic lymphocytic leukemia in 3 (6%) patients. Complement studies showed low C3 level in 22/50 (43%) and elevated soluble C5b-9 level in 27/34 (79%) patients. Twenty-nine patients received chemotherapy (including bortezomib in 22), whereas 8 and 13 patients received various immunosuppressive drugs or symptomatic measures alone, respectively. Patients who achieved hematological response after chemotherapy had higher renal response rates ( = .0001) and median renal survival (hazard ratio, 0.22; 95% confidence interval, 0.05-0.92; = .009) than those receiving conservative/immunosuppressive therapy. In conclusion, our results suggest that chemotherapy adapted to the B-cell clone may constitute an efficient strategy for C3G in the setting of MIg, as rapid achievement of hematological response appears to result in improved renal survival.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1182/blood-2016-08-737163DOI Listing
March 2017

High glucose repatterns human podocyte energy metabolism during differentiation and diabetic nephropathy.

FASEB J 2017 01 17;31(1):294-307. Epub 2016 Oct 17.

INSERM Unité 1211, Laboratory of Rare Diseases, Metabolism, and Genetics, Bordeaux University, Bordeaux, France.

Podocytes play a key role in diabetic nephropathy pathogenesis, but alteration of their metabolism remains unknown in human kidney. By using a conditionally differentiating human podocyte cell line, we addressed the functional and molecular changes in podocyte energetics during in vitro development or under high glucose conditions. In 5 mM glucose medium, we observed a stepwise activation of oxidative metabolism during cell differentiation that was characterized by peroxisome proliferator-activated receptor-γ coactivator 1α (PGC-1α)-dependent stimulation of mitochondrial biogenesis and function, with concomitant reduction of the glycolytic enzyme content. Conversely, when podocytes were cultured in high glucose (20 mM), stepwise oxidative phosphorylation biogenesis was aborted, and a glycolytic switch occurred, with consecutive lactic acidosis. Expression of the master regulators of oxidative metabolism transcription factor A mitochondrial, PGC-1α, AMPK, and serine-threonine liver kinase B1 was altered by high glucose, as well as their downstream signaling networks. Focused transcriptomics revealed that myocyte-specific enhancer factor 2C (MEF2C) and myogenic factor 5 (MYF5) expression was inhibited by high glucose levels, and endoribonuclease-prepared small interfering RNA-mediated combined inhibition of those transcription factors phenocopied the glycolytic shift that was observed in high glucose conditions. Accordingly, a reduced expression of MEF2C, MYF5, and PGC-1α was found in kidney tissue sections that were obtained from patients with diabetic nephropathy. These findings obtained in human samples demonstrate that MEF2C-MYF5-dependent bioenergetic dedifferentiation occurs in podocytes that are confronted with a high-glucose milieu.-Imasawa, T., Obre, E., Bellance, N., Lavie, J., Imasawa, T., Rigothier, C., Delmas, Y., Combe, C., Lacombe, D., Benard, G., Claverol, S., Bonneu, M., Rossignol, R. High glucose repatterns human podocyte energy metabolism during differentiation and diabetic nephropathy.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1096/fj.201600293RDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5161522PMC
January 2017

Pathogenic Variants in Complement Genes and Risk of Atypical Hemolytic Uremic Syndrome Relapse after Eculizumab Discontinuation.

Clin J Am Soc Nephrol 2017 01 31;12(1):50-59. Epub 2016 Oct 31.

Due to the number of contributing authors, the affiliations are provided in the Supplemental Material.

Background And Objectives: The complement inhibitor eculizumab has dramatically improved the outcome of atypical hemolytic uremic syndrome. However, the optimal duration of eculizumab treatment in atypical hemolytic uremic syndrome remains debated. We report on the French atypical hemolytic uremic syndrome working group's first 2-year experience with eculizumab discontinuation in patients with atypical hemolytic uremic syndrome.

Design, Setting, Participants & Measurements: Using the French atypical hemolytic uremic syndrome registry database, we retrospectively identified all dialysis-free patients with atypical hemolytic uremic syndrome who discontinued eculizumab between 2010 and 2014 and reviewed their relevant clinical and biologic data. The decision to discontinue eculizumab was made by the clinician in charge of the patient. All patients were closely monitored by regular urine dipsticks and blood tests. Eculizumab was rapidly (24-48 hours) restarted in case of relapse.

Results: Among 108 patients treated with eculizumab, 38 patients (nine children and 29 adults) discontinued eculizumab (median treatment duration of 17.5 months). Twenty-one patients (55%) carried novel or rare complement genes variants. Renal recovery under eculizumab was equally good in patients with and those without complement gene variants detected. After a median follow-up of 22 months, 12 patients (31%) experienced atypical hemolytic uremic syndrome relapse. Eight of 11 patients (72%) with complement factor H variants, four of eight patients (50%) with membrane cofactor protein variants, and zero of 16 patients with no rare variant detected relapsed. In relapsing patients, early reintroduction (≤48 hours) of eculizumab led to rapid (<7 days) hematologic remission and a return of serum creatinine to baseline level in a median time of 26 days. At last follow-up, renal function remained unchanged in nonrelapsing and relapsing patients compared with baseline values before eculizumab discontinuation.

Conclusions: Pathogenic variants in complement genes were associated with higher risk of atypical hemolytic uremic syndrome relapse after eculizumab discontinuation. Prospective studies are needed to identify biomarkers predictive of relapse and determine the best strategy of retreatment in relapsing patients.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.2215/CJN.06440616DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5220663PMC
January 2017

Atypical haemolytic uraemic syndrome and pregnancy: outcome with ongoing eculizumab.

Nephrol Dial Transplant 2016 12 1;31(12):2122-2130. Epub 2016 Sep 1.

Department of Nephrology Transplantation-Dialysis, Centre Hospitalier Universitaire de Bordeaux, Bordeaux, France.

Background: A therapeutic strategy based on complement blockade by eculizumab is widely used to treat atypical haemolytic uraemic syndrome (aHUS). Recent data are available on the administration of eculizumab during pregnancy in patients treated for paroxysmal nocturnal haemoglobinuria but there are very few data for aHUS patients.

Methods: We analysed the use of eculizumab for the treatment of aHUS during five pregnancies in three patients and studied an additional pregnancy without eculizumab. Obstetrical data and maternal and foetal complications during pregnancy, at delivery, and during the post-partum period were recorded.

Results: The mean age at pregnancy was 28.5 (range 25-33) years. The mean serum creatinine before pregnancy was 189 (range 130-300) µmol/L and the mean eGFR was 32 (range 18-45) mL/min/1.73 m. One patient who stopped eculizumab 3 weeks after conception had a termination due to a relapse of HUS at 12 weeks of gestation (WG) during a first pregnancy and an intrauterine death at 24 WG despite continuous eculizumab treatment during a second pregnancy. In the other four pregnancies, treatment stabilized clinical and laboratory markers until 29-34 WG, but did not prevent hemolysis, elevated liver enzymes and low platelet count (HELLP) syndrome in one patient or pre-eclampsia in two other patients. All babies were born preterm and two presented with growth retardation. The mean body weight was 1632.5 (range 1070-2500) g. The dose of eculizumab had to be increased during all pregnancies due to incomplete complement blockade.

Conclusions: Eculizumab therapy during pregnancy displayed no overt safety issues but did not appear to prevent HELLP syndrome or pre-eclampsia in these high-risk chronic kidney disease patients.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1093/ndt/gfw314DOI Listing
December 2016

Epidemiology and pathophysiology of adulthood-onset thrombotic microangiopathy with severe ADAMTS13 deficiency (thrombotic thrombocytopenic purpura): a cross-sectional analysis of the French national registry for thrombotic microangiopathy.

Lancet Haematol 2016 May 16;3(5):e237-45. Epub 2016 Apr 16.

Service d'Hématologie biologique, Hôpital Lariboisière, Assistance Publique-Hôpitaux de Paris and EA3518, Institut Universitaire d'Hématologie-Hôpital Saint Louis, Université Paris Diderot, Paris, France. Electronic address:

Background: Thrombotic thrombocytopenic purpura is a thrombotic microangiopathy related to a severe deficiency of ADAMTS13 (a disintegrin and metalloprotease with thrombospondin type 1 repeats, member 13; activity <10%). We aimed to investigate the association between mechanisms for ADAMTS13 deficiency and the epidemiology and pathophysiology of thrombotic thrombocytopenic purpura at initial presentation.

Methods: Between Jan 1, 1999, and Dec 31, 2013, we did a cross-sectional analysis of the French national registry for thrombotic microangiopathy to identify all patients with adult-onset thrombotic microangiopathy (first episode after age 18 years) who had severe ADAMTS13 deficiency at presentation. ADAMTS13 activity, anti-ADAMTS13 IgG, and ADAMTS13 gene mutations were investigated by a central laboratory. We collected patients' clinical data for correlation with their ADAMTS13 phenotype and genotype. We used logistic regression analysis to identify variables significantly associated with idiopathic thrombotic thrombocytopenic purpura, as measured by estimated odds ratios (ORs) and 95% CIs. This study is registered with ClinicalTrials.gov, number NCT00426686.

Findings: We enrolled 939 patients with adult-onset thrombotic thrombocytopenic purpura, of whom 772 (82%) patients had available data and samples at presentation and comprised the cohort of interest. The prevalence of thrombotic thrombocytopenic purpura in France was 13 cases per million people. At presentation, 378 (49%) patients had idiopathic thrombotic thrombocytopenic purpura, whereas 394 (51%) patients had disease associated with miscellaneous clinical situations (infections, autoimmunity, pregnancy, cancer, organ transplantation, and drugs). Pathophysiologically, three distinct forms of thrombotic thrombocytopenic purpura were observed: 585 (75%) patients had autoimmune disease with anti-ADAMTS13 IgG, 166 (22%) patients had acquired disease of unknown cause and 21 (3%) patients had inherited disease (Upshaw-Schulman syndrome) with mutations of the ADAMTS13 gene. Idiopathic thrombotic thrombocytopenic purpura were mainly autoimmune (345 [91%] cases), whereas non-idiopathic diseases were heterogeneous, including a high rate of unexplained mechanisms for ADAMTS13 deficiency (133 [34%] cases). Obstetrical thrombotic thrombocytopenic purpura cases (n=62) were specifically remarkable because of the high rate of patients with Upshaw-Schulman syndrome (21 [34%] patients).

Interpretation: Our study shows that thrombotic thrombocytopenic purpura is a heterogeneous syndrome, and that features of the disease at presentation are strongly associated with the mechanisms of ADAMTS13 deficiency. In addition to mechanistic insight, our findings could have implications for the initial therapeutic management of patients with this disorder.

Funding: Assistance Publique-Hôpitaux de Paris.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/S2352-3026(16)30018-7DOI Listing
May 2016

Improved renal recovery in patients with atypical hemolytic uremic syndrome following rapid initiation of eculizumab treatment.

J Nephrol 2017 Feb 19;30(1):127-134. Epub 2016 Mar 19.

Medical School Hannover, Hannover, Germany.

Background: Eculizumab is approved for atypical hemolytic uremic syndrome (aHUS). Guidelines discuss the importance of prompt treatment. We report a post hoc analysis investigating the effect of baseline factors, including patient characteristics and time from the latest aHUS manifestation to eculizumab initiation, on change from baseline in estimated glomerular filtration rate (eGFR) and other outcomes.

Methods: Data were pooled from four phase 2, open-label, single-arm, prospective clinical studies of eculizumab for patients with aHUS. Multivariate regressions identified predictors of eGFR change from baseline. The proportion of patients achieving sustained eGFR increase (defined: ≥15 ml/min/1.73 m for ≥28 days) and platelet count normalization were evaluated 1 year post-treatment. Baseline characteristics and eGFR outcomes were summarized by time to treatment from last aHUS manifestation [≤7 days (n = 21) versus >7 days (n = 76)].

Results: Baseline eGFR were similar between groups. Multivariate regression analysis demonstrated time from aHUS manifestation to eculizumab treatment, age, baseline lactate dehydrogenase (LDH) and baseline hemoglobin were independently predictive of eGFR change from baseline. Mean eGFR change from baseline at 1 year was significantly higher in patients treated in ≤7 days than >7 days (57 vs. 23 ml/min/1.73 m, p = 0.0098). After 1 year, 17/21 and 36/76 patients in the ≤7 and >7 day groups, respectively, achieved a sustained increase in eGFR. Mean time to platelet count normalization was similar between groups.

Conclusions: Younger age, higher baseline LDH and lower baseline hemoglobin were associated with greater eGFR improvements. Early eculizumab initiation led to improved renal recovery, demonstrating the importance of rapid diagnosis and treatment of patients with aHUS.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s40620-016-0288-3DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5316393PMC
February 2017