Publications by authors named "Mohamed Shantier"

5 Publications

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Collapsing Glomerulopathy Affecting Native and Transplant Kidneys in Individuals with COVID-19.

Nephron 2020 7;144(11):589-594. Epub 2020 Sep 7.

Nottingham Renal and Transplant Unit, Nottingham University Hospitals NHS Trust, Nottingham, United Kingdom,

Since the emergency of novel coronavirus COVID-19 (SARS-CoV-2) in December 2019, infections have spread rapidly across the world. The reported incidence of acute kidney injury (AKI) in the context of COVID-19 is variable, and its mechanism is not well understood. Data are emerging about possible mechanisms of AKI including virus-induced cytopathic effect and cytokine storm-induced injury. To date, there have been few reports of kidney biopsy findings in the context of AKI in COVID-19 infection. This article describes 2 cases of collapsing glomerulopathy, 1 in a native kidney and, for the first time, 1 in a kidney transplant. Both individuals were black, and both presented without significant respiratory compromise. Indeed, the 2 patients we describe remained systemically well for the majority of their inpatient stay, which would support the hypothesis that for these patients, AKI was caused by a cytopathic viral effect, rather than that of a cytokine storm or acute tubular necrosis caused by prolonged hypovolaemia or the effect of medication known to exacerbate AKI. Here, we report 2 cases of AKI with collapsing glomerulopathy in COVID-19, one of which is in a kidney transplant recipient, not previously described elsewhere.
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http://dx.doi.org/10.1159/000509938DOI Listing
November 2020

Use of the Living Kidney Donor Profile Index in the Canadian Kidney Transplant Recipient Population: A Validation Study.

Can J Kidney Health Dis 2020 20;7:2054358120906976. Epub 2020 Feb 20.

The Kidney Transplant Program and the Multi-Organ Transplant Program, University Health Network, Toronto, ON, Canada.

Background: The Living Kidney Donor Profile Index (LKDPI) was derived in a cohort of kidney transplant recipients (KTR) from the United States to predict the risk of total graft failure. There are important differences in patient demographics, listing practices, access to transplantation, delivery of care, and posttransplant mortality in Canada as compared with the United States, and the generalizability of the LKDPI in the Canadian context is unknown.

Objective: The purpose of this study was to externally validate the LKDPI in a large contemporary cohort of Canadian KTR.

Design: Retrospective cohort validation study.

Setting: Toronto General Hospital, University Health Network, Toronto, Ontario, Canada.

Patients: A total of 645 adult (≥18 years old) living donor KTR between January 1, 2006 and December 31, 2016 with follow-up until December 31, 2017 were included in the study.

Measurements: The predictive performance of the LKDPI was evaluated. The outcome of interest was total graft failure, defined as the need for chronic dialysis, retransplantation, or death with graft function.

Methods: The Cox proportional hazards model was used to examine the relation between the LKDPI and total graft failure. The Cox proportional hazards model was also used for external validation and performance assessment of the model. Discrimination and calibration were used to assess model performance. Discrimination was assessed using Harrell's C statistic and calibration was assessed graphically, comparing observed versus predicted probabilities of total graft failure.

Results: A total of 645 living donor KTR were included in the study. The median LKDPI score was 13 (interquartile range [IQR] = 1.1, 29.9). Higher LKDPI scores were associated with an increased risk of total graft failure (hazard ratio = 1.01; 95% confidence interval [CI] = 1.0-1.02; = .02). Discrimination was poor (C statistic = 0.55; 95% CI = 0.48-0.61). Calibration was as good at 1-year posttransplant but suboptimal at 3- and 5-years posttransplant.

Limitations: Limitations include a relatively small sample size, predicted probabilities for assessment of calibration only available for scores of 0 to 100, and some missing data handled by imputation.

Conclusions: In this external validation study, the predictive ability of the LKDPI was modest in a cohort of Canadian KTR. Validation of prediction models is an important step to assess performance in external populations. Potential recalibration of the LKDPI may be useful prior to clinical use in external cohorts.
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http://dx.doi.org/10.1177/2054358120906976DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7036490PMC
February 2020

Increased Weight Gain During the Long Interdialytic Period Is Associated with Minor Effects on Blood Pressure Control in Clinically Stable In-Centre Haemodialysis Patients.

Nephron 2019 9;141(2):87-97. Epub 2018 Nov 9.

Nephrology Services, Saolta University Healthcare Group, Galway, Ireland,

Background/aims: Three-day-a-week chronic haemodialysis (cHD) involves 1 long (72 h) and 2 short (48 h) inter-dialytic periods (IDPs). We aimed to determine whether BP control following the long IDP is inferior to the short IDPs.

Methods: All pre- and post-dialysis BP and weight measurements over a 4-week period were retrospectively analyzed among 135 clinically stable cHD patients at 2 academic centres with comparisons between measurements recorded following short and long IDPs. Subsequently, 23 clinically stable cHD patients underwent 24-h ambulatory blood pressure monitoring (ABPM) during the final day/night cycle of the long IDP and 1 short IDP within the same week.

Results: In combined and separate analyses of the 2 retrospective cohorts, pre-dialysis BP parameters were not different following long and short IDPs despite greater inter-dialytic weight gain (IDWG) during the long IDP. Subgroup analyses of the total cohort showed no evidence for inferior BP control during the long IDP among those with high %IDWG. In the ABPM study, nocturnal hypertension and loss of nocturnal dipping were frequent. Furthermore, daytime systolic blood pressure (SBP) and pulse pressure were modestly higher during the last day/night cycle of the long compared with short IDP.

Conclusion: In stable cHD patients, the greater IDWG that occurred during the long IDP was not associated with overtly inferior BP control as reflected in pre-dialysis BP measurements. However, modestly higher daytime SBP was evident towards the end of the long IDP by 24 h ABPM. Thus, while fluid gain has well-documented associations with hypertension and adverse cardiovascular outcomes, the excess IDWG that occurs during the long IDP exerts relatively minor effects on BP control in patients on well-established dialysis regimens that are better identified by ambulatory monitoring.
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http://dx.doi.org/10.1159/000494221DOI Listing
December 2019

Comparison of Percutaneous and Open Surgical Techniques for First-Time Peritoneal Dialysis Catheter Placement in the Unbreached Peritoneum.

Perit Dial Int 2015 Sep-Oct;35(5):576-85. Epub 2014 Jul 31.

Nephrology, Adelaide & Meath Hospital, Dublin, Ireland.

Background: The percutaneous Seldinger method of peritoneal dialysis catheter (PDC) insertion has gained favor over recent years whereas traditionally it was reserved for patients considered not fit for general anesthesia. This blind technique is believed to be less safe, and is hence avoided in patients with previous laparotomy incisions. Reports on the success of this method may therefore be criticized for selection bias. In those with no prior abdominal surgery the optimal method of insertion has not been established.

Methods: We retrospectively reviewed the outcomes of first-time PDC placements comparing the percutaneous (group P) and surgical (group S) insertion techniques in patients without a history of previous abdominal surgery in a single center between January 2003 and June 2010. We assessed catheter survival at 3 and 12 months post-insertion and compared complication rates between the two groups.

Results: A total of 63 percutaneous and 64 surgical catheter insertions were analyzed. No significant difference was noted in catheter survival rates between group P and group S (86.2% vs 80% at 3 months, p = 0.37; and 78.3% vs 71.2% at 12 months, p = 0.42 respectively). Early and overall peritonitis rates were similar (5% vs 5.3%; p = 1, and 3.5 vs 4.9 episodes per 100 patient-months; p = 0.13 for group P and group S respectively). There were also no significant differences between the two groups in exit site leaks (15.9% in group P vs 6.3% in group S; p = 0.15), poor initial drainage (9.5% in group P vs 10.9% in group S, p = 0.34) or secondary drainage failure (7.9% in group P vs 18.8% in group S, p = 0.09).

Conclusion: This study illustrates the success and safety of percutaneous PDC insertion compared with the open surgical technique in PD naive patients without a history of prior abdominal surgery. Catheter survival was favorable with percutaneous insertion in this low-risk patient population but larger prospective studies may help to determine whether either method is superior. The percutaneous technique can be recommended as a minimally invasive, cost-effective procedure that facilitates implementing an integrated care model in nephrology practice.
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http://dx.doi.org/10.3747/pdi.2013.00003DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4597991PMC
July 2016

A comparative analysis of percutaneous and open surgical techniques for peritoneal catheter placement.

Perit Dial Int 2012 Nov-Dec;32(6):628-35. Epub 2012 May 1.

Nephrology, Adelaide and Meath Hospital, Dublin, Ireland.

Background: Peritoneal dialysis (PD) is the preferred available option of renal replacement therapy for a significant number of end-stage kidney disease patients. A major limiting factor to the successful continuation of PD is the long-term viability of the PD catheter (PDC). Bedside percutaneous placement of the PDC is not commonly practiced despite published data encouraging use of this technique. Its advantages include faster recovery and avoidance of general anesthesia.

Methods: We carried out a retrospective analysis of the outcomes of 313 PDC insertions at our center, comparing all percutaneous PDC insertions between July 1998 and April 2010 (group P, n = 151) with all surgical PDC insertions between January 2003 and April 2010 (group S, n = 162).

Results: Compared with group P patients, significantly more group S patients had undergone previous abdominal surgery or PDC insertion (41.8% vs 9.3% and 33.3% vs 3.3% respectively, p = 0.00). More exit-site leaks occurred in group P than in group S (20.5% vs 6.8%, p = 0.002). The overall incidence of peritonitis was higher in group S than in group P (1 episode in 19 catheter-months vs 1 episode in 26 catheter-months, p = 0.017), but the groups showed no significant difference in the peritonitis rate within 1 month of catheter insertion (5% in group P vs 7.4% in group S, p = 0.4) or in poor initial drainage or secondary drainage failure (9.9% vs 11.7%, p = 0.1, and 7.9% vs 12.3%, p = 0.38, for groups P and S respectively).Technical survival at 3 months was significantly better for group P than for group S (86.6% vs 77%, p = 0.037); at 12 months, it was 77.7% and 68.7% respectively (p = 0.126). No life-threatening complications attributable to the insertion of the PDC occurred in either group.

Conclusions: Our analysis demonstrates further encouraging outcomes of percutaneous PDC placement compared with open surgical placement. However, the members of the percutaneous insertion group were primarily a selected subset of patients without prior abdominal surgery or PDC insertion, therefore limiting the comparability of the groups. Studies addressing such confounding factors are required. Local expertise in catheter placement techniques may affect the generalizability of results.
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http://dx.doi.org/10.3747/pdi.2011.00187DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3524906PMC
May 2013
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