Publications by authors named "Leandro Burgos Pratx"

6 Publications

  • Page 1 of 1

A Randomized Trial of Convalescent Plasma in Covid-19 Severe Pneumonia.

N Engl J Med 2021 02 24;384(7):619-629. Epub 2020 Nov 24.

From the Clinical Pharmacology Section (V.A.S., P.S., M.V.B., N.S.), Intermediate Care Unit (M.G.V., C.V., H.G.M.), and Infectious Diseases Section (M.L.S.), Department of Internal Medicine, and the Departments of Research (V.A.S., D.H.G., L.G.P., W.H.B.) and Transfusional Medicine (L.D.B.P., D.M.S., P.J.C., S.A.), Hospital Italiano de Buenos Aires, Buenos Aires; Department of Virology, Leloir Institute Foundation, Buenos Aires (A.V.G., D.S.O.), the Departments of Transfusional Medicine (K.R.), Infectious Diseases, Sanatorio Agote (G.P.V.), and Critical Care, Clínica Zabala (E.A.M.), Swiss Medical, Buenos Aires, the Departments of Infection Control (W.C.) and Transfusional Medicine (O.A.T.), Hospital Universitario Austral, Pilar, the Departments of Internal Medicine (F.M.R.) and Transfusional Medicine (M.S.), Clínica Santa Isabel, Buenos Aires, the Departments of Emergency and Internal Medicine (L.D.B.P., G.F.) and Transfusional Medicine (W.E.S.), Hospital Italiano Agustín Rocca, San Justo, the Departments of Medicine (M.H.L.) and Transfusional Medicine (I.F.), Hospital General de Agudos José María Ramos Mejía, Buenos Aires, the Departments of Internal Medicine (P.E.P.) and Transfusional Medicine (E.R.), Sanatorio Trinidad de Palermo, Buenos Aires, the Departments of Clinical Research (N.A.F., M.E.) and Transfusional Medicine (G.A.S.), Hospital Privado de la Comunidad de Mar del Plata and Escuela Superior de Medicina Universidad Nacional de Mar del Plata, Mar del Plata (N.A.F., M.E.), the Departments of Internal Medicine (P.R.) and Transfusional Medicine (J.P.), Hospital Zonal Ramón Carrillo, Bariloche, and the Departments of Infectious Diseases (E.C.N.) and Transfusional Medicine (A.M.), Sanatorio Británico de Rosario, Santa Fé - all in Argentina; and the Biostatistics Research Branch (D.F.), Division of Clinical Research (D.F., H.C.L.), National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD.

Background: Convalescent plasma is frequently administered to patients with Covid-19 and has been reported, largely on the basis of observational data, to improve clinical outcomes. Minimal data are available from adequately powered randomized, controlled trials.

Methods: We randomly assigned hospitalized adult patients with severe Covid-19 pneumonia in a 2:1 ratio to receive convalescent plasma or placebo. The primary outcome was the patient's clinical status 30 days after the intervention, as measured on a six-point ordinal scale ranging from total recovery to death.

Results: A total of 228 patients were assigned to receive convalescent plasma and 105 to receive placebo. The median time from the onset of symptoms to enrollment in the trial was 8 days (interquartile range, 5 to 10), and hypoxemia was the most frequent severity criterion for enrollment. The infused convalescent plasma had a median titer of 1:3200 of total SARS-CoV-2 antibodies (interquartile range, 1:800 to 1:3200). No patients were lost to follow-up. At day 30 day, no significant difference was noted between the convalescent plasma group and the placebo group in the distribution of clinical outcomes according to the ordinal scale (odds ratio, 0.83; 95% confidence interval [CI], 0.52 to 1.35; P = 0.46). Overall mortality was 10.96% in the convalescent plasma group and 11.43% in the placebo group, for a risk difference of -0.46 percentage points (95% CI, -7.8 to 6.8). Total SARS-CoV-2 antibody titers tended to be higher in the convalescent plasma group at day 2 after the intervention. Adverse events and serious adverse events were similar in the two groups.

Conclusions: No significant differences were observed in clinical status or overall mortality between patients treated with convalescent plasma and those who received placebo. (PlasmAr number, NCT04383535.).
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February 2021

Acquired factor XIII deficiency in patients under therapeutic plasma exchange: A poorly explored etiology.

J Clin Apher 2021 Feb 17;36(1):59-66. Epub 2020 Sep 17.

Department of Applied Biochemistry, Section of Hematology and Hemostasis, Central Laboratory, Hospital Italiano de Buenos Aires. Instituto Universitario del Hospital Italiano, Buenos Aires, Argentina.

Introduction: Factor XIII (FXIII) deficiency may cause bleeding under certain clinical circumstances. Therapeutic plasma exchange (TPE) may lead to a transient deficiency.

Objectives: To describe the clinical evolution of patients with acquired FXIII deficiency secondary to TPE.

Methods: We respectively studied a cohort of consecutive patients from 2014 to 2019 who were treated with TPE with FXIII levels <50%. The FXIII was measured after the start of the TPE course, on days between the TPE sessions, due to suspected acquired deficiency. All TPE were performed using continuous flow cell separator. In all cases, the initial replacement fluid applied was albumin. Apheresis procedures were held at 24to 48 hours intervals.

Results: Eighteen patients were included, 13 of them were recipients of kidney transplants. The main TPE prescription was humoral rejection. Median FXIII at diagnosis (measured on days between sessions of the TPE course) was 19%(IQR17-25). The median of apheresis procedures before measurement of FXIII was 3(IQR2-4). Among the total cohort, 10 patients suffered hemorrhages. None of the patients without history of kidney transplants had bleeding (n = 5), however, 10/13 with kidney transplants did. Five kidney transplant patients received therapy with FXIII concentrate because of life-threatening bleeding. In all cases, the bleeding stopped within the first 24 hours. All patients had their FXIII levels measured again after finishing the TPE course, with normal results.

Conclusions: TPE is an under-diagnosed cause of acquired FXIII deficiency since routine coagulation tests remain unaltered. It might cause major bleeding, particularly in patients with a recent history of surgery like kidney transplants.
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February 2021

Impact of the volume of blood collected by phlebotomy on transfusion requirements in preterm infants with birth weight of less than 1500 g. A quasi-experimental study.

Arch Argent Pediatr 2020 04;118(2):109-116

Servicio de Neonatología, Departamento de Pediatría, Hospital Italiano de Buenos Aires, Ciudad Autónoma de Buenos Aires.

Introduction: Anemia is a complication in very low birth weight (VLBW) infants, and lab tests are a predominant risk factor. At least one red blood cell transfusion is given in more than 50 % of cases. Transfusions are associated with a higher risk for infections, intracranial hemorrhage, necrotizing enterocolitis, and bronchopulmonary dysplasia. In 2012, Hospital Italiano de Buenos Aires implemented a strategy to collect a lower blood volume by phlebotomy. The objective of this study was to assess its association with the number of transfusions.

Methods: Before-and-after, quasi-experimental study. The number of transfusions was compared between two groups of VLBW preterm infants with different blood collection volumes. The correlation between the collection volume and the number of transfusions was assessed estimating Spearman's coefficient. A logistic regression model was used to adjust for confounders.

Results: The study included 178 patients with a mean gestational age of 29.4 weeks (standard deviation: 2.7) and a birth weight of 1145 g (875-1345). The baseline red series profile was similar between both groups. The number of transfusions (p = 0.017) and the transfusion volume (p = 0.048) decreased significantly. The correlation coefficient was 0.83. In the multivariate analysis, collection volume and birth weight were associated with a requirement of more than three transfusions.

Conclusion: A lower blood collection volume in VLBW preterm infants is independently associated with fewer transfusion requirements.
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April 2020

Role of HLA-DP and HLA-DQ on the clearance of hepatitis B virus and the risk of chronic infection in a multiethnic population.

Liver Int 2017 10 30;37(10):1476-1487. Epub 2017 Mar 30.

Scientific and Technological Research Council (CONICET), Buenos Aires, Argentina.

Background & Aims: HBV infection exhibits geographical variation in its distribution in South America. While HBV rates are low in central Argentina, the north-western region exhibits intermediate HBV rates. Unfortunately, the reasons that could explain this difference are still unknown.

Methods: A total of 1440 Argentines were recruited and grouped into HBV patients, HBV-resolved individuals and healthy controls. Genetic ancestry was assessed by analysis of biparental lineages and ancestry autosomal typing. SNPs of HLA-DPA1 (rs3077), HLA-DPB1 (rs9277542), HLA-DQB1 (rs2856718) and HLA-DQB2 (rs7453920) were determined, and HBV genotyping was performed by phylogenetic analysis in HBV patients.

Results: Native American ancestry prevailed in the north-western region when compared with central Argentina (P<.0001). However, no differences were observed among the three groups of each region. The distribution of HBV genotypes revealed significant differences (P<.0001). Three SNPs (rs3077, rs9277542 and rs7453920) showed a significant association with protection against chronic HBV and viral clearance in both regions. The remaining SNP showed a significant association with susceptibility to chronic HBV. The frequency rates of rs3077-T, related to protection against chronic HBV and viral clearance, were lower in north-western Argentina when compared with central Argentina. The same uneven frequency rates were observed for SNP rs9277542.

Conclusions: This is the first study addressing the associations between the HLA-DP and HLA-DQ loci and the protection against chronic HBV and viral clearance in a multiethnic South American population. The uneven distribution of HLA-DP and HLA-DQ supports the HBV epidemiological differences observed in these two regions of Argentina with dissimilar ancestry genetic background.
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October 2017

Increased prevalence of human herpesvirus type 8 (HHV-8) genome among blood donors from North-Western Argentina.

J Med Virol 2017 03 31;89(3):518-527. Epub 2016 Aug 31.

Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Departamento de Microbiología, Inmunología y Biotecnología, Cátedra de Genética Forense y Servicio de Huellas Digitales Genéticas, Buenos Aires, Argentina.

The prevalence of HHV-8 infection varies widely in South American populations, displaying geographical variations in its distribution. The heterogeneous genetic contributions provided by the transatlantic parental populations that modified the Native American genomes may explain this epidemiological observation. Aiming to determine the prevalence of HHV-8 genome among healthy South American blood donors and its potential association with genetic ancestry, 772 individuals were screened by a highly sensitive PCR protocol and ancestry was assessed in 414 samples. HHV-8 DNA was significantly more prevalent among North-western Argentines than among those from the metropolitan region (P = 0.001) and Bolivians (P = 0.0008), but no differences were found when compared with Peruvians and Paraguayans. Although significant differences were observed in the ancestry components of the studied populations, no association was found in the genetic admixture between HHV-8 [+] and HHV-8 [-] samples from the same place. These results support the hypothesis of the existence of geographical factors related to HHV-8 prevalence which could be explained by the presence of specific risk factors, cultural characteristics or behaviors, probably related to contaminated saliva and/or sexual transmission. The presence of HHV-8 in South American blood units available for transfusion and an increased risk of infection in some provinces of North-western Argentina represent a hazard for immunosuppressed recipients. J. Med. Virol. 89:518-527, 2017. © 2016 Wiley Periodicals, Inc.
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March 2017

Influence of ethnicity on the distribution of genetic polymorphisms associated with risk of chronic liver disease in South American populations.

BMC Genet 2015 Jul 29;16:93. Epub 2015 Jul 29.

National Scientific and Technical Research Council (CONICET), Av. Rivadavia 1917, C1033AAJ, Buenos Aires, Argentina.

Background: The global burden of chronic liver disease is rising. Besides environmental, behavioral, viral and metabolic factors, genetic polymorphisms in patatin-like phospholipase-3 (PNPLA3) and vitamin D receptor (VDR) genes have been related to the development of chronic liver disease and progression towards liver cancer. Although their prevalence differs remarkably among ethnic groups, the frequency of these polymorphisms in South American populations -whose genetic background is highly admixed- has been poorly studied. Hence, the aim of this study was to characterize polymorphisms related to chronic liver disease and their association with the genetic ancestry of South American populations.

Results: DNA samples from 258 healthy unrelated male volunteers were analyzed. The frequencies of G and C alleles of rs738409 polymorphism (PNPLA3 gene) were 74 % and 26 %, respectively; whereas the bAt (CCA) haplotype (VDR gene) was observed in 32.5 % of the samples. The GG genotype of PNPLA3 rs738409 and the bAt (CCA) haplotype -associated with an increased risk of chronic liver disease and progression towards liver cancer- were significantly more frequent among samples exhibiting maternal and paternal Native American haplogroups (63.7 % and 64.6 %), intermediate among admixed samples (45.1 % and 44.9 %; p = 0.03) and the lowest for Non-native American ancestry (30.1 % and 29.6 %; p = 0.001 and p = 0.0008).

Conclusions: These results suggest that individuals with Native American ancestry might have a high risk of chronic liver disorders and cancer. Furthermore, these data not only support the molecular evaluation of ancestry in multi-ethnic population studies, but also suggest that the characterization of these variants in South American populations may be useful for establishing public health policies aimed at high risk ethnic communities.
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July 2015