Detection of alloimmunization in Glanzmann Thrombasthenia and Bernard-Soulier Syndrome: Data from a Brazilian Center.

INTRODUCTION: The Glanzmann Thrombasthenia (GT) and Bernard-Soulier Syndrome (BSS) are rare hereditary disorders of platelet function. Their treatment often requires platelet transfusion, which can lead to the development of alloantibodies. OBJECTIVE: In this study, we aim to develop a strategy for alloantibody detection and to describe the frequency of alloimmunization in a patient population from a single center in southeastern Brazil. METHODS: Samples from patients with GT or BSS were tested using the Platelet Immunofluorescence Test (PIFT). If a positive result was obtained, a confirmatory step using the Monoclonal Antibody Immobilization of Platelet Antigens (MAIPA) and Luminex bead-based platelet assay (PAKLx) was executed. MAIN RESULTS: Among 11 patients with GT, we detected the presence of alloantibodies in 5 using PIFT, with confirmation through MAIPA and PAKLx in 2 (1 anti-HLA and 1 anti-HPA), resulting in a frequency of 18.1%. Among 4 patients with BSS, PIFT was positive in 3, with confirmation by MAIPA and PAKLx in 1 (anti-HLA), showing a frequency of 25%. The two patients with anti-HLA antibodies exhibited a panel reactive antibody (PRA-HLA) testing greater than 97%. CONCLUSION: Our study highlights the importance of identifying platelet alloimmunization in this patient population. The proposed algorithm for platelet alloantibodies detection allows resource optimization.

Predicting SARS-CoV-2 Variant Spread in a Completely Seropositive Population Using Semi-Quantitative Antibody Measurements in Blood Donors.

SARS-CoV-2 serologic surveys estimate the proportion of the population with antibodies against historical variants, which nears 100% in many settings. New approaches are required to fully exploit serosurvey data. Using a SARS-CoV-2 anti-Spike (S) protein chemiluminescent microparticle assay, we attained a semi-quantitative measurement of population IgG titers in serial cross-sectional monthly samples of blood donations across seven Brazilian state capitals (March 2021−November 2021). Using an ecological analysis, we assessed the contributions of prior attack rate and vaccination to antibody titer. We compared anti-S titer across the seven cities during the growth phase of the Delta variant and used this to predict the resulting age-standardized incidence of severe COVID-19 cases. We tested ~780 samples per month, per location. Seroprevalence rose to >95% across all seven capitals by November 2021. Driven by vaccination, mean antibody titer increased 16-fold over the study, with the greatest increases occurring in cities with the highest prior attack rates. Mean anti-S IgG was strongly correlated (adjusted R2 = 0.89) with the number of severe cases caused by Delta. Semi-quantitative anti-S antibody titers are informative about prior exposure and vaccination coverage and may also indicate the potential impact of future SARS-CoV-2 variants.

Associação Brasileira de Hematologia, Hemoterapia e Terapia Celular Consensus on genetically modified cells. VII. Present and future of technologies for production of CAR cell therapies.

Chimeric Antigen Receptor T (CAR-T) cells are certainly an important therapy for patients with relapsed and/or refractory hematologic malignancies. Currently, there are five CAR-T cell products approved by the FDA but several research groups and/or biopharmaceutical companies are encouraged to develop new products based on CAR cells using T or other cell types. Production of CAR cells requires intensive work from the basic, pre-clinical to translational levels, aiming to overcome technical difficulties and failure in the production. At least five key common steps are needed for the manipulation of T-lymphocytes (or other cells), such as: cell type selection, activation, gene delivery, cell expansion and final product formulation. However, reproducible manufacturing of high-quality clinical-grade CAR cell products is still required to apply this technology to a greater number of patients. This chapter will discuss the present and future development of new CAR designs that are safer and more effective to improve this therapy, achieving more selective killing of malignant cells and less toxicity to be applied in the clinical setting.

Higher risk of death from COVID-19 in low-income and non-White populations of São Paulo, Brazil.

INTRODUCTION: Little evidence exists on the differential health effects of COVID-19 on disadvantaged population groups. Here we characterise the differential risk of hospitalisation and death in São Paulo state, Brazil, and show how vulnerability to COVID-19 is shaped by socioeconomic inequalities. METHODS: We conducted a cross-sectional study using hospitalised severe acute respiratory infections notified from March to August 2020 in the Sistema de Monitoramento Inteligente de São Paulo database. We examined the risk of hospitalisation and death by race and socioeconomic status using multiple data sets for individual-level and spatiotemporal analyses. We explained these inequalities according to differences in daily mobility from mobile phone data, teleworking behaviour and comorbidities. RESULTS: Throughout the study period, patients living in the 40% poorest areas were more likely to die when compared with patients living in the 5% wealthiest areas (OR: 1.60, 95% CI 1.48 to 1.74) and were more likely to be hospitalised between April and July 2020 (OR: 1.08, 95% CI 1.04 to 1.12). Black and Pardo individuals were more likely to be hospitalised when compared with White individuals (OR: 1.41, 95% CI 1.37 to 1.46; OR: 1.26, 95% CI 1.23 to 1.28, respectively), and were more likely to die (OR: 1.13, 95% CI 1.07 to 1.19; 1.07, 95% CI 1.04 to 1.10, respectively) between April and July 2020. Once hospitalised, patients treated in public hospitals were more likely to die than patients in private hospitals (OR: 1.40%, 95% CI 1.34% to 1.46%). Black individuals and those with low education attainment were more likely to have one or more comorbidities, respectively (OR: 1.29, 95% CI 1.19 to 1.39; 1.36, 95% CI 1.27 to 1.45). CONCLUSIONS: Low-income and Black and Pardo communities are more likely to die with COVID-19. This is associated with differential access to quality healthcare, ability to self-isolate and the higher prevalence of comorbidities.

Three-quarters attack rate of SARS-CoV-2 in the Brazilian Amazon during a largely unmitigated epidemic.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spread rapidly in Manaus, the capital of Amazonas state in northern Brazil. The attack rate there is an estimate of the final size of the largely unmitigated epidemic that occurred in Manaus. We use a convenience sample of blood donors to show that by June 2020, 1 month after the epidemic peak in Manaus, 44% of the population had detectable immunoglobulin G (IgG) antibodies. Correcting for cases without a detectable antibody response and for antibody waning, we estimate a 66% attack rate in June, rising to 76% in October. This is higher than in São Paulo, in southeastern Brazil, where the estimated attack rate in October was 29%. These results confirm that when poorly controlled, COVID-19 can infect a large proportion of the population, causing high mortality.

Correction: Mortality among blood donors seropositive and seronegative for Chagas disease (1996-2000) in São Paulo, Brazil: A death certificate linkage study.

[This corrects the article DOI: 10.1371/journal.pntd.0005542.].

FcγR2B B2.4 haplotype predicts increased risk of red blood cell alloimmunization in sickle cell disease patients.

BACKGROUND: Red blood cell (RBC) alloimmunization is an important transfusion complication which is prevalent among sickle cell disease (SCD) patients. Autoimmune diseases are a known risk factor for RBC alloimmunization, suggesting that autoimmunity and post-transfusion alloantibody development occur through similar physiopathological pathways. Polymorphisms in the FcγR2B gene have already been associated with several autoimmune disorders and hypothetically could be associated with RBC alloimmunization. Our goal was to evaluate if important polymorphisms of FcγR2B have an impact on the risk of RBC alloimmunization among SCD patients. STUDY DESIGN AND METHODS: This was a case-control study in which alloimmunized and non-alloimmunized SCD patients were compared in terms of the genotype frequency of the FcγR2B polymorphisms -386G/C, -120 T/A, and 695C/T, genotyped through direct Sanger sequencing. RESULTS: A total of 237 patients met the eligibility criteria, 120 cases (alloimmunized) and 117 controls (non-alloimmunized). RBC alloimmunization was associated with female sex (p < 0.001), lifetime number of RBC units transfused (p = 0.002) and 120 T/A FcγR2B genotype (p = 0.031). The FcγR2B promoter region haplotype 2B.4 (386C120A) was positively associated with RBC alloimunization (p = 0.045). The logistic regression (LR) model identified female sex (OR 10.03, CI 95% 5.16-19.49; p < 0.001) and FcγR2B 2B.4 haplotype (OR 4.55, CI95% 1.1118.65; p = 0.035) as independent predictors of RBC alloimmunization in SCD patients. CONCLUSION: SCD patients with the FcγR2B 2B.4 haplotype had over a fourfold higher risk for RBC alloimmunization. This highlights the role played by FcγR2B on RBC alloimmunization and may be helpful in identifying the immune responders.

Weak D types 38 and 11: determination of frequencies in a Brazilian population and validation of an easy molecular assay for detection.

CONCLUSIONS: Recent evidence shows that, among Brazilians, the distribution of weak D types significantly differs from that represented in people of European descent, with a high percentage of weak D types 38 and 11. Our goal was to determine the population frequencies of weak D types 38 and 11 in a Brazilian population and to validate a molecular approach to identify these two variants. Blood donors were sequentially enrolled in the study in a 5-year period. Donors with serologic weak D phenotype had the RHD coding region sequenced. The frequencies of weak D type 38 and weak D type 11 (CDe-associated) were calculated. Two allele-specific-polymerase chain reaction (AS-PCR) assays were designed to detect RHD*weak D type 38 and RHD*weak partial 11 and were validated with samples positive and negative for these two variants, respectively. A total of 618,542 donors were enrolled, of which 265 presented with a serologic weak D phenotype. When considering all donors evaluated, the frequencies of weak D types 38 and 11 were 0.013 and 0.002 percent, respectively. In the subgroup of donors with a serologic weak D phenotype, the frequencies of weak D types 38 and 11 were 30.2 and 4.9 percent, respectively. The two proposed AS-PCR assays for detection of RHD*weak D type 38 and RHD*weak partial 11 showed 100 percent accuracy. The frequencies of weak D types 38 and 11 among Brazilians are high compared to that previously described for other populations. The AS-PCR assays to detect RHD*weak D type 38 and RHD*weak partial 11 represent potentially helpful tools for investigating Brazilian individuals with these weak D phenotypes.

Trends in platelet distributions from 2008 to 2017: a survey of twelve national and regional blood collectors.

BACKGROUND: This multi-national study evaluated changes in platelet (PLT) unit distributions at 12 national or regional blood collectors over a 10-year period. METHODS: Data on the total number of PLT distributions, the collection method, that is apheresis vs whole blood-derived (WBD), the PLT unit characteristics and post-collection modifications were obtained from 12 national or regional blood collectors from 2008 through 2017. Individual WBD PLT units were converted to apheresis equivalent units (i.e. a dose of PLTs) by dividing by 4, the typical pool size; WBD units that were pooled before distribution were counted as a single dose. RESULTS: Overall at these 12 blood collectors, the total number of PLTs distributed in 2008 was 1 373 200, which rose by 10·2% to 1 513 803 in 2017. The Japanese Red Cross, which distributes only apheresis PLTs, had a 13·4% increase in the number of distributions between the years 2008 and 2017, while the other 11 blood collectors combined demonstrated a 6·8% increase in distributions between these two years. Between the years 2008 and 2017, the changes in the proportion of apheresis, platelet-rich plasma and buffy coat PLT distributions were -29·9%, -70·7% and 80·0%, respectively. CONCLUSION: The number of PLT distributions increased during the 10-year study period despite prophylactic PLT transfusion thresholds having remained fairly consistent over the last decade. Perhaps this increase is in part driven by increased administration of platelets to patients with massive haemorrhage or an increase in stem cell transplantation. The use of buffy coat PLTs is increasing at these collectors.

Impact on mortality of being seropositive for hepatitis C virus antibodies among blood donors in Brazil: A twenty-year study.

INTRODUCTION: Hepatitis C virus (HCV) infection is a major health problem associated with considerable risk of mortality in different regions of the world. The purpose of this study was to investigate the contribution of HCV infection on all-cause and liver-related mortality, in a large cohort of blood donors in Brazil. METHODS: This is a retrospective cohort study of blood donors from 1994 to 2013, at Fundação Pró-Sangue-Hemocentro de São Paulo (FPS). This cohort included 2,892 and 5,784 HCV antibody seropositive and seronegative donors, respectively. Records from the FPS database and the Mortality Information System (SIM: a national database in Brazil) were linked through a probabilistic record linkage (RL). Mortality outcomes were defined based on ICD-10 (10th International Statistical Classification of Diseases and Related Health Problems) codes listed as the cause of death on the death certificate. Hazard ratios (HRs) were estimated for outcomes using Cox multiple regression models. RESULTS: When all causes of death were considered, RL identified 209 deaths (7.2%) among seropositive blood donors and 190 (3.3%) among seronegative blood donors. Donors seropositive for HCV infection had a 2.5 times higher risk of death due to all causes (95% CI: 1.76-2.62; p<0.001). When only liver-related causes of death were considered, RL identified 73 deaths among seropositive blood donors and only 6 among seronegative blood donors. Donors seropositive for HCV infection had a 23.4 times higher risk of death due to liver related causes (95% CI: 10.2-53.9; p<0.001). Donors seropositive for HCV had a 29.5 (95%CI: 3.9-221.7), 2.8 (95% CI: 1.4-5.5) and a 1.9 (95% CI: 1.2-3.0) times higher risk of death due to hepatocellular carcinoma, infection or trauma, respectively, compared to seronegative donors. CONCLUSIONS: All-cause and liver-related mortality rate was increased among blood donors seropositive for HCV compared with the mortality rate among seronegative blood donors. Our data confirms HCV as a relevant cause of death in Brazil and also suggest that interventions directed at following patients even after access to specific drug treatment are urgent and necessary.

External Quality Assessment for Zika Virus Molecular Diagnostic Testing, Brazil.

We conducted an external quality assessment of Zika virus molecular diagnostic tests in Brazil using a new Zika virus standard. Of 15 laboratories, 73% showed limited sensitivity and specificity. Viral load estimates varied significantly. Continuous quality assurance is needed to adequately estimate risk for Zika virus-associated disease and determine patient care.

Mortality among blood donors seropositive and seronegative for Chagas disease (1996-2000) in São Paulo, Brazil: A death certificate linkage study.

BACKGROUND: Individuals in the indeterminate phase of Chagas disease are considered to have mortality rates similar to those of the overall population. This study compares mortality rates among blood donors seropositive for Chagas disease and negative controls in the city of São Paulo, Brazil. METHODOLOGY/PRINCIPAL FINDINGS: This is a retrospective cohort study of blood donors from 1996 to 2000: 2842 seropositive and 5684 seronegative for Chagas disease. Death status was ascertained by performing probabilistic record linkage (RL) with the Brazil national mortality information system (SIM). RL was assessed in a previous validation study. Cox Regression was used to derive hazard ratios (HR), adjusting for confounders. RL identified 159 deaths among the 2842 seropositive blood donors (5.6%) and 103 deaths among the 5684 seronegative (1.8%). Out of the 159 deaths among seropositive donors, 26 had the 10th International Statistical Classification of Diseases and Related Health Problems (ICD-10) indicating Chagas disease as the underlying cause of death (B57.0/B57.5), 23 had ICD-10 codes (I42.0/I42.2/I47.0/I47.2/I49.0/I50.0/I50.1/ I50.9/I51.7) indicating cardiac abnormalities possibly related to Chagas disease listed as an underlying or associated cause of death, with the others having no mention of Chagas disease in part I of the death certificate. Donors seropositive for Chagas disease had a 2.3 times higher risk of death due to all causes (95% Confidence Interval (95% CI), 1.8-3.0) than seronegative donors. When considering deaths due to Chagas disease or those that had underlying causes of cardiac abnormalities related to Chagas disease, seropositive donors had a risk of death 17.9 (95% CI, 6.3-50.8) times greater than seronegative donors. CONCLUSIONS/SIGNIFICANCE: There is an excess risk of death in donors seropositive blood for Chagas disease compared to seronegative donors. Chagas disease is an under-reported cause of death in the Brazilian mortality database.

Transfusion of older red blood cell units, cytokine burst and alloimmunization: a case-control study.

BACKGROUND: Experimental data have shown that the transfusion of older red blood cell units causes alloimmunization, but the clinical applicability of this statement has never been properly assessed in non-sickle cell patients. It has been hypothesized that older units have higher numbers of cytokines, increasing the risk of alloimmunization related to antigen-presenting events. The goal of this study was to evaluate the association between the transfusion of older red blood cell units subjected to bedside leukodepletion and alloimmunization. METHODS: All patients submitted to transfusions of bedside leukodepletion red blood cell units proven to have become alloimmunized in one oncologic service between 2009 and 2013 were enrolled in this study. A control group was formed by matching patients without alloimmunization in terms of number of transfusions and medical specialty. The median age of transfused units, the percentage of transfused red blood cell units >14 days of storage in relation to fresher red cell units (≤14 days of storage) and the mean age of transfused units older than 14 days were compared between the groups. RESULTS: Alloimmunized and control groups were homogeneous regarding the most relevant clinical variables (age, gender, type of oncological disease) and inflammatory background (C-reactive protein and Karnofsky scale). The median age of transfused red blood cell units, the ratio of older units transfused compared to fresher units and the mean age of transfused units older than 14 days did not differ between alloimmunized and control patients (17 vs. 17; 68/32 vs. 63.2/36.8 and 21.8±7.0 vs. 21.04±7.9; respectively). CONCLUSION: The transfusion of older red blood cell units subjected to bedside leukodepletion is not a key risk factor for alloimmunization. Strategies of providing fresh red cell units aiming to avoid alloimmunization are thus not justified.

A comprehensive protocol to evaluate the use of blood and its components in Latin America and the Caribbean.

Blood transfusion safety is a critical part of appropriate health care. Considering the limited information available on the use of blood and its components in Latin America and the Caribbean, the Grupo Cooperativo iberoamericano de Medicina Transfusional (Ibero-American Cooperative Group for Transfusion Medicine; GCIAMT), through its Research and International Affairs committees, carried out a project to develop a protocol that would facilitate the evaluation of blood usage at the country, jurisdiction, and institutional levels in varied country contexts. Experts in blood safety from the Pan American Health Organization (Washington, DC, United States), the University of São Paulo (São Paulo, Brazil), the Hemocentro of São Paulo (São Paulo, Brazil), and GCIAMT designed a 2-step comprehensive blood-use evaluation protocol: step 1 collects data from blood requests, and step 2, from medical charts. At a minimum, 1 000 analyzed requests are necessary; as such, study periods vary depending on the number of transfusion requests issued. An Internet-based application, the Modular Research System-Study Management System (MRS-SMS), houses the data and produces reports on how hospitals request blood, how blood is issued, who requires blood and blood components, and as an added benefit, how many blood units are wasted and what the real demand for blood is.

Blood Donor Test-Seeking Motivation and Prior HIV Testing Experiences in São Paulo, Brazil.

HIV test-seeking behavior among blood donors has been observed worldwide and may pose a threat to the safety of the blood supply. We evaluated current test-seeking motivations and prior alternative HIV testing experiences among blood donors in São Paulo, Brazil. All candidate or potential blood donors were consecutively approached and recruited to participate in the study upon presentation at Fundação Pró-Sangue Hemocentro, the largest blood bank in Brazil. Participants were recruited between August 2012 and May 2013 after they were screened for donor eligibility. Questionnaires were administered through audio computer-assisted self-interview. Among 11,867 donors, 38 % previously tested for HIV apart from blood donation, of whom 47.7 % tested at public facilities and 2.7 % acknowledged getting tested for HIV as the primary reason for donating. Dissatisfaction with prior alternative testing experience was reported by 2.5 % of donors. Current test-seeking motivation was associated with dissatisfaction with prior alternative testing experience and testing at a public alternative facility. The most common reasons for dissatisfaction were too long of a wait to get tested and for results, counseling was too long, lack of privacy, and low confidence in the equipment and accuracy of the test. Lack of awareness about the availability of free and confidential public HIV testing services as well as dissatisfaction with past HIV testing and counseling experiences motivate some individuals to test at blood banks. Test-seeking behavior among blood donors may be best addressed by improving alternative testing programs, particularly with respect to time delays, privacy and perceptions about test accuracy. Educational campaigns on safe blood donation and HIV testing for diagnosis, risk counseling and referral to care are also needed for the general public and for health care providers.