External quality control program in infectious diseases screening at laboratories and blood banks in Latin America: an analysis of the past 5 years.

Objective: To evaluate the screening of blood samples for infectious disease markers at laboratories and blood banks in Latin America per the findings of an External Quality Assessment Program (EQAP). Methods: This qualitative analysis used data from the EQAP coordinated by the Fundação Pro Sangue Hemocentro de São Paulo with the support of the Pan American Health Organization to assess the performance of blood screening for infectious diseases from 2014 to 2018 in Latin America. Each participating laboratory or blood bank received an identical blind panel with 24 blood samples with variable reactivity for all the screening parameters. Panels were processed at each participating facility and results were returned to the Fundação Pro Sangue Hemocentro de São Paulo for individual and joint analyses. Two types of discrepant results were potential failures: false positive results (FPRs) and false nonreactive results (FNRRs). Results: A total of 23 136 samples were evaluated. Global rates of FPR, FNRR, and concordant results were 0.3%, 1.0% and 98.7%, respectively. Seven FNRRs were found for HBsAg (1.0%), 12 for syphilis (2.6%), and 21 for Chagas disease (2.9%). No FNRRs were found for the HIV, HCV, and HTLV viruses. The average accuracy of all the laboratories and blood banks participating in the EQAP during the study period was 99.5% (standard deviation, 0.5%). Conclusion: The findings of this qualitative analysis are positive for blood safety in Latin America, with an average accuracy of 99.5% among the participating laboratories and blood banks. This report reflects an important improvement in blood bank serological screening EQAP-PAHO report since the 2003.

External quality control program in infectious diseases screening at laboratories and blood banks in Latin America: an analysis of the past 5 years / Programa de control externo de la calidad en el tamizaje de enfermedades infecciosas en laboratorios y bancos de sangre de América Latina: análisis de los últimos 5 años / Programa externo de controle de qualidade na triagem de doenças infecciosas em laboratórios e bancos de sangue da América Latina: análise dos últimos 5 anos

[ABSTRACT]. Objective. To evaluate the screening of blood samples for infectious disease markers at laboratories and blood banks in Latin America per the findings of an External Quality Assessment Program (EQAP). Methods. This qualitative analysis used data from the EQAP coordinated by the Fundação Pro Sangue Hemocentro de São Paulo with the support of the Pan American Health Organization to assess the performance of blood screening for infectious diseases from 2014 to 2018 in Latin America. Each participating laboratory or blood bank received an identical blind panel with 24 blood samples with variable reactivity for all the screening parameters. Panels were processed at each participating facility and results were returned to the Fundação Pro Sangue Hemocentro de São Paulo for individual and joint analyses. Two types of discrepant results were potential failures: false positive results (FPRs) and false nonreactive results (FNRRs). Results. A total of 23 136 samples were evaluated. Global rates of FPR, FNRR, and concordant results were 0.3%, 1.0% and 98.7%, respectively. Seven FNRRs were found for HBsAg (1.0%), 12 for syphilis (2.6%), and 21 for Chagas disease (2.9%). No FNRRs were found for the HIV, HCV, and HTLV viruses. The average accuracy of all the laboratories and blood banks participating in the EQAP during the study period was 99.5% (standard deviation, 0.5%). Conclusion. The findings of this qualitative analysis are positive for blood safety in Latin America, with an average accuracy of 99.5% among the participating laboratories and blood banks. This report reflects an important improvement in blood bank serological screening EQAP-PAHO report since the 2003.

[RESUMEN]. Objetivo. Evaluar el tamizaje de muestras de sangre en las que se analizan marcadores de enfermedades infecciosas en laboratorios y bancos de sangre de América Latina según los resultados de un programa de evaluación externa de la calidad (EQAP, por su sigla en inglés). Métodos. Este análisis cualitativo utilizó datos del EQAP —coordinado por la Fundação Pro Sangue Hemocentro de São Paulo con el apoyo de la Organización Panamericana de la Salud— para evaluar la eficacia del tamizaje sanguíneo para la detección de enfermedades infecciosas que se realizó entre el 2014 y el 2018 en América Latina. Cada laboratorio o banco de sangre participante recibió un panel idéntico para análisis a ciegas compuesto por 24 muestras de sangre con reactividad variable para todos los parámetros del tamizaje. Los paneles se procesaron en cada establecimiento participante y los resultados se enviaron a la Fundação Pro Sangue Hemocentro de São Paulo donde se realizaron análisis individuales y conjuntos. Había dos tipos de resultados discrepantes que eran posibles fallas del tamizaje: los positivos falsos (PF) y los negativos falsos (NF). Resultados. En total se evaluaron 23 136 muestras. Las tasas generales de PF, NF y resultados concordantes fueron, respectivamente, del 0,3%, 1,0% y 98,7%. Se obtuvieron siete NF en casos de HBsAg (1,0%), 12 en casos de sífilis (2,6%) y 21 en casos de enfermedad de Chagas (2,9%). No se obtuvieron NF en casos de infección por virus del VIH, el VHC o el VLTH. La precisión promedio de todos los laboratorios y bancos de sangre participantes en el EQAP durante el periodo de estudio fue del 99,5% (desviación típica: 0,5%). Conclusión. Los resultados de este análisis cualitativo son positivos en lo referente a la seguridad sanguínea en América Latina, con una precisión promedio del 99,5% entre los laboratorios y bancos de sangre participantes. Este informe refleja la considerable mejora del tamizaje serológico que se realiza en los bancos de sangre, en comparación con los resultados del informe del EQAP que contó con el apoyo de la OPS y se publicó en el 2003.

[RESUMO]. Objetivo. Avaliar a triagem de marcadores de doenças infecciosas em amostras de sangue realizada em laboratórios e bancos de sangue da América Latina de acordo com os resultados de um Programa Externo de Avaliação de Qualidade (EQAP, na sigla em inglês). Métodos. Esta análise qualitativa usou dados do EQAP coordenado pela Fundação Pró-Sangue Hemocentro de São Paulo, com o apoio da Organização Pan-Americana da Saúde, para avaliar o desempenho da triagem de sangue quanto a doenças infecciosas no período de 2014 a 2018 na América Latina. Cada laboratório ou banco de sangue participante recebeu um painel cego idêntico com 24 amostras de sangue de reatividade variável para todos os parâmetros de triagem. Os painéis foram processados em cada estabelecimento participante e os resultados foram devolvidos à Fundação Pró-Sangue Hemocentro de São Paulo para análises individuais e conjuntas. Dois tipos de resultados discrepantes representavam falhas em potencial: resultados falso-positivos e resultados falso-negativos (não reativos). Resultados. Foram avaliadas 23.136 amostras. As taxas globais de resultados falso-positivos, falso-negativos e concordantes foram de 0,3%, 1,0% e 98,7%, respectivamente. Foram encontrados sete resultados falso-negativos para HBsAg (1,0%), 12 para sífilis (2,6%) e 21 para doença de Chagas (2,9%). Não houve resultados falso-negativos para os vírus HIV, HCV e HTLV. A acurácia média de todos os laboratórios e bancos de sangue que participaram do EQAP durante o período do estudo foi de 99,5% (desvio padrão de 0,5%). Conclusões. Os resultados desta análise qualitativa são positivos para a segurança do sangue na América Latina, com uma acurácia média de 99,5% entre os laboratórios e bancos de sangue participantes. Este rela- tório reflete uma melhoria importante na triagem sorológica dos bancos de sangue em relação aos resultados do relatório do EQAP apoiado pela OPAS que foi publicado em 2003.

Detection of unreported usage of the antiretroviral drug lamivudine in two blood donors.

BACKGROUND: Unreported HIV antiretroviral (ARV) drug usage by blood donors compromises the ability to detect evidence of HIV infection in blood screening tests and represents a risk for blood transfusion safety. Our objective was to determine the frequency of undeclared ARV drug use by blood donors with altered HIV markers. STUDY DESIGN AND METHODS: This was a retrospective cross-sectional analysis of donations that were tested for HIV antibody (ab), antigen (ag), and RNA by chemiluminescent immunoassay and nucleic acid screening tests. Positive samples were retested and were subjected to ARV drug testing by high-performance liquid chromatography-tandem mass spectrometry. RESULTS: Of 345,252 blood donations, 361 (0.1%) were positive on initial testing. Samples from 296 (81.9%) of these donations were available for further analysis. The presence of HIV ab/ag and/or RNA was confirmed in 83 (28.0%) of these samples. All 296 bloods were subjected to ARV testing. The ARV drug lamivudine, at 11.3 and 6.7 ng/mL, was detected in 2 of 83 (2.4%) donations that were HIV positive. Other drugs were not detected. CONCLUSION: Unreported ARV usage was identified in two candidates for blood donation. More intensive efforts to educate donors about disclosure and to investigate the extent of this phenomenon in Brazil are needed.

Improved detection of hepatitis C virus-positive blood donors and determination of infection status.

BACKGROUND: In low-risk populations, variability in the sensitivity of current serological tests for Hepatitis C virus (HCV) blood donor screening may lead to the presence of false-positive results. This contributes to the unnecessary loss of blood donor samples as well as to difficulty in accurate donor counselling. The present study determined the optimal cut-off value of a chemiluminescent immunoassay for identification of HCV-reactive blood donors. STUDY DESIGN AND METHODS: In a retrospective cross-sectional analysis of 193 973 blood donations, 578 samples that were positive for HCV antibody in a chemiluminescent immunoassay and/or RNA screening tests were identified. Blood from 379 of these positive samples was available for retesting by a second confirmatory HCV immunoassay followed by a receiver operating characteristic (ROC) curve analysis. Donors were also recalled for a new analysis. RESULTS: Only 71 (18.7%) blood samples remained HCV-positive upon retesting, while 233 (61.5%) now tested negative and 75 (19.8%) yielding indeterminate results. A signal to cutoff ratio ≥4.32 was determined as the best differential threshold between a positive and negative result, increasing the positive predictive value from 27.3% to 66.7%. CONCLUSION: Using a higher threshold for an HCV-positive blood sample enhances the chemiluminescent immunoassay screening test´s accuracy and helps to improve donor counselling and notification processes.

External quality control program in infectious diseases screening at laboratories and blood banks in Latin America: an analysis of the past 5 years / Programa de control externo de la calidad en el tamizaje de enfermedades infecciosas en laboratorios y bancos de sangre de América Latina: análisis de los últimos 5 años / Programa externo de controle de qualidade na triagem de doenças infecciosas em laboratórios e bancos de sangue da América Latina: análise dos últimos 5 anos

ABSTRACT Objective. To evaluate the screening of blood samples for infectious disease markers at laboratories and blood banks in Latin America per the findings of an External Quality Assessment Program (EQAP). Methods. This qualitative analysis used data from the EQAP coordinated by the Fundação Pro Sangue Hemocentro de São Paulo with the support of the Pan American Health Organization to assess the performance of blood screening for infectious diseases from 2014 to 2018 in Latin America. Each participating laboratory or blood bank received an identical blind panel with 24 blood samples with variable reactivity for all the screening parameters. Panels were processed at each participating facility and results were returned to the Fundação Pro Sangue Hemocentro de São Paulo for individual and joint analyses. Two types of discrepant results were potential failures: false positive results (FPRs) and false nonreactive results (FNRRs). Results. A total of 23 136 samples were evaluated. Global rates of FPR, FNRR, and concordant results were 0.3%, 1.0% and 98.7%, respectively. Seven FNRRs were found for HBsAg (1.0%), 12 for syphilis (2.6%), and 21 for Chagas disease (2.9%). No FNRRs were found for the HIV, HCV, and HTLV viruses. The average accuracy of all the laboratories and blood banks participating in the EQAP during the study period was 99.5% (standard deviation, 0.5%). Conclusion. The findings of this qualitative analysis are positive for blood safety in Latin America, with an average accuracy of 99.5% among the participating laboratories and blood banks. This report reflects an important improvement in blood bank serological screening EQAP-PAHO report since the 2003.

RESUMEN Objetivo. Evaluar el tamizaje de muestras de sangre en las que se analizan marcadores de enfermedades infecciosas en laboratorios y bancos de sangre de América Latina según los resultados de un programa de evaluación externa de la calidad (EQAP, por su sigla en inglés). Métodos. Este análisis cualitativo utilizó datos del EQAP —coordinado por la Fundação Pro Sangue Hemocentro de São Paulo con el apoyo de la Organización Panamericana de la Salud— para evaluar la eficacia del tamizaje sanguíneo para la detección de enfermedades infecciosas que se realizó entre el 2014 y el 2018 en América Latina. Cada laboratorio o banco de sangre participante recibió un panel idéntico para análisis a ciegas compuesto por 24 muestras de sangre con reactividad variable para todos los parámetros del tamizaje. Los paneles se procesaron en cada establecimiento participante y los resultados se enviaron a la Fundação Pro Sangue Hemocentro de São Paulo donde se realizaron análisis individuales y conjuntos. Había dos tipos de resultados discrepantes que eran posibles fallas del tamizaje: los positivos falsos (PF) y los negativos falsos (NF). Resultados. En total se evaluaron 23 136 muestras. Las tasas generales de PF, NF y resultados concordantes fueron, respectivamente, del 0,3%, 1,0% y 98,7%. Se obtuvieron siete NF en casos de HBsAg (1,0%), 12 en casos de sífilis (2,6%) y 21 en casos de enfermedad de Chagas (2,9%). No se obtuvieron NF en casos de infección por virus del VIH, el VHC o el VLTH. La precisión promedio de todos los laboratorios y bancos de sangre participantes en el EQAP durante el periodo de estudio fue del 99,5% (desviación típica: 0,5%). Conclusión. Los resultados de este análisis cualitativo son positivos en lo referente a la seguridad sanguínea en América Latina, con una precisión promedio del 99,5% entre los laboratorios y bancos de sangre participantes. Este informe refleja la considerable mejora del tamizaje serológico que se realiza en los bancos de sangre, en comparación con los resultados del informe del EQAP que contó con el apoyo de la OPS y se publicó en el 2003.

RESUMO Objetivo. Avaliar a triagem de marcadores de doenças infecciosas em amostras de sangue realizada em laboratórios e bancos de sangue da América Latina de acordo com os resultados de um Programa Externo de Avaliação de Qualidade (EQAP, na sigla em inglês). Métodos. Esta análise qualitativa usou dados do EQAP coordenado pela Fundação Pró-Sangue Hemocentro de São Paulo, com o apoio da Organização Pan-Americana da Saúde, para avaliar o desempenho da triagem de sangue quanto a doenças infecciosas no período de 2014 a 2018 na América Latina. Cada laboratório ou banco de sangue participante recebeu um painel cego idêntico com 24 amostras de sangue de reatividade variável para todos os parâmetros de triagem. Os painéis foram processados em cada estabelecimento participante e os resultados foram devolvidos à Fundação Pró-Sangue Hemocentro de São Paulo para análises individuais e conjuntas. Dois tipos de resultados discrepantes representavam falhas em potencial: resultados falso-positivos e resultados falso-negativos (não reativos). Resultados. Foram avaliadas 23.136 amostras. As taxas globais de resultados falso-positivos, falso-negativos e concordantes foram de 0,3%, 1,0% e 98,7%, respectivamente. Foram encontrados sete resultados falso-negativos para HBsAg (1,0%), 12 para sífilis (2,6%) e 21 para doença de Chagas (2,9%). Não houve resultados falso-negativos para os vírus HIV, HCV e HTLV. A acurácia média de todos os laboratórios e bancos de sangue que participaram do EQAP durante o período do estudo foi de 99,5% (desvio padrão de 0,5%). Conclusões. Os resultados desta análise qualitativa são positivos para a segurança do sangue na América Latina, com uma acurácia média de 99,5% entre os laboratórios e bancos de sangue participantes. Este relatório reflete uma melhoria importante na triagem sorológica dos bancos de sangue em relação aos resultados do relatório do EQAP apoiado pela OPAS que foi publicado em 2003.

Transfusion-Acquired HIV: History, Evolution of Screening Tests, and Current Challenges of Unreported Antiretroviral Drug Use in Brazil.

Prevention of HIV acquisition by blood transfusion from its emergence to the present day is reviewed, and current challenges are delineated. The experience of Fundação Pró-Sangue/Hemocentro de São Paulo, Brazil, is highlighted in the quest for improvements in blood safety and the evolution of increasingly sensitive and specific screening tests. Concerns and establishing stringent criteria in the screening of potential blood donors are emphasized, and the current criteria for identifying and deferring candidates at high risk of acquiring sexually transmitted diseases are summarized. Future challenges relate to the identification of donors with unreported use of antiretroviral drugs for prophylaxis against possible HIV exposure or for treatment of an HIV infection whose viral expression is undetectable by current analyses. There is a need to better understand the motivation of HIV-exposed donors and to educate them about the risk of transfusion-mediated HIV transmission despite having low or undetectable viral loads. In situations in which traditional HIV RNA or antibody detection assays remain negative, more sensitive analyses are needed to identify potential donors at risk for HIV transmission.

SARS-CoV-2 antibody dynamics in blood donors and COVID-19 epidemiology in eight Brazilian state capitals: A serial cross-sectional study.

Background: The COVID-19 situation in Brazil is complex due to large differences in the shape and size of regional epidemics. Understanding these patterns is crucial to understand future outbreaks of SARS-CoV-2 or other respiratory pathogens in the country. Methods: We tested 97,950 blood donation samples for IgG antibodies from March 2020 to March 2021 in 8 of Brazil's most populous cities. Residential postal codes were used to obtain representative samples. Weekly age- and sex-specific seroprevalence were estimated by correcting the crude seroprevalence by test sensitivity, specificity, and antibody waning. Results: The inferred attack rate of SARS-CoV-2 in December 2020, before the Gamma variant of concern (VOC) was dominant, ranged from 19.3% (95% credible interval [CrI] 17.5-21.2%) in Curitiba to 75.0% (95% CrI 70.8-80.3%) in Manaus. Seroprevalence was consistently smaller in women and donors older than 55 years. The age-specific infection fatality rate (IFR) differed between cities and consistently increased with age. The infection hospitalisation rate increased significantly during the Gamma-dominated second wave in Manaus, suggesting increased morbidity of the Gamma VOC compared to previous variants circulating in Manaus. The higher disease penetrance associated with the health system's collapse increased the overall IFR by a minimum factor of 2.91 (95% CrI 2.43-3.53). Conclusions: These results highlight the utility of blood donor serosurveillance to track epidemic maturity and demonstrate demographic and spatial heterogeneity in SARS-CoV-2 spread. Funding: This work was supported by Itaú Unibanco 'Todos pela Saude' program; FAPESP (grants 18/14389-0, 2019/21585-0); Wellcome Trust and Royal Society Sir Henry Dale Fellowship 204311/Z/16/Z; the Gates Foundation (INV- 034540 and INV-034652); REDS-IV-P (grant HHSN268201100007I); the UK Medical Research Council (MR/S0195/1, MR/V038109/1); CAPES; CNPq (304714/2018-6); Fundação Faculdade de Medicina; Programa Inova Fiocruz-CE/Funcap - Edital 01/2020 Number: FIO-0167-00065.01.00/20 SPU N°06531047/2020; JBS - Fazer o bem faz bem.

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.

Influence of unreported HIV prophylaxis on the kinetics of post-blood donation HIV seroconversion.

BACKGROUND: In 2020, of 110,000 blood donors screened for HIV exposure two individuals were identified who were viral RNA-positive but seronegative. One of the donors, borderline negative in a pooled screening test for HIV RNA, utilized antiretroviral drugs as post-exposure, pre-donation prophylaxis. The kinetics of subsequent HIV seropositivity in both donors are described. STUDY DESIGN AND METHODS: Both donors were recalled and interviewed, and blood was obtained at intervals for HIV antibodies and RNA testing. RESULTS: One donor used antiretroviral prophylaxis for 30 days due to a relationship with an HIV-positive partner. In follow-up samples, seroconversion was noted at 70 days, and viral RNA was detected at 105 days, after blood donation. In contrast, the other donor seroconverted in <25 days and the appearance and titer of HIV RNA was in accordance with the typical pre-seroconversion window. CONCLUSION: The use of anti-viral prophylaxis by blood donors in the acute phase of HIV infection delays seroconversion. A 6-month deferral in blood donation after HIV prophylaxis, as currently recommended in Brazil, would have been sufficient in this case to mitigate the risk of transfusion-transmitted HIV. Ultimately, improvement in donor compliance with selection procedures for blood donation is needed to optimize blood safety.

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.

Occult and active hepatitis B virus detection in donated blood in São Paulo, Brazil.

BACKGROUND: The present study determined the HBV antigen, antibody, and DNA status in blood donations deemed to be HBV positive. Individuals with an occult HBV infection (OBI), defined as being positive for HBV DNA but negative for HBV surface antigen (HBsAg), as well as those with active infection (HBsAg-positive), were identified and characterized. STUDY DESIGN AND METHODS: From a total pool if 198,363 blood donations, we evaluated in a cross-sectional study, 1106 samples that were positive in screening tests for antibody to HBV core antigen (HBcAb), HBsAg, and/or HBV DNA by nucleic acid testing (NAT-HBV). The presence of genetic variants in the HBV pol/S gene in individuals with an active HBV infection was also determined. RESULTS: OBIs were detected in six of 976 samples (0.6%) that were positive only for HBcAb. The rate of HBV active infection was 0.024% (48/198,363) and there was a predominance of HBV sub-genotype A1 (62.2%, 28/45), followed by D3 (17.8%, 8/45). Mutations in the S gene were found in 57.8% (26/45) and immune escape mutations in 37.8% (17/45) of active HBV-infected donors. Among them, T123N, G145A, and D144G high-impact immune escape mutations were identified. CONCLUSION: Highly sensitive molecular tests improve the capacity to detect OBIs. When NAT is performed in pooled samples, HBcAb test has value in the detection of donors with OBI and improves transfusion safety. Mutations in the S gene are frequent in HBsAg-positive blood, including those associated with diagnostic failure and vaccine escape mutations.

Correlation between SARS-COV-2 antibody screening by immunoassay and neutralizing antibody testing.

BACKGROUND: The efficacy of convalescent plasma (CP), an alternative for the treatment of COVID-19, depends on high titers of neutralizing antibodies (nAbs), but assays for quantifying nAbs are not widely available. Our goal was to develop a strategy to predict high titers of nAbs based on the results of anti-SARS-CoV-2 immunoassays and the clinical characteristics of CP donors. STUDY DESIGN AND METHODS: A total of 214 CP donors were enrolled and tested for the presence of anti-SARS-CoV-2 antibodies (IgG) using two commercial immunoassays: EUROIMMUN (ELISA) and Abbott (Chemiluminescence). Quantification of nAbs was performed using the Cytopathic Effect-based Virus Neutralization test. Three criteria for identifying donors with nAbs ≥ 1:160 were tested: - C1: Curve ROC; - C2: Conditional decision tree considering only the IA results and - C3: Conditional decision tree including both the IA results and the clinical variables. RESULTS: The performance of the immunoassays was similar referring to both S/CO and predictive value for identifying nAbs titers ≥1:160. Regarding the studied criteria for identifying CP donors with high nAbs titers: (a) C1 showed 76.1% accuracy if S/CO = 4.65, (b) C2 presented 76.1% accuracy if S/CO ≥4.57 and (c) C3 had 71.6% accuracy if S/CO was ≥4.57 or if S/CO was between 2.68-4.57 and the last COVID-19-related symptoms were recent (within 19 days). CONCLUSION: SARS-CoV-2 IgG immunoassays (S/CO) can be used to predict high anti-SARS-CoV-2 nAbs titers. This study has proposed different criteria for identifying donors with ≥1:160 nAbs titers, all with high efficacy.

Detection and analysis of blood donors seropositive for syphilis.

BACKGROUND: The increasing incidence of syphilis worldwide has called attention to the risk of transmission by transfusion. AIMS: To determine the prevalence of active syphilis in blood donors and characterise the serological profile of syphilis-positive donors. METHODS: Samples positive for Treponema pallidum using the chemiluminescent microparticle immunoassay (CMIA) during blood donor screening from 2017 to 2018 were tested by the Venereal Disease Research Laboratory (VDRL) non-treponemal test and for anti-T. pallidum IgM by ELISA (Immunoassay Enzyme test for detection of IgM antibodies). The INNO-LIA Syphilis test (Line Immuno Assay solid test for confirmation antibodies to Treponema pallidum) was performed as a confirmatory test on samples that were positive on ELISA-IgM but negative on VDRL. ELISA-IgM (+) samples were also tested for T. pallidum DNA in sera by real-time polymerase chain reaction (PCR). RESULTS: Of 248 542 samples screened, 1679 (0.67%) were positive for syphilis by CMIA. Further analysis was performed on 1144 (68.1%) of these samples. Of those tested, 16% were ELISA IgM(+)/VDRL(+), 16.5% were ELISA IgM(-)/VDRL(+), 4.1% were ELISA IgM(+)/VDRL(-), and 63.4% were ELISA IgM (-)/VDRL(-). The INNO-LIA Syphilis test results were 33 (3%) positive, 2 (0.2%) undetermined and 12 (1%) negative. Of the 230 EIA-IgM(+) samples (20.1%), 5 (2.2%) were PCR positive. The prevalence of active syphilis in 2017 and 2018 was 0.1% and 0.07%, respectively, and overall prevalence of serologic markers for syphilis was highest among male, unmarried, 25-34-year-olds with a high school education and who were first-time donors. CONCLUSION: There is a risk of transfusion-transmitted syphilis in blood banks that exclusively use the VDRL test for donor screening, as is currently the situation in some Brazilian blood centres, as well as in other blood centres around the world.

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.

Using droplet digital PCR to screen for rare blood donors: Proof of principle.

BACKGROUND: Digital droplet PCR (ddPCR) is a very sensitive high throughput genotyping methodology. To date, the use of ddPCR in immunohematology is restricted to fetal genotyping of red blood cell antigens. Our hypothesis is that this technology could be applied to screen for rare red blood cell genotypes, such as Di(b-). METHODS: Nucleic acid of 3168 donors was extracted for viral screening routine in pools of 6, which were converted into three types of 48-donor pools: control pools (only DI*B/*B samples), pools with varying amount of DI*A/*B samples (n = 1-5) and a pool with one rare DI*A/*A sample. Pools were genotyped using ddPCR to detect and quantify DI*A and DI*B alleles. RESULTS: DI*A allele was accurately detected in all pools containing Di(a + b+) samples and in the pool containing one Di(a + b-) sample. No copies were detected in the control pools (n = 60). The ratio between the number of DI*A and DI*B copies varied significantly between the pools and the triplicates. CONCLUSION: The proposed ddPCR assay was accurate in identifying the rare DI*A allele in large pools of donors and can be applied to screen for Di(b-) phenotype. The strategy can potentially be extended to search for other rare RBC phenotypes.

Hepatitis B virus among hematopoietic stem cell transplant recipients: Antiviral impact in seroconversion, engraftment, and mortality in a Latin American center.

BACKGROUND: Hepatitis B virus (HBV) infection is a worldwide concern with a broad distribution. In immunosuppressed populations, such as solid organ and hematopoietic stem cell transplant (HSCT) recipients, it can reactivate leading to acute hepatic failure. Different risk factors are known for higher rates of reactivation, and entecavir, tenofovir, and lamivudine are often used for prophylaxis and treatment. However, data regarding the impact of antiviral drugs in neutrophil and platelet engraftment are still unknown and concern the management of viral hepatitis post-HSCT. METHODS: We performed a single-center, retrospective, observational study reviewing medical records of patients referred for hematopoietic stem cell transplant from 2010 to 2017, which were also HBV infected, aiming to describe outcomes related to antiviral treatment and also the impact on platelet and neutrophil recovery after transplant. A secondary goal consisted of analyzing the impact of HBV infection in early and late mortality post-HSCT. The study included patients with positive blood bank screening for hepatitis B infection (HBsAg, Anti-HBc or HBV-NAT), confirmed later on by a laboratory routine serology. RESULTS: A total of 1132 hematopoietic stem cell recipients were assessed between 2010 and 2017. Eighty-six patients were confirmed to have HBV infection, of which six were HBsAg-positive, 20 were isolated anti-HBc-positive, and 60 had resolved infection (anti-HBc-positive and anti-HBs-positive). With regard to prophylaxis, 19 patients underwent HSCT on HBV antiviral therapy or prophylaxis: two were HBeAg-positive, three were HBeAg-negative and HBV-DNA was only detectable in three of them. Moreover, one patient had an occult HBV infection. Regarding therapy, 9 patients were on entecavir, 6 patients on lamivudine, two on tenofovir, and two of them on a combination of tenofovir + lamivudine due to HIV co-infection. Reverse seroconversion was not identified in any patients receiving antiviral therapy or prophylaxis, but it was detected in one patient with occult hepatitis B and another with resolved infection. No severe side effects led to therapy discontinuation in the treated group, which also did not have any significant delay in neutrophil or platelet engraftment when compared to patients without antiviral therapy. In addition, the only factors associated with increased mortality were transplant onset after 50 years, allogeneic transplant and myeloablative conditioning regimens. Interestingly, the presence of HBsAg or detectable HBV-DNA was not related to worse outcomes, neither the use of rituximab. In multivariate analysis, the use of antiviral therapy, the occurrence of graft-versus-host disease or CMV reactivation also was not linked to increased mortality. CONCLUSIONS: To sum up, HBV serology, ALT, and HBV-DNA monitoring are essential to detect hepatic flares earlier, even in populations with chronic inactive hepatitis, due to the possibility of later seroconversion. HBV infection was not related to increased 2-year mortality post-transplant. Antiviral prophylaxis did not cause any important clinical or laboratory side effects that could demand discontinuation, and its use was not associated with later neutrophil and platelet engraftments.

Detection of HIV-1 infections in blood donors during the pre-seroconversion window period in São Paulo, Brazil.

By decreasing the pre-seroconversion window period, nucleic acid testing (NAT) has improved the safety of blood products and reduced the risk of transfusion-transmitted infections. Between 2011 and 2017, NAT determinations for approximately 898,202 donations were performed at Fundação Pró-Sangue/Hemocentro de São Paulo (FPS-HSP). Three seronegative HIV-viremic donations were detected. The NAT yield rate per million donations was 3.34 for HIV, and the acute HIV-1 infections detected are described, followed by a brief review of the situation in Brazil.

SMIM1 intron 2 gene variations leading to variability in Vel antigen expression among Brazilian blood donors.

BACKGROUND: There is a significant inter-individual heterogeneity of Vel antigen expression which can lead to inaccuracies on Vel phenotyping of blood donors and, potentially, to hemolytic post-transfusion reactions. Our aim was to evaluate the impact of genetic variants in the SMIM1 intron 2 on the expression of Vel antigen among Brazilian blood donors harboring the c.64_80del17 deletion in heterozygosity. METHODS: Donors presenting the SMIM1 c.64_80del17 in heterozygosity were included in the study and subjected to SMIM1 intron 2 direct sequencing aiming to genotype the following polymorphisms: rs143702418, rs1181893, rs191041962, rs6673829, rs1175550 and rs9424296. RESULTS: SMIM1 intron 2 sequencing was performed on two hundred donors presenting one c.64_80del17 allele. The rs1175550 polymorphism significantly impacted on Vel antigen expression. Variations in the strength of agglutination on Vel phenotyping were also observed according to the rs6673829 genotype, but this difference did not persist with statistical relevance after multivariate analysis. CONCLUSION: The presence of the rs1175550A allele of SMIM1 is significantly and independently associated with a decrease in Vel antigen expression. Even though the population in Brazil is intensely mixed, the allele frequencies obtained in the current study were very similar to that reported for Europeans.

Detection of HIV-1 infections in blood donors during the pre-seroconversion window period in São Paulo, Brazil

Abstract By decreasing the pre-seroconversion window period, nucleic acid testing (NAT) has improved the safety of blood products and reduced the risk of transfusion-transmitted infections. Between 2011 and 2017, NAT determinations for approximately 898,202 donations were performed at Fundação Pró-Sangue/Hemocentro de São Paulo (FPS-HSP). Three seronegative HIV-viremic donations were detected. The NAT yield rate per million donations was 3.34 for HIV, and the acute HIV-1 infections detected are described, followed by a brief review of the situation in Brazil.

High-throughput strategy for molecular identification of Vel- blood donors employing nucleic acids extracted from plasma pools used for viral nucleic acid test screening.

BACKGROUND: Serologic methods to determine the Vel- phenotype require the use of rare human antisera and do not allow for many samples to be tested simultaneously, which limits their application as a tool to search for rare donors. This study developed a low-cost molecular screening strategy using real-time polymerase chain reaction (PCR) and DNA, extracted from plasma pools for viral nucleic acid test (NAT) screening, to identify Vel- and Vel+(W) donors. STUDY DESIGN AND METHODS: A total of 4680 blood donors from the Brazilian southeast region were genotyped through real-time PCR targeting the 17-nucleotide (c.64_80del) deletion in the SMIM1 gene, which determines the Vel- phenotype, by using remaining nucleic acid from plasma pools of six donors, routinely discarded after the release of viral NAT results. RESULTS: Twenty pools tested reactive and individual testing of samples from reactive pools identified 19 heterozygous donors with the SMIM1*64_80del deletion (0.40%) and one homozygous donor (0.02%). Fourteen of the 19 donors were confirmed as Vel- or Vel+(W) using anti-Vel human antiserum. CONCLUSION: The DNA pool genotyping strategy using real-time PCR designed to detect the deletion in the SMIM1 gene proved effective and accurate in identifying donors with the Vel- and Vel+(W) phenotypes. The fact that remaining nucleic acid from routine viral NAT screening was used makes this technique economically attractive and definitely superior to the serologic techniques available to search for this rare phenotype.