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.

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.

Hepatitis B status in hemodialysis patients / Situação da hepatite B em pacientes em hemodiálise

ABSTRACT BACKGROUND: Patients on chronic dialysis present a high prevalence of hepatitis B virus infection. Despite infection-control practices, surveillance of serological markers, and hepatitis B vaccination, there are still outbreaks of the disease in dialysis centers. OBJECTIVE: This study aims to assess the serologic and vaccination status for hepatitis B in hemodialysis patients. METHODS: This cross-sectional study assessed serologic markers and hepatitis B vaccination status of chronic kidney disease patients on regular dialysis program in São Carlos, SP, Brazil. Patients without information about hepatitis B status (anti-HBc, HBsAg and anti-HBs) were referred for testing. Individuals with uncertain or incomplete immunization status and without serological conversion (anti-HBs <10mIU/mL) were referred to vaccination, with adverse effects monitored. RESULTS: The study included 130 from a total of 181 dialysis patients. The majority were male (63.8%), mean age 53.9 years. All patients were already screened and negative for HBsAg, and 73.8% were vaccinated against hepatitis B (59.2% complete and 14.6% incomplete schedule), with a seroconversion rate of 75.3%. Only 11 (8.5%) patients had prior dosage of anti-HBc (negative). Among the 47 patients referred for anti-HBc testing, four were anti-HBc positive and one indeterminate. Of the total of patients referred to immunization, 34 have actually received HBV vaccine; among them five had mild adverse effects. CONCLUSION: Despite the benefit of dosing of anti-HBc and anti-HBs before admission to dialysis, economic constraints have reduced the screening to only HBsAg. Since occult HBV infection has already been demonstrated in hemodialysis patients, the measure of anti-HBc should be encouraged.

RESUMO CONTEXTO: Pacientes cronicamente em diálise apresentam alta prevalência de infecção por vírus da hepatite B. Apesar de práticas de controle de infecção, vigilância de marcadores sorológicos e vacinação contra a hepatite B, ainda há surtos da doença em centros de diálise. OBJETIVO: Este estudo tem como objetivo avaliar o estado sorológico e a vacinação contra hepatite B em pacientes em hemodiálise. MÉTODOS: Estudo transversal avaliando marcadores sorológicos e vacinação contra a hepatite B em pacientes com doença renal crônica em programa regular de hemodiálise em São Carlos, SP, Brasil. Pacientes sem marcadores sorológicos para hepatite B disponíveis (anti-HBc, HBsAg e anti-HBs) foram encaminhados para testagem. Em caso de situação vacinal desconhecida, incompleta ou sem resposta vacinal (anti-HBs <10mIU/mL), os pacientes foram encaminhados para vacinação, sendo os efeitos adversos monitorados. RESULTADOS: O estudo incluiu 130 de um total de 181 pacientes em diálise. A maioria era do sexo masculino (63,8%), com idade média de 53,9 anos. Todos os pacientes já haviam sido rastreados e eram negativos para HBsAg, e 73,8% foram vacinados contra a hepatite B (59,2% esquema completo e 14,6% esquema incompleto), com uma taxa de soroconversão de 75,3%. Apenas 11 (8,5%) pacientes dispunham de dosagem prévia de anti-HBc (negativo). Entre os 47 pacientes encaminhados para testagem anti-HBc, quatro eram anti-HBc reagentes e um indeterminado. Do total de pacientes encaminhados à imunização, 34 receberam efetivamente a vacina contra o HBV; entre eles, cinco tiveram efeitos adversos leves. CONCLUSÃO: Apesar do benefício da dosagem de anti-HBc e anti-HBs antes da admissão à diálise, restrições econômicas reduziram o rastreio apenas à dosagem de HBsAg. Como a infecção oculta por HBV já foi demonstrada em pacientes em hemodiálise, a dosagem de anti-HBc deve ser incentivada.

Hepatitis B status in hemodialysis patients.

BACKGROUND: Patients on chronic dialysis present a high prevalence of hepatitis B virus infection. Despite infection-control practices, surveillance of serological markers, and hepatitis B vaccination, there are still outbreaks of the disease in dialysis centers. OBJECTIVE: This study aims to assess the serologic and vaccination status for hepatitis B in hemodialysis patients. METHODS: This cross-sectional study assessed serologic markers and hepatitis B vaccination status of chronic kidney disease patients on regular dialysis program in São Carlos, SP, Brazil. Patients without information about hepatitis B status (anti-HBc, HBsAg and anti-HBs) were referred for testing. Individuals with uncertain or incomplete immunization status and without serological conversion (anti-HBs <10mIU/mL) were referred to vaccination, with adverse effects monitored. RESULTS: The study included 130 from a total of 181 dialysis patients. The majority were male (63.8%), mean age 53.9 years. All patients were already screened and negative for HBsAg, and 73.8% were vaccinated against hepatitis B (59.2% complete and 14.6% incomplete schedule), with a seroconversion rate of 75.3%. Only 11 (8.5%) patients had prior dosage of anti-HBc (negative). Among the 47 patients referred for anti-HBc testing, four were anti-HBc positive and one indeterminate. Of the total of patients referred to immunization, 34 have actually received HBV vaccine; among them five had mild adverse effects. CONCLUSION: Despite the benefit of dosing of anti-HBc and anti-HBs before admission to dialysis, economic constraints have reduced the screening to only HBsAg. Since occult HBV infection has already been demonstrated in hemodialysis patients, the measure of anti-HBc should be encouraged.

Yellow fever vaccination status and safety in hemodialysis patients.

BACKGROUND: The adverse effects of yellow fever (YF) vaccine in dialysis patients are not well known. There is concern about the risks and benefits of the vaccine in immunocompromised patients living in endemic areas, particularly given the risk of resurgence of urban YF with the spread of Aedes aegypti mosquitoes. The purpose of this study was to assess the coverage and safety of YF vaccine in chronic dialysis patients. METHODS: A cross-sectional study of 130 chronic dialysis patients was performed. Data were collected on clinical characteristics and YF vaccine status. Patients not vaccinated against YF or without a booster vaccination within the last 10 years were referred to receive the vaccine, and adverse effects were monitored. RESULTS: Previous vaccination was verified in 44 patients within the last 10 years and in 26 patients at more than 10 years ago, with no mention of adverse effects. Thirty-six patients had never been vaccinated and 24 had an unknown vaccination status. Of the total 86 patients referred for immunization, 45 actually received the YF vaccine, with 24.4% experiencing mild local adverse effects and 4.4% experiencing fever. No serious adverse effects attributable to YF vaccine were observed (anaphylaxis, neurological or viscerotropic disease). CONCLUSIONS: YF vaccine coverage among hemodialysis patients is low, and the vaccine appeared to be safe in this population with a small sample size.