A rare vascular injury in a blood donor after whole blood donation.

BACKGROUND: Blood donation is a safe process though reactions may still occur. We describe a rare vascular complication in a frequent donor, with improvements in the collection process aimed at avoiding future events. METHODS: A 63-year-old woman presented with local pain and an apparent collection in the left arm 8 days after donation. Duplex ultrasound identified a superficial liquid collection and signs of arteriovenous fistula (AVF) between the cubital vein and an arterial branch. A computed tomography (CT)-angio performed 1 day after ultrasound did not identify signs of AVF, followed by a new duplex which confirmed CT-angio findings. It was assumed that a traumatic AVF evolved with spontaneous thrombosis. In the early follow-up (18 days), a progressive regression of hematoma was observed without any sequelae. RESULTS: Investigation showed a faster whole blood bag collection time (3 min; normal: 5-9 min), and the processed packed red blood cell had a brighter red color than usual. The donor reported local bleeding after needle withdrawal, not observed in previous donations and a bruise forming on the same day. No arterial puncture (AP) was noticed by the collection staff during the procedure. The staff was retrained and actions were taken focusing on more active surveillance of late reactions, highlighting the importance of post-donation information by the donors, regardless of any adverse reaction observed, to detect late complications. CONCLUSION: We described an uncommon AP in a donor that was not identified, leading to an AVF that spontaneously thrombosed.

Treatment of severe COVID-19 patients with either low- or high-volume of convalescent plasma versus standard of care: A multicenter Bayesian randomized open-label clinical trial (COOP-COVID-19-MCTI).

Background: Administration of convalescent plasma may serve as an adjunct to supportive treatment to prevent COVID-19 progression and death. We aimed to evaluate the efficacy and safety of 2 volumes of intravenous convalescent plasma (CP) with high antibody titers for the treatment of severe cases of COVID-19. Methods: We conducted a Bayesian, randomized, open-label, multicenter, controlled clinical trial in 7 Brazilian hospitals. Adults admitted to hospital with positive RT-PCR for SARS-CoV2, within 10 days of the symptom onset, were eligible. Patients were randomly assigned (1:1:1) to receive standard of care (SoC) alone, or in combination with 200 mL (150-300 mL) of CP (Low-volume), or 400 mL (300-600 mL) of CP (High-volume); infusion had to be performed within 24 h of randomization. Randomization was centralized, stratified by center. The primary outcome was the time until clinical improvement up to day 28, measured by the WHO ten-point scale, assessed in the intention-to-treat population. Interim and terminal analyses were performed in a Bayesian framework. Trial registered at ClinicalTrials.gov: NCT04415086. Findings: Between June 2, 2020, and November 18, 2020, 129 patients were enrolled and randomly assigned to SoC (n = 42), Low-volume (n = 43) or High-volume (n = 44) CP. Donors presented a median titer of neutralizing antibodies of 1:320 (interquartile range, 1:160 to 1:1088). No evidence of any benefit of convalescent plasma was observed, with Bayesian estimate of 28-day clinical improvement of 72.7% (95%CI, 58.8 to 84.7) in the SoC versus 64.1% (95%ci, 53.8 to 73.7) in the pooled experimental groups (mean difference of -8.7%, 95%CI, -24.6 to 8.2). There was one case of cutaneous mild allergic reaction related to plasma transfusion and one case of suspected transfusion-related acute lung injury but deemed not to be related to convalescent plasma infusion. Interpretation: In this prospective, randomized trial of adult hospitalized patients with severe COVID-19, convalescent plasma was not associated with clinical benefits. Funding: Brazilian Ministry of Science, Technology and Innovation, Fundação de Amparo à Pesquisa do Estado de São Paulo.

The 4-Year Experience with Implementation and Routine Use of Pathogen Reduction in a Brazilian Hospital.

(1) Background: We reviewed the logistics of the implementation of pathogen reduction (PR) using the INTERCEPT Blood System™ for platelets and the experience with routine use and clinical outcomes in the patient population at the Sírio-Libanês Hospital of São Paulo, Brazil. (2) Methods: Platelet concentrate (PC), including pathogen reduced (PR-PC) production, inventory management, discard rates, blood utilization, and clinical outcomes were analyzed over the 40 months before and after PR implementation. Age distribution and wastage rates were compared over the 10 months before and after approval for PR-PC to be stored for up to seven days. (3) Results: A 100% PR-PC inventory was achieved by increasing double apheresis collections and production of double doses using pools of two single apheresis units. Discard rates decreased from 6% to 3% after PR implementation and further decreased to 1.2% after seven-day storage extension for PR-PCs. The blood utilization remained stable, with no increase in component utilization. A significant decrease in adverse transfusion events was observed after the PR implementation. (4) Conclusion: Our experience demonstrates the feasibility for Brazilian blood centers to achieve a 100% PR-PC inventory. All patients at our hospital received PR-PC and showed no increase in blood component utilization and decreased rates of adverse transfusion reactions.

Surrogate test performance for SARS-CoV-2 neutralizing antibodies (nAbs) for convalescent plasma (CCP): How useful could they be?

BACKGROUND: COVID-19 high-titer CCP selection is a concern, because neutralizing antibody (nAb) testing requires sophisticated labs and methods. Surrogate tests are an alternative for measuring nAb levels in plasma bags, including those that are pathogen-reduced. STUDY DESIGN/METHODS: We studied a panel consisting of 191 samples from convalescent donors tested by nAb (CPE-VNT), obtained from 180 CCP donations (collection: March 20-January 21) and 11 negative controls, with a total of 80 and 111 serum and plasma samples (71 amotosalen/UV treated), with nAb titers ranging from negative to 10,240. Samples were blindly tested for several surrogates: one anti-RBD, two anti-spike, and four anti-nucleocapsid tests, either isolated or combined to improve their positive predictive values as predictors of the presence of high-titer nAbs, defined as those with titers ≥160. RESULTS: Except for combined and anti-IgA/M tests, all isolated surrogate tests showed excellent performance for nAb detection: sensitivity (98.3%-100%), specificity (85.7%-100%), PPV (98.9%-100%), NPV (81.3%-100%), and AUC (0.93-0.96), with a variable decrease in sensitivity and considerably lower specificity when using FDA authorization and concomitant nAb titers ≥160. All surrogates had AUCs that were statistically different from CPE-VNT if nAb≥160, including when using combined, orthogonal approaches. CONCLUSIONS: Surrogate tests (isolated or in combination) have an indirect good performance in detecting the presence of nAb, with lower sensitivity and specificity when high nAb titer samples are used, possibly accepting a considerable number of donors whose nAb titers are actually low, which should be evaluated by each laboratory responsible for CCP collection.

COVID-19 convalescent plasma cohort study: Evaluation of the association between both donor and recipient neutralizing antibody titers and patient outcomes.

BACKGROUND: Current evidence regarding COVID-19 convalescent plasma (CCP) transfusion practices is limited and heterogeneous. We aimed to determine the impact of the use of CCP transfusion in patients with previous circulating neutralizing antibodies (nAbs) in COVID-19. METHODS: Prospective cohort including 102 patients with COVID-19 transfused with ABO compatible CCP on days 0-2 after enrollment. Clinical status of patients was assessed using the adapted World Health Organization (WHO) ordinal scale on days 0, 5, and 14. The nAbs titration was performed using the cytopathic effect-based virus neutralization test with SARS-CoV-2 (GenBank MT126808.1). The primary outcome was clinical improvement on day 14, defined as a reduction of at least two points on the adapted WHO ordinal scale. Secondary outcomes were the number of intensive care unit (ICU)-free days and the number of invasive mechanical ventilation-free days. RESULTS: Both nAbs of CCP units transfused (p < 0.001) and nAbs of patients before CCP transfusions (p = 0.028) were associated with clinical improvements by day 14. No significant associations between nAbs of patients or CCP units transfused were observed in the number of ICU or mechanical ventilation-free days. Administration of CCP units after 10 days of symptom onset resulted in a decrease in ICU-free days (p < 0.001) and mechanical ventilation-free days (p < 0.001). CONCLUSION: Transfusion of high titer nAbs CCP units may be a determinant in clinical strategies against COVID-19. We consider these data as useful parameters to guide future CCP transfusion practices.

An international comparison of HIV prevalence and incidence in blood donors and general population: a BEST Collaborative study.

BACKGROUND AND OBJECTIVES: Efficiency in mitigating HIV transmission risk by transfusion may vary internationally. We compared HIV prevalence and incidence in blood donors across different jurisdictions in relation to those rates in the general population and differences in deferral practices. MATERIALS AND METHODS: Data from 2007 to 2016 were collected in Australia, Brazil (São Paulo), Canada, England, France, Italy, Ireland, Japan, the Netherlands, New Zealand, Norway, Spain (Basque Country), USA (Vitalant) and Wales. For each country/region, the number of HIV antibody-positive donations and nucleic acid testing (NAT)-only-positive donations was broken down according to first-time or repeat donor status, along with the relevant denominators. RESULTS: There is a modest correlation between HIV prevalence among first-time donors and HIV prevalence in the general population. However, rates of HIV-positive donations in repeat donors, a proxy for incidence, do not correlate with incidence rates in the general population. Rates in donors from Italy and Basque Country, where deferral criteria for men having sex with men are less stringent, are higher compared with most other jurisdictions. Rates of NAT-only-positive donations are extremely low and do not differ significantly after adjustment for multiple comparisons. CONCLUSION: Donor HIV rates are only weakly associated with those observed in the general population. Countries with less stringent deferral criteria have higher HIV rates in their donor population, but the rates remain very low.

Lessons learned in the collection of convalescent plasma during the COVID-19 pandemic.

BACKGROUND: The lack of definitive treatment or preventative options for COVID-19 led many clinicians early on to consider convalescent plasma (CCP) as potentially therapeutic. Regulators, blood centres and hospitals worldwide worked quickly to get CCP to the bedside. Although response was admirable, several areas have been identified to help improve future pandemic management. MATERIALS AND METHODS: A multidisciplinary, multinational subgroup from the ISBT Working Group on COVID-19 was tasked with drafting a manuscript that describes the lessons learned pertaining to procurement and administration of CCP, derived from a comprehensive questionnaire within the subgroup. RESULTS: While each country's responses and preparedness for the pandemic varied, there were shared challenges, spanning supply chain disruptions, staffing, impact of social distancing on the collection of regular blood and CCP products, and the availability of screening and confirmatory SARS-CoV-2 testing for donors and patients. The lack of a general framework to organize data gathering across clinical trials and the desire to provide a potentially life-saving therapeutic through compassionate use hampered the collection of much-needed safety and outcome data worldwide. Communication across all stakeholders was identified as being central to reducing confusion. CONCLUSION: The need for flexibility and adaptability remains paramount when dealing with a pandemic. As the world approaches the first anniversary of the COVID-19 pandemic with rising rates worldwide and over 115 million cases and 2·55 million deaths, respectively, it is important to reflect on how to better prepare for future pandemics as we continue to combat the current one.

Anti-A and SARS-CoV-2: an intriguing association.

BACKGROUND: Blood groups and anti-A isohemagglutinin may be involved in susceptibility to SARS-CoV-2 infection. MATERIALS AND METHODS: We retrospectively studied 268 COVID-19 convalescent plasma donors and 162 COVID-19 inpatients (total 430 subjects, confirmed by RT-PCR) and 2,212 healthy volunteer first-time blood donors as a control group. These were further divided into two groups: those with anti-A (blood types O and B) and those without it (types A and AB). Titres of nucleoproteins, and neutralizing SARS-CoV-2 antibody were measured in the convalescent plasma donors and inpatients. Multivariate logistic regression and non-parametric tests were applied. RESULTS: Persons having types O or B showed less infection prevalence than those of types A or AB (OR = 0·62, 95% CI 0·50-0·78; P < 0·001), but there was no difference when COVID-19 inpatients were analysed. Immunoglobulins M, G and A were lower in COVID-19 subjects of types O or B group than those of A or AB (0·16 vs. 0·19; P = 0·03, 2·11 vs. 2·55; P = 0·02, 0·23 vs. 0·32; P = 0·03, respectively). CONCLUSION: In this retrospective cohort, COVID-19 individuals were less likely to belong to blood types O and B, and also had lower SARS-CoV-2 antibody titres than A and AB individuals. COVID-19 severity did not associate with the blood groups.

A longitudinal study of convalescent plasma (CCP) donors and correlation of ABO group, initial neutralizing antibodies (nAb), and body mass index (BMI) with nAb and anti-nucleocapsid (NP) SARS-CoV-2 antibody kinetics: Proposals for better quality of CCP collections.

INTRODUCTION: Little is known about the neutralizing (nAb) and binding antibody kinetics in COVID-19 convalescent plasma donors, especially during the first 100 days after disease onset. MATERIALS AND METHODS: A cohort of previously RT-PCR positive (detected by nasopharyngeal swab during the acute phase), male convalescent patients, all with mild symptoms, were enrolled in serial blood sample collection for a longitudinal nAb titers and anti-nucleocapsid (NP) antibodies (IgM, IgG and IgA) evaluation. NAbs were detected by a cytopathic effect-based virus neutralization test (CPE-based VNT), carried out with SARS-CoV-2 (GenBank: MT350282). RESULTS: A total of 78 male volunteers provided 316 samples, spanning a total of 4820 days of study. Although only 25% of donors kept nAb titers ≥160 within 100 days after the onset of disease, there was >75% probability of sustaining nAb titers ≥160 in volunteers whose initial nAb titer was ≥1280, weight ≥ 90 kg or obese, according to their body mass index (BMI), as evidenced by Kaplan-Meier analysis and Cox hazard regression (all p < .02). There was no correlation between the ABO group, ABO antibody titers and persistent high nAb titers. High IgG anti-NP (S/CO ≥5.0) is a good surrogate for detecting nAb ≥ 160, defined by the ROC curve (sensitivity = 90.5%; CI95%: 84.5%-94.7%). CONCLUSION: Selection of CCP donors for multiple collections based on initial high nAb titers (≥1280) or BMI ≥ 30 kg/m2 provides a simple strategy to achieve higher quality in CCP programs. High IgG anti-NP levels can also be used as surrogate markers for high nAb screening.

Screening for SARS-CoV-2 antibodies in convalescent plasma in Brazil: Preliminary lessons from a voluntary convalescent donor program.

BACKGROUND: Coronavirus disease 2019 (COVID-19) convalescent plasma (CCP) collection began in two Brazilian hospitals for treatment of severe/critical patients. METHODS AND MATERIALS: Mild/moderate COVID-19 convalescents were selected as CCP donors after reverse transcription polymerase chain reaction (RT-PCR) confirmed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and absence of symptoms for ≥14 days plus (a) age (18-60 years), body weight greater than 55 kg; (b) immunohematological studies; (c) no infectious markers of hepatitis B virus, hepatitis C virus, human immunodeficiency virus, human T-lymphotropic virus-1/2, Chagas and syphilis infection; (d) no HLA antibodies (multiparous); (e) second RT-PCR (nasopharyngeal swab and/or blood) negativity; (f) virus neutralization test (cytopathic effect-based virus neutralization test neutralizing antibody) and anti-nucleocapsid protein SARS-CoV-2 IgM, IgG, and IgA enzyme-linked immunosorbent assays. RESULTS: Among 271 donors (41 females, 230 males), 250 presented with neutralizing antibodies. Final RT-PCR was negative on swab (77.0%) or blood (88.4%; P = .46). Final definition of RT-PCR was only defined at more than 28 days after full recovery in 59 of 174 (33.9%) RT-PCR -ve, and 25/69 RT-PCR +ve (36.2%; 13 between 35 and 48 days). Neutralizing antibody titers of 160 or greater were found in 63.6%. Correlation between IgG signal/cutoff of 5.0 or greater and neutralizing antibody of 160 or greater was 82.4%. Combination of final RT-PCR -ve with neutralizing antibody ≥160 was 41.3% (112/271). Serial plasma collection showed decline in neutralizing antibody titers and IgA levels (P < .05), probably denoting a "golden period" for CCP collection (≤28 days after joining the program); IgA might have an important role as neutralizing antibody. Donor's weight, days between disease onset and serial plasma collection, and IgG and IgM levels are important predictors for neutralizing antibody titer. CONCLUSIONS: RT-PCR +ve cases are still detected in 36.2% within 28 to 48 days after recovery. High anti-nucleocapsid protein IgG levels may be used as a surrogate marker to neutralizing antibody.

In vitro and in vivo validation of stored swine erythrocyte viability to establish an experimental model of homologous red blood cell transfusion: a pilot study.

OBJECTIVE: To develop experimental models of erythrocyte transfusion, the first step is to ensure the viability of the red blood cells transfused. In this pilot study, we assessed the viability of transfused red blood cells with validation in vitro and in vivo of homologous swine erythrocytes stored for 14 days. METHODS: Blood collected from one Agroceres swine was stored in two red blood cell units. In vivo validation was performed by labeling the red blood cells with Na25¹CrO4 and recovering the viable erythrocytes after 24 hours of infusion in one autologous and four homologous animals. In vitro validation was performed at baseline and after 14 days in sixteen red blood cell units by measuring hemoglobin, hematocrit, hemolysis index and free hemoglobin. A post-mortem splenectomy was performed to evaluate the splenic sequestration of erythrocytes, and the radioactivity of the supernatant samples was counted to evaluate intravascular hemolysis. RESULTS: After 14 days of storage, the red blood cell units had lower volumes and equivalent total concentrations of hemoglobin and hematocrit compared to human standards. The free hemoglobin concentration increased from 31.0±9.3 to 112.4±31.4 mg/dL (p<0.001), and the hemolysis index increased from 0.1±0.1 to 0.5±0.1% (p<0.001). However, these tests were within the acceptable range for human standards. The percentage of radioactivity in supernatant samples was similar at baseline and after 24 hours, thus excluding significant hemolysis. No evidence of splenic sequestration of radioactive erythrocytes was found. CONCLUSION: Swine red blood cells stored for 14 days are viable and can be used in experimental studies of transfusion. These validation experiments are important to aid investigators in establishing experimental models of transfusion.

Validação in vitro e in vivo da viabilidade de eritrócitos suínos estocados para estabelecer um modelo experimental de transfusão homóloga de hemácias: estudo piloto / In vitro and in vivo validation of stored swine erythrocyte viability to establish an experimental model of homologous red blood cell transfusion: a pilot study

Objetivo: Para desenvolver modelos experimentais de transfusão de hemácias, o primeiro passo é assegurar a viabilidade dos eritrócitos transfundidos. Avaliamos a viabilidade de eritrócitos transfundidos com validação in vitro e in vivo de eritrócitos suínos homólogos armazenados por 14 dias. Métodos: Neste estudo piloto, o sangue coletado de um suíno Agroceres® foi estocado em duas unidades de hemácias. A validação in vivo foi realizada pela marcação dos eritrócitos com Na2 51CrO4 e recuperação dos eritrócitos viáveis após 24 horas da infusão em um animal autólogo e quatro homólogos. A validação in vitro foi realizada na avaliação basal e após 14 dias, pela mensuração da hemoglobina, hematócrito, índice de hemólise e hemoglobina livre em seis unidades de hemácias. Foi realizada uma esplenectomia post-mortem para avaliar o sequestro esplênico de eritrócitos, e a radioatividade das amostras de sobrenadante foi contada para avaliar a hemólise intravascular. Resultados: Após 14 dias de estocagem, as unidades de hemácias tinham volumes menores e concentração total de hemoglobina equivalente em comparação aos padrões humanos. A concentração de hemoglobina livre aumentou de 31,0±9,3 para 112,4±31,4mg/dL (p<0,001) e o índice de hemólise aumentou de 0,1±0,1 para 0,5±0,1% (p<0,001). Entretanto, esses testes se encontravam dentro da faixa aceitável para os padrões humanos. A percentagem de radioatividade nas amostras de sobrenadante foi similar na avaliação basal e após 24 horas, afastando, assim, a presença de hemólise significante. Não se encontraram evidências de sequestro esplênico de eritrócitos radioativos. ...

Objective: To develop experimental models of erythrocyte transfusion, the first step is to ensure the viability of the red blood cells transfused. In this pilot study, we assessed the viability of transfused red blood cells with validation in vitro and in vivo of homologous swine erythrocytes stored for 14 days. Methods: Blood collected from one Agroceres® swine was stored in two red blood cell units. In vivo validation was performed by labeling the red blood cells with Na2 51CrO4 and recovering the viable erythrocytes after 24 hours of infusion in one autologous and four homologous animals. In vitro validation was performed at baseline and after 14 days in sixteen red blood cell units by measuring hemoglobin, hematocrit, hemolysis index and free hemoglobin. A post-mortem splenectomy was performed to evaluate the splenic sequestration of erythrocytes, and the radioactivity of the supernatant samples was counted to evaluate intravascular hemolysis. Results: After 14 days of storage, the red blood cell units had lower volumes and equivalent total concentrations of hemoglobin and hematocrit compared to human standards. The free hemoglobin concentration increased from 31.0±9.3 to 112.4±31.4mg/dL (p<0.001), and the hemolysis index increased from 0.1±0.1 to 0.5±0.1% (p<0.001). However, these tests were within the acceptable range for human standards. The percentage of radioactivity in supernatant samples was similar at baseline and after 24 hours, thus excluding significant hemolysis. No evidence of splenic sequestration of radioactive erythrocytes was found. Conclusion: Swine red blood cells stored for 14 days are viable and can be used in experimental studies of transfusion. These validation experiments are important to aid investigators in establishing experimental models of transfusion. .

Immune-mediated pancytopenia induced by oxaliplatin: a case report.

BACKGROUND: Drug-induced immune pancytopenia is considered an uncommon disorder. CASE REPORT: A 76-year-old woman with metastatic gastric adenocarcinoma received 15 cycles of FOLFOX-6 (oxaliplatin/folinic acid/fluorouracil) with a complete response. Upon disease progression, she was restarted on FOLFOX; during the seventh cycle of treatment, 1 hour after completing her oxaliplatin infusion, she presented oral bleeding, petechiae and generalized hematomas. Her platelet (PLT) count decreased from 164 x 10(9)/L to less than 5 x 10(9)/L within a 3-hour period and her white blood cells (WBCs) decreased from 5 x 10(9) to 1.5 x 10(9)/L. One day later she presented a decrease in hemoglobin level (from 11.4 to 10 g/dL, reaching 8.9 g/dL after 5 days). The patient's PLT and lymphocyte count started to recover after 3 days of immunosuppressive treatment. STUDY DESIGN AND METHODS: PLT, red blood cell (RBC), and WBC antibody detection tests were performed in the presence and absence of oxaliplatin. PLT-associated antibodies were evaluated by monoclonal antibody immobilization of PLT antigen assay and flow cytometry; WBC antibodies were tested by flow cytometry; and RBC antibodies were evaluated by gel and indirect antiglobulin test tube testing drug-treated RBCs and untreated RBCs in the presence of drug. RESULTS: Positive reactions were obtained only in the presence of the drug (1 mg/mL) for all tests performed (PLTs, RBCs, and WBCs). CONCLUSIONS: Our case convincingly demonstrates that oxaliplatin led to the production of drug-dependent PLT, RBC, and WBC antibodies inducing pancytopenia in the patient. The oxaliplatin was discontinued and patient's hematologic values recovered to normal levels.

Transfusion transmitted Chagas disease: is it really under control?

Transfusion transmitted Chagas disease was recognized as a medical problem more than 50 years ago. However, little attention was paid to it by Transfusion Medicine, medical authorities or regulatory agencies as a major problem and threat (especially after the advent of HIV/AIDS); perhaps because it was mainly restricted to tropical regions, usually in less developed countries. With the intense human migratory movement from developing to developed countries, it became more common and evident. The scope of this review is to cover the main transfusional aspects of American trypanosomiasis (Chagas disease), including the main strategies to prevent it through donor questionnaires, specific serological testing and alternative methods such as leukofiltration and pathogen reduction procedures, in order to increase the blood safety in both developing and developed countries.

Introdução do NAT no Brazil: algumas considerações adicionais: [carta ao editor] / NAT application in Brazil: some additional aspects to be considered: [letter to the editor]

The authors comment on a recent letter to the Editor which dealtwith the introduction of NAT in Brazil.

Dengue em doadores de sangue: necessitamos de triagem laboratorial no Brasil?: [carta ao editor] / Dengue in blood donors: do we need laboratorial screening?: [letter to editor]

Over the last 20 years, dengue has re-emerged in Brazil causing successive outbreaks with thousands of cases of dengue fever and hundreds of deaths. Similar to other Flaviviruses, the majority of the infections are asymptomatic. This can potentially lead to the collection of blood from a viremic donor, raising the possibilitiy of transfusional dengue. However, the paucity of such cases strongly contrasts to the number of cases observed globally. Dr. Estácio Ramos has advocated the urgent introduction of laboratorial screening of blood donations by use of an antigenic test in ELISA format (NSI). We would rather suggest more caution in postulating a mesure that may cause an uçndersirable impact on the cost and availability of blood in our country. We believe that a cost-benefit analysis, based on solid scientific data, is mandatory before any specific measure is adopted. Towards that end, we are performing a survey of dengue RNA among blood donors from six Brazilian cities (Rio de Janeiro, São Paulo, Ribeirão Preto, Goiânia, Fortaleza and Campo Grande) collec ted during the epidemic season (March-May, 2008) which may foster this discussion. Rev.Bras.Hematol.Hematoter. 2008, 30(5):417-418.

A probable case of hepatitis B virus transfusion transmission revealed after a 13-month-long window period.

BACKGROUND: Transfusion-transmitted hepatitis B virus (HBV) infection in recipients with drug-related immunodeficiency is rarely described in endemic areas. Hepatitis B surface antigen (HBsAg)-negative infectious donor blood can be identified by sensitive nucleic acid testing (NAT). Two immunodeficient patients who received blood components from a single seronegative blood donor subsequently found to contain HBV DNA are described. MATERIALS AND METHODS: Multiple samples from the implicated donor and the two recipients were tested for HBV serologic and molecular markers. HBV genome fragments were amplified, sequenced, and phylogenetically analyzed. RESULTS: The implicated donation had low-level HBV DNA due to the donor being in the window period before the donor's seroconversion. Recipient 1 had been vaccinated to HBV and carried anti-HBs but remained negative for all other HBV markers until she developed acute hepatitis B (viral load 2.7 x 10(8) IU/mL and alanine aminotransferase [ALT] level 1744 IU/L) 13 months after transfusion of red cells. Identical HBV sequences from both donor and recipient provided evidence of transfusion-related infection. Recipient 2, who received platelets from the same donation while receiving major chemotherapy, remained uninfected. CONCLUSIONS: In unusual circumstances, HBV incubation time can be considerably prolonged. Both active and passive neutralizing antibodies to HBV likely delayed, but did not prevent, acute infection when the immune system was impaired. HBV NAT may have interdicted the infectious unit, although the donation viral load could not be quantified and odds of detection calculated.

Primary screening of blood donors by nat testing for HCV-RNA: development of an "in-house" method and results.

An "in-house" RT-PCR method was developed that allows the simultaneous detection of the RNA of the Hepatitis C Virus (HCV) and an artificial RNA employed as an external control. Samples were analyzed in pools of 6-12 donations, each donation included in two pools, one horizontal and one vertical, permitting the immediate identification of a reactive donation, obviating the need for pool dismembering. The whole process took 6-8 hours per day and results were issued in parallel to serology. The method was shown to detect all six HCV genotypes and a sensitivity of 500 IU/mL was achieved (95% hit rate). Until July 2005, 139,678 donations were tested and 315 (0.23%) were found reactive for HCV-RNA. Except for five false-positives, all 310 presented the corresponding antibody as well, so the yield of NAT-only donations was zero, presenting a specificity of 99.83%. Detection of a window period donation, in the population studied, will probably demand testing of a larger number of donations. International experience is showing a rate of 1:200,000 - 1:500,000 of isolated HCV-RNA reactive donations.

Replacement of HIV p24 Ag test by a multiplex RT-PCR method for primary screening of blood donors.

Nucleic Acid Testing (NAT) as a tool for primary screening of blood donors became a reality in the end of the 1990 decade. We report here the development of an "in-house" RT-PCR method that allows the simultaneous (multiplex) detection of HCV and HIV-RNA in addition to an artificial RNA employed as an external control. This method detects all HIV group M subtypes, plus group N and O, with a detection threshold of 500 IU/mL. After validation, the method replaced p24 Ag testing, in use for blood donation screening since 1996 at our services. From July 2001 to February 2006, 102,469 donations were tested and 41 (0.04%) were found HIV-RNA reactive. One NAT-only reactive donation (antibody non-reactive) was observed, with subsequent seroconversion of the implied donor, giving a yield of 1:102,469. This rate is in contrast to the international experience that reports a detection of approximately 1:600,000 - 1:3,100,000 of isolated HIV-RNA donations.