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.

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.

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.

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.

Real-time symptomatic case of transfusion-transmitted dengue.

BACKGROUND: Dengue virus transmission by blood transfusion is a rarely reported event. CASE REPORT: During a dengue outbreak in São Paulo city, a regular plateletpheresis donor informed the blood bank of being diagnosed a few days after donation. The recipient was hospitalized and displayed symptoms and laboratory evidence of dengue after transfusion. RESULTS: The donor was immunoglobulin (Ig)G, IgM, and polymerase chain reaction nonreactive on the index sample, seroconverting 20 days later. The platelet units were transfused into two patients. One of them developed fever 3 days after transfusion, with high viral load. His pretransfusion sample was negative for IgG, IgM, and dengue RNA, while the second recipient did not show any symptoms nor laboratory evidence of dengue infection. CONCLUSIONS: This case brings additional evidence that dengue is indeed transmissible by blood transfusion and clinical manifestations, although rare, do occur.

Does offering human immunodeficiency virus testing at the time of blood donation reduce transfusion transmission risk and increase disclosure counseling? Results of a randomized controlled trial, São Paulo, Brazil.

BACKGROUND: In a randomized controlled trial (RCT) in a blood bank in São Paulo, we tested the hypotheses that offering client-centered human immunodeficiency virus (HIV) counseling and testing to blood donors would: 1) reduce the risk of HIV contamination in the blood supply by diverting higher-risk, test-seeking donors away from donation and 2) increase return for results and referrals to care. STUDY DESIGN AND METHODS: We randomly selected weeks between August 2012 and May 2013 when donors were offered HIV counseling and testing (n = 6298), leaving usual procedure weeks as control (n = 5569). RESULTS: Few candidate donors chose HIV testing (n = 81, 1.3%). There was no significant difference in herpes simplex virus Type 2 (HSV-2) prevalence (a marker of sexual risk) among donors during intervention weeks compared to control (10.4% vs. 11.1%, p = 0.245). No donor choosing testing was HIV infected, and there was no difference in HSV-2 prevalence between testers and donors (9.9% vs. 10.4%, p = 0.887). Returning for positive results did not differ between testers and donors (three of three vs. 58 of 80, p = 0.386). A higher proportion of donors acknowledged that HIV testing was a strong motivation to donate during intervention weeks compared to control (2.6% vs. 2.0%, p = 0.032). CONCLUSION: The evidence of our RCT is that offering HIV counseling and testing at the time of donation would not change the risk of contamination in the blood supply, nor improve results disclosure and referral to care.

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.

Apheresis in developing countries around the World.

At the combined American Society for Apheresis (ASFA) Annual Meeting/World Apheresis Association (WAA) Congress in San Francisco, California, in April of 2014, the opening session highlighted the status of apheresis outside of the United States. The organizers invited physicians active in apheresis in countries not usually represented at such international gatherings to give them a forum to share their experiences, challenges, and expectations in their respective countries with regard to both donor and therapeutic apheresis. Apheresis technology is expensive as well as technically and medically demanding, and low and median income countries have different experiences to share with the rest of the world. Apheresis procedures also require resources taken for granted in the developed world, such as reliable electrical power, that can be unpredictable in parts of the developing world. On the other hand, it was obvious that there are significant disparities in access to apheresis within the same country (such as in Brazil), as well as between neighboring nations in Africa and South America. A common trend in the presentations from Brazil, Indonesia, Malaysia, Nigeria, and South Africa, was the need for more and better physicians and practitioners' training in the indications of the various apheresis modalities and patient oversight during the procedures. As ASFA and WAA continue to work together, and globalization allows for increased knowledge-sharing, improved access to apheresis procedures performed by qualified personnel with safety and high-quality standards will be increasingly available.

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.

Unexpected detection of Plasmodium vivax and Plasmodium falciparum DNA in asymptomatic blood donors: fact or artifact?

A study searching for Plasmodium vivax and Plasmodium falciparum DNA among blood donors from the non-endemic area in Brazil reported a rate of 7.41%. This number is at least three times higher than what has been observed in blood donors from the Amazon, an endemic area concentrating >99% of all malaria cases in Brazil. Moreover, the majority of the donors were supposedly infected by P. falciparum, a rare finding both in men and anophelines from the Atlantic forest. These findings shall be taken with caution since they disagree with several publications in the literature and possibly overestimate the actual risk of malaria transmission by blood transfusion in São Paulo city.