Back to base pairs: What is the genetic risk for red bloodcell alloimmunization?
Blood reviews. 2021;:100794
Red blood cell (RBC) alloimmunization is a serious complication of blood transfusions, challenging selection of compatible units for future transfusions. Genetic characteristics may be associated with the risk of RBC alloimmunization and may therefore serve to identify high-risk patients. The aim of this systematic review was to summarize the available evidence on genetic risk factors for RBC alloimmunization. Electronic databases were searched up to April 2020 for studies (Search terms included transfusion, alloimmunization and genetic). A total of 2581 alloimmunized cases and 26,558 controls were derived from 24 studies. The alleles that were most frequently studied and that demonstrated significant associations in a meta-analysis with alloimmunization to the Duffy(a) antigen were HLA-DRB1*04 (Odds Ratio 7.80 (95%CI 4.57-13.33)), HLA-DRB1*15 (OR 3.76 (95%CI 2.14-6.59)), and HLA-DRB1*03 (OR 0.12 (95%CI 0.05-0.29)). Furthermore, significant associations with anti-K formation was found for the alleles HLA-DRB1*10 (OR 2.64 (95%CI 1.41-4.95)), HLA*DRB1*11 (OR 2.11, (95%CI 1.34-3.32)), and HLA-DRB1*13 (OR 1.71 (95%CI 1.26-2.33)). Overall, the available evidence was of moderate to low quality, hampering interpretation of reported results. There is an urgent need for high quality evidence on genetic risk factors for RBC alloimmunization.
Seroprevalence of Dengue and Zika Virus in Blood Donations: A Systematic Review
Transfusion medicine reviews. 2018;33((1):):35-42.
The presence of antibodies to Zika virus (ZIKV) and dengue virus (DENV) can be detected in blood donations. Donation-based surveillance provides an alternative strategy to estimate population prevalence by detecting antibodies that are circulating. To estimate population prevalence, we conducted a systematic review of literature on the seroprevalence of ZIKV and DENV antibodies in blood donations. We searched PubMed and Web of Science for studies that reported the seroprevalence of ZIKV and DENV in blood donations. The title and abstract of each study were screened by 2 reviewers simultaneously for possible inclusion, and the full text of selected studies was reviewed to ensure that they met inclusion criteria (used primary data collection, reported evidence of immunoglobulin M (IgM) or immunoglobulin G (IgG) antibodies in the blood supply, and included a representative sample of the total population). Immunoglobin test measuring levels of antibodies to IgM and IgG and number of positive cases were extracted from each study. No exclusions were made based on language or country. Our initial search identified 1890 studies after excluding duplicates, of which 76 were assessed for full text eligibility to ensure that they met our final inclusion criteria. There were 14 studies included in our review; 11 examined the seroprevalence of DENV, and 3 examined ZIKV. The highest seroprevalence by IgM was 2.82% for DENV and 0.53% for ZIKV. Our results indicate that the seroprevalence of ZIKV and DENV antibody presence in countries with active transmission is higher than reports by traditional surveillance in some countries. This finding is expected due to the large percentage of asymptomatic cases. The highest seroprevalence was observed for IgG, which can persist over long periods of time compared to IgM. Screening of blood donations may help supplement traditional surveillance measures, especially during outbreak settings.
Global status of visceral leishmanial infection among blood donors: a systematic review and meta-analysis
Transfusion and Apheresis Science : Official Journal of the World Apheresis Association : Official Journal of the European Society for Haemapheresis. 2017;56((5):):748-754
INTRODUCTION Transmission of Leishmania through transfusion has been reported from various Visceral leishmaniasis (VL) endemic areas of the world. The true burden of Leishmania infection in blood donors remains generally unknown. Thus, the present systematic review attempted to determine the global prevalence of Leishmania infection among blood donors. METHODS Data were extracted through five English and five Persian databases during the period from 1997 to 2016. Overall, 16 articles fulfilled the inclusion criteria and were used for data extraction in this systematic review. RESULTS In total, 13,743 blood donors from different regions of world were examined. The prevalence rate of Leishmania infection according to seropositivity obtained 7% (95%CI: 5%, 8%). The lowest and the highest prevalence were related to Bangladesh 0.25% (95%CI: 0.0%, 1.0%) and Brazil, 16% (95%CI: 12%, 19%). Seroprevalence rate of leishmaniasis among females was more (4.60%) than males. Of 15 studies included in the meta-analysis, the pooled prevalence rate of molecular tests was obtained 2% (95%CI: 1%, 3%) in which Iran and Spain had the lowest and the highest prevalence, 0.05% and 7%, respectively. Our analysis showed that L. infantum was more common than L. donovani as etiological agent of VL among all donors. CONCLUSION Our data confirms the presence of asymptomatic carriers of VL in endemic areas and supplies as an attentive to the likelihood of these carriers acting as blood donors. Moreover, we conclude that molecular tests for screening in asymptomatic blood donor provide an accurate estimate of the rate of infection over serological tests.
The contribution of unsafe blood transfusion to human immunodeficiency virus incidence in sub-Saharan Africa: reexamination of the 5% to 10% convention
BACKGROUND Historical estimates have attributed 5% to 10% of new human immunodeficiency virus (HIV) infections in sub-Saharan Africa (SSA) to unsafe blood transfusions. Although frequently cited, the validity of this statistic is uncertain or outdated. Recent estimates suggest blood transfusion's contribution to new HIV infections in the region may be much lower. STUDY DESIGN AND METHODS We searched the peer-reviewed and gray literature for quantitative estimates of the specific contribution of unsafe blood transfusion to the proportion of new HIV infections occurring in SSA. The sources and methods used to generate attribution estimates were evaluated against published country-specific HIV prevalence data. RESULTS Despite multiple secondary citations, a primary published source attributing 5% to 10% of new HIV infections to blood transfusions in SSA could not be established for the current era. The United Nations Programme on HIV and AIDS (UNAIDS) modes of transmission (MOT) reports representing 15 countries suggest that between 0 and 1.1% of new HIV infections per year (median, 0.2% or approx. two out of 1000 new infections each year) may be attributable to blood transfusions. CONCLUSION Recent modeled estimates suggest that blood transfusions account for a very low proportion of new HIV infections in SSA, likely an order of magnitude lower than 5% to 10%. Direct quantification of risk is challenging given the paucity of data on the variables that impact transfusion-associated HIV. Specifically, data on HIV incidence in blood donors, blood bank laboratory test performance, and posttransfusion surveillance are lacking. Findings suggest an urgent need for improved surveillance and modeling of transfusion-associated HIV transmission in the region. Copyright © 2016 AABB.