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.
ABO blood groups and hepatitis B virus infection: a systematic review and meta-analysis
BMJ open. 2020;10(1):e034114
OBJECTIVE Hepatitis B virus (HBV) infection is a major public health problem worldwide. Several studies have reported that ABO blood groups may be associated with HBV infection. However, its association is still controversial. We performed a meta-analysis to investigate whether ABO blood groups were associated with HBV infection. DESIGN Systematic review and meta-analysis. DATA SOURCES Relevant studies available before 1 December 2019 were identified by searching PubMed, EMBASE, Web of Science, ScienceDirect and the Cochrane Library. ELIGIBILITY CRITERIA All cross-sectional or cohort studies from which the data of ABO blood group distribution and HBV infection could be extracted. DATA EXTRACTION AND SYNTHESIS Studies were identified and extracted by two reviewers independently. Risk ratios (RRs) and 95% CIs were pooled by random-effect models to quantify this association. RESULTS Thirty-eight eligible articles including 241 868 HBV-infected subjects and 6 487 481 uninfected subjects were included. Overall, the risk of HBV infection had decreased by 8% in subjects with blood group B when compared with non-B blood group (RR=0.92, 95% CI 0.86 to 0.98). In the subgroup analyses, the inverse relationship between blood group B and HBV infection remained stable in higher endemic areas (HBV prevalence ≥5%), Asian people, larger sample size studies (≥2000), general population and blood donors, lower middle income group and studies published before the year 2010. Additionally, subjects with blood group O had a 12% increased risk of HBV infection (RR=1.12, 95% CI 1.01 to 1.24) in higher endemic areas. In the sensitivity analysis, the pooled risk estimates of blood group B and HBV infection were still stable. CONCLUSIONS Our data suggested that the blood group B was associated with a lower risk of HBV infection. More research is needed to clarify the precise role of the ABO blood group in HBV infection to address the global question of HBV infection.
Effect of plateletpheresis on total platelet count and mean platelet volume: A meta-analysis
J Evid Based Med. 2020
OBJECTIVE Currently, there are discrepancies in the reports on the extent of the reduction in platelet count after platelet donation by apheresis, and its impact on mean platelet volume (MPV). This study was conducted to meta-analyze the effect of plateletpheresis on platelet count and on mean platelet volume, based on studies published between 1980 and 2018. METHODS Medline-Pubmed, Scielo, ScienceDirect, and Scopus databases were searched from inception to December 31 2019. The PRISMA guidelines, reproducibility, and evaluation of the methodological quality were guaranteed. Heterogeneity was evaluated with DerSimonian-Laird's, publication bias with a Begg's test. Sensitivity analysis and cumulative meta-analysis were also conducted, as well as a forest plot. RESULTS Twenty-five studies with 3769 donors were systematized to analyze platelet count, and seven studies with 1176 donors to observe MPV. Most studies were published in India and the United States. There was a postprocedure reduction in both variables. The reduction in platelet count was 14.3 x 10(3) /muL (95% CI 11.4 to 17.1 x 10(3) muL). The reduction in MPV was 1.43 fL (95% CI 0.3 to 2.5 fL). The analysis of subgroups showed that, in the case of platelet count, the reduction is not statistically significant two weeks after donation. CONCLUSION Platelet donation by apheresis reduces platelet count and MPV in donors, which is detrimental to the purposes of the procedure; although the decrease is not clinically significant for the donor or the recipient. This demonstrates the need for subsequent studies to evaluate variables, such as donation frequency and donation intervals, should be considered to evaluate if the reported decrease is easily compensated, without adverse consequences for donors, or if modifications in donor selection criteria are required.
High-dose intravenous versus oral iron in blood donors with iron deficiency: The IronWoMan randomized, controlled clinical trial
Clinical nutrition (Edinburgh, Scotland). 2019
INTRODUCTION Frequent blood donation often leads to iron deficiency and even anemia but appropriate strategies for detection and prevention are currently not mandatory. At the Medical University of Graz, we conducted a single-center prospective clinical trial to compare oral and IV iron supplementation in iron deficient blood donors including Austrian regular whole blood and platelet apheresis donors. We aimed to determine the difference of transferrin saturation between the treatment groups 8-12 weeks iron administration besides other parameters of iron status and blood count. METHODS 176 healthy male and female blood donors with iron deficiency (ferritin ≤30 ng/mL) were randomized to either a single dose of IV ferric carboxymaltose (1000 mg, n = 86) or oral iron (II)fumarate (100 tablets of 100 mg [10 per week], n = 90). RESULTS Between 2014 and 2016, 172 donors (137 women) completed the study; 4 in the oral group were lost to follow-up. At follow-up, median (IQR) transferrin saturation and ferritin were significantly higher in the intravenous group (27 [23-35]%, vs 21.0 [16-32]%; p < 0.001 and 105 [75-145] ng/mL vs 25 [17-34] ng/mL; p < 0.001, respectively) while median (IQR) hemoglobin levels were comparable (IV, 13.6 [13.0-14.4] g/dL vs oral, 13.6 [13.0-14.2] g/dL). The frequency of adverse effects was comparable (38% in both groups) and no serious adverse events occurred. CONCLUSIONS A single dose of 1000 mg of intravenous iron is highly effective to counteract iatrogenic iron deficiency in blood donors. Oral iron appears to be an acceptable alternative. The assessment of body iron stores should play a key role in maintaining blood donors' health. This trial was registered at www.clinicaltrials.gov as NCT01787526 on February 8, 2013 and at www.clinicaltrialsregister.eu (EudraCT identifier: 2013-000327-14) on September 24, 2013.
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.
Impact of increasing sample volume from 4 ml to 8 ml on bacterial detection rates in apheresis platelets: a meta-analysis
Vox Sanguinis. 2015;108((3):):318-20.
Some blood centres have increased sample volume of in-process cultures to improve detection of bacterial contamination when screening apheresis platelet units. We performed a meta-analysis to evaluate extant published North American data comparing apheresis platelet bacterial contamination rates from 4 ml and 8 ml sample volume. Pooled results indicate an 8 ml sample volume yields higher true-positive rates than 4 ml resulting in a significant increase in the detection rate and interdiction of contaminated units, which should contribute to reduced risk of adverse transfusion outcomes. Copyright 2014 International Society of Blood Transfusion.
The impact of intensive serial plasmapheresis and iron supplementation on iron metabolism and Hb concentration in menstruating women: a prospective randomized placebo-controlled double-blind study
Kinetics of CFU-Mk after automated plateletpheresis
Vox Sanguinis. 2001;81((3):):167-71.
BACKGROUND AND OBJECTIVES Platelet count, thrombopoetin (TPO) level and the compartment of megakaryocyte progenitor cells (CFU-Mk) are major determinants in the regulation of thrombopoiesis. The aim of this study was to investigate the potential changes in the compartment of CFU-Mk and their correlation with serum TPO levels and platelet count after plateletpheresis. MATERIALS AND METHODS Twelve healthy individuals were randomly assigned to undergo single-donor plateletpheresis. A collagen-based in vitro culture system was used to determine the number of peripheral blood (PB) CFU-Mk before and after donation and on days 1, 4 and 7 thereafter. TPO levels were measured by a specific enzyme-linked immunosorbent assay and whole blood counts were performed using an automated cell counter. RESULTS The pre-apheresis platelet count (mean +/- SEM: 276 +/- 13 x 10(9)/l) decreased after plateletpheresis to a nadir of 194 +/- 8 x 10(9)/l (P < 0.001), showed a gradual increase on days 1 and 4, and reached pre-apheresis values by day 7 (280 +/- 11). The serum TPO levels were found to be significantly increased on days 1 and 7 as compared to baseline levels (baseline value 103.3 +/- 18.5 pg/ml versus day-1 value 135.8 +/- 25.8 pg/ml and day-7 value 132 +/- 30.19 pg/ml; P < 0.03 and P < 0.03, respectively). The numbers of CFU-Mk in PB were significantly elevated on day 4 only (125 +/- 21 colonies/ml of PB versus pre-apheresis values of 68 +/- 18 colonies/ml of PB, P < 0.005). CONCLUSIONS These findings suggest that platelet loss during plateletpheresis affects thrombopoiesis at the progenitor cell level, probably through alterations in TPO plasma concentrations.