Body-wide chimerism and mosaicism are predominant causes of naturally occurring ABO discrepancies.

Routine ABO blood group typing of apparently healthy individuals sporadically uncovers unexplained mixed-field reactions. Such blood group discrepancies can either result from a haematopoiesis-confined or body-wide dispersed chimerism or mosaicism. Taking the distinct clinical consequences of these four different possibilities into account, we explored the responsible cause in nine affected individuals.

Immunoglobulin Class Profiles of ABO Antibodies in Saliva and Serum of Healthy Individuals.

Introduction: The coronavirus disease (COVID-19) pandemic gave rise to studies investigating the association of ABO blood group with COVID-19 susceptibility. It is hypothesized that ABO antibodies might play a role in neutralizing SARS-CoV-2. However, ABO antibodies were exclusively analyzed in blood samples.

White paper on pandemic preparedness in the blood supply.

Background And Objectives: In March 2020, the WHO declared the SARS-CoV-2 corona virus a pandemic which caused a great disruption to global society and had a pronounced effect on the worldwide supply of blood.

Materials And Methods: In 2022 an on-line meeting was organised with experts from Austria, Canada, Germany, Greece, Netherlands and United States to explore the opportunities for increasing preparedness within blood systems for a potential future pandemic with similar, or more devastating, consequences. The main themes included the value of preparedness, current risks to the blood supply, supply chain vulnerabilities, and the role of innovation in increasing resiliency and safety.

Lower Levels of ABO Anti-A and Anti-B of IgM, IgG and IgA Isotypes in the Serum but Not the Saliva of COVID-19 Convalescents.

Individuals with ABO type O, naturally possessing anti-A and anti-B antibodies in their serum, are underrepresented among patients infected with SARS-CoV-2 compared with healthy controls. The ABO antibodies might play a role in the viral transmission. Therefore, we aimed to quantify anti-A/anti-B, including their subclasses IgM, IgG and IgA, in the serum and saliva of Caucasians (n = 187) after mild COVID-19 to compare them with individuals who had never been infected with SARS-CoV-2.

External quality assessment providers' services appear to more impact the immunohaematology performance of laboratories than national regulatory and economic conditions.

Objectives: Medical laboratories may, at their own discretion, exceed but not undercut regulatory quality requirements. Available economic resources, however, may drive or hinder eagerness to exceed minimum requirements. Depending on the respective scopes of regulatory and economic framework conditions, differing levels of quality efforts to safeguard laboratory performance can be anticipated.

Characterization of the novel alleles: HLA-A*01:305, HLA-B*58:120, HLA-C*04:428Q and HLA-C*05:01:56.

Four new HLA class I alleles were characterized by next-generation sequencing and haplotypes determined.

Leukocyte-Reactive Antibodies in Female Blood Donors: The Austrian Experience.

Introduction: Antibody-mediated transfusion-related acute lung injury (TRALI) is caused by antibodies against human leukocyte antigens (HLAs) or human neutrophil antigens (HNAs), and is one of the most serious complications associated with transfusion medicine. Prevention strategies like testing allo-exposed female blood donors have not yet been introduced nationwide in Austria. To assess the need and feasibility of routine leukocyte antibody testing, the prevalence of leukocyte-reactive antibodies in an Austrian female donor population was been determined using classical cell-based methods which were compared with a high-throughput bead-based method.

To Win the Battle, First Know Your Enemy: Error Rates in Immunohematology External Quality Assessment Results.

Background: As some errors in pretransfusion testing remain unrecognized, error rates and the resulting need for corrective measures are probably underestimated. External quality assessment (EQA) schemes could provide valuable input for identifying error-prone laboratory tests because they are designed to monitor test performance and errors. So far, however, there are only limited published data on error rates in such schemes.

Quantitative PCR of INDELs to measure donor-derived cell-free DNA-a potential method to detect acute rejection in kidney transplantation: a pilot study.

The quantification of donor-derived cell-free DNA (ddcfDNA) in recipient's plasma is a novel, but technically challenging noninvasive method to assist the diagnosis of acute rejection (AR). A quantitative real-time PCR (qPCR) approach targeting insertion/deletion polymorphisms (INDEL) was adapted to measure ddcfNA in plasma samples from 29 kidney transplant recipients obtained at time of clinically indicated biopsies (eight patients with a histologically verified AR, nine with borderline rejection and 12 without evidence of rejection). Measured ddcfDNA levels of smaller INDEL amplicon targets differed significantly (P = 0.

West Nile and Usutu Virus Infections and Challenges to Blood Safety in the European Union.

West Nile virus (WNV) and Usutu virus (USUV) circulate in several European Union (EU) countries. The risk of transfusion-transmitted West Nile virus (TT-WNV) has been recognized, and preventive blood safety measures have been implemented. We summarized the applied interventions in the EU countries and assessed the safety of the blood supply by compiling data on WNV positivity among blood donors and on reported TT-WNV cases.

Time from venipuncture to cell isolation: Impact on granulocyte-reactive antibody testing.

Background And Objectives: Classical neutrophil-reactive antibody testing depends on the quick isolation of neutrophils from freshly taken whole blood. To allow a better logistic preparation before testing, the influence of time interval between venipuncture and cell isolation has been evaluated in this study.

Materials And Methods: Neutrophils and whole leukocytes were isolated from EDTA whole blood immediately (T0) as well as 4, 8 and 24 h after blood donation (T4, T8 and T24).

Evidence for the positive impact of ISO 9001 and ISO 15189 quality systems on laboratory performance - evaluation of immunohaematology external quality assessment results during 19 years in Austria.

Background ISO 9001 and ISO 15189 have been established as continuative models for quality systems beyond national laws, mandatory standards and guidelines of expert associations regarding analytical and organisational performance of medical laboratories and transfusion services. Although widely used, their impact on laboratory performance has not been investigated. Methods We retrospectively analysed the results of 167 laboratories in 59 distributions of the Austrian red cell immunohaematology external quality assessment (EQA) scheme in the years 1999-2017.

Selection strategies for newly registered blood donors in European countries.

Background: Two selection strategies for newly-registered blood donors are available: a single-visit selection called the standard selection procedure (SSP), and a two-stage selection named predonation and donation screening (PDS). This study reviews the selection strategies for newly-registered donors currently applied in European countries.

Material And Methods: We collected data on donor selection procedures, blood donation, laboratory screening and HIV, HCV and HBV positive donors/donations from 2010 to 2013 in 30 European countries by using questionnaires.

Standardized genotyping of HLA STR by CE as surrogate for HLA class I and II markers and for identification of HLA identical siblings.

Linkage disequilibria (LD) between alleles and haplotypes of human leucocyte antigen, locus A (HLA) and STR loci located in the human major histocompatibility complex were analyzed in order to investigate whether or not HLA alleles and haplotypes are predictable by alleles or haplotypes of HLA STRs. Standardized genotyping of eight STR loci (D6S2972, D6S2906, D6S2691, D6S2678, D6S2792, D6S2789, D6S273, and DQIV) was performed by CE on 600 individuals from 150 Austrian Caucasoid families with known HLA-A,-B,-C and -DRB1 typing. From those, 576 full haplotypes of four HLA and eight STR loci were obtained.

Blood donor selection in European Union directives: room for improvement.

Background: Transfusion-transmissible infections have made both blood bankers and health authorities overly cautious. The general public expects and hence reinforces this policy. To obtain a high level of blood product safety, blood and plasma donors have to meet increasingly stringent eligibility criteria; however, it is not known whether this policy translates into improved outcomes for patients.

Responder individuality in red blood cell alloimmunization.

Many different factors influence the propensity of transfusion recipients and pregnant women to form red blood cell alloantibodies (RBCA). RBCA may cause hemolytic transfusion reactions, hemolytic disease of the fetus and newborn and may be a complication in transplantation medicine. Antigenic differences between responder and foreign erythrocytes may lead to such an immune answer, in part with suspected specific HLA class II associations.

Sequence-based definition of eight short tandem repeat loci located within the HLA-region in an Austrian population.

Sequenced allelic ladders are a prerequisite for reliable genotyping of short tandem repeat (STR) polymorphisms and consistent results across instrument platforms. For eight STR-loci located on the short arm of chromosome 6 (6p21.3), a sequenced based nomenclature was established according to international recommendations.

The distribution of MICA alleles in an Austrian population: evidence for increasing polymorphism.

The Major Histocompatibility Complex Class I Chain-Related Gene A (MICA) is located 46.4 Kb centromeric to HLA-B locus on chromosome 6; 84 alleles have been described so far. To assess the distribution of MICA alleles in an Austrian population, 322 unrelated Austrian blood donors have been typed for MICA by direct sequencing of amplified exons 2-5; sequencing of exon 6 and separating alleles by haplotype specific primers or by cloning was performed to resolve ambiguities.

Frequency and prognostic value of D alloantibodies after D-mismatched allogeneic hematopoietic stem cell transplantation after reduced-intensity conditioning.

Background: Due to the fact that the ABO and D system is inherited independently from the HLA system, approximately 40% of allogeneic hematopoietic stem cell transplants (HSCT) are performed across the blood group barrier. Reports on the development of de novo anti-D in patients undergoing reduced-intensity conditioning (RIC) followed by D-mismatched allogeneic HSCT are rare. The objective of this study was to evaluate the frequency of anti-D alloimmunization after D-mismatched HSCT following RIC and its prognostic impact on transplant outcome.

Germline mutations of STR-alleles include multi-step mutations as defined by sequencing of repeat and flanking regions.

Well defined estimates of mutation rates are a prerequisite for the use of short tandem repeat (STR-) loci in relationship testing. We investigated 65 isolated genetic inconsistencies, which were observed within 50,796 allelic transfers at 23 STR-loci (ACTBP2 (SE33), CD4, CSF1PO, F13A1, F13B, FES, FGA, vWA, TH01, TPOX, D2S1338, D3S1358, D5S818, D7S820, D8S1132, D8S1179, D12S391, D13S317, D16S539, D17S976, D18S51, D19S433, D21S11) in Caucasoid families residing in Austria and Switzerland. Sequencing data of repeat and flanking regions and the median of all theoretically possible mutational steps showed valuable information to characterise the mutational events with regard to parental origin, change of repeat number (mutational step size) and direction of mutation (losses and gains of repeats).