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Background and Objectives Materials and Methods Results Conclusion Some blood operators routinely screen blood donations for high‐titre (HT) anti‐A/B to reduce the risk of a haemolytic transfusion reaction due to out‐of‐group plasma‐rich components. We assessed donor factors associated with an increased likelihood of screening positive and compared routine data between England and Australia.Data were assessed from HT screening during 2018–2020 in Australia and 2018–2021 in England, totalling nearly 6 million blood donations. Screening was performed using a Beckman Coulter PK7300 analyser with a micro‐titre plate saline direct agglutination test in both countries, although different reagent red cells were chosen. HT‐positive was defined as testing positive at a titre of 128 or above.The likelihood of a donor testing HT‐positive was greater for females than males, declined with age and was dependent on the ABO group. However, the proportion of donors testing HT‐positive was consistently higher in Australia than in England: overall, 14% of group O donations and 5% of group A donations in England tested HT‐positive, compared with 51% and 22%, respectively in Australia. English data also showed that donors from Black, Asian or mixed ethnic backgrounds were more likely to test HT‐positive than White donors.These data demonstrate that donor sex, age, ABO group and ethnicity affect the likelihood of testing HT‐positive. Differences in testing methods likely had a significant impact on the proportion of donors testing as HT‐positive or ‐negative rather than any differences in donor populations. [ABSTRACT FROM AUTHOR]

Background and Objectives: Australian Red Cross Lifeblood (Lifeblood) performs red blood cell (RBC) antibody screening on every whole blood donation. An alternate strategy has been proposed whereby an antibody screen is performed on the first donation and only repeated following pregnancy, transfusion or a significant break between donations (>2 years). We assess the blood safety risks associated with removing antibody screening for every whole blood donation. Materials and Methods: A retrospective desktop analysis included all whole blood donations collected by Lifeblood between 01 May 2018 and 30 April 2019 to quantify the antibodies that would have been undetected with the alternate strategy. The strategy was further assessed using the Alliance of Blood Operators Risk‐Based Decision‐Making framework. Results: One hundred and seventy‐one routine donors had antibodies for the first time, but reported no sensitizing event since their last donation. Forty‐seven of these had antibodies of a clinically significant specificity and titre that have the potential to cause a haemolytic transfusion reaction (HTR). The calculated risk of undetected antibodies being transfused to an incompatible recipient is 1 in 82,200. Conclusion: The estimated risk of HTRs with the alternate strategy results in an increased risk. While the alternate strategy is identified as the most cost‐effective option within the Australian setting, this additional residual risk was not deemed to be acceptable. Blood services would need to determine whether the increase in residual risk stemming from implementation of such a strategy is tolerable. [ABSTRACT FROM AUTHOR]

Background and Objectives: A newborn presented with jaundice in Thailand. The cord red cells tested positive by direct antiglobulin test (DAT) for an unknown maternal red cell antibody. Initial blood group sequencing suggested that the infant carried a novel variant RHAG c.140T>C, responsible for a low‐prevalence antigen in the RHAG blood group system (ISBT 030). We report here on testing of samples from the infant's parents and older sibling to define a new antigen in the RHAG system. Materials and Methods: Massive parallel sequencing (MPS) using a custom‐designed panel was performed on all four family members. Extended serological testing was also performed to determine whether family members with the same variant as the infant showed reactivity with the antibody in the maternal plasma. Results: We identified a novel single nucleotide variant (SNV) (RHAG c.140T>C, p.[Phe47Ser]) in samples from three of the four family members tested (the infant, the older sibling and the father). The variant was not detected in the mother's sample. Maternal plasma showed positive agglutination with all family members tested; however, when tested with routine panel cells, no reactivity was observed. Conclusion: This case study showed that the presence of the novel variant (RHAG c.140T>C), encoding a p.(Phe47Ser) change in the RhAG glycoprotein, was the apparent cause of incompatibility between maternal plasma and that of red cells from the proband, father and older sibling of the proband. We propose this variant to be a new low‐prevalence antigen in the RHAG blood group system. [ABSTRACT FROM AUTHOR]