Blood group genotype analysis of Australian reagent red blood cell donors across three genotyping platforms: consistent detection of 7·0% phenotype genotype nonconcordance

Background and Objectives Standards mandate reagent red blood cells (RBCs) must be homozygous for certain antigens. Genotyping provides an enhanced approach to characterizing RBCs as mutations encoding weakened antigen expression may be detected. This study aimed to genotype reagent RBC donors and compare outcomes with serological phenotype. Genotyping was undertaken using three commercially available platforms. Materials and Methods Blood samples were collected from donors (n = 300) who contribute to reagent RBC panels. Genotyping was performed on at least one of three commercial platforms; BLOODchip Reference v4.1 (Progenika); human erythrocyte antigen (HEA) and RHD BeadChip (BioArray Solutions Ltd); Hemo ID Blood Group Genotyping Panel (Agena Bioscience). Results Genotype and phenotype were concordant for 279 of 300 donors (21 of 300; 7·0% nonconcordance). Five donors carried RH mutations and fifteen donors carried FY mutations, including two donors who had an incorrect phenotype reported. One donor carried RH and FY mutations. Conclusion Discrepancies between genotype and phenotype were detected in 7·0% of reagent RBC donors tested in clinically significant blood group systems. Genotyping of reagent RBC donors can improve transfusion safety by optimizing sensitivity of antibody screening and identification panels.