A simple genotyping procedure without DNA extraction to identify rare blood donors.

International audienceTransfusion-induced alloimmunization has severe clinical consequences including haemolytic transfusion reactions, impaired transfused RBCs longevity and greater difficulty in finding compatible blood. Molecular analysis of genomic DNA now permits prediction of blood group phenotypes based on identification of single nucleotide polymorphisms. Implementation of molecular technologies in donor centres would be helpful in finding RBC units for special patient populations, but DNA extraction remains an obstacle to donor genotyping. We propose a simple method compatible with high throughput that allows blood group genotyping using a multiplex commercial kit without the need for DNA extraction. The principle relies on pre-PCR treatment of whole blood using heating/cooling procedure in association with a recombinant hotstart polymerase. In a prospective analysis, we yielded 5628 alleles identification and designated 63 donors with rare blood, that is either negative for a high-frequency antigen or with a rare combination of common antigens. The procedure was optimized for simplicity of use in genotyping platform and would allow not only to supply antigen-matched products to recipients but also to find rare phenotypes. This methodology could also be useful for establishing a donor repository for human platelet antigens (HPA)-matched platelets since the same issues are involved for patients with neonatal alloimmune thrombocytopenia or post-transfusion purpura