SMIM1 intron 2 gene variations leading to variability in Vel antigen expression among Brazilian blood donors.

Background: There is a significant inter-individual heterogeneity of Vel antigen expression which can lead to inaccuracies on Vel phenotyping of blood donors and, potentially, to hemolytic post-transfusion reactions. Our aim was to evaluate the impact of genetic variants in the SMIM1 intron 2 on the expression of Vel antigen among Brazilian blood donors harboring the c.64_80del17 deletion in heterozygosity.

High-throughput strategy for molecular identification of Vel- blood donors employing nucleic acids extracted from plasma pools used for viral nucleic acid test screening.

Background: Serologic methods to determine the Vel- phenotype require the use of rare human antisera and do not allow for many samples to be tested simultaneously, which limits their application as a tool to search for rare donors. This study developed a low-cost molecular screening strategy using real-time polymerase chain reaction (PCR) and DNA, extracted from plasma pools for viral nucleic acid test (NAT) screening, to identify Vel- and Vel+(W) donors.

Study Design And Methods: A total of 4680 blood donors from the Brazilian southeast region were genotyped through real-time PCR targeting the 17-nucleotide (c.