BACKGROUND
The high homology and opposite orientation of RH genes promote rearrangements between them and generate a large number of RHD and RHCE variants which can be inherited together. Searching of RHD‐CE genotypes predicting partial antigens in donors is of interest in order to find more closely matched donors for African descent patients. This study aimed to evaluate a molecular approach to search for RhCE variants in a cohort of individuals with altered expression of D antigen and determine the association of RH variant alleles in Brazilian blood donors.
METHODS
From 80,961 blood samples tested, 421 with atypical D typing results were studied. The samples were phenotyped for C, c, E, e antigens. Rh variants were identified using molecular techniques.
RESULTS
All 421 samples had altered RHD alleles, being 56·3% of them partial D. Among them, 94·9% presented variant RHCE*ce and the most common associations were: RHD*weak D type 4.2.2 with RHCE*ceAR; RHD*DAR linked to RHCE*ceVS.02; RHD*weak D type 4.0 linked to RHCE*ceVS.02 and RHCE*ce (c.48C, c.105T, c.733G, c.744C, c.1025T). Among the samples with RhCE variants, 10·6% predict partial c, partial e, hrB‐ and/or hrS‐ and 100% express low prevalence antigens.
CONCLUSION
Targeting individuals with altered expression of D antigen can be a good strategy for finding donors with RhCE variants. In our study 94·9% of the partial D samples revealed altered RHCE variant alleles and 5·7% of the samples with altered RHD allele predicted partial c, partial e and the lack of the high prevalence hrBand hrSantigens.