Practical aspect of D weak testing in CHC Zemun

Abstract

The aim of investigation was to summarise the percentage of D weak phenotype at recipients and pregnant women in our hospital. We also wanted to see what Rh phenotype is dominant in that typed RBCs. The routine D typing was performed using tube technique with two different series of anti-D reagents. Samples marked as phenotype D weak were further investigated with two IgM anti-D reagents from different manufactures. RBCs were also tested for RH phenotype with monoclonal test reagents anti-C, anti E, anti-c and anti-e. During 2009, 11779 patient and pregnant woman samples were routinely D typed. After we performed the indirect antiglobulin test D weak expression was exhibited for 42 samples (0, 35%). Among the 42 D weak positive samples dominant RH phenotypes were CcDw ee (78,5%) and CCDw ee (16,6%). Agglutinations with the two IgM reagents showed different intensity of the reactions. RBC of 14 samples (33.3%) did not react with both reagents and six samples had score of agglutination between +3 to +4 (14, 2%). The percentage of D weak phenotype in this study is correspondent to those described in the literature. Respecting the current recommendation for D antigen typing and also with adequate selection of anti-D test serums we can distinguish weak D phenotype by serological typing. Molecular testing is the best solution to resolve of an accurate D antigen status, but in our country it is still not implemented.