Investigation of weak d phenotype frequency in blood donors and patients: A tertiary care hospital study

Abstract

Background and objectives: RhD is the most important and complex blood group system after ABO bloodgroup system for transfusion purpose. Weak D refers to reduced expression of D antigen on red blood cells. Our study is designed to determine the frequency of weak D antigen among healthy donors and patients coming to our tertiary care hospital which is important while labelling the donor and patient; as the donor is labelled D positive, patient as D negative also to highlight its clinical implications related to risk of alloimmunization in blood recipients having RhD negative blood group. The probable cause for reduced antigen D expression could be missense mutations seen in alleles of all weak D type. Material and Methods: In our centre all blood donors and patients samples are tested for ABO and RhD using anti-D IgM monoclonal and a blend anti-D IgM and IgG reagents. The blood samples which were negative for agglutination by immediate spin method were further tested for weak D using IgG anti-D in the IAT phase with LISS/Coomb’s gel card. Results: A total 54222 blood samples were tested(4977 donors, 49245 patients) during the period of January 2023 to December 2023.Among these 51242 were Rh D positive(94.50%) and remaining 2180 (4.02%) were Rh D negative. A total of 80 were weak D positive constituting 3.66% of Rh D negative and 0.147% of total individual screened. Conclusion: This study shows the prevalence of weak D antigen in our population and to inform them about their status as donor and recipient of blood to prevent the hazards of blood transfusion.