Evaluation of prevalence of weak D antigen among rhesus-negative patients in tertiary care hospitals in Bangladesh: A multicenter study

Background and Objectives: In 1939, D antigen was discovered which is believed to be the most immunogenic antigen in Rhesus (Rh) blood group system. There are some D variants such as weak D, partial D, and DEL due to gene polymorphism. These variants can cause RhD-positive person to behave like RhD negative which could result in alloimmunization. Clinically weak D antigen is very important due to its strong immunogenicity in spite of its low frequency. Hence, we need to know the prevalence of weak D variants in the community. The purpose of this study is to find out weak D prevalence among the Bangladeshi population. Methods: It is a retrospective study done over the last 5 years, from January 2015 to December 2019, at the department of transfusion medicine of three tertiary care hospitals in Bangladesh. A total of 177,702 patients were enrolled in the study. Blood samples that were negative for RhD were tested for weak D by indirect antiglobulin test according to institutional protocol. Results: Out of 177,702 patients, 7359 (4.1%) were found to be RhD negative and among those, 14 (0.19%) were weak D antigen positive. Conclusion: Weak D antigen is prevalent in Bangladesh and every RhD-negative individual should be checked for the presence of weak D to prevent RhD alloimmunization.