A retrospective study on the prevalence of weak D antigen (Du) in a blood bank in a tertiary care hospital in Maharashtra, India

Abstract

Background: One of the most immunogenic blood groups known to humans is the Rhesus (Rh) blood group. The Rh blood group with variable expression of D antigen is one of the complex systems in immunohematology. Sometimes, the variable expression of RhD antigen leads to the presence of weaker forms that are not detected by routine laboratory procedures. Aims: The study was conducted to determine the frequency of RhD negativity and weak D antigens. Settings and Design: This retrospective study was conducted in the Department of Immunohematology and Transfusion Medicine at a tertiary care center hospital for three years from June 2017 to June 2020. Materials and Methods: All the serial Rh grouping tests were conducted by the gel technique or by the tube method with two Anti-D reagents. Negative D antigen samples were further tested for weak D antigen by Coombs Test. Statistical analysis used the Statistical Package for Social Sciences (SPSS). Results: Out of a total of 17262 samples, 15400 (89.2%) tested Rh-positive, and 1866 (10.8%) tested Rh-negative. Weak D was positive in 52(0.027%) samples out of the RhD negative samples. Conclusion: The frequency of weak D antigen is low, but the strong immunogenicity of RhD antigen calls for the need for appropriate testing. This is of concern in RhD negative pregnant females, as it can cause alloimmunization if accidentally weak D antigen-positive blood is transfused.

Keywords

• alloimmunization
• d antigen
• du
• rh blood group
• weak d