Genotypic Frequency of Rh Cw Antigen in Blood Donors of Northern Pakistan.

OBJECTIVE: To determine the genotypic frequency of Rh Cw antigen in blood donors of Northern Pakistan. STUDY DESIGN: Descriptive cross-sectional study. Place and Duration of the Study: Department of Molecular Haematology, Armed Forces Institute of Transfusion (AFIT), Rawalpindi, Pakistan, from August 2022 to January 2023. METHODOLOGY: Blood donors were randomly selected. Venous blood samples were taken in K3-EDTA anticoagulant tubes. ABO and Rh D grouping were performed conventionally. DNA for Rh Cw genotyping was extracted via Chelex TM, followed by PCR amplification using an ABI 2700 thermal cycler. Human growth hormone (HGH) acts as an internal control. Amplified products underwent Polyacrylamide gel Electrophoresis (PAGE). RESULTS: There were 400 randomly chosen donors whose ages ranged from 26-35 years, with a predominantly male population (94.8%) of Punjabi origin (67.8%). The majority (87.3%) was RhD positive. Blood group B was the most prevalent (35%) in the studied population, followed by O (34.75%). Only 1.5% had Rh Cw antigen. Rh Cw was more prevalent in ABO-positive participants (87.25%) compared to ABO-negative (12.75%). CONCLUSION: There was a 1.5% prevalence of Rh Cw antigen genotype in randomly selected Northern Pakistani blood donors. Rh Cw prevalence was higher in ABO-positive participants. Significant correlation (<0.05) existed between RhD and Cw antigens. Given the implications of anti-Cw antibody, including Cw antigen-positive cells in antibody screening is recommended. KEY WORDS: Alloimmunisation, Blood donors, HDFN, Phenotype, Rh antigens, Transfusion.