Molecular characterisation of RhD variants in North Indian blood donor population

• Published in: Transfusion medicine (Oxford, England) Vol. 30; no. 4; pp. 295 - 303
• Main Authors: Khetan, Dheeraj, Verma, Anviti, Chaudhary, Rajendra K., Shukla, Jai Shankar
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01.08.2020
• Subjects: D variants; MALDI‐TOF; mass array; prevalence; RHD gene; RHD genotyping; weak D
• ISSN: 0958-7578; 1365-3148
• DOI: 10.1111/tme.12690

Objectives A molecular analysis of serologically RhD variant samples was conducted to find the incidence of various D variants in our blood donor population. Background Determining a blood donor's RhD phenotype and genotype is important as transfusion of units with a weak D or partial D phenotype can result in immunisation of the recipients. Methods Samples with discrepant D and weak D phenotypes identified on testing with at least five different monoclonal anti‐D antisera were considered serological RhD variant and subjected to molecular testing (Massarray kit, Agena Bioscience, San Diego) for variant RHD gene. Results A total of 39 samples, including 19 RhD discrepant samples and 20 weak D samples, were identified as serological RhD variant from a total of 4386 samples. Thirteen (13/39) samples carried variants leading to weak D phenotype, and eight samples had variants leading to partial D categories. Seven samples (7) could not be characterised, whereas 11 samples were identified as Rh negative (RHD*01N.01) after molecular testing. Overall incidence of D variants in the study population was 0.48%. RHD*weak D type 1(5, 0.1%) and RHD*DFR1 (5, 1%) were the most common variants identified. Conclusions Few samples with weak reaction on serological testing were found to be partial D variant and vice versa. Donor centres should develop a protocol for genotyping of samples with aberrant results on serological testing for assessing the actual RhD status of an individual as results of serological testing may be misleading.