Frequency of partial D in Western India

Area of Science:

• Transfusion Medicine
• Immunogenetics
• Blood Group Serology

Background:

• Partial D variants are clinically significant due to the potential for alloimmunization in RhD-positive individuals lacking specific D epitopes.
• Previous molecular studies on D variants have largely focused on European, African, and East Asian populations, with limited data from the Indian population.
• Understanding the prevalence and characteristics of partial D in diverse populations is crucial for transfusion safety and compatibility.

Purpose of the Study:

• To screen the Indian population for the presence of partial D using serological methods.
• To molecularly classify identified partial D variants using multiplex polymerase chain reaction (M-PCR).
• To determine the incidence and predominant types of partial D in West India.

Main Methods:

• Serological screening of 10,000 RhD-positive individuals from West India for partial D using a commercial partial D kit.
• Investigation of blood samples with serological RhD discrepancies referred from blood banks in West India.
• Molecular characterization of partial D-positive samples using multiplex polymerase chain reaction (M-PCR).

Main Results:

• Fifteen partial D cases were detected through population screening, and 45 were identified from referred samples.
• Population screening indicated that one-third of partial D cases were DFR (Deletion, Fusion, and Recombination) variants when tested with the partial D kit.
• The incidence of partial D in West India was determined to be at least 0.15% using the partial D kit. M-PCR achieved higher classification rates (76.6%) compared to the partial D kit (63.4%).

Conclusions:

• The study establishes the presence and incidence of partial D in the Indian population, highlighting its clinical relevance.
• DFR partial D variants were found to be predominant in the studied West Indian population.
• Multiplex PCR is a valuable tool for accurate classification of partial D variants, aiding in transfusion management.