Blood group genotyping in multi-transfused patients

Area of Science:

• Transfusion Medicine
• Genetics
• Hematology

Background:

• Classical hemagglutination assays for red blood cell (RBC) phenotyping can be unreliable in chronically transfused patients due to prior transfusions.
• Accurate RBC phenotyping is critical for safe transfusion management.

Purpose of the Study:

• To evaluate the utility of DNA-based blood group genotyping compared to traditional phenotyping in multi-transfused patients.
• To identify discrepancies and assess the risk of alloimmunization.

Main Methods:

• Red blood cell genotyping was performed on DNA samples from 39 multi-transfused patients (thalassemia, sickle cell disease).
• Specific kits were used to determine polymorphisms for RHD, RHCE, and Kell, Kidd, Duffy blood group systems.
• Genotyping results were compared with existing hemagglutination-based phenotyping data.

Main Results:

• Discrepancies between genotyping and phenotyping were observed in 51% of patients (19 out of 37), affecting 25 alleles.
• In 12 patients, these discrepancies posed a significant risk for alloimmunization.
• Genotyping revealed a higher accuracy in defining RBC phenotypes.

Conclusions:

• Blood group genotyping is essential for accurate transfusion management in chronically transfused individuals.
• Genotyping is particularly vital when patients have not undergone initial phenotyping before transfusions commence.
• Implementing genotyping can mitigate the risk of transfusion complications like alloimmunization.