Phenotypic Identification of Blood Groups in Blood Donors: A Peruvian Multicenter Analysis.

Background: Red blood cell alloimmunization currently continues to be a significant problem during the blood transfusion process, where phenotypic identification plays a clinically relevant role in its prevention. The objective of the study was to carry out the phenotypic identification of blood groups in blood donors from three hospitals in Lima. Methods: A cross-sectional study was conducted, including 20,141 blood donors in three hospitals in Lima, Perú during the period from January to June 2023. Red blood cell phenotyping was performed by the gel agglutination method using gel cards with the IH-500 automated system. Results: A predominance of donors within the age group of 29 to 38 years (30.9%) was observed, with the majority being men (69.5%). Most donors were Peruvian (97.9%), and among foreign donors (2.1%), Venezuelans predominated (1.5%). In the distribution of the ABO and RhD blood groups, the O Rh+ phenotype predominated in 79% of the donors. In the phenotypic distribution of the Rh system, the presence of the D antigen was observed in 98.1% of the donors, with the c phenotype being the most frequent (76.4%). For the Kidd system, 70.7% of the donors presented the Jka antigen and 81.9% the Jkb antigen. In the Duffy system, 77.7% of the donors presented the Fya antigen and 50% the Fyb antigen. For the MNS system, 93.7% of donors had the S antigen and 76.1% had the s antigen. It was also found that 1.5% of donors are carriers of the Kell antigen, all of which are clinically important. Conclusion: The phenotypic identification of blood groups in blood donors from three hospitals in Lima highlighted the clinical relevance of identifying less common antigens in the Kell, Kidd, Duffy, and MNS systems to prevent alloimmunization during blood transfusions.