Trends of ABO and Rh phenotypes in transfusion-dependent patients in Pakistan

The objective of this study was to determine the prevalence of ABO and Rh phenotypes in the general Pakistan population. This information could be used to help reduce the rate of alloimmunization in patients with blood disorders, such as thalassemia major, who require frequent blood transfusions. A total of 242 patients with blood disorders requiring frequent blood transfusions were enrolled in the study. ABO and Rh typing was performed on samples from these patients using tube and gel methods. Of these 242 patients, 146 (60.4%) were male and 96 (39.6%) were female. The prevalence of ABO and D phenotypes was as follows: group O, D+ (38.8%), group O, D– (2.5%), group B, D+ (32.2%), group A, D+ (17.4%), group A, D– (1.7%), and group AB, D+ (7.4%). Of the 242 patients, 232 (95.8%) were D+ and 10 (4.2%) were D–. The most prevalent Rh antigen was found to be e (97%), followed by D (95%), C (89.6%), c (62.8%), and lastly, E (22.6%). The prevalence of Rh phenotypes was: R₁R₁ (37.7%), R₁r (33.4%), R₁R₂ (19.4%), R₂r (5.2%), and rr (4.3 %). All of the D– patients were rr. In our study, the highest prevalence of ABO phenotypes was group O and the most prevalent Rh antigen was e. Rh phenotyping, along with antibody screening and identification should be performed prior to transfusion of patients requiring multiple transfusions to reduce and possibly prevent the rate of alloimmunization. Immunohematology2016;32:170–173.