The Prevalence of Red Blood Cell Alloantibodies in Lower Northern Thailand

Hemolytic transfusion reactions due to the presence of pre-existing alloantibodies are among the most common immunologic adverse effects in transfusion medicine. In addition to determining the presence and characteristics of the specific alloantibodies, one of the major obstacles is the selection of compatible blood units that lack the corresponding antigens to avoid such transfusion reactions. A delay in this process can lead to various detrimental complications.

To characterize the prevalence and specificity of alloantibodies in patients from lower northern Thailand who required a blood transfusion.

A retrospective review of the Blood Bank database of Naresuan University, Thailand, was conducted. Thirty one thousand four hundred patients who had been screened for the presence of alloantibodies between January 2007 and April 2014 were reviewed. The standard test tube method was used in all patients to identify the specificity of alloantibodies against red blood cell surface antigens.

Among the 31,400 patients, 169 patients (0.54%) were found to have pre-existing red blood cell alloantibodies. Anti-Mi (anti-Miltenberger blood group) was the most common alloantibody identified (43.79%). Other common alloantibodies were anti-E (18.34%), anti-P1 (17.75%), anti-Lea (17.16%), and anti-Leb (9.47%).

To minimize hemolytic transfusion reactions, we recommend greater availability and issuing of Mi, E, P1, Lea, and Leb-matched blood units for patients with known alloantibodies against these antigens, or for patients who require multiple transfusions. This is in addition to the standard pre-transfusion screening and cross-matching processes.