Prevalence and characteristics of irregular antibodies in northern Vietnamese blood donors

Irregular antibodies with the potential for causing transfusion reactions can be detected in healthy donors. The prevalence and characteristics of irregular antibodies in many populations are well known; however, the data of Vietnamese blood donors have not yet been reported. Our study was performed to assess the frequency and specificities of irregular antibodies among healthy blood donors in the north of Vietnam. A total of 199,281 blood donor samples were screened for irregular antibodies from 2021 to 2023. Antibody screening was performed by both microplate and tube methods. Positive tests were further confirmed using a gel card method. Subsequently, antibody identification was performed. The occurrence of a positive antibody detection test was 0.37 percent. Most cases had only one antibody (99.1%); the proportion of donors who had two and three antibodies accounted for 0.8 and 0.1 percent, respectively. The most frequently identified antibodies were of the MNS blood group system, with anti-Mi^a being the highest (72.7%) and then anti-M (12.9%), followed by the Lewis blood group system with anti-Le^a (6.5%) and anti-Leb (2.4%). The results show the rate and characteristics of irregular antibodies in northern Vietnamese blood donors. These findings provide essential data to support recommendations for implementing antibody detection in donor testing nationwide. Moreover, the results underscore the importance of selecting appropriate reagent panels.