An Experience with Unexpected Antibody Screening Tests using a Panel That Included Di(a) Cells in Koreans / 대한수혈학회지

BACKGROUND: In Korea, a screening panel of cells from abroad without Di(a) positive cells has been commonly used when a patient has an unexpected antibody screening test. It has been reported that Di(a) occurs with a frequency of 6.14 to 14.5% among Koreans. However, the current popular antibody screening panels contain no Di(a) positive cells. In this study, we evaluate the clinical usefulness of the Di(a) Cell Panel (Diagnostic Grifols, Barcelona, Spain) for Koreans. METHODS: A total of 3,372 pretransfusion samples were employed for unexpected antibody screening testing using panels of cells by the DG Gel microtube column agglutination system, including additional Di(a) cells (Diagnostic Grifols, Barcelona, Spain). The positive cases in this system were confirmed again with DiaMed Di(a) antigen positive panel cells (DiaMed Ag, Cresssier, Morat, Switzerland) and this was followed by sequence- based Diego genotyping. RESULTS: The positive detection rate of an unexpected antibody screening test using SeraScan Diana I and II was 1.07% (36/3372), and seven samples were reactive (1+~2+) with the SeraScan Di(a) panel cells (0.21%). However, among the 5 available genotyped samples, two cases were typed as Di(a-b+). CONCLUSION: Even though there is discrepancy between the genotype and the two antibody screening kits, the addition of Di(a) positive cells as unexpected antibody screening panel cells is recommended.

The Clinical Significance of Antibody Screening Test Including Di(a+) Panel Cell in Asian-Mongoloid Populations

The Di(a) antigen is well known as one of the antigens with low incidence among Caucasians; however, it has been discovered with a relatively higher incidence among Mongoloid populations. Thus, it has been speculated that the incidence of unexpected antibody against the Di(a) antigen might be relatively higher among these populations. Hemolytic transfusion reactions (HTRs) and hemolytic disease of the newborns (HDNs) caused by anti-Di(a) have been reported sporadically. However, there has been no prospective study on the incidence of anti-Di(a) in Mongoloid populations particularly. The authors conducted a series of antibody screening tests on 11,219 Korean individuals for 25 months, by using three kinds of screening cells including Di(a) cell. Anti-Di(a) was detected in 8 patients, seven of whom had a history of transfusions or were multigravida. The incidence of anti-Di(a) measured in this study was higher than expected, ranked third among unexpected antibodies identified during the period of the study, so it is strongly recommended that the Di(a+) panel cell must be incorporated into antibody screening test for safer transfusion in Asian-Mongoloid populations.