Human neutrophil antigen-2a expression on neutrophils from healthy adults in western Japan

BACKGROUND: Human neutrophil antigen-2a (HNA-2a)-specific MoAb, which is necessary to prepare panel neutrophils and to determine the phenotype of patients' neutrophils, has been produced in many laboratories in Japan. The frequency of the HNA-2a-positive population in western Japan is unknown. STUDY DESIGN AND METHODS: A cell line secreting an HNA-2a-specific MoAb, TAG4, was established. TAG4 was characterized by flow cytometry, and the reactivities of TAG4 and another HNA-2a-specific MoAb, 7D8, were compared in an inhibition assay and two-color flow cytometry. TAG4 was tested against granulocytes from 408 healthy adult volunteers in western Japan. RESULTS: TAG4 reacted with neutrophils, but not with the other blood cells. The reactivity of TAG4 with granulocytes treated with glycosyl-phosphatidylinositol-specific phospholipase C was markedly reduced. The reactivity of TAG4 and 7D8 was similar, but 7D8 did not prevent TAG4 from binding. A total of 406 of 408 donors were TAG4 positive. The mean percentage of HNA-2a expression of females was 70.2 percent, and that of males was 66.8 percent. CONCLUSION: TAG4 and 7D8 seem to bind to different epitopes of HNA-2a. The frequency of the HNA-2a-positive population is 99.5 percent of healthy adults in western Japan. The mean percentage of HNA-2a expression of females was greater than in males.