A study on HL-A system in Japanese.

Two hundred unrelated Japanese individuals were HL-A typed with UCLA Research Tray T3 (Terasaki's Tray), which contains specificities added after the Fifth International Workshop. Phenotype, gene and haplotype frequencies were calculated with standard errors and delta values. HL-A9, HL-A5 and W10 had a higher frequency and HL-A1, 3 and 8 had a lower frequency in Japanese than in Caucasians. The frequent haplotypes were HL-A9-HL-A5, HL-A9-HL-A7 and HL-A2W10. HL-A9-HL-A5 showed very positive high linkage disequilibrium parameter (delta value) and HL-A9-W10 showed negative high value. The sera designated as anti-HL-A, W5 and W15 in the T3 Tray which react identically in Caucasians showed different patterns of reaction when tested in the Japanese population. Five hundred Japanese parous women's sera were tested for cytotoxic antibodies. Some Japanese antisera showed high correlation coefficient values on HL-A2, HL-A9, HL-A10, HL-A11 and HL-A12. The women providing the anti-HL-5 complex sera and their immunizing persons were HL-A typed. These complex sera reactions were compared with the antisera in the T3 Tray. A new group of sera (SN-1), "operationally monospecific" and cross-reacting with W22, was found in the present study. Population and family studies suggested that the sera SN-1 are third in frequency within the second series (phenotypic frequency 17-22%) and show high delta values with HL-A11 in the Japanese population.