IMMUNOGENETICS OF HTLV-I II AND ASSOCIATED DISEASES/

The ethnic background of human T-lymphotropic virus types I and II(HTL V-I/II) infections and associated diseases was investigated in associa tion with human leukocyte antigens (HLA) (alleles) and haplotypes. Jap anese HTLV-I carriers were characterized by two categories of HLA clas s I antigens (A24, A26, B7, B61, Cw1, and Cw7) and class II alleles (D RB10101, 0803, 1403, 1501, and 1502 and DQB1*0303, 0501, and 0601); o ne category was associated with adult T-cell leukemia (ATL) patients a nd the other with HTLV-I-associated myelopathy/tropical spastic parapa resis (HAM/TSP) patients. The ATL-associated haplotypes had unique DRB 1-DQB1 alleles (0901-0303, 1501-0602, 1401-0503), which were correlate d with a low immune responsiveness to HTLV-I, while the HAM/TSP haplot ypes had different DRB1-DQB1 alleles (0101-0501, 0803-0601, 1502-0601) , which were correlated with a high immune responsiveness to HTLV-I. B oth ATL- and HAM/TSP-associated haplotypes were found among HTLV-I car riers and the patients from other ethnic groups (Jamaican blacks, Ande s natives, South American mestizos, and Mashhadi Jews). HLA haplotypes of HTLV-II carriers were different from those of HTLV-I carriers amon g South American natives. These results suggested that HTLV-I/II infec tions and the associated diseases might be determined by immunogenetic factors segregated with HLA alleles and haplotypes.