Distribution of HLA antigens in Ticuna Indians of Brazil: results of typing a leprosy-affected family.
HLA typing was performed in 1978, using antisera recognizing specificities defined by the Seventh Workshop, on lymphocytes separated and frozen in the field during a 1976 expedition among Amazonian Ticuna Indians. Family segregation of HLA antigens was used to ascertain haplotypes of a sample of essentially unrelated reproductive-age adults. "Expaternal" haplotypes were also included in the total of 81 haplotypes used for calculating the A and B locus gene frequencies. Common A and B locus antigens among the Ticuna were Aw24, Aw31, A2, Bw39, B40, Bw35, and B15.1. Bw53 were also present. No A or B locus "blanks" were found. A slight degree of European admixture was apparent. Bw16-reactive cells from certain persons consistently failed to react with Oxford antisera capable of recognizing the Bw38 or Bw39 subspecificities. Cw1 and Cw3 were found in association with typical South American Indian haplotypes. The results of HLA typing of a large extended family with multiple cases of leprosy are depicted and compared to recently reported family studied of leprosy.