Ethnic segregation of HTLV‐I and HTLV‐II carriers among South American native Indians

Abstract

To investigate the genetic background of human T-cell leukemia virus type I (HTLV-I) and II (HTLV-II) carriers among South American native Indians, we analyzed HLA DRB1*-DQB1* haplotypes of the virus carriers from Andes highlands and Orinoco lowlands by the PCR-RFLP genotyping method. It was revealed that the HTLV-I-carrying Andes natives had one of the 5 HLA haplotypes: DRB1*-DQB1* 0403-0302, 0802-0402, 0901-0303, 1406-0302 and 0407-0302, and that the Orinoco HTLV-II carriers had one of the 3 HLA haplotypes: DRB1*-DQB1* 1402-0301, 1602-0301 and 0404-0302. The HLA haplotypes of Andes HTLV-I carriers and Orinoco HTLV-II carriers were mutually exclusive. The haplotypes associated with HTLV-I carriers were commonly found among the Andes Indians and Japanese, which is the known HTLV-I endemic population, while the haplotypes associated with HTLV-II carriers were specifically found among the Orinoco Indians and North American Indians, among whom HTLV-II is endemic. These results suggested that HLA haplotypes might be ethnically segregated among South American natives and might be involved in the susceptibility to HTLV-I and HTLV-II infections.

HTLV-Is in Argentina are phylogenetically similar to those of other South American countries, but different from HTLV-Is in Africa

“…Hence, recent introductions from other populations seem unlikely considering that the efficiency of transmission of this virus is considerably low. Our suggestion has been supported by the presence of this virus among different native inhabitants in North and South America [Fujiyoshi et al, 1995;Kaplan et al, Fig. 3.…”

“…In these countries, HTLV-I has been found in various ethnic populations, including whites, blacks, mestizos, mulattoes and Japanese immigrants. It should be noted that the presence of HTLV-I has also been identified among native inhabitants of South America (Amerindians) in Argentina [Bouzas et al, 1994], Colombia [Duenas-Barajas et al, 1992;Zaninovic et al, 1994], Chile [Cartier et al, 1993;Fujiyoshi et al, 1995], and Brazil [Ishak et al, 1995].…”

Global epidemiology of HTLV-I infection and associated diseases

“…Host genetic background including human leukocyte antigen (HLA) genotype, and HTLV-I proviral load are thought to predict the risk of these diseases among HTLV-I carriers (Usuku et al, 1988;Bangham, 2003). The genetic background of HTLV-I carriers (South America native Indians and individuals living in Andes highlands and Orinoco lowlands) was investigated, and the results suggested that HLA haplotypes might be ethnically segregated and might be involved in the susceptibility to HTLV-I infection (Fujiyoshi et al, 1995). High levels of HTLV-I proviral load may be associated with HTLV-I diseases; however, risk factors for high proviral load are uncertain (Takenouchi et al, 2003;Murphy et al, 2004a).…”

A new genotype of TT virus (TTV) infection among Colombian native Indians

“…Among Colombian native Indians, a high prevalence of human T-cell lymphotropic virus-type I (HTLV-I), HTLV-II [Zaniovic et al, 1994;Fujiyoshi et al, 1995], and GB virus C (GBV-C) Asian type [Tanaka et al, 1998], which are mainly found in the Asian population, has been noted. A high prevalence of TTV is found in Japan [Okamoto et al, 1998].…”