Detection of Antibodies to Human T-Cell Leukemia Virus Types 1 and 2 in Breast Milk from East Asian Women

Abstract

We investigated the incidence of human T-cell leukemia virus type I (HTLV-1) infection in a total of 17 regions in four countries, including 13 regions in Japan, as well as Korea (Seoul and Busan), China, and Vietnam, by testing breast milk using a particle agglutination assay (PA) and line immunoassay (LIA). Among 266 samples from Japan, 24 (9.0%) were positive on PA and 3 (1.1%) were positive on LIA. Among 50 samples from Seoul, 2 were positive on PA and 1 was positive on LIA. In contrast, all 50 samples from Busan were negative on both tests, suggesting the maldistribution of HTLV-1 infectants in South Korea. The numbers of positive samples were 2/91 on PA and 1/91 on LIA for China and 1/88 on both PA and LIA for Vietnam. In China, one sample with a high probability of HTLV-2 infection was identified by LIA and synthetic peptide enzyme-linked immunosorbent assay (ELISA). We examined HTLV-1 antibody in breast milk samples using commercially available test kits, suggesting the existence of HTLV-1 carriers in endemic areas in Southeast Asia and an HTLV-2 infectant in China. As a part of human ethno-epidemiological research, these results constitute valuable epidemiological data. Further studies on the sensitivity, specificity, and reliability of assays using antibodies to HTLV-1 and 2 in breast milk will be necessary for large-scale epidemiological surveys of HTLV infection.Key words breast milk; human T-cell leukemia virus type II; line immunoassay; particle agglutination assay Adult T-cell leukemia (ATL) is a malignant CD4-positive T-cell neoplasm caused by infection with human T-cell leukemia virus type I (HTLV-1). Because HTLV-1 is a retrovirus, its genomic RNA is incorporated into target cells, and DNA is incorporated into the host genome as a provirus via reverse transcriptase.

High Prevalence of HTLV-1 Infection among Japanese Immigrants in Non-endemic Area of Brazil

“…A high prevalence of HTLV-1 infection can be found in the endemic regions of equatorial Africa, the Caribbean islands, Japan, Colombia, northeast Australia, Papua New Guinea and Brazil, that has heterogeneous geographic distribution. However, the highest infection rate has been observed to occur in the islands of Kyushu and Okinawa, in southwestern Japan, and Hokkaido, in north of Japan, with approximately 1.1 million of infected individuals [ 3 , 4 ]. In Brazil, HTLV-1 was first described in 1986 among Japanese immigrants from Okinawa, Southern Japan, residing in the city of Campo Grande, state of Mato Grosso do Sul.…”

Human T-cell lymphotropic virus type I and II seroprevalence among volunteer blood donors in Thailand

“…Almost 10-20 million people in the world are thought to be infected by HTLV-I/II. In Asia to date, incidence of some cases of HTLV-I/II have been reported across many countries including China, Malaysia, Philippines, Indonesia and Vietnam, yet only two Asian countries, Japan and South Korea have implemented mandatory screening of blood donors for HTLV-I/II antibodies [6][7][8][9][10][11]. In many endemic regions, HTLV-I co-infections with other TTI pathogens have also been reported among the high-risk populations [10,12].…”