Concurrent infections with Strongyloides and T-cell leukemia virus and their possible effect on immune responses of host.

Sera from 91 patients with strongyloidiasis in Okinawa prefecture, Japan, were examined for the presence of the concurrent infection with adult T-cell leukemia (ATL) virus by detecting the antibody to ATL-associated virus antigen (anti-ATLA). As high as 73.6% of the patients were found to be positive for the anti-ATLA antibody, whereas in 38 Strongyloides-negative controls, the positive rate was only 18.4% A significant increase of OKT 4+ cells and a decrease of OKT 8+ cells were noted among the patients positive for anti-ATLA antibody. A considerable rise of spontaneous proliferation of peripheral lymphocytes and a depression of mitogen-induced proliferative responses were also found in the patients. The increase of background mitogenesis was considered to be due to the concurrent infection with the ATL virus, but the depressed responses to mitogenic stimuli seemed to have no relation with the presence of the viral infection. The possible contribution of strongyloidiasis as a cofactor predisposing to ATL viral infection or leading the virus carriers to ATL patients was discussed.