Laboratory study of HIV-1 and HTLV-I/II coinfection.

A Retroviral Coinfection Clinic was established in 1991 at Charity Hospital Medical Center of Louisiana to study patients dually infected with human immunodeficiency virus (HIV) and human T lymphotropic virus (HTLV-I, HTLV-II). Eight patients were evaluated clinically, and by immunological and virological studies. Multiple neuromuscular diseases were observed, including tropical spastic paraparesis, polymyositis, and polyneuropathies. Only one patient developed AIDS. HIV-1 infected patients with HTLV-I, but not HTLV-II, coinfection have maintained stable CD4 counts, despite the fact that quantitative HIV DNA PCR suggests a relatively high copy number. HTLV-I/II antigens were detected in lymphocyte cultures from four patients, and lymphoblastoid cell lines have been established from two. These results support the contention that upregulated HTLV-I/II virus expression and disease manifestations occur during coinfection with HIV, sometimes in association with normal CD4 counts.