Coinfection With HIV-1 and Human T-Cell Lymphotropic Virus Type II in Intravenous Drug Users Is Associated With Delayed Progression to AIDS

• DOI: 10.1097/01.qai.0000179426.04166.12
• Publication Date: 2005-12-07T09:02:42Z
• Authors: Marco Turci; Elisabetta Pilotti; Paola Ronzi; Giacomo Magnani; Antonio Boschini; Saverio G Parisi; Donato Zipeto; Antonella Lisa; Claudio Casoli; Umberto Bertazzoni
• Keywords: Adult; Male; antiretroviral therapy; 610; HIV Infections; CD8-Positive T-Lymphocytes; Polymerase Chain Reaction; White People; human T-cell lymphotropic virus infection; 03 medical and health sciences; T-Lymphocyte Subsets; Humans; Viremia; Substance Abuse, Intravenous; HTLV infection; HIV infection; antiretroviral therapy; long term nonprogressor; Retrospective Studies; human T-cell lymphotropic virus type II proviral load; Acquired Immunodeficiency Syndrome; 0303 health sciences; Human T-lymphotropic virus 2; long-term nonprogressor; 3. Good health; Italy; HIV infection; intravenous drug user; HTLV-II Infections; Disease Progression; HIV-1; Female

Human T-cell lymphotropic virus (HTLV) type II has spread among intravenous drug users (IDUs), many of whom are coinfected with HIV-1. We have investigated the rate of HTLV-II infection in 3574 Italian IDUs screened for HIV-1, HTLV-I, and HTLV-II from 1986 to the present. HTLV-II proviral load was determined by a real-time polymerase chain reaction specifically designed for tax amplification. The frequency of HTLV-II infection was 6.7% among HIV-1-positive subjects and 1.1% among HIV-1-negative subjects (P < 0.0001). For examination of AIDS progression, a group of 437 HIV-1-monoinfected subjects and another group of 96 HIV-1/HTLV-II-coinfected subjects were monitored. Enrollees were matched at entry by CD4 cell counts and followed for an average of 13 years. HIV-1/HTLV-II coinfection was associated with older age (P < 0.0001) and higher CD4 (P < 0.0001) and CD8 (P < 0.001) cell counts compared with monoinfected IDUs. The number of long-term nonprogressors for AIDS was significantly higher (P < 0.0001) among coinfected patients (13 [13.5%] of 96 patients) than HIV monoinfected patients (5 [1.1%] of 437 patients), showing that HTLV-II exerts a protective role. An increased incidence of liver disease and hepatitis C virus positivity among coinfected IDUs was observed. Five coinfected subjects undergoing antiretroviral therapy showed a significant (P < 0.05) increase in HTLV-II proviral load concomitant to a decrease in HIV-1 viremia, suggesting that the treatment is ineffective against HTLV-II infection.