Coinfection with human T-cell lymphotropic virus type I and HIV in Brazil: impact on markers of HIV disease progression

People infected with both human T-cell lymphotropic virus type I (HTLV-I) and HIV appear to have more advanced disease than people infected with HIV only, despite higher CD4 cell counts. HTLV-I is a virus that destroys immune cells of the lymph system. CD4 cells are immune system cells that are depleted during HIV infection. Researchers evaluated the disease stage, CD4 cell counts and other laboratory measures of 27 HIV-positive, HTLV-I-positive patients (coinfection) and 99 HIV-positive, HTLV-I-negative (single infection) comparison subjects. Twenty-three percent of coinfected patients and 5% of singly infected patients acquired their infections by injection drug use or blood transfusion. Of coinfected patients, 44% were in the late stages of HIV infection, compared to only 21% of singly infected individuals. Coinfected individuals had higher average total lymph cell, white blood cell and CD4 cell counts than HIV-infected counterparts.
Objectives.--To study the effect of human T-cell lymphtropic virus type I (HTLV-I) on markers of human immunodeficiency virus (HIV) disease progression. Design.--A retrospective, nested case-control study. Setting.--A university hospital outpatient HIV clinic in Rio de Janeiro, Brazil. Participants.--Human immunodeficiency virus--seropositive adults participating in a prospective HIV cohort study. Main Outcome Measures.--The HIV clinical stage, [CD4.sup.+] lymphocyte counts, and other laboratory parameters in 27 individuals infected with HIV and HTLV-I (coinfection) and 99 age-matched, HIV-seropositive, HTLV-seronegative controls (single infection). Results.--Variables independently associated with coinfection included higher [CD4.sup.+] lymphocyte count (odds ratio [OR], 2.3; 95% confidence limits [CL], 1.3,4.1), higher [CD4.sup.+] percentage (OR, 2.0; 95% CL, 1.3, 3.2), [[beta].sub.2]-microglobulin level of 254 nmol/L or more (OR, 6.8; 95% CL, 1.3, 35.4), World Health Organization stages 3 and 4 (OR, 4.4; 95% CL, 1.1, 18.0), and reporting a parenteral risk factor (OR, 7.4; 95% CL, 1.4, 38.9). When stratified by p24 antigenemia, coinfection was associated with an estimated 82% higher [CD4.sup.+] lymphocyte count (P