Higher mortality in HIV-2/HTLV-1 co-infected patients with pulmonary tuberculosis in Guinea-Bissau, West Africa, compared to HIV-2-positive HTLV-1-negative patients.

OBJECTIVES: To investigate the effect of human T-lymphotropic virus type 1 (HTLV-1) on CD4 counts and mortality in tuberculosis (TB) patients with or without human immunodeficiency virus (HIV). METHODS: A prospective study on 280 hospitalized patients with pulmonary TB was performed in Guinea-Bissau, 1994-1997, including HIV, CD4 counts and clinical outcome. We compared the CD4 count levels at the time of inclusion between HIV-negative and HIV-positive patients, with or without HTLV-1. Mortality was determined while patients were on treatment for TB. RESULTS: Median CD4% was significantly higher in HIV-positive subjects co-infected with HTLV-1 compared to HTLV-1-negative patients. Two hundred thirty-three individuals were included in the analysis of mortality, and among HIV-negative subjects the mortality was 18.6/100 person-years . In HIV-2-positive HTLV-1-negative subjects the mortality was 39.5/100 person-years and in HIV-2/HTLV-1 co-infected patients it was 113.6/100 person-years (adjusted mortality rate ratio 4.7, 95% CI 1.5-14.4; p < 0.01). When all HIV-positive patients were analyzed together, corresponding mortality rates were 53.5/100 person-years and 104.8/100 person-years , respectively (not significant). CONCLUSIONS: HIV/HTLV-1 co-infected patients hospitalized for pulmonary TB had a high mortality and had significantly higher CD4% compared to only HIV-positive subjects. This may imply that HTLV-1 has an adverse effect on the immune system in HIV-infected subjects, independently of the CD4 count, that makes co-infected subjects more vulnerable to TB.

Increased prevalence of HTLV-1 in patients with pulmonary tuberculosis coinfected with HIV, but not in HIV-negative patients with tuberculosis.

BACKGROUND: Few and inconclusive results have been presented regarding the influence of human T-lymphotropic virus 1 (HTLV-1) infection on the risk of acquiring tuberculosis (TB). METHODS: In 1994-1997, we performed a prospective study on hospitalized adult patients with pulmonary TB in Guinea-Bissau and compared the clinical outcome in HIV-2 and HIV-negative patients. We determined the prevalence of HTLV-1 in all patients screened and diagnosed with TB in that study and compared the infection rate with a serosurvey of HTLV-1 in a population sample from a community-based study conducted at the same time and in the same city. RESULTS: In the TB group, a total of 32 (11.4%) of 280 patients were positive for HTLV-1. This was significantly higher compared with the population-based group in which 74 (3.5%) of 2117 were HTLV-1 positive [crude odds ratio (OR) = 3.6; 95% confidence interval (CI) 2.2 to 5.6, P < 0.001]. However, in a logistic regression analysis controlling for age, gender, and HIV result, the difference was no longer significant (OR = 1.61; 95% CI 0.95 to 2.70, P = 0.074). In HIV-negative patients, no association was found between HTLV-1 and TB (OR = 1.18; 95% CI 0.48 to 2.89, P = 0.71), whereas a significant association was found in HIV-positive patients (OR = 2.41; 95% CI 1.26 to 4.61, P = 0.008). CONCLUSIONS: The immunosuppressive effect of HTLV-1 alone was not enough to increase the risk of TB in a highly endemic country, but HTLV-1 increased the risk of TB among HIV-infected individuals.