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.
Norrgren
Hans R
HR
Division of Infection Medicine, Department of Clinical Sciences, Lund University, Lund, Sweden. hans.norrgren@med.lu.se
Bamba
Sana
S
Larsen
Olav
O
Da Silva
Zacarias
Z
Aaby
Peter
P
Koivula
Tuija
T
Andersson
Sören
S
D000328:Adult; D005260:Female; D015658:HIV Infections / Q000150:complications* / Q000453:epidemiology / Q000821:virology; D015497:HIV-1 / Q000302:isolation & purification; D015498:HIV-2 / Q000302:isolation & purification; D015481:HTLV-I Antibodies / Q000097:blood*; D015490:HTLV-I Infections / Q000150:complications / Q000453:epidemiology* / Q000821:virology; D015368:Human T-lymphotropic virus 1 / Q000302:isolation & purification; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D011446:Prospective Studies; D014397:Tuberculosis, Pulmonary / Q000150:complications* / Q000453:epidemiology
D015481:HTLV-I Antibodies