Alcohol consumption, high viral load and low CD4 cell count appeared to be independent risk factors for developing active tuberculosis in patients with HIV, according to research. "We have identified several characteristics associated with progression from latent tuberculosis infection to active tuberculosis disease in HIV-infected adults treated with preventive therapy," the researchers are quoted in a Healio report as saying.
Richard E Chaisson, director of the Centre for Tuberculosis Research at Johns Hopkins University, and colleagues evaluated 908 participants in the Soweto/Johns Hopkins Novel Tuberculosis Prevention Regimens Trial – a open-label, randomised, controlled trial comparing novel combination TB preventive regimens to daily isoniazid for a 6-month period. The investigators wrote that 12-week therapy with the combination regimens – including rifapentine (Priftin, Sanofi-Aventis) or rifampin with isoniazid – had a similar efficacy as isoniazid taken daily for 6 months in preventing active TB or death in HIV-infected adults with latent TB infection.
In a more recent multivariate analysis, Chaisson and colleagues examined risk factors for incident TB infection in adults assigned the shorter, 12-week regimens. These included tuberculin skin test (TST) induration size of more than 15 mm vs. 5 mm to 9 mm (HR=2.74; 95% CI, 1.06–7.06); self-reported alcohol consumption (HR=2.08; 95% CI, 1.21–3.5); alcohol consumption of more than 10 units weekly (HR=2.87; 95% CI, 1.14–7.23); baseline viral load greater than the median (HR=3.13; 95% CI, 1.64–5.97); and a baseline CD4 cell count less than 500 cells/mm3 (HR=1.94; 95% CI, 1.07–3.49). While past or present smoking was linked with an elevated risk for incident TB, this relationship was attenuated in the multivariate analysis (HR=0.98; 95% CI, 0.49–1.98).
"Our results may be generalisable to HIV-infected adults in other high-burden settings with CD4 cell counts above 200 cells/mm3," the researchers wrote. "Modifying the baseline independent risk factors of alcohol consumption, high viral load, and low CD4 cell count could reduce the tuberculosis risk profile in HIV-infected adults. Performing a TST before tuberculosis preventive therapy may also be useful for risk stratification in adults infected with HIV."
[link url="http://www.healio.com/infectious-disease/respiratory-infections/news/online/%7b1c459d6c-176e-49f2-971a-cd5751d69b3f%7d/alcohol-intake-viral-load-cd4-count-linked-to-active-tb-in-hiv-patients"]Full Healio report[/link]
[link url="http://ofid.oxfordjournals.org/content/2/1/ofu120.full"]Open Forum Infectious Diseases abstract[/link]