Macrophage-activating cytokines in human immununodeficiency virus type 1-infected and -uninfected patients with pulmonary tuberculosis

Tuberculosis (TB) is the most common opportunistic infection in human immun odeficiency virus type 1 (HIV-1)-infected patients globally and occurs thro ughout the course of HIV-1 disease. Here the production of interferon (IFN) -gamma and tumor necrosis factor (TNF)-alpha by peripheral blood mononuclea r cells (PBMC) of HIV-1-infected versus -uninfected patients with newly dia gnosed pulmonary TB (PTB) was compared. Findings were correlated with cytok ine profiles, clinical presentation, and expression of inducible nitric oxi de (iNOS). Most HIV-1/PTB patients with a CD4 cell count of 200-500 cells/m uL had high IFN-gamma production and radiographic evidence of atypical PTB. Low IFN-gamma production and radiographic evidence of reactivated PTB char acterized both HIV-1/PTB patients with a CD4 cell count greater than or equ al to 500 cells/mL and HIV-1-uninfected patients. TNF-alpha levels were sim ilar in all HIV-1/PTB patients, regardless of CD4 cell count. Induction of iNOS in PBMC was low and was associated with low IFN-gamma production. Thes e data underscore the potential pathogenic role of macrophage-activating cy tokines in TB in HIV-1-infected patients.