Tuberculosis (TB) is the most common opportunistic infection in African patients who die from AIDS, yet the stage of immunodeficiency at which TB develops is uncertain. We studied the immune status of HIV-infected outpatients with pulmonary TB in relation to their clinical presentation in a cross-sectional study of 216 HIV-seropositive and 146 HIV-seronegative ambulatory incident cases of smear-positive and culture-positive pulmonary TB in Kinshasa, Zaire. HIV-seropositive and seronegative patients had median CD4 lymphocyte counts of 316.5/microL and 830.5/microL, respectively. Of the HIV-seropositive patients, 32.9% had less than 200 CD4 lymphocytes/microL, 37% between 200 and 499, and 30.1% 500 or more. Clinical AIDS, as defined by the WHO clinical case-definition or a modified version, was of similar limited use as a predictor of immunodeficiency. Among HIV-seropositive patients, oral candidosis, lymphopenia, a negative tuberculin purified protein derivative test, and cutaneous anergy were strongly associated with CD4 counts of less than 200/microL, and seemed to be better markers of immune dysfunction. We conclude that pulmonary TB develops across a broad spectrum of HIV-induced immunodeficiency and that a diagnosis of pulmonary TB is of limited use as a marker of stage of HIV disease in African HIV-infected outpatients.
PIP: Between March 1989 and September 1991, physicians compared CD4 lymphocyte counts of 216 HIV-seropositive patients whose sputum smears tested positive for pulmonary tuberculosis (TB) with those of 146 HIV- negative patients who also tested positive for TB at a TB screening center in Kinshasa, Zaire. The researchers wanted to investigate the immune status of HIV-infected outpatients with pulmonary TB in relation to clinical criteria. HIV seropositive patients had much lower CD4 lymphocyte counts than did HIV seronegative patients (total CD4 count, 316.5/mcl vs. 830.5/mcl; CD4 count, 13% vs. 36%; p .001). 90.4% of HIV-positive patients had CD4 counts 800 compared with 48% of HIV- negative patients. 32.9% of HIV-positive patients had CD4 counts 200 while just 1.4% of HIV-negative patients did. As CD4 counts fell, weight loss, diarrhea during the previous month, past or present herpes zoster, and oral candidosis occurred more frequently (p = .004 for oral candidosis and p = .02 for the rest). Negative purified protein derivative RT23 (PPD) tests and cutaneous anergy occurred more often as immunodeficiency rose (p .001). Increased immunosuppression was also characterized by no detectable cavitation on chest radiography, anemia, and low total lymphocyte counts (p = .02 for absence of cavitation and p .001 for the others). These results suggested that pulmonary TB occurred along the continuum of immunodeficiency as defined by CD4 counts. Thus, it is not likely to be a marker of the severity of HIV infection. Instead weight loss, diarrhea during the previous month, past or present herpes zoster, oral candidosis, negative PPD test and cutaneous anergy, absence of detectable cavitation on chest radiography, anemia, and low total lymphocyte appeared to be better markers of the severity of HIV-related immunodeficiency.