Tuberculosis in African Americans: clinical characteristics and outcome.

This study examined the clinical characteristics and outcome of pulmonary tuberculosis in African Americans hospitalized in a teaching hospital in south-central Los Angeles from May 1992 through April 1994. The charts of 41 African Americans with culture-positive Mycobacterium tuberculosis were reviewed. Predisposing factors for pulmonary tuberculosis were identified in nearly half of cases. Cough and fever were the most common symptoms. Seventy-six percent had positive acid-fast bacilli (AFB) smears. Nine patients were human immunodeficiency virus (HIV)-positive, and 6 of 9 HIV-positive patients had positive AFB smears whereas 17 of 19 HIV-negative patients had positive AFB smears. Radiographic changes were not significantly different between HIV-positive and HIV-negative patients. Drug resistance was identified in nine of 31 patients (29%). Eight of 41 patients (19.5%) died, with 2 being drug resistant. Human immunodeficiency virus infection was a major predisposing factor for tuberculosis, and no statistical differences were found in radiographic features or AFB smear positivity between HIV-positive and HIV-negative patients. Drug resistance and mortality were disproportionately high. These results indicate that HIV infection and drug resistance are major problems that predispose for tuberculosis infection and make its treatment difficult.

Zidovudine therapy, CD4+ and CD8+ counts are associated with a longer survival following AIDS onset.

In 60 patients followed from the onset of acquired immunodeficiency syndrome (AIDS) to death, survival was determined by Cox Proportional Hazards Analysis in relationship to seven variables: time-dependent CD4+ and CD8+ peripheral lymphocyte counts, zidovudine treatment, cytomegalovirus (CMV) retinitis, time from AIDS onset, calendar year of AIDS onset (cohort effect), and age. Two significant prognostic variables were identified: zidovudine therapy and either CD4+ or CD8+ counts (the latter could not be distinguished due to concomitant high correlation). Treatment with zidovudine reduced the death rate by 75% compared to no treatment. When included in a proportional hazards regression with all covariates except for the other T lymphocyte count, every increase in CD4+ count of 10 cells was equivalent to a decline in the mortality rate by 13% (p = 0.046), and every increase in CD8+ count of 10 cells lowered the mortality by 1.4% (p = 0.0031). Patients treated with zidovudine and without CMV retinitis showed the slowest decline of both CD4+ and CD8+ counts. Both CD4+ and CD8+ levels are useful predictors of survival in patients with AIDS.