PREDICTIVE MARKERS OF SURVIVAL IN HIV-SEROPOSITIVE AND HIV-SERONEGATIVE TANZANIAN PATIENTS WITH EXTRAPULMONARY TUBERCULOSIS

Setting: Prediction of survival in Tanzanian patients with extrapulmon ary tuberculosis (TB). Objective: To evaluate the prognostic value of clinical and laboratory parameters on survival in human immunodeficien cy virus (HIV) seropositive and HIV seronegative patients with extrapu lmonary TB. Design: Over an 8-month period 192 consecutive patients wi th extrapulmonary TB, admitted to a major referral centre in Tanzania, were enrolled in the study. Their symptoms, signs and PPD skin test r esults were noted. Their sera were tested for HIV and analyzed for bet a-2-microglobulin content. Univariate risk factors for 12 months' surv ival after the start of anti-TB chemotherapy were entered into a stepw ise Cox regression model. Survival probabilities were estimated accord ing to the number of risk factors. Result: Of the 192 patients 126 (65 .6%) were HIV-infected, and 29.7% had disseminated TB. Thirty-five pat ients, of whom 24 (68.6%) were HIV-positive, withdrew from the study i mmediately after hospital discharge. For survival analysis 157 patient s remained. Within 12 months' follow-up after initiation of anti-TB th erapy, the case fatality rate of the 102 HIV-infected patients was 22% and of the 55 HIV seronegative patients 2% (P < 0.001). In the HIV se ropositive patients the following independent risk factors were signif icantly associated with a decreased probability of survival: periphera l lymphadenopathy (Hazard Rate Ratio (HRR) 5.2, 95% Confidence Interva l [CI] 1.7-16.2), a decreased activity score (bedridden > 50%/day) (HR R 4.5, 95% CI 1.7-11.7), lymphopenia of < 1000/mu L (HRR 4,4, 95% CI 1 .7-11.8), and mycobacteraemia (HRR 4.0, 95% CI 1.2-13.1). An anergic P PD skin test reaction proved to be another independent risk factor whe n the analysis was performed on 89 patients with available Mantoux tes t results. In the HIV seropositive patients, the 12 months' survival p robabilities were 93%, 86%, 54% and 0% for presence of 0, 1, 2 and > 2 risk factors respectively. Conclusion: Estimation of survival probali lities in patients,vith extrapulmonary TB may be possible without perf orming CD4 cell counts.