Tuberculin responsiveness as a surrogate prognostic marker in hospitalized HIV-infected patients with tuberculosis in...

In resource-limited settings, access to CD4 lymphocyte counts for prognostication in HIV-associated tuberculosis (HIV-TB) remains limited. Tuberculin skin test (TST) reactivity reflects cell-mediated immunity and may serve as a simple surrogate prognostic marker. This study evaluated the association between tuberculin responsiveness and clinical outcomes in hospitalized HIV-infected patients with pulmonary tuberculosis.

A hospital-based observational cohort study was conducted among 107 HIV-positive adults admitted with pulmonary tuberculosis. Tuberculin reactivity was assessed using the Mantoux method with 10 TU purified protein derivative. Nutritional status was assessed using body mass index (BMI). The primary outcome was clinical status at hospital discharge. A parallel cohort of 100 HIV-negative pulmonary tuberculosis patients was evaluated using identical methods.

Among HIV-positive patients, 33 (30.8%) demonstrated TST induration >10 mm; all had mild-moderate undernutrition and were discharged alive within six weeks. Twenty-six patients (24.3%) had induration 5-10 mm; all were severely undernourished, with 23.1% mortality. Forty-eight patients (44.9%) were anergic or had induration <5 mm; 62.5% died and 25.0% left moribund. Increasing induration showed a graded inverse association with mortality (p < 0.001). HIV-negative patients demonstrated substantially lower overall mortality (3% vs 33.6%). While preserved TST reactivity (>10 mm) predicted 100% survival in both groups, anergy carried dramatically different implications: 5.7% mortality in HIV-negative versus 62.5% in HIV-positive patients.

Tuberculin reactivity demonstrated a strong, HIV-specific graded association with outcomes. TST may retain adjunctive prognostic value in resource-limited settings where advanced immunological testing is unavailable.