Response to empirical anti-tuberculosis treatment in patients with sputum smear-negative presumptive pulmonary tuberculosis

BACKGROUND: In many cases, physicians initiate anti-tuberculosis (TB) treatment based only on symptoms or radiographic findings without confirmation of pulmonary TB by acid-fast bacilli (AFB) smear. It has not been well known which clinical characteristics could be used as predictors for positive culture or real TB in patients with sputum smear-negative presumptive pulmonary TB. OBJECTIVE: We tried to elucidate treatment outcomes in patients with sputum smear-negative presumptive pulmonary TB and to find predictors of positive culture results. METHODS: We reviewed data of the patients who had been treated as presumptive TB with negative AFB smear on the basis of clinical and radiographic features from December 1998 to December 2000 at a university hospital in Korea. We reviewed medical records and radiographs of patients and analyzed possible predictors for positive culture. RESULTS: One hundred and one patients were enrolled. Among them, pulmonary TB was confirmed by culture in 32 patients (31%). Thirty-one (96.9%) out of 32 culture-positive patients showed clinical or radiographic improvement as did 50 (72.5%) out of 69 culture-negative patients. The predictor for a positive culture result is the presence of patchy consolidation in an initial radiograph (p = 0.025; OR 2.89; 95% CI 1.14-7.28). CONCLUSIONS: The empirical anti-TB treatment in patients with sputum smear-negative presumptive pulmonary TB was effective and adequate, especially presented with patchy consolidation in initial chest radiographs in Korea.