Spontaneously healed asymptomatic pulmonary tuberculosis: Prevalence of airflow obstruction, and correlation between high-resolution CT findings and pulmonary function tests

RATIONALE AND OBJECTIVES: We investigated the relationships between spontaneously healed asymptomatic pulmonary tuberculosis (SHAPTB), airflow obstruction (AFO), and high-resolution computed tomography (HRCT) findings. MATERIALS AND METHODS: We selected 82 participants with SHAPTB diagnosed by interferon-γ release assay and 8044 with normal chest radiographs (CXR). We applied a CT scoring system for the extent of tuberculous sequelae to correlate the HRCT findings with pulmonary function test. We compared the AFO prevalence between subjects with and without SHAPTB. RESULTS: The subjects with SHAPTB diagnosed by interferon-γ release assay had a significantly higher prevalence of AFO (13.4% [11/82]) than those with normal CXR (7.4% [595/8044]). The important HRCT findings that correlated with AFO were the number of lung segments with TB sequelae and the CT score for emphysema. CONCLUSION: The subjects with SHAPTB had a higher AFO prevalence than those with normal CXR, and the important HRCT findings correlated with AFO were the extent of tuberculous sequelae and emphysema.