Interferon-γ release assay in the diagnosis of laryngeal tuberculosis

Abstract

Conclusion: The T-SPOT test for Mycobacterium tuberculosis infection (T-SPOT.TB) can be used for early diagnosis of laryngeal tuberculosis (TB). Objective: The incidence of TB is increasing on a global scale. Laryngeal TB is the most common extrapulmonary form of TB and its early diagnosis is still difficult. This study investigated the performance of the interferon-γ release assay in the diagnosis of laryngeal TB. Methods: A total of 83 patients with laryngeal neoplasms were confirmed to have laryngeal TB by pathology, acid-fast staining, and/or fluorescence quantitative PCR. In addition, 52 patients with vocal cord polyps were enrolled as the control group. Two groups underwent both T-SPOT.TB and tuberculin skin test (TST). Results: T-SPOT.TB was positive in 75 cases in the laryngeal TB group and 4 cases in the control group, showing a sensitivity of 90.3% (75/83) and a specificity of 92.3% (48/52). The TST was positive in 42 cases and 20 cases, respectively, in these two groups. Obviously, TST and T-SPOT.TB were significantly different in terms of sensitivity when applied for detection of laryngeal TB (p < 0.05).