T-SPOT.TB Negative and Diagnosed as Interstitial Pulmonary Tuberculosis by NGS: a Case Report and Literature Review.

Background: Tuberculosis is an airborne infectious disease with multiple morphologic changes on chest imaging. Tuberculosis-specific enzyme-linked immunospot assay (T-SPOT.TB) is widely used in the diagnosis of tuberculosis. Clinically, pulmonary tuberculosis with T-SPOT.TB negative and interstitial changes is very rare.

Methods: T-SPOT.TB, pathogenetic testing, chest CT scan, next-generation sequencing (NGS).

Results: Laboratory tests showed negative T-SPOT.TB and sputum antacid staining, chest CT showed interstitial fibrosis and multiple high-density shadows in both lungs, and sputum NGS showed Mycobacterium tuberculosis infection.

Conclusions: Negative T-SPOT.TB and interstitial lung changes do not exclude Mycobacterium tuberculosis infection. NGS has a high specificity in the detection of pathogens in infectious diseases, especially in complex, mixed infectious diseases.