Evaluation of the effectiveness of IgM and IgG anti-tuberculosis antibodies in the primary diagnosis of patients with suspect

Abstract

This study assessed the diagnostic value of serological assays for IgM and IgG antibodies in the initial work-up of tuberculosis, including extrapulmonary disease. In a single-center observational cohort (n=200; 64 – active TB, 136

– controls), ELISA IgM/IgG testing was performed at baseline as part of a comprehensive diagnostic algorithm. IgM demonstrated very low sensitivity (4.7%) with high specificity (99.3%); PPV 75.0%, NPV 68.9% (LR+≈6.38; LR−≈0.96). IgG showed sensitivity 20.3% and specificity 86.8%; PPV 41.9%, NPV 69.8% (LR+≈1.53; LR−≈0.92). Serology is unsuitable for screening or ruling out active TB and should be considered only as an adjunct in patients with moderate/ high pre-test probability; definitive diagnosis still relies on microbiological and molecular confirmation.