Abstract Background: Tuberculosis (TB) remains a global health challenge, with pulmonary (PTB) and extrapulmonary (EPTB) forms requiring different diagnostic approaches. Cytokine profiles, particularly tumor necrosis factor-alpha (TNF-α) and interferon-gamma (IFN-γ), may serve as potential biomarkers for distinguishing between TB manifestations. Objectives: To determine whether TNF-α and IFN-γ cytokine levels and their ratio can distinguish between PTB and EPTB patients compared to healthy controls, and to evaluate their diagnostic performance as biomarkers. Materials and Methods: This cross-sectional study enrolled 200 participants from Baghdad, Iraq, including 80 PTB patients, 60 EPTB patients, and 60 healthy controls. Serum TNF-α and IFN-γ levels were measured using enzyme-linked immunosorbent assay (ELISA). The TNF-α/IFN-γ ratio was calculated, and diagnostic performance was assessed using receiver operating characteristic (ROC) curve analysis. Results: PTB patients demonstrated significantly higher IFN-γ levels (229.07 ± 45.3 pg/mL) compared to EPTB patients (90.14 ± 21.8 pg/mL) (pConclusion: Cytokine profiling, particularly IFN-γ levels and the TNF-α/IFN-γ ratio, demonstrates promising diagnostic potential for distinguishing PTB from EPTB. These biomarkers could complement existing diagnostic tools, potentially improving TB diagnosis and management strategies.
Ahmed et al. (Tue,) studied this question.