Decreased Osteopontin Expression as a Reliable Prognostic Indicator of Improvement in Pulmonary Tuberculosis: Impact of the Level of Interferon-γ-Inducible Protein 10

Abstract

Background/Aims: Osteopontin (OPN) expression is increased during the course of various chronic inflammatory diseases, including tuberculosis (TB). However, its prognostic value in TB management remains unclear. This study aimed to determine whether OPN could associate with other cytokines serving as a reliable biomarker for evaluating the effectiveness of early anti-TB treatments. Methods: Smear-positive pulmonary TB patients (n = 20) were recruited, and the plasma levels of OPN, IP-10, TNF-α, and IL-12 were measured by ELISA before initiation of anti-TB therapy and after sputum smear conversion. The C-reactive protein (CRP) levels and erythrocyte sedimentation rate (ESR) were also tracked during anti-TB treatment. Results: OPN expression was significantly elevated in patients with smear-positive pulmonary TB, and was closely related with disease severity. Monitoring during the treatment course revealed that its expression, along with that of IFN-γ-induced protein 10 (IP-10), decreased significantly only after sputum smear conversion. Moreover, OPN levels positively correlated with CRP levels before and after anti-TB treatment. Furthermore, OPN markedly promoted IP-10 expression in peripheral blood mononuclear cells. Conclusion: Association between OPN and IP-10 may serve as a reliable prognostic indicator for improvement during the early treatment of pulmonary TB, and may help clinicians in tailoring an effective TB treatment regimen.