Evaluation of the Feasibility of using Urine IP-10 as a Biomarker to Assess the Treatment Response to the Pharmacotherapy of Active Pulmonary Tuberculosis in the Intensive and Continuation Phase

Abstract

Introduction: Tuberculosis is well known for its chronicity, treatment failures, and drug resistance. Interferon-gamma Inducible Protein 10 (INF IP-10) has been reported to be relatively specific for assessing the severity of tuberculosis, and it can be easily estimated in both urine and blood. Objective: To determine whether urinary IP-10 levels can be used as a biomarker for monitoring treatment response in patients with active Pulmonary Tuberculosis (PTb). Materials and Method: 40 participants were enrolled. Urine samples were collected at diagnosis, at the end of 1st, 2nd & 6 months. Sputum smear and culture were done at diagnosis, end of 2nd and 6th month. IP-10 levels were estimated and correlated with treatment response. Results: All the patients were positive for Mycobacterium Tuberculosis (Mtb) at baseline. At the end of 2nd and 6 months, all of them became smear and culture-negative. The mean urine IP-10 values at diagnosis, end of 1st, 2nd and 6th month were 10.76 ± 2.76, 15.37 ± 3.09, 21.83 ± 4.10 and 8.38 ± 2.46 pg/dl. IP-10 levels increased following intensive therapy and decreased significantly towards the end of treatment. The mean values of IP-10 at baseline, at the end of 2nd and 6th month were correlated with mean scores of clinical symptoms at respective time points. Pearson’s linear correlation was done which showed that IP-10 values and clinical symptoms did not correlate with each other with p=0.836. Conclusion: Increase in IP-10 level during the intensive therapy indicates the response to treatment and bacterial clearance. Hence urinary IP-10 can be considered as biomarker for monitoring treatment response in PTb patients.