Serum levels of soluble urokinase plasminogen activator receptor (suPAR) as a marker of tuberculosis treatment efficacy

Abstract

BackgroundUpon diagnosis, Pulmonary Tuberculosis patients are treated for TB for a period of 6–9 months. At present, there exists very little indication of the efficacy of the particular treatment. A few previous studies have shown that soluble urokinase plasminogen activator receptor (SuPAR) may be used as treatment efficacy marker. SuPAR is a cellular receptor for serine protease urokinase plasminogen activator (uPA). Bacterial endotoxins and cytokines of the innate immune system stimulate the secretion of uPA in monocytes & neutrophils. Serum SuPAR levels are elevated when TB is active and decrease when the patient responds positively to therapy. ObjectiveTo investigate if SuPAR levels decline upon treatment and whether serum SuPAR levels may be used as a biomarker to monitor Tuberculosis treatment efficacy. DesignThe study was conducted in the department of Biochemistry at VIMS, Ballari, Karnataka. The study subjects were randomly selected from RNTCP centre of VIMS. ControlsTwelve tuberculin skin test positive healthy controls from the community. CasesA total of 60 cases were enrolled for the study and were divided into 3 groups with 20 in each, based on the duration of TB treatment. Group I (n=20): Newly diagnosed pulmonary TB patients before initiation of DOTS. Group II (n=20): TB patients, 2–3 months after initiation of DOTS. Group III (n=20): TB patients who had completed 6 months of DOTS. MethodologyHb%, TC, DC(P)%, DC(L)% & ESR were measured by standard procedures. Serum suPAR was measured by the quantitative sandwich enzyme immunoassay technique using the R & D systems Human uPAR Quantikine ELISA Kit. ResultsThe suPAR levels were elevated before treatment (3.27+2.08ng/ml) and dropped significantly in groups after 2 months of initiation of therapy (2.18+1.17ng/ml) and after completion of 6 months of treatment (1.50+0.93ng/ml). ConclusionThe decrease in suPAR levels in PTB patients with treatment is a manifestation of treatment efficacy. Hence suPAR levels can be used to guide clinical decisions in TB management.