Evaluation of Serum Complement Component 1Q Subcomponent C (C1qC) as a Marker for Tuberculosis

Abstract

A B S T R A C T BACKGROUNDDespite several efforts, tuberculosis (TB) continues to be a global concern. For proper management of TB, more sensitive and specific biomarkers for early and accurate diagnosis of TB are still required. Blood based host markers are more appealing as an alternate to sputum-based diagnostics. Thus, in the present study, we evaluated the potential of Serum Complement Component 1 Q Subcomponent C (C1qC) as a marker for tuberculosis. METHODSSerum samples from 84 subjects which included 39 smear positive pulmonary TB patients and 45 controls (Latent TB n=15, Healthy n= 15 and patients with respiratory diseases other than TB n= 15) were collected and Enzyme Linked Immunosorbent Assay was performed to estimate the serum C1qC levels. RESULTSThe mean (±SD) serum C1qC levels in TB, Healthy, Latent TB and patients with respiratory diseases other than TB was found to be 21.80 (±4.39), 13.64 (±1.32), 15.18(±1.29) and 17.31(±1.87) pg/ml respectively. The AUC of serum C1qC to discriminate TB patients from controls was found to be 0.924 (95% CI, 0.869-0.978). At an optimal cut-off value of 16.99 pg/ml, the sensitivity and specificity of serum C1qC to discriminate TB from controls was found to be 84.62% (95% CI, 69.47%-94.14%) and 84.44% (95% CI, 70.54%-93.51%) respectively with a likelihood ratio of 5.44. CONCLUSIONSThe levels of serum C1qC in TB patients was found to be significantly higher than controls. C1qC seems to be a promising marker for the diagnosis and therapeutic monitoring of TB, though further elaborate studies in larger cohorts are required to establish the role for C1qC in the diagnosis and therapeutic monitoring of TB.