Association between acute phase reactants, interleukin-6, tumor necrosis factor-α, and disease activity in Takayasu's arteritis patients

Background To investigate the association between blood biomarkers and disease activity of Takayasu's arteritis (TAK) in a follow-up cohort. Methods Disease activity was assessed by clinical manifestations and repeated vascular Doppler examinations. The association between erythrocyte sedimentation rate (ESR), serum levels of high-sensitive C-reactive protein (hsCRP), interleukin-6(IL-6), and tumor necrosis factor-alpha (TNF alpha) and disease activity were analyzed by logistic regression and survival analysis. Kaplan-Meier method was used to estimate the cumulative remission rate curve, log-rank tests for group comparison, and Cox regression for estimating hazard ratios of these parameters for disease activity. Results 428 patients were included. 188 patients were in active disease, and 240 patients were in inactive disease at baseline. Elevation of ESR, hsCRP, and IL-6 were associated with active disease at baseline and during follow-up. Cox regression and Kaplan-Meier analysis showed that lower possibility and longer time to remission were associated with elevated ESR (hazard ratio [HR] = 0.32, 80 vs 33 weeks, p < 0.001), hsCRP (HR = 0.45, 70 vs 31 weeks, p < 0.001), and IL-6 (HR = 0.54, 66 vs 34 weeks, p < 0.01) in patients with active disease at baseline, while higher risk and shorter time for relapse were associated with elevated ESR (HR = 2.1, 59 vs 111 weeks, p < 0.001), hsCRP (HR = 2.1, 79 vs 113 weeks, p < 0.001), IL-6 (HR = 2.5, 64 vs 117 weeks, p < 0.001), and TNF alpha (HR = 2.7, 65 vs 114 weeks, p < 0.001) in patients with inactive disease at baseline. Conclusions Elevated ESR, CRP, and IL-6 are associated with active disease, lower possibility, and longer time to achieve disease remission. Elevation of any among ESR, CRP, IL-6, and TNF alpha is associated with high risk and short time for relapse during follow-up.