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-α (TNFα) 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 TNFα (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 TNFα is associated with high risk and short time for relapse during follow-up.