Abstract
In spondyloarthritis, little is known about the relation between circulating cytokines and patient phenotype. We have quantified serum levels of T helper type 1 cell (Th1), Th2 and Th17 cytokines in patients with recent-onset axial spondyloarthritis (AxSpA) from the DESIR cohort, a prospective, multicenter French cohort consisting of 708 patients with recent-onset inflammatory back pain (duration >3 months but <3 years) suggestive of AxSpA. Serum levels of Th1, Th2, and Th17 cytokines were assessed at baseline in patients from the DESIR cohort fulfilling the ASAS criteria (ASAS+) and were compared with age- and sex-matched healthy controls. At baseline, ASAS+ patients (n = 443) and healthy controls (n = 79) did not differ in levels of most of the Th1, Th2 and Th17 cytokines except for IL-31, and sCD40L, which were significantly higher for ASAS+ patients than controls (p < 0.001 and p = 0.012, respectively). On multivariable analysis of ASAS+ patients, IL-31 level was associated with sCD40L level (p < 0.0001), modified Stoke AS Spine Score (mSASSS) < 1 (p = 0.035). The multivariable analyses showed that IL-31 was an independent factor associated with mSASSS < 1 (p = 0.001) and low bone mineral density (p = 0.01). Increased level of IL-31 might protect against structural damage but is also related to low BMD.