Activated coagulation is associated with the disease activity of axial spondyloarthritis

Activation of the coagulation system has been related to disease activity in some inflammatory diseases. Here, we aimed to investigate the relationship between coagulation function and the disease activity of axial spondyloarthritis (axSpA).

This study retrospectively recruited 144 axSpA patients and 55 healthy controls. The patients were divided into an active group (Bath Ankylosing Spondylitis Disease Activity Index, BASDAI ≥ 4) and a remission group (BASDAI < 4). The coagulation, inflammatory and clinical parameters were detected. The correlations between these parameters were analyzed with Spearman's correlation analysis. Receiver operating characteristic (ROC) curve analysis was performed to compare the values of these variables in discriminating disease activity. Furthermore, binary logistic regression analysis was used to assess the risk factors for axSpA disease activity.

Fibrinogen (FIB) was increased in the axSpA group compared to healthy controls (P < 0.001). Additionally, FIB and D-dimer were higher in the active group than in the remission group (P < 0.05, respectively). FIB and D-dimer were positively correlated with ESR, CRP, BASDAI, Bath Ankylosing Spondylitis Functional Index (BASFI) and Bath Ankylosing Spondylitis Metrology Index (BASMI) (P < 0.05, respectively). The area under the curve (AUC) of FIB was higher than that of ESR, CRP and D-dimer. The optimal cut-off value of FIB was 3.23 g/L, with a specificity of 62.0% and sensitivity of 75.0%. FIB (OR = 4.335, 95% CI: 1.262-14.888, P = 0.020) and BASFI score (OR = 1.878, 95% CI: 1.441-2.448, P < 0.001) were independent risk factors affecting disease activity.

Activated coagulation is closely related to the disease activity of axSpA. FIB and D-dimer might be novel indicators for monitoring the disease activity of axSpA.