An interaction between the inflammatory condition and the hypercoagulable condition occurs in primary Sjögren syndrome.

This study aimed to assess the D-dimer level in patients with primary Sjögren syndrome (pSS), uncover its relationship with clinical symptoms, and appraise its predictive value in discriminating disease activity. The laboratory parameters of 101 consecutive patients with pSS and 101 healthy controls were analyzed and compared. Patients were divided into two subgroups according to their D-dimer levels, for the comparison of clinical features. Pearson's correlations were used to measure the relationships between D-dimer levels and other variables. The area under the curve (AUC) was calculated to predict disease activity. The erythrocyte sedimentation rate (ESR), high-sensitivity C-reactive protein (hsCRP) level, and D-dimer level were each higher in patients with pSS than in healthy controls. Compared with the low-D-dimer-level patients, those with elevated D-dimer levels exhibited higher ESRs (p < 0.0001) and higher levels of hsCRP (p < 0.0001), fibrinogen (p < 0.0001), and immunoglobulin A (p = 0.002). Cases with elevated D-dimer levels were prone to be more severe, based on ESSDAI evaluation (p < 0.0001). Patients with higher D-dimer levels had more articular involvement (p < 0.0001), which was significantly correlated with both the ESR (r = 0.21, p = 0.03) and hsCRP level (r = 0.56, p = 0.001). The D-dimer level may help to discriminate low disease activity from moderate/high disease activity (AUC = 0.754). The D-dimer level was correlated positively with both the ESR and hsCRP level in patients with pSS. The ESR and levels of hsCRP, fibrinogen, and disease activity were higher in the elevated D-dimer level group. The D-dimer level was demonstrated to have predictive value in differentiating pSS disease activity. Key Points •D-Dimer was higher in patients with pSS. •D-Dimer may help for predicting the disease activity in patients with pSS.