Comparative Analysis of Coagulation Activation in Rheumatoid Arthritis Patients Treated With TNF Inhibitors Versus JAK Inhibitors

Objectives This study aims to investigate the activation of the coagulation system of RA patients and assess changes during anti-inflammatory treatment with tumor necrosis factor blockers (anti-TNF) and Janus kinase inhibitors (JAKi). Methods Biomarkers for the coagulation system, including D-dimer, fibrinogen, prothrombin time, activated partial thrombin time, prothrombin fragment 1 + 2, thrombin-antithrombin complex (TAT), activated factor IX, antithrombin complex, and von Willebrand factor (vWF), were longitudinally measured in 83 RA patients treated with anti-TNF and 38 RA patients with JAKi. Data were collected at baseline, after 1, 3, and 6 months. Results The mean age was 57 (±14) years; 76% was female. The mean DAS28-CRP was 3.6 (±1.3) for anti-TNF users and 4.1 (±1.4) for JAKi users at baseline and declined in both groups. Baseline coagulation markers levels were comparable between groups. In anti-TNF users, D-dimer and fibrinogen levels significantly declined (−0.31 mg/L, p = 0.01 and −0.71 g/L, p < 0.001, respectively), whereas TAT significantly increased after 6 months follow-up (1.46 μg/L, p = 0.03) and no effect on vWF ( p = 0.98). In JAKi users, vWF declined significantly during the 6 months follow-up (−37.41%, p < 0.001); additionally, there were reductions of D-dimer, fibrinogen, and TAT that did not reach significance (−0.17 mg/L, p = 0.59; −0.49 g/L, p = 0.12; and 0.68 μg/L, p = 0.27, respectively). Conclusions The prothrombotic tendency in active RA declined during effective treatment with both anti-TNF and JAKi. Altogether, the biomarkers used in this study suggest that an increased VTE risk in the first 6 months due to either treatment with anti-TNF or JAKi is unlikely.