Elevated levels of d-dimer are associated with inflammation and disease activity rather than risk of venous thromboembolism in patients with granulomatosis with polyangiitis in long term observation

Purpose: Granulomatosis with polyangiitis (GPA) is one of antineutrophil cytoplasmic autoantibody (ANCA) - associated vasculitis. The disease is characterized by necrotizing inflammation of small vessels causing tissue ischemia in a variety of organs. The aim of the present study was an evaluation of inflammation, coagulation and fibrinolysis biomarkers, and their possible associations with various clinical and laboratory parameters in GPA patients. Methods: A group of 100 consecutive patients with GPA were prospectively followed in the study. In all patients, echocardiography and laboratory tests were performed. Results: The patients were followed-up for a median of 4.0 +/- 1.9 years. Circulating d-dimer concentrations were elevated in a majority (56%) of GPA patients, and were significantly higher in GPA patients in the active stage compared to those in remission (median 652 vs. 405 ng/ml, p = 0.0002). In 23 patients (23%) venous thromboembolism (VTE) was diagnosed during observation. However, there were no differences in d-dimer concentrations between patients with and without VTE either in active stage or in remission. Correlation analysis showed that the levels of d-dimer correlated with hs-CRP (r = 0.42, p < 0.0001) and creatinine concentrations (r = 0.58; p < 0.0001), but not with ANCA levels. Conclusions: In patients with GPA elevated levels of d-dimer are associated with disease activity and inflammation rather than with the risk of venous thromboembolism. The value of d-dimer as a biomarker of venous thromboembolism episodes in patients with small vessel vasculitis is low.