Clinical associations with venous thromboembolism in anti-neutrophil cytoplasm antibody-associated vasculitides

Objective. To assess potential associations for the development of venous thromboembolic events in patients with ANCA-associated vasculitides (AAV). Methods. Four hundred and seventeen patients enrolled to participate in randomized controlled trials conducted by the European Vasculitis Society were identified. Univariate and multivariate analyses were performed to validate previously proposed and identify novel risks associated with venous thromboembolism (VTE) in AAV. Results. VTE occurred in 41 of 417 (9.8%) patients. Uncorrected univariate analysis identified BVAS (odds ratio, OR= 1.05, 95% CI: 1.01, 1.10; P = 0.013), subsequent development of malignancy (OR = 2.6, 95% CI: 1.19, 5.71; P = 0.017), mucous membrane or eye involvement (OR = 2.13, 95% CI: 1.10, 4.11; P = 0.024) and baseline creatinine (OR = 1.08, 95% CI: 0.99, 1.18; P = 0.037) as being associated with the development of VTE. Multivariate analysis highlighted CRP (per 10 mg/l increase, OR= 1.05, 95% CI: 1.01, 1.09; P = 0.025), cutaneous involvement (OR = 4.83, 95% CI: 1.63, 14.38; P = 0.005) and gastrointestinal involvement (OR = 6.27, 95% CI: 1.34, 29.37; P = 0.02) among the BVAS items as well as baseline creatinine (per 100 mmol/l increase, OR= 1.17, 95% CI: 1.02, 1.35; P = 0.029) as being associated with VTEs. Conclusion. Our results highlight a role of CRP, baseline creatinine, and cutaneous and gastrointestinal involvement in the risk stratification as being associated with thromboembolic events. Moreover, there might be an association between VTEs and subsequent development of malignancy and disease activity in general.