Veneuze trombo-embolieën bij ANCA-geassocieerde vasculitis

Objective

To assess the incidence of venous thromboembolism (VTE) and its relationship with disease activity and classic risk factors in a homogeneous cohort of patients with antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV).

Design

Retrospective.

Method

Patients with AAV who were diagnosed at the University Medical Center Groningen between 1995 and 2006 and treated with cyclophosphamide and corticosteroids were included. We retrieved data from status assessments and by questionnaire, from which we calculated the incidence of AAV-associated VTE (VTE occurring 3 months before or following diagnosis of AAV), expressed as VTE/100 person-years. We analysed whether this was related to periods of active disease, defined as the period of 3 months before or 3 months after diagnosis or relapse.

Results

198 patients were included and followed for 6.1 (0.2-17.6) years. Twenty-three patients (12%) developed 25 AAV-associated VTEs (17 deep venous thromboses, 3 pulmonary embolisms and 5 both), of which 52% developed during active disease. Overall, the incidence of VTE was 1.8/100 person-years, increasing to 6.7 during active disease. VTEs occurred less frequently in patients with Wegener granulomatosis than in patients with microscopic polyangiitis or vasculitis limited to the kidneys. Classic risk factors for VTE were present in most patients, but they were distributed equally over patients with and without an AAV-associated VTE.

Conclusion

The incidence of VTE is higher in patients with active/non-active AAV. This finding cannot be explained by the presence of classic risk factors, but is probably associated with endothelial changes or hypercoagulability caused by AAV or its treatment.