Material and methods
In the prospective study, we recruited consecutive patients with AAV. All of them were tested for cryofibrinogen and cryoglobuline. Clinical signs and symptoms, activity of AAV and laboratory parameters were evaluated at the time of analysis for cryofibrinogen.
One hundred twenty nine patients with AAV (average age of appoximately 50 years) were enrolled in our study. All patients tested negative for cryoglobulin, while cryofibrinogen was detected in 42 (32.6%) patients. The prevalence of CF did not depend on the type of AAV or ANCA specificity. The rate of lungs, kidney and other organs disease and the median BVAS were comparable in patients with and without CF. However, hemorrhagic alveolitis and skin necrosis or ulcers occurred more frequently in patients with CF. Secondary CF was also associated with a higher VDI and an increased incidence of venous thrombotic complications and mortality. Plasma cryofibrinogen level positively correlated with ESR, a1-globulin and a2-globulin levels.
Secondary CF was detected in one third of patients with AAV treated with immunosuppressive agents. CF was not related to AAV activity. However, it was associated with a higher incidence of necrotic skin lesions, venous thrombotic events and probably with more severe course of vasculitis.
ANCA-associated vasculitis, cryofibrinogen, venous thrombotic events.