Background Cryofibrinogen is a cryoprotein that was first identified in 1955 by Korst and Kratochvil. Unlike cryoglobulin, cryofibrinogen precipitate forms only in plasma and not in the serum.

Objectives A few series have described the clinical manifestations and epidemiological data of cryofibrinogenemia (CF). But sometimes CF is crucial in clinical manifestation of different diseases. Moreover in cases with no verified diagnosis CF may be a reason of severe skin lesions and thrombotic events.

Methods Between 2005 and 2012, 512 patients were tested for CF in hospital. A total of 294 patients had positive test results. Cryofibrinogen were analised in plasma with standard method – the sera and plasma were chilled at 4°C for 7 days and finally analyzed after precipitate or gel formation.

Results All cryofibrinogen-positive patient were divided into 2 groups: with essential (eCF) and secondary (sCF) CF. In group with essential CF differential diagnoses include cryoglobulinemia, peripheral vascular disease, thrombotic thrombocytopenia purpura, disseminated intravascular coagulation, coumarin necrosis, hereditary hypercoagulable states, antiphospholipid syndrome, infective endocarditis and other infections, primary systemic vasculitides, and purpura fulminans. There are 223 patients with essential CF and 71 with secondary CF. The mean age of patients in the group of essential CF was 42±13 years, in the group of secondary CF – 47±10 years old. The most common reasons for secondary CF were: SLE (42,6%) and cryoglobulinemia (30,8%); CF was revealed in ANCA-associated vasculitis (9.8%), rheumatoid arthritis (4,2%), Takayasu arteritis (2,8%), thromboangigitis obliterans (2,8%), dermatomyositis, sarcoidosis, Caroli disease, Sjogren syndrome, ulcerative colitis, Crohn's disease all 1,4%. In both groups skin manifestations are inaugural and suggestive in more than 72% of cases: skin ulcers (50% in essential, 41,7% in secondary), purpura (58,3% eCF, 29,2% sCF), livedo reticularis (8,3% in eCF, 12,5% sCF) and Raynaud phenomenon (20,8% in eCF, 33,3% in sCF). In 2% cases because of gangrenes amputations were perfomed (all of them had secondary CF). Less frequent manifestations included venous thrombosis (3,5%), arterial thrombosis (2,1%), arthralgia, myalgia, neurological symptoms. We identified 5 cases of lymphoprolifirating disoders and 2 cases of solid cancers cancer (lung, colon) during follow up (3-7 years). Most of patients with essential CF treated with warfarin (35%), danasol (17%). glucocorticosteroid (9%), combination of anticoagulants and steroids (34%). All patients with secondary CF received the treatment of the main disease, but in some cases it was not enough, and therapy were enhanced by anticoagulants (warfarin).

Conclusions CF is more common, than it's expected. A defect in the fibrinolysis process clotting small and medium arteries might be a reason for dangerous complications. CF can be a predictor of lymphoprolifirative diseases or solid cancer. Effective treatment is still unknown.

Disclosure of Interest None declared