[Investigational and methodological difficulties in the demonstration of cryoglobulins].

Cryoglobulins and cryofibrinogens are special forms of cryopathies. With regard to the clinical findings, determination and analysis of cryoproteins can support the diagnostics. Because cryoproteins occur in patients and healthy persons, occasionally it may be difficult to estimate the clinical significance. We determined and analyzed cryproteins in 47 patients with the following diagnoses: urticaria (8), morbus Raynaud (10), acrocyanosis (7), vasculitis (3), collagenosis (6), lupus erythematosus (2), suspect of cryoproteinemia (9) and of cryofibrinogenemia (2). There were cryoproteins in 42 patients of the following characteristics: immunoglobulins A, G, M (14), fibrinogen (2), immunoglobulins A, G, M together with fibrinogen (26) with a considerable predominance of IgM. There was no correlation between the diagnoses and the cryoprotein types, and therefore it is reasonable to determine cryoproteins in close cooperation with the clinics. Contamination of the cryoprecipitates with hemoglobin from red blood cells can simulate alpha 2-macroglobulin and cause misinterpretations.