Studies on Cryoprecipitation

Abstract

Summary Cryoglobulin obtained from a patient suffering from idiopathic cryoglobulinemia was characterized immunochemically. This cryoglobulin (2.7 g/100 ml plasma) was produced by the patient in addition to the normal level of major serum proteins and immunoglobulins (IgG, IgA, IgM and IgD). It possesses a λ-type light polypeptide chain and a γ1-type heavy chain with Gm 4 characteristics. Treatment of the cryoglobulin with papain produced Fab and Fc fragments which individually or collectively showed no cryoprecipitation at 3°C. In contrast, the native cryoglobulin molecule formed a gel matrix when the temperature was reduced below 37°C. Rabbit antisera to this cryoglobulin possessed cryoglobulin-specific antibody determinants which were directed toward the Fd pieces of the Fab fragment. The Fab fragments displayed a dimermonomer equilibrium depending on the hydrogen ion concentration of the media.