Eighty cases of cryoglobulinemia were studied on its components and biological activities, and following conclusions were obtained.
(1) Eighty cases of cryoglobulinemia were classified into following three types. Type I cryoglobulin which was composed of simple monoclonal immunoglobulin (8 cases). Type II cryoglobulin which was mixed cryoglobulin with a monoclonal component and polyclonal immunoglobulins (19 cases). Type III cryoglobulin which was mixed cryoglobulins without detection of monoclonal component (53 cases).
(2) The cryoprecipitate was found the largest amount in type I, and the least amount in type III.
(3) In the 63.1% (12/19) of type II cryoglobulin, M-protein was detected only in the purified cryoprecipitate, but that was not demonstrated in the original serum by immunoelectrophoresis.
(4) It was suggested that type III cryoglobulin may also contain M-component which could not detected because of the small quantities of cryoprecipitates.
(5) RF activity was detected in mixed type cryoglobulins (type II, III) at high frequency. But there was no clear differences in the occurrence of ANF activity between the cryoglobulin types.