On the Nature of Cryoglobulins

The cryoglobulins of two patients were studied. Each of the two cryoprecipitates consisted of two components. The first one, from the serum of a patient with “idiopathic cryoglobulinemia,” was composed of a 19 S and a 7 S component. Immunologic studies suggest that the 19 S component was an antibody to IgG, which had become abnormal and antigenic by the loss of sialic acid but retained its antigenic IgG determinants. The altered solubility, which renders the combination of these two globulins a cryoprecipitate, may also be the consequence of the absence of sialic acid from the 7 S component. The second cryoglobulin was obtained from a patient with multiple myeloma. The cryoprecipitate was composed of a 7 S and a 3.5 S, but the 3.5 S composed of a 7 S and a 3.5 S, but the 3.5 S component constituted a cryoglobulin by itself. The 3.5 S also appeared in the urine of the patient, where it also had the qualities of a cryoglobulin. This 3.5 S cryoglobulin was a κ-type light chain by antigenic properties and chemical constituents with the possible exception of cystine.