Cryoimmunoglobulinemia in four sisters.

Mixed-typed cryoproteins, consisting of IgG and IgM, were demonstrated in the sera of four sisters. While the IgG component was polyclonal in every instance, in two of them the IgM component was found to be monoclonal with type chi light chains. Clinical diagnoses included the purpura-weakness-arthralgias syndrome, posthepatitis cirrhosis, congestive heart failure and mitral stenosis. The cryocrit differed in the four sisters, ranging from 3 to 16%; in addition, rheumatoid factor activity was consistently associated with both washed cryoprecipitates and their isolated IgM components. Endomembraneous deposits of IgG and IgM were revealed by immunofluorescent studies of the renal biopsy specimen from one patient. A genetic abnormality, possibly of the autosomal recessive type, is suggested in this instance of familial cryoglobulinemia.