Mixed IgM-IgG cryoglobulinemia terminating in polyarteritis nodosa.

A case of mixed IgM-IgG cryoglobulinemia and polyarteritis nodosa is described. The patient exhibited non-deforming arthritis, Raynaud's phenomena, cutaneous vasculitis, and a sensory neuropathy.. The terminal phase of the illness was characterized by hypertension and retroperitoneal hemorrhage, with widespread large vessel arteritis. The isolated cryoprecipitate contained IgM, IgG, and C3 and possessed rheumatoid factor activity. Mild reduction in serum complement (CH50 and C3) was noted on one occasion. The evidence that these cryoprecipitable proteins may be acting as immune complexes and contributing to the arterial lesions is reviewed.