[Renal and neurologic symptoms due to cryoglobulinemia complicated with rheumatoid arthritis and Sjögren's syndrome].

A 55-year-old woman with rheumatoid arthritis and Sjögren's syndrome developed complications of acute renal failure and symmetrical polyneuropathy. Laboratory examination revealed macroglobulinemia, positive cryoglobulin, and low complement levels. Kidney biopsy specimen revealed "thrombi" in glomerular capillary loops that were positive for PAS stain and negative for Congo red stain. Sural nerve biopsy specimens showed axonal degeneration and subsequent myelin loss due to vasculitis. We, therefore, diagnosed renal failure and polyneuropathy due to cryoglobulinemia, and treated the patient with double filtration plasmapheresis. Moreover, lymph node biopsy specimen revealed malignant lymphoma of the follicular, small-cell lymphoplasmocytic type which seemed to be related to the macroglobulinemia. The complication of cryoglobulinemia must be taken into consideration in patients with autoimmune disease or lymphoproliferative disorder complicated with renal or neurologic symptoms.