Akutes Nierenversagen bei IgM-Plasmozytom mit Hyperviskositats-Syndrom

History and clinical findings: Two days after starting withdrawal treatment for alcohol and drug abuse a 56-year-old woman developed acute renal failure. The patient was in a poor general condition and disoriented as to time and place. She had uraemic oral fetor and leg oedema. She had previously fractured both arms 3 months before. Investigations: Biochemical tests indicated renal failure: creatine 1791 μmol/l, urea 51.7 mmol/l, potassium 5.3 mmol/l, phosphate 1.86 mmol/l. Serum protein electrophoresis suggested paraproteinaemia with M gradients in the γ-fraction. Immune fixation electrophoresis demonstrated monoclonal IgM gammopathy of χ-type (IgM 44.1 g/l). Haemoglobin level was reduced to 66 g/l. Bone marrow biopsy showed replacement of normal haematopoiesis by highly atypical plasma cells (>30% of cell population). Magnetic resonance imaging revealed diffuse changes in the pelvis and vertebrae suggesting plasmacytoma, confirming the diagnosis of IgM plasmacytoma of χ-type. Treatment and course: Focal neurological symptoms (e.g. intermittent anisocoria and visual disturbances) suggested a hyperviscosity syndrome, although the serum protein level was nearly normal. Plasma viscosity was 2.2 mPas (normal range 1.2-1.38 mPas), lowered to 1.5 mPas by plasmapheresis, after which the neuropsychiatric symptoms improved. Chemotherapy for the plasmacytoma in stage IIIB was initiated (VAD scheme) and dialysis became necessary for terminal renal failure. Conclusion: Due to the raised level of IgM protein level and its high molecular size a hyperviscosity syndrome with paraproteinaemic coma may occur, even though total plasma protein is nearly normal.