Acute renal failure in primary macroglobulinemia with small-molecule IgM.

Primary macroglobulinemia with acute renal failure developed in a 46-year-old man after administration of contrast medium (containing diatrizoate sodium and meglumine [Urografin]) for intravenous pyelography. On admission, the monoclonal protein peak could not be detected in serum by cellulose acetate electrophoresis, but the serial electrophoresis revealed a gradual increase in monoclonal protein peak, which later became two peaks. The serum of the patient contained the monoclonal small-molecule IgM kappa-chain protein with 13 to 14 Svedberg units in sedimentation constants, which is antigenetically the same as native IgM heavy chain. Although acute renal failure is extremely rare in primary macroglobulinemia, the small-molecule IgM seems to be one factor that induces acute renal failure.