IgG-K-Multiple Myeloma With Hyperviscosity Syndrome—Response to Plasmapheresis

Serum hyperviscosity has been identified in a variety of pathological conditions, including macroglobulinemia (Waldenström), certain polyclonal gammopathies, and, rarely, multiple myeloma.¹⁻⁹The hyper-viscosity syndrome¹⁻⁴may lead to malaise, hemorrhagic diathesis, ocular disturbances, Ménière's syndrome, central nervous system dysfunction, or renal and cardiac abnormalities, depending upon the organs primarily affected. Plasmapheresis¹,²,⁴,⁸,¹⁰⁻¹³may be the only effective therapy. This report describes two patients with IgG-K multiple myeloma and severe hyperviscosity syndrome. Life-threatening manifestations of serum hyper-viscosity, hemorrhage in one patient, and bizarre neurological dysfunctions in the other responded to vigorous plasmapheresis. Patient Summaries Patient 1. —A 54-year-old Negro woman was admitted in January 1969 with a three-month history of low back pain, anemia, and a bone marrow determination compatible with multiple myeloma. There was mild arteriolar narrowing in the ocular fundi, tenderness over the lower thoracic and lumbar spine, pain on truncal movement, and generalized hyperactive reflexes. Findings of