Hyperviscosity syndrome in paraproteinemia. Managed by plasma exchange; monitored by serum tests.

Clinical and laboratory indices of hyperviscosity were studied in three patients presenting with this complication of paraproteinemia. Serum viscosity correctly predicted the presence of clinical hyperviscosity syndrome in patients with stable hemoglobin and albumin concentrations. Serum viscosity also correlated with total protein and paraprotein levels. A simple exponential model proved not only to describe the kinetics of blood viscosity during plasma exchange but also to predict protein concentration at symptomatic recovery. Construction of such a protein-viscosity curve helps manage by plasma exchange patients with paraproteinemia who develop hyperviscosity syndrome.