Rheumatoid hyperviscosity syndrome

Two patients with rheumatoid arthritis and a serum hyperviscosity syndrome are described. Both patients had nodular rheumatoid arthritis, weakness and dyspnea, bleeding diathesis, a striking purplish red palmar erythema and high serum viscosity. Their serum had high titers of rheumatoid factor and large amounts of intermediate IgG complexes. Viscosity measurements of the isolated protein fractions suggested that the high serum viscosity was due to the interaction of rheumatoid factor with the intermediate IgG complexes, resulting in the formation of large molecular conglomerates. Viscosity measurements following recombination of the isolated protein fractions, the effects of sulfhydryl reagents on the viscosities measured and the determination of intrinsic viscosities confirmed this hypothesis.