Pulmonary hypertension secondary to serum hyperviscosity in a patient with rheumatoid arthritis.

A patient with rheumatoid arthritis who was evaluated for dyspnea of six months' duration is described. Although no primary cardiac or parenchymal lung disease was identified, right heart catheterization revealed marked pulmonary hypertension. The patient was presumed to have pulmonary arteritis. Evaluation of her hyperproteinemia, however, led to the discovery of a polyclonal gammopathy with a marked increase in plasma viscosity. Although the classic clinical findings of the hyperviscosity syndrome were minimal, the patient underwent plasmapheresis, resulting in a marked reduction of pulmonary artery pressures (from 53 +/- 4 mm Hg, mean +/- SD, to 30 +/- 3 mm Hg, p less than 0.05) and pulmonary vascular resistance (from 707 +/- 63 dynes/second/cm5 to 421 +/- 72 dynes/second/cm5, p less than 0.05) concomitant with a return to normal plasma viscosity. Her dyspnea completely resolved. This represents the first successful treatment of pulmonary hypertension by plasmapheresis. Protein evaluation revealed the presence of intermediate complexes of IgG rheumatoid factor. The hyperviscosity syndrome should be considered in the differential diagnosis of pulmonary hypertension in patients with rheumatoid arthritis and other disorders associated with a polyclonal or monoclonal gammopathy. Pulmonary hypertension secondary to the hyperviscosity syndrome is reversible by plasmapheresis. Immunosuppressive therapy that reduces immunoglobulin production may provide a means of long-term treatment.