Rituximab for treatment of rheumatoid hyperviscosity syndrome: Pulmonary arterial hypertension and post- partum cardiomyopathy cases

Hyperviscosity syndrome (HVS) is a rare manifestation of rheumatoid arthritis with few reported cases. Although plasmapheresis is effective as the first line treatment in life threatening manifestations such as pulmonary hypertension, stroke, retinal hemorrhages and congestive heart failure, data on effective maintenance immunosuppressive therapy is lacking. HVS is characterized by abnormal immunoglobulin production. Rituximab is a powerful B cell depleting therapy which can theoretically eliminate pathogenic B cells and decrease immunoglobulin production in HVS. We report two cases of rheumatoid HVS who presented with either severe pulmonary arterial hypertension or post-partum cardiomyopathy. The case of pulmonary arterial hypertension was treated with two cycles of plasmapheresis followed by rituximab 1000 mg IV separated by 2 weeks and repeat dosing every 6 months. The second case was a post-partum cardiomyopathy which presented with inflammatory polyarthritis and compensated congestive heart failure. She was treated with prednisone followed by rituximab infusion. As far as we know, these are the first two cases of rheumatoid HVS which have been treated with rituximab.