Seronegative inflammatory arthritis in the myelodysplastic syndromes.

The myelodysplastic syndromes (MDS) are a group of therapeutically refractory anemias resulting from a clonal stem cell disorder often associated with cytogenetic abnormalities. Immunologic abnormalities and occasionally vasculitis have been reported although no series has characterized an associated arthritis. All cases of MDS diagnosed in 1990 by bone marrow biopsy and followed up at the authors' institution were reviewed. Of the 28 consecutive patients, 8 had acute seronegative inflammatory arthritis temporally related to the initial discovery of cytopenia. Five patients had a symmetric polyarthritis resolving only with use of steroids or upon evolution to leukemia, and 3 had episodes of oligoarthritis with systemic features including fever, pleuritis, pericarditis, and hemolytic anemia. Arthrocenteses in 2 cases did not show crystals or infection. Serological studies were nondiagnostic. The arthritis and systemic features responded to steroids in all 5 treated patients. Inflammatory arthritis appears to be common in MDS. Most compelling is the apparent bone marrow response to steroids in 2 cases, possibly identifying a treatable subgroup.