Materials and Methods

Subjects for study were chosen from patients at the Robert B. Brigham Hos-pital chiefly on the basis of availability for biopsy and for the collection of synovial fluid. There were 53 patients with rheumatoid arthritis who had a positive serum or euglobulin latex fixation testz0 for rheumatoid factor, and 30 patients with rheumatoid arthritis and a negative latex test. The high proportion of seronegative rheumatoid arthritis patients reflects a deliberate attempt to obtain such patients for study. Of these 83 patients, 80 had “classical” or “definite” and three had “probable” rheumatoid arthritis according to the Arthritis and Rheumatism Association criteria. 21 In addition, 21 patients with degenerative joint disease were also studied. Biopsies were obtained from 86 of the 104 patients and were, in all cases, consistent with the diagnosis. Synovial fluid was usually obtained from the knee joint, allowed to clot briefly at room temperature, centrifuged, aliquoted, and frozen at-70’C. A portion of the synovial fluid for immunofluorescent study was collected in 0.01 M disodium ethylenediaminetetraacetate. The cells from this fluid were washed four times in 0.01 M phosphate-buffered saline (pH 7.5) containing 1% human albumin. They were resuspended in this same buffer, smeared on siliconized microscope slides, dried, fixed in alcohol, and stored at-20’C.