Elution and Characterization of Lymphocytes from Rheumatoid Inflammatory Tissue

Lymphocytes were eluted from the synovial tissue of 19 patients with classical rheumatoid arthritis. The tissue was minced and dissociated by treatment with crude collagenase and DNase, The cell suspension obtained was filtered and incubated in plastic culture flasks overnight at 37°C, The cells that did not adhere to the plastic surface were harvested and the lymphocytes further purified by the Ficoll‐Isopaque gradient centrifugation technique. The lymphocyte yield varied from 0.64 to 32 × 10 6 cells. Differential counts showed on the average 85% lymphocytes, 12% macrophage‐like cells, and variable proportions of polymorphonuclear granulocytes, unclassified cells, and dead cells. An average of 77% of the cells were viable as assessed by the trypan blue exclusion test. This cell suspension was investigated for lymphocyte populations, T lymphocytes were predominant in all experiments (mean, 73.6%), The mean percentage of B lymphocytes was 9.7%, whereas the proportion of Fc‐receptor‐bearing lymphocytes was on the average 6.0%,