The incidence, nature and significance of activated lymphocytes has been investigated in P.A. and healthy subjects. The incidence of these cells using discontinuous Ficoll gradient analysis was studied in R.A. patients with different disease activity and in those undergoing gold therapy. The density gradient also provided a method for separating lymphocyte subpopulations for the further study of surface markers. These included the possession of surface Ig and receptors for sheep erythrocytes and IgG (Fc). R.A. patients, particularly those with clinically active disease, had more circulatory activated lymphocytes (immunoblasts) and low density lymphocytes than healthy subjects. This increase in low density cells was not seen in patients receiving gold therapy. Surface marker analysis showed that the population of low density (activated) lymphocytes in R.A. were enriched in surface Ig bearing cells and depleted of cells with sheep erythrocyte receptors, in comparison with the high density (small) lymphocytes. However, by comparison, high avidity Fc receptors were found predominantly on the dense lymphocytes whereas low avidity Fc receptors were more common on the low density cells. The role of the activated cells ir R.A. is considered with particular reference to the increased B cell activation in peripheral blood. The propagation of R.A. by activated lymphocytes is discussed in relation to their abnormal migratory patterns to inflammatory sites.
|Date of Award||1979|