Lymphocyte activation status, expression of adhesion molecules and adhesion to human endothelium in rheumatoid...

The synovial tissue of patients with rheumatoid arthritis (RA) is characterized by infiltration with inflammatory cells, mainly memory helper cells (CD4+CD29+). An important initiating step in tissue infiltration is the adhesion of peripheral blood lymphocytes to the vascular endothelium. Therefore, we studied lymphocyte-endothelium adhesion in 40 RA patients and in 19 controls by a sensitive fluorimetric assay, using human umbilical vascular endothelial cells. Furthermore, expression of adhesion molecules VLA (CD29) and LFA-1 (CD11a) on CD4+ and CD8+ T cells was determined. In order to evaluate the activation state of lymphocytes, the soluble interleukin-2 receptor (sIL2R) was measured. The relationship to disease activity was evaluated using the Ritchie articular index. RA patients had a higher percentage of CD4+ cells (p < 0.005) and a lower percentage of CD8+ cells (p < 0.001) than controls did. The CD4+CD29+/CD4+CD29- ratio and the CD8+CD29+/CD8+CD29- ratio were increased in patients with active RA (p < 0.01 and p < 0.05, respectively) and in patients with inactive disease (p = 0.09 and p < 0.005, respectively) compared with controls. LFA-1 (CD11a) was present on almost all T lymphocytes and its density did not differ between patients and controls. Serum levels of sIL2R were significantly higher in both patient groups compared with controls (p < 0.0005); patients with active disease showed significantly higher levels than patients with inactive disease (p < 0.05). Lymphocyte-endothelium adhesion was not increased in patients, although the expression of the adhesion molecule CD29 on T lymphocytes of RA patients was higher.(ABSTRACT TRUNCATED AT 250 WORDS)