INCREASE IN ADHESION MOLECULES ON CD4-FLUID FROM PATIENTS WITH RHEUMATOID-ARTHRITIS( CELLS AND CD4+ CELL SUBSETS IN SYNOVIAL)

Objective. To elucidate the role of adhesion molecules in the pathogen esis of rheumatoid arthritis (RA). Methods. We evaluated their express ion and that of an activation marker on CD4+ cell populations and CD4 cell subsets in specimens of peripheral blood (PB) and synovial fluid (SF) obtained from 10 patients with RA and 7 with osteoarthritis (OA) . A 2 or 3-color immunofluorescent method was used for analysis. Resul ts. The SF from both groups of patients showed a greater density of ad hesion molecules including LFA-1 alpha, LFA-1 beta, CD2, VLA-4 alpha a nd VLA-5 alpha on CD4+ cells, and a higher percentage of CD4+HLA-DR+ c ells compared with their PB. IN PB-CD4+ cell subsets from the arthriti c and healthy subjects, the CD4+CD45RO+ cell population showed an incr eased expression of adhesion molecules compared with CD4+CD45RA+ cell population. The expression of adhesion molecules on circulating CD4+ c ell population and CD4+ cell subsets from the patients with RA and OA was comparable to that from healthy subjects. SF from both groups of p atients showed a higher percentage of CD4+CD45RO+ cells and a lower pe rcentage of CD4+CD45RA+ cells. In SF-CD4+ cell subsets from patients w ith RA, the CD4+CD45RO+ cell population had an increased expression of VLA-4 alpha compared to the CD4+CD45RA+ cell population; however, the re was no significant difference in other adhesion molecule expression and the percentage of HLA-DR+ cells between the 2 cell subsets. Furth ermore, the expression of VLA-4 alpha on the CD4+CD45RO+ cell populati on in SF from patients with RA was significantly higher than that in m atched PB. In CD4+CD45RA+ cell population from both groups of patients , SF showed an enhanced expression of adhesion molecules and an increa sed percentage of HLA-DR + cells compared with matched PB. Conclusion. Our results suggest that increased expression of adhesion molecules a nd increased percentage of HLA-DR+ cells on CD4+ cells in SF may be re sponsible for cellular interactions between these cells and synovial c ells or extracellular matrix.