[Aberrant expression of adhesion molecules in rheumatoid arthritis]

The regulation of lymphocyte migration to specific tissues is complex and involves lymphocyte-endothelial interactions at sites of extravasation. Adhesion molecules play a vital role in the migration of lymphocyte into and out of the tissues. Therefore, excessive induction of adhesion molecules on the vascular endothelium might result in the accumulation of lymphocytes in the rheumatoid synovium. The rheumatoid synovium exhibits functionally as well as morphologically altered synovial vessels, which are probably induced by inflammatory mediators. It should be pointed out that the immunocompetent cells confront various extracellular matrix after extravasation. The signalling through receptors for extracellular matrix modify the subsequent cellular responses against certain target tissues. Thus, interaction of immunocompetent cells with endothelium as well as extracellular matrix through adhesion molecules is critical for the pathogenesis of rheumatoid arthritis.