In PsA SFMC’s, we observed 23.1% ± 3.2 of CD4+ and 5.2% ± 0.6 of CD8+ T cells expressing CD146; in RA SFMC CD4+(17.9% ± 2.6) and CD8+ (3.7% ± 0.4) expressed CD146 where as the number for OA were ((CD4+(3.5% ± 0.5), CD8+0.6% ± 0.5). Here, MCAM is linked to rheumatoid arthritis.