Synovitis in rheumatoid arthritis: Scoring of characteristic histopathological features

Synovial tissue specimens obtained from the knee joints of 40 patients with rheumatoid arthritis (RA) and from 22 patients with osteoarthritis (OA) we re examined histologically. The histopathological features of RA synovitis and OA synovitis were then compared. Seven criteria items of histopathologi cal features characteristic to RA synovitis were given a score of 1-3 point s each in order to evaluate the histological severity of the seven items. T heir total scores were then calculated. A comparison of the total RA synovi tis score and the total OA synovitis score revealed that RA synovitis showe d more than 11 points (maximum 20 points), while OA synovitis showed less t han 10 points in all but two cases. Furthermore, the total scores of RA syn ovitis were then determined in the same manner for other joints, where it w as confirmed that five other joints had scores of more than 11 points as we ll; that is, the intercarpal, wrist, elbow, ankle and hip joints in 52 pati ents with RA, From these results, it was concluded that in the histological examination of biopsied synovial tissue of RA, if the total score for syno vitis is more than 11 points (maximum 20 points), an histological diagnosis of RA synovitis can be confirmed.