AUTOIMMUNITY TO CARTILAGE LINK PROTEIN IN PATIENTS WITH RHEUMATOID-ARTHRITIS AND ANKYLOSING-SPONDYLITIS

Objective, To determine whether patients with rheumatoid arthritis (RA ) and ankylosing spondylitis (AS) express cellular immunity to cartila ge link protein (LP), Methods, LP was purified from human fetal epiphy seal and bovine adult nasal cartilage. It was used in proliferation as says with the peripheral blood lymphocytes (PBL) isolated from 83 pati ents with RA, 21 patients with AS, and 30 healthy controls. Results. P atients with RA (34%) and AS (71%) expressed a significantly higher pr evalence of cellular immune responses to human LP compared with the he althy control group (13%). Such significant differences were not obser ved for bovine LP. Half the patients with RA responding to LP exhibite d cellular immunity to both human and bovine protein, In the AS group, PBL from a majority of responders to LP recognized only human LP. Con clusion, These data suggest that LP is a potential autoantigen in the development of RA and AS and that cellular immune reactivity to common and distinct LP epitopes in patients with RA and AS may play a role i n the pathogenesis of these diseases.