Autoimmunity to Collagen

Abstract

Thirty-one patients with seronegative psoriatic arthritis, 27 patients with rheumatoid arthritis, 10 with psoriasis alone, and 20 normal volunteers were studied for autoimmunity to human collagens. Cellular and humoral responses were frequently observed in the 2 groups with arthritis, but the subjects without arthritis did not display reactivity to native collagens. These data demonstrate that collagens function as autoantigens in both psoriatic and rheumatoid arthritis.Psoriatic arthritis is an inflammatory arthritis of unknown etiology that occurs in approximately 5 to 7% of persons with psoriasis (1). The disorder is characterized by an asymmetric distribution of arthritis at onset of disease, the frequent coexistence of dystrophy of the nails and spondylitis, an increased an tissues. Types I and I11 collagens are widely distributed in dermal and organ parenchyma; type I1 collagen appears to be restricted to cartilaginous and ocular tissues; and types IV and V collagens are recently isolated species accounting for a small proportion of the collagen content of some connective tissues (29). In this article, we report that some of these collagens function as cellular and humoral autoantigens in psoriatic arthritis as well as in RA. MATERIALS AND METHODS PatientsPsoriatic arthritis. We studied 3 1 patients with psoriatic arthritis (mean age, 54 years; range, 28-72) who were part of a larger population that we recently analyzed (I).