[Detection of anti-collagen type I and II antibodies by an immunoenzymatic technique (ELISA): results in rheumatoid arthritis, systemic lupus erythematosus and leprosy (author's transl)].

An attempt was made to detect antibodies against type I and/or II collagen in sera from patients with rheumatoid arthritis, systemic lupus erythematosus (SLE) and leprae. This study was performed with an immunoenzymatic technique: ELISA (enzyme-linked immunosorbent assay). The following steps were performed: bovine collagen type I or II was adsorbed on glass beads; possible free sites were saturated by incubating the beads with sheep serum; then, the antibodies specifically bound to collagen were detected by a peroxidase-labelled anti-immunoglobulin; the immune complexes at the surface of the beads were revealed by a substrate specific for peroxidase and of great stability: Trinder's reactive. Using conditions previously shown to be optimal, the prevalence of anti-collagen antibodies was as follows. In patients with lepromatous leprae the percentages of positive sera against collagen type I and II were 40% and 44%, respectively; in patients with tuberculoid leprae the percentages were lower: 10% and 30%, respectively. Ten per cent of the SLE patients had antibodies against collagen type I, half of the prevalence noted for anti-collagen type II antibodies (20%). Finally, 13.6% of the patients with rheumatoid arthritis had antibodies against collagen type I, a percentage very similar to that of the patients with anti-collagen type II antibodies (14.6%).