IgG subclasses in collagen-induced arthritis in the rat.

Using a solid-phase double-antibody radioimmunoassay IgG antibodies to native bovine type II collagen were measured as total IgG and as subclasses of IgG (IgG1, IgG2a, IgG2b, IgG2c ) in arthritic and non-arthritic Sprague-Dawley rats. Statistically significant differences were observed between arthritic and non-arthritic animals for IgG1, IgG2a, IgG2b and total IgG. The significance of these results and their possible relevance to the human disease are discussed.