The relationship between the complex of immunoglobulin A and alpha-1-antitrypsin, its constituent components and the acute-phase response as measured by C-reactive protein in rheumatoid arthritis treated with gold or D-penicillamine.

Serum levels of immunoglobulin A (IgA), alpha 1-antitrypsin (AT), their complex (IgA-alpha 1AT) and C-reactive protein (CRP) were measured prior to treatment and at 6 months, in 45 rheumatoid arthritis (RA) patients. Twenty-five patients were treated with D-penicillamine (DPA) and 20 patients with gold (sodium aurothiomalate). The level of circulating complex was reduced by both treatments (p less than 0.001). There was a significant correlation between the circulating levels of IgA-alpha 1AT complex and serum IgA (p less than 0.05). No relationship was observed between the level of circulating complex and CRP. These findings suggest that formation of IgA-alpha 1AT complex in RA is dependent on the level of IgA. The complex is reduced by gold and DPA but it does not reflect an acute phase response as measured by CRP.