Circulating protein complexes in D-penicillamine therapy of rheumatoid arthritis. Correlation between IgG- and alpha 1-antitrypsin-IgA complexes and clinical response.

Eighteen of 24 patients with rheumatoid arthritis showed intermediate IgG-containing complexes on preparative ultracentrifugation before treatment with D-penicillamine. Serial analyses of these showed strikingly close correlation in reduction of IgG as well as alpha 1-antitrypsin-IgA complexes. Three patients did not respond to treatment clinically, and retained both types of complexes. Complexes virtually disappeared in all responders. Only small changes were found in total IgG or IgM levels and the reduction of IgA levels was moderate, except for one case who developed IgA deficiency. The importance of further analysis of non-responders is stressed.