Immune Complexes and the Treatment of Biliary Cirrhosis

To the Editor: In the February 8 issue of the Journal, Epstein and his associates reported that immune-complex activity in the serums of patients with primary biliary cirrhosis diminished during treatment with penicillamine, and followed improvement in biochemical variables and a decrease in serum IgM concentrations.¹ We suggest that immune complexes in primary biliary cirrhosis probably do not have a major pathogenic role in bile-duct destruction but, rather, that they simply represent IgM aggregated in vivo as a result of increased serum IgM concentrations. Immunoglobulin aggregates, produced by heating at 60° to 63°C, cannot be distinguished from true antigen–antibody.