Catabolism of human serum IgG in health, rheumatoid arthritis, and active tuberculous disease. Possible influence of IgG structure

Abstract

The catabolism of serum IgG was studied in 5 healthy volunteers, 6 patients with rheumatoid arthritis, and 4 patients with active tuberculous disease. A greatly increased rate of catabolism was observed in the 4 rheumatoid patients with active disease (T1/2 = 12 to 14 days) compared to that observed in the healthy controls (T1/2 = 19 to 24 days). The patients with tuberculous disease showed an intermediate rate of catabolism (T1/2 = 15 to 17 days). It is suggested that the differences in individual rates of IgG elimination reflect degrees of recognition of the molecular structure of this protein.