Objective: To investigate the humoral immune response to common food antigens in Japanese children with IDDM.
Research design and methods: IgG antibodies to cow's milk, beta-lactoglobulin, bovine serum albumin (BSA), alpha-lactalbumin, and hens egg ovalbumin were examined by enzyme-linked immunosorbent assay in the sera of 33 patients with IDDM, ages 11.8 +/- 3.4 years. The data were compared with that of 50 normal subjects, ages 10.3 +/- 5.1 years, who acted as control subjects. A positive antibody to a food antigen was defined as an antibody titer greater than the 95th percentile value in normal subjects.
Results: Children with IDDM had significantly higher median titers of IgG antibodies to beta-lactoglobulin and ovalbumin (P = 0.03 and P = 0.0005 respectively). More children with IDDM than control subjects had positive IgG antibody to ovalbumin (21 vs. 6%, P = 0.04). Titers, as well as the number of positive antibodies to other food antigens, including BSA, did not differ between the two groups.
Conclusions: Japanese children with IDDM show an enhanced humoral immune response to beta-lactoglobulin and ovalbumin, a phenomenon that may be related to the pathogenesis of the disease.