Background: The IgG responses to food antigens are preferentially restricted to the IgG1 and IgG4 subclasses. Increased levels of IgG1 and IgG4 antibodies against food allergens have been reported in girls and adults with current atopic eczema.
Objective: To study the relation between the levels of IgG1 and IgG4 antibodies against beta-lactoglobulin and ovalbumin and the development of atopic disease.
Material and methods: Atopic symptoms were recorded in 36 girls from birth to 7 years of age. Blood samples were taken at 3 and 8 months and at 2, 4, and 7 years. IgG1 and IgG4 antibodies were measured by ELISA.
Results: Anti-beta-lactoglobulin IgG1 was detected at all ages, peaking at 8 months. Anti-beta-lactoglobulin IgG4 antibodies were detected in 18 to 29 girls at different ages and the antibody levels peaked at 2 years. The levels of anti-beta-lactoglobulin IgG1 were lower in atopic, as compared with healthy individuals at 4 and 7 years (P < .01 and P < .05) and lower anti-beta-lactoglobulin IgG4 antibody levels were found in atopic individuals (P < .05) at 4 years. Anti-ovalbumin IgG1 antibodies were detected in 3/35 girls at 3 months and in 16/35 to 26/35 girls later in life. The number of positive samples and antibody levels peaked at 2 years. Anti-ovalbumin IgG4 positive samples increased from 4/33 at 8 months to 30/32 at 7 years. The levels increased up to 2 years and then remained stable. The anti-ovalbumin IgG1 antibody levels were lower in atopic girls at 4 years (P < .05), while the anti-ovalbumin IgG4 antibody levels were similar at all ages.
Conclusion: An early IgG1 response and later appearing IgG4 antibodies to the two food antigens beta-lactoglobulin and ovalbumin are common during the first years of life. The levels were similar in the nonatopic and the atopic girls up to four years; then they tended to be lower in the first group.