The clinical and immunological development of AD children may be associated with age-related changes in the genetic background of cytokine gene polymorphisms.

Fifty-two boys and 26 girls with severe AD, age 6 months to 5 years, were enrolled. Investigation included clinical (dermatologic allergy, food allergy, and respiratory allergy symptoms) assessments and evaluations of laboratory parameters (blood count, humoral immunity, IgE, specific IgE and IgG to food and respiratory allergens). Single nucleotide polymorphisms in the genes for IL-1, IL-1R, IL-2, IL-4, IL-6, IL-10, IL-12, TGFβ, TNF⍺ and IFNγ were investigated by PCR with sequence specific primers. The genotypic frequencies and haplotypes were compared to 100 healthy donors.

Significant differences in cytokine gene polymorphisms between AD and healthy population were found in the promoter sequence of IL-10 (the genotype frequency C/C at position −819, 63% versus 47%, p=0.04; frequency of A/G at position −1082, 48% versus 69%, p=0.001), while less significant differences appeared in other tested positions. Clinical and laboratory parameters, however, were independent of genetic background. Half of all severe AD children had elevated values of IgE, 40% had positive IgE to egg white, while low IgG occurred in 44%.

Within currently known cytokine gene polymorphisms, notable differences in AD children were only found in IL-10, an important regulatory cytokine, but these polymorphisms were independent of the clinical and immunological profiles of the investigated AD children.