A Prospective Study in Children With a Severe Form of Atopic Dermatitis: Clinical Outcome in Relation to Cytokine Gene Polymorphisms
Abstract
Background and Objective: The course of atopic dermatitis (AD) in childhood is characterized by typical changes in phenotype, including a shift from skin involvement to respiratory allergy usually around the third year of age. We thus designed a prospective study to monitor the outcome of severe AD and to investigate the association between cytokine gene polymorphisms and clinical manifestations.
Methods: Clinical and laboratory follow-up of 94 patients with severe AD and 103 healthy controls was performed using routine methodology. Allele, genotype, and haplotype frequencies of single nucleotide polymorphisms of 13 selected cytokine/receptor genes were analyzed using PCR with sequence-specific primers.
Results: In our study, genotypes of 7 polymorphisms-IL-4 -1098G/T and -590C/T, IL-6 -174C/G and nt565A/G, and IL-10 -1082A/G, -819C/T, and -592A/C were significantly associated with atopic AD (P<.05). A significant association was also found for TNF-alpha AA and IL-4 GC haplotypes and AD.
We confirm the progressive clinical improvement of AD together with a decrease in the severity index SCORAD (SCORing atopic dermatitis) during childhood (P<.05). We found significant differences between IL-4R alpha + 1902 A/G and positivity of tree pollen-specific IgE (P<.05) in the AD group.
Moreover, a weak association was also found between IL-10 -819C/T and IL-10 -590A/C and the appearance of allergic rhinitis (P<0.1). Conclusions: We confirmed a clinical shift in allergic phenotype in the first 3 years of life, and showed an association between IL-4, IL-6, and IL-10 polymorphisms and AD.
Our data indicate that IL-4 alpha and IL-10 polymorphisms may be considered predictive factors of respiratory allergy in children with AD.