A major susceptibility locus for atopic dermatitis maps to chromosome 3q21.

Atopic dermatitis (eczema) is a chronic inflammatory skin disease with onset mainly in early childhood It is commonly the initial clinical manifestation of allergic disease, often preceding the onset of respiratory allergies. Along with asthma and allergic rhinitis, atopic dermatitis is an important manifestation of atopy that is characterized by the formation of allergy antibodies (IgE) to environmental allergens. In the developed countries, the prevalence of atopic dermatitis is approximately 15%, with a steady increase over the past decades. Genetic and environmental factors interact to determine disease susceptibility and expression, and twin studies indicate that the genetic contribution is substantial. To identify susceptibility loci for atopic dermatitis, we ascertained 199 families with at least two affected siblings based on established diagnostic criteria. A genome-wide linkage study revealed highly significant evidence for linkage on chromosome 3q21 (Zall=4.31, P= 8.42 10(-6)). Moreover, this locus provided significant evidence for linkage of allergic sensitization under the assumption of paternal imprinting (hlod=3.71,alpha=44%), further supporting the presence of an atopy gene in this region. Our findings indicate that distinct genetic factors contribute to susceptibility to atopic dermatitis and that the study of this disease opens new avenues to dissect the genetics of atopy.

Prospective, double-blind, placebo-controlled, multicentre study on the effect of high-dose, intravenous immunoglobulin in children and adolescents with severe bronchial asthma.

OBJECTIVE: In order to study the effect of high-dose, intravenous immunoglobulin (i.v.IG) in severe childhood asthma, we investigated 31 children and adolescents (15 girls, 16 boys) aged 9-22 years (median age of 14 years) suffering from severe bronchial asthma. METHODS: In a prospective, double-blind fashion, patients received either four doses of i.v.IG (1 g/kg body weight) or identical doses of intravenous human serum albumin. The first two doses were given on two consecutive days, followed by two further doses at 4 week intervals. RESULTS: There was no statistical difference in the actively treated group when compared with the placebo group in symptom-score, bronchial hyperreactivity or peak-flow-variability. There was a trend for fewer total days of upper respiratory tract infections and also symptom-scores in the i.v.IG group but these did not reach statistical significance. CONCLUSION: Our data indicate that treatment with i.v.IG in asthmatic children did not show a significant reduction in the incidence of upper respiratory tract infections, but the patients who did have upper respiratory infections in the i.v.IG-group appear to have less protracted infections. Severity and bronchial hyperreactivity do not seem to be affected by the treatment as performed in our study.