Association between mast cell chymase genotype and atopic eczema: comparison between patients with atopic eczema alone and those with atopic eczema and atopic respiratory disease

Background It has remained unclear whether genetic background of patients w ith atopic eczema (AE) alone is identical to that of patients with both AE and atopic respiratory disease. Objective We aimed to assess whether there is a genetic difference between these two groups of AE patients. Method We determined the genotype with regard to an allelic polymorphism in the gene for mast cell chymase (MCC; a serine protease secreted from mast cells) in 169 AE patients. Results MCC genotype was significantly associated with pure AE patients who did not have a predisposition to atopic respiratory disease and whose seru m IgE concentration was < 500 IU/mL. The distribution of MCC genotypes also differed significantly between the latter patients and those AE patients w ith bronchial asthma and a serum IgE concentration of > 2000 IU/mL. Conclusion These results suggest that pure AE is associated with genetic va riants of MCC, and that the genetic basis of pure AE differs from that of A E associated with atopic asthma.