Filaggrin loss-of-function mutations as a predictor for atopic eczema, allergic sensitization and eczema-associated asthma in Polish children population

Background. Loss-of-function mutations in the filaggrin (FLG) gene were identified as a major risk factor for atopic eczema. Objectives. The aim of the study was to investigate the importance of 4 common FLG null mutations in the susceptibility to atopic eczema and other allergic phenotypes in Polish children population. Material and methods. The FLG mutations were determined in 158 children younger than 2 years of age. All subjects were selected using a detailed questionnaire and blood samples for total and specific IgE measurements were obtained. Cases of atopic eczema were diagnosed according to the criteria of Hanifin and Rajka and skin examination. All FLG mutations were genotyped by real-time PCR assays with a subsequent melting curve analysis using a SimpleProbe (R) probes. Results. The combined genotype of all 4 mutations (carriage of >= 1 FLG mutation) was significantly associated with atopic eczema (p = 0.016). The odds ratio (OR) for individuals carrying 1 of these 4 null mutations was 5.52 (95% CI; 1.11 divided by 37.12). The significant association between either the combined FLG genotype or 2282del14 deletion and eczema was seen only in the allergic group. The association with asthma was restricted to asthma occurring in the context of eczema (OR, 6.27; 95% CI, 0.89 divided by 53.56; p = 0.042). Conclusions. Our study confirms the previous findings that FLG mutations are strongly associated with atopic eczema and confer a significant risk of allergic sensitization and asthma in the context of eczema. These results underline the role of the epidermal barrier and filaggrin insufficiency in the pathogenesis of atopic eczema and eczema-associated asthma.