Differences in Genetic Variations Between Treatable and Recalcitrant Atopic Dermatitis in Korean.

Purpose: Variations in barrier-or immune response-related genes are closely related to the development of atopic dermatitis (AD). This study was designed to identify genetic variations and clinical features to predict 'recalcitrant AD.' Methods: AD patients were classified as treatable and recalcitrant. Treatable AD patients showed satisfactory clinical improvement with basic and topical treatments. Recalcitrant AD patients used systemic immune-suppressants for over 4 weeks as they had not shown clinical improvement with basic and topical treatments. The frequency of gene variations in barrier- (FLG3321delA, FLG K4022X, KLK7, SPINK 1156, SPINK 1188, SPINK 2475) and immune response-(DEFB1, KDR, IL-5RA, IL-9, and IL-12RB1a, b) related genes were compared between each AD group and the controls. Results: Of all, 249 treatable AD and 32 recalcitrant AD were identified. Heterozygous mutations (Hetero) in KLK7 was more frequent in recalcitrant AD patients than treatable AD, without statistical significance. Hetero in DEFB1 was more frequent in treatable AD patients. However, no other significant genetic differences between treatable and recalcitrant AD was observed. Instead, higher initial Eczema Area Severity Index (EASI) score, serum immunoglobulin E(IgE) level, allergen specific IgE for house dust mites, and family history of atopic diseases were associated with recalcitrant AD with statistical significance. Conclusions: According to our study, no genetic variation to predict recalcitrant AD was identified, suggesting that clinical manifestation, rather than genetic variations of AD patients is more likely to be an important factor in predicting the prognosis of AD. Further large-scale studies on the correlation between genetic variation and recalcitrant AD are needed.