Abstract
BACKGROUND: Atopic dermatitis (AD), a chronic inflammatory skin condition, affects up to 20% of children and 10% of adults globally, driven by a type 2 immune response via IL-4 and IL-13 through IL-4Rα. The rs1801275 variant in IL-4Rα gene, a glutamine-to-arginine substitution (Q576R), increases AD severity and atopic comorbidities. This study examines rs1801275's prevalence and clinical impact in Vietnamese population. METHODS: A cross-sectional study (January-May 2021) with 113 AD patients (Hanifin and Rajka criteria) and 213 healthy controls has been conducted. Demographics, clinical features, and SCORAD severity were assessed via questionnaires and dermatologist evaluations. rs1801275 variant was genotyped using allele-specific real-time PCR. Frequencies were compared, and associations with AD severity were analyzed using Fisher's Exact Test, Kruskal-Wallis test, and logistic regression, adjusting for age and sex. RESULTS: Allele frequencies (A: 82.74% vs 79.58%; G: 17.26% vs 20.42%) and genotypes of AD patient and control groups, respectively, showed no significant difference (p = 0.315), indicating no link to AD susceptibility. However, the G allele was associated with higher SCORAD severity in the dominant model (AG+GG vs AA: median 40 vs 30.5, p = 0.010; OR 4.67, p = 0.005) and additive model (p = 0.023), with a dose effect (AA: 30.5, AG: 39, GG: 49.65). Age group independently predicted severity (OR 2.31-2.43, p < 0.05). CONCLUSION: The rs1801275 variant correlates with increased severity in G allele carriers, per SCORAD, in dominant model. These findings support personalized AD management in Vietnam, though larger studies are needed for GG genotypes.