Combination of FLG mutations and SNP of TSLP (rs1898671) influence on atopic dermatitis occurrence

Introduction
Atopic dermatitis (AD) is a common, chronic, relapsing and heterogeneous inflammatory skin disease. Its main causes are genetic predispositions, the epidermal barrier defect, and immune system dysfunction. Thymic stromal lymphopoietin (TSLP) is highly expressed in the epidermis of AD patients and its production is triggered by exposure to environmental factors, allergens, microorganisms and irritants. Aim: To search for the associations between rs1898671 polymorphism in the promotor region of the TSLP gene (SNP) and AD occurrence and course.

Material and methods
The frequency of polymorphism occurrence was examined, connection with IgE level, the severity of AD, itching, and concomitant asthma occurrence and combination with FLG gene mutations (2282del4, R501X) in the population of northern Poland. Blood samples were collected from 239 patients with AD and 170 controls. SNP of TSLP and FLG null mutations were analysed. PCR and RFLP restriction fragment length polymorphism analysis was used.

Results
No polymorphisms of studied cytokines caused more frequent occurrence of AD compared to controls. We found no associations between TSLP gene polymorphism and AD severity (p = 0.395), IgE level (p = 0.895), VAS (p = 0.918) or concomitant asthma (p = 0.742).

Conclusions
The SNP of TSLP rs1898671 does not influence the AD course and occurrence. 2282del4 FLG mutation is a key influencer in AD. However, the coexistence of FLG mutations and SNP of TSLP may play a protective role.