Self-Reported Allergic Rhinitis and/or Allergic Conjunctivitis Associate with IL13 rs20541 Polymorphism in Finnish Adult Asthma Patients.

BACKGROUND

Our aim was to observe factors associated with IL13 rs20541 polymorphism and other factors with or without allergic comorbidities such as subject-reported allergic rhinitis (AR) and/or allergic conjunctivitis (AC) symptoms in adult asthmatics.

METHODS

A population-based sample of Finnish adult asthma patients (n = 1,156) and matched controls (n = 1,792) filled in a questionnaire. Asthma was diagnosed based on a typical history of asthma symptoms and lung function tests. Skin prick tests with 17 aeroallergens and blood tests including analysis of interleukin 13 (IL13) rs20541 (G/A) genotypes were performed for a subsample (n = 193).

RESULTS

The proportion of asthmatics reporting AR was 61.9% and reporting AC was 40.7%. After adjustments, the presence of the IL13 rs20541A- allele (OR 3.06, 95% CI 1.42-6.58, p = 0.004) or multisensitization (adjusted OR 4.59, 95% CI 1.48-14.26, p = 0.008) was associated with AR/AC asthma. Nasal polyps and acetylsalicylic acid-exacerbated respiratory disease was also associated with AR/AC asthma.

CONCLUSIONS

Adult AR/AC asthma could putatively be a phenotype, characterized by the presence of atopic and/or eosinophilic factors and a high prevalence of the IL13 rs20541A- allele. Studies on the mechanisms behind this and in other populations are needed.