Parental celiac disease and risk of asthma in offspring: a Danish nationwide cohort study

Allergic manifestations in autoimmune gastrointestinal disorders

Allergic disorders target a young population, are increasing in both incidence and prevalence and are associated with significant disease burden. They result from the complex interplay between (epi)genetic and environmental factors, resulting in a Th2 inflammatory process targeting the epithelium of the respiratory tract (allergic rhinitis and asthma), skin (atopic dermatitis), and gastrointestinal tract (food allergy). Although the exact pathogenic mechanisms remain elusive, an altered immune system response in the gut is increasingly recognized as a relevant step. Allergic and gastrointestinal autoimmune disorders share several epidemiological, pathogenic and risk factors and several treatment modalities. Here we revise the current literature and show that allergic disorders are highly prevalent in gastrointestinal autoimmune diseases, including celiac disease, inflammatory bowel disease, autoimmune pancreatitis, and autoimmune cholangiopathies. No data are available for some autoimmune diseases, such as autoimmune gastritis and autoimmune enteropathy. To ensure the comprehensive care of patients with autoimmune gastrointestinal disorders, along with disease-specific factors, the presence of allergic disorders should be evaluated and treated when present, possibly targeting shared molecular pathways. Future studies are needed to define the exact pathogenic mechanisms underpinning the association between allergic and autoimmune diseases of the gastrointestinal tract.

Bidirectional Association between Asthma and Irritable Bowel Syndrome: Two Population-Based Retrospective Cohort Studies

Background

There is a demonstrated association between asthma and irritable bowel syndrome (IBS). In this study, we examined the bidirectional association between asthma and IBS using a nationwide database.

Methods

We conducted two retrospective cohort studies using data obtained from the National Health Insurance of Taiwan. Study 1 included 29,648 asthma patients newly diagnosed between 2000 and 2010. Study 2 included 29,875 IBS patient newly diagnosed between 2000 and 2010. For each study, four subjects without asthma and IBS were selected, respectively, frequency-matched by sex, age, and the diagnosis date. All four cohorts were followed up until the end of 2011 to estimate incident IBS for Study 1 and incident asthma for study 2. Adjusted hazard ratios (aHRs) were estimated using the Cox proportional hazards model after controlling for sex, age and comorbidities.

Results

The incidence of IBS was 1.89 times higher in the asthma cohort than in the comparison cohort (8.26 vs. 4.36 per 1,000 person-years), with an aHR of 1.57 [95% confidence interval (CI) = 1.47–1.68]. The aHRs remained significant in all subgroups measured by sex, age and the presence of comorbidities. In contrast, the incidence of asthma was 1.76 times higher in the IBS cohort than the comparison cohort (7.09 vs. 4.03 per 1,000 person-years), with an aHR of 1.54 (95% CI = 1.44−1.64). Similarly, aHRs remained significant in all subgroups measured by sex, age and the presence of comorbidities.

Conclusion

The present study suggests a bidirectional association between asthma and IBS. Atopy could be a shared pathophysiology underlying this association, deserving a further investigation.