Systematic review: the association between eosinophilic oesophagitis and coeliac disease.

BACKGROUND: The relationship between eosinophilic oesophagitis (EoE) and coeliac disease (CD) remains controversial, with studies yielding varied results. AIM: To systematically review the evidence of a possible association between both diseases.
METHODS: Electronic searches were performed with keywords relating to EoE and CD in the MEDLINE, EMBASE and SCOPUS databases. Summary estimates were calculated. A random-effects model was used depending on heterogeneity (I(2) ). Publication bias was assessed with the aid of funnel plot analysis, along with the Begg-Mazumdar, Harbord and Egger tests.
RESULTS: The search yielded 197 references; 30 were included in the quantitative summary, with most of these presenting methodological inconsistencies. Significant publication bias in favour of short studies reporting positive associations between both diseases was documented. The prevalence of EoE in CD ranged from 0% to 10.7% (I(2)  = 78.9%). Prevalence of CD in EoE varied between 0.16% and 57.1% (I(2)  = 89%). One high-quality, prospective, randomly selected, population-based study documented a 1.1% prevalence of CD, with no patients presenting EoE. Clinical and methodological heterogeneity hindered the performance of quantitative summaries for prevalence data. A gluten-free diet was effective in achieving histological remission of EoE in 32.1% of coeliac patients (95% confidence interval, 14.9-52.2%; I(2)  = 52.2%), which was similar to that expected for wheat elimination in EoE patients.
CONCLUSIONS: While a lack of valid studies prevents us from completely ruling out a true association between EoE and CD, currently available evidence does not support this hypothesis. Indeed, the only epidemiological study with sufficient validity points to the independence of both diseases.