Assessing eosinophilic cationic protein as a biomarker for monitoring patients with eosinophilic esophagitis treated with specific exclusion diets

Background: Eosinophilic esophagitis (EoE) is a complex pathology. Attempts have been made in order to relate EoE with the intake of certain food. The problem is to establish which foods are really involved in the pathophysiology of this condition and to objectify a reliable inflammation biomarker for the follow-up of patients undergoing pharmacological treatment and/or diets. Our aim is to assess the food sensitization profile of patients with objective diagnosis of EoE and objectify the utility of ECP as an inflammation biomarker for the follow-up of patients with EoE treated with specific diets, based on the hypothesis that we will observe a decrease and clinical improvement after maintenance of these diets. Methods: A total of 19 subjects were included between 1 January 2012 and 30 June 2015. Diets based on allergy testing were established. Prior to the initiation of the diets, baseline ECP was determined. Appointments were arranged for the patients between 4 and 6 months later to assess the clinical response to the specific diets and to request a second blood sample for blood counts and serum ECP levels to compare with the previous baseline. Results: 19 patients diagnosed with EoE (12 males and 7 females) between January 2012 and June 2015, aged between 17 and 68 (33.52; SD 13.67 years), were included consecutively, 15 of whom showed optimum response to specific diets based on allergy testing. A statistically significant difference ECP decrease was observed in our patients. Discussion: Until now most of the studies previously published in reference to the use of ECP as a biomarker for monitoring patients on treatment with diets show consistent but insignificant decreases in ECP levels. However, ECP seems to be a good marker of inflammation if the determinations are performed avoiding confounding factors. Conclusion: The serial determination of ECP is useful when monitoring patients with EoE treated with specific diets.