Since its initial description in the early 1990s , eosinophilic esophagitis (EoE) was considered a clinicopathologic syndrome, for which the diagnostic hallmark consisted of esophageal symptoms coupled with high concentrations of intraepithelial eosinophils in esophageal biopsies.
Despite the significant amount of knowledge gained on EoE in the last two decades, the former diagnostic definition for EoE has remain unchanged in the Consecutive consensus guidelines published in 2007, 2011, and 2013. According to them, both clinic and pathologic information should be taken into consideration and neither of these parameters should be interpreted in isolation. Clinical-pathological dissociation is commonly described in patients with EoE, which means that asymptomatic periods do not necessarily imply resolution of eosinophilic inflammation, while dysphagia or food impaction may occur in patients without eosinophilic inflammation. Notably, both symptoms and biological activity have been reported to be major determinants for patient’s quality of life.
EoE is a chronic disease with a remarkable diagnostic delay. Thus, patients usually develop adaptive behaviors that allow them to better cope with symptoms. In this regard, dysphagia may be reduced by food avoidance, modifying the consistency of foods consumed, altering eating pace, or restricting social activities around food. Therefore, assessment of dysphagia in EoE may be challenging, because it depends not only on the activity of the disease, but also on the effectiveness of behavioral adaptation strategies taken by the patients to minimize symptoms.
The limitations of the “classic” scales or questionnaries to assess dysphagia on the basis of quantifying the frequency and intensity of factual esophageal symptoms, have being tryed to overcome by an international group of experts through the developed and validation of the “EoE activity index (EEsAI)”, a patient-reported outcome (PRO) instrument for adult patients that quantifies both difficulties foreseen by patients in eating 8 different food consistencies and dietary or behavioral modifications for these specific foods.
The same group of researchers who originally developed the EEsAI instrument have recently published important data on the accuracy of esophageal symptoms to predict the inflammatory activity of EoE (this is, the presence or absence of eosiophilic infiltration in esophageal biopsies). In a multinational cohort of 269 adult EoE patients the diagnostic accuracy of distinct EEsAI PRO score cut-off values were correlated to endoscopic and histologic remission of EoE. Unfortunately, the EEsAI score exhibited a sensitivity and specificity markedly low: sensitivity and specificity values for EEsAI PRO score of 20 to predict histologic remission (peak eosinophil count <15/HPF) were 48.6% and 70.9%, respectively. These cut-off points showed an overall poor diagnostic accuracy, with an area under the receiving operator characteristics (ROC) curve of only 0.61. Moreover, the EEsAI instrument could not adequately predict remission of endoscopic findings.
Overall, this study draws a relevant message for clinical practice, since esophageal symptoms alone showed a modest predictive capacity for estimating the presence of either histological or endoscopic remission in adult patients with EoE. The study is therefore pivotal to understand that clinicians should not make assumptions about the biological activity of EoE exclusively upon symptoms, so histologic analysis through endoscopy for diagnosis and monitoring of the disease currently continues to be necessary.