Introduction

Non-invasive biomarkers are needed to improve the management of eosinophilic esophagitis (EoE). We investigated whether eosinophil and lymphocyte counts could be used to diagnose EoE among patients with dysphagia and assess histological, endoscopic, and clinical disease activity in patients with known EoE.

Aims & Methods

This was a prospective study conducted at four EoE referral centers (Pisa, Padova, Humanitas Research Hospital, Milano Policlinico San Donato). We enrolled consecutive patients undergoing esophagogastroduodenoscopy (EGD) for suspected or known EoE who had performed blood counts within one month before EGD. Histological remission and non-EoE-related dysphagia (NED) were defined according to current guidelines on EoE. Endoscopic characteristics were classified according to the EoE reference score (EREFS). Demographic, clinical and full blood count data were collected. After the EGD, all patients completed the Dysphagia Symptom Questionnaire over 14 days (DSQ). Kruskal-Wallis Rank Sum Test and Pearson’s Chi-squared were used for comparisons. ROC curve analysis was used to assess the diagnostic accuracy. Spearman’s test was used for correlations. Significance threshold was p<0.05.

Results

We included 210 consecutive patients. Of these, 123 had EoE (58.5% active; 41.5% in histological remission) while 87 had non-EoE dysphagia (NED). Characteristics in Table 1. Absolute eosinophil count (AEC) of active EoE was significantly higher than NED (335 vs 90/mm3; p<0.001), and so was eosinophil percentage (4.6% vs 1.1%; p<0.001), and median lymphocyte percentage (30 vs 27%; p<0.001). ROC curve analysis showed that a cut-off of 155 eosinophils/mm3 had an AUC of 0.85, with 71% specificity and 87% sensitivity for the identification of EoE among patients with dysphagia (Figure 1a). Other ROC analyses on the diagnosis of EoE reported in Table 2. With regards to disease monitoring, only eosinophil counts differed significantly between EoE and NED. Median AEC of active EoE was higher than EoE in remission (335 vs 200/mm3; p<0.01), and so was eosinophil percentage (4.6 vs 1.4%; p<0.001) (Table 3). Based on ROC analysis, a cut-off of 325 eosinophils/mm3 had and AUC of 0.70 for the identification of histological remission in EoE, with a specificity of 52.7%% and sensitivity of 82.3% (Figure 1b) (Table 3). There was modest positive correlation between AEC and the EREFS with Spearman’s Rho of 0.4 (p<0.0001), but there was no correlation between AEC and DSQ scores (Rho= -0.01; p=0.9).

Conclusion

Our results show that the AEC in peripheral blood has good accuracy for the diagnosis of EoE in patients with dysphagia and moderate accuracy for monitoring histological disease activity. In addition, AEC was modestly correlated with endoscopic disease activity (EREFS score) but not with symptoms.

Disclosure

Speaker or Consultancy for Apogee Therapeutics, Dr Falk Pharma, Malesci, JB Pharmaceuticals, Sanofi, Alfasigma