Background and study aim: Eosinophilic esophagitis (EoE) is an immune-allergic mediated clinicopathologic ‎condition characterized by symptoms of esophageal dysfunction with prominent ‎eosinophilic infiltrate in the esophageal mucosa. Interleukin 5 (IL-5) play a role in ‎eosinophil esophageal trafficking in EoE patients.  This study aimed to assess serum ‎interleukin 5 as an indicator of EoE in patients with chronic upper GIT symptoms‎‎.‎
Patients and Methods: ‎‎‎ This study included 80 adults with at least one of chronic upper GIT symptoms not ‎responded to standard daily PPI therapy for 8 weeks, in whom upper GIT endoscopy ‎was done with histopathological assessment of esophageal biopsies. EoE was ‎diagnosed by detection of ≥15 eosinophils/high power field (HPF). Ten apparently ‎healthy subjects were enrolled as a control group. Interleukin-5 (IL-5) in serum by ‎ELISA was measured in all subjects‎.‎
Results: By histopathological examination, six patients (7.5%) were diagnosed to have EoE. ‎Endoscopic esophageal furrows, fissures/wrinkles; white exudate/granularity and ‎concentric rings (trachealization) were significantly more frequent in patients with EoE ‎than non EoE. Median concentration of serum IL-5 in EoE patients was 222.2pg/ml ‎with range 187.5-307pg/ml while, it was 32.1pg/ml with range 15.6-113.6pg/ml in non ‎EoE patients and 11.8pg/ml with range 13.4-38.2pg/ml in controls with P value < ‎‎0.001. ROC curve analysis showed that serum IL-5 can significantly predict EoE at a ‎cut-off value of ≥103.2pg/ml with sensitivity 100%, specificity 93.2%, PPV 54.5%, ‎NPV 100%, Accuracy 93.8%, AUC = 0.989 and (95%CI) = 0.96-1.0‎‎‎‎‎.
Conclusion: Serum interleukin 5 could be used as an indicator for eosinophilic esophagitis diagnosis ‎in patients with chronic upper GIT symptoms. However, histopathological diagnosis ‎still necessary‎