Non or minimally invasive methods for monitoring the treatment response in EoE, able of replacing endoscopic exams with esophageal biopsies, are largely desired. However, at the moment only invasive methods alowing endoscopic and histological examination of the oesophagus have provided accuracy enought for a reliable assessment of the activity of EoE.
In a recent research published in the Alimentary Pharmacology & Therapeutics a gruop of researchers obtained blood and serum samples from the adult EoE patients who participated in a randomized controlled trial with topic budesonide. Thery compared several analytical parameters before and after achieving disease remission, in order to identify changes in potencial peripheral markers of the disease. Absolute blood eosinophil count, serum-CCL-17, eotaxin-3, eosinophil cationic protein and mast cell tryptase all significantly decrease in EoE patients after receiving effective treatment with budesonide, but not in those patients who received a placebo.
Absolute blood eosinophil count resulted the most accurate marker, since it significantly correlated with esophageal eosinophil density before (Sperman rho = 0.28) and after (Spearman rho = 0.42) treatment. Howver ROC-AUC analysis only showed a moderate diagnostic yield. A cut-off point of 300 eos/mm3 provided a sensitivity of 88% but a suboptimal specificity of only 56%.
According to the authors, this research cannot draw conclusions whether these biomarkers can be used for diagnostic purposes in EoE patients, but suggests that a decrease of the number of peripheral blood eosinophils could indicate a successful treatment
response to topical corticosteroid therapy in EoE.
Further studies are, thus, needed, to identify and develop an alternative method for monitoring the presence of inflammation while avoiding the use of endoscopy.