Serum Biomarkers for the Diagnosis of Eosinophilic Esophagitis and Eosinophilic Gastroenteritis

Objective Clinically useful serum biomarkers for the diagnosis and monitoring of eosinophilic gastrointestinal diseases are not available. This study was conducted to examine the possible value of eosinophil-related proteins as serum biomarkers. Methods The serum concentrations of 49 cytokines, chemokines, and other proteins were measured in 29 patients with eosinophilic gastrointestinal diseases and 80 controls. Results The levels of interleukin (IL)-5, IL-33, eotaxin-3, and thymic stromal lymphopoietin (TSLP), previously reported as possible biomarkers of eosinophilic esophagitis, were not significantly elevated in the serum. In contrast, the B cell-attracting chemokine (BCA)-1/chemokine (C-X-C motif) ligand (CXCL) 13 and hemofiltrate C-C chemokine (HCC)-1/CC chemokine ligand (CCL) 14α levels were significantly elevated, while the granulocyte chemotactic protein (GCP)-2/CXCL6 levels were suppressed in patients with eosinophilic esophagitis as well as in those with eosinophilic gastroenteritis. The cutaneus T cell-attracting chemokine (CTACK)/CCL27, stromal cell-derived factor (SDF)-1/CXCL12, macrophage inflammatory protein (MIP)-3β/CCL19, and squamous cell carcinoma antigen (SCCA) 2 levels were elevated only in patients with eosinophilic esophagitis. However, there were large overlaps of data obtained from the patient and control groups, indicating that these serum biomarkers are not adequately sensitive for clinical use with presently available assay systems. Conclusion Of the 49 investigated serum proteins, none were shown to be adequately sensitive for use as biomarkers for the diagnosis or monitoring of eosinophilic gastrointestinal diseases.