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Investigation of Periostin and TARC Levels in the Search for a Non-Invasive Biomarker in Children and Adults with Eosinophilic Esophagitis
Monday, March 7, 2016
South Exhibit Hall H (Convention Center)
Anubha Tripathi, MD, Lisa J Workman, BA, Kush S Patel, BS, Barrett H Barnes, MD, Thomas A.E. Platts-Mills, MD PhD FAAAAI, Scott P. Commins, MD PhD
Rationale:  Currently, the only test for pathologic assessment of disease progression and treatment response in Eosinophilic Esophagitis (EoE) is esophagogastroduodenoscopy, which poses the potential for significant procedure-related risk.  Therefore, establishing non-invasive biomarkers to monitor disease status is essential.  Since periostin and thymus and activation regulated chemokine (TARC) have been implicated in facilitating eosinophil tissue infiltration in allergic esophageal responses, we sought to measure these levels in patients with EoE.

Methods:  Sera from children (n=20) and adults (n=3) with biopsy-diagnosed EoE were obtained and analyzed for periostin (Periostin/OSF-2 (human), Phoenix Pharmaceuticals, Inc.) and TARC (human CCL-17 (TARC), BioLegend, Inc.) by ELISA.

Results:  Mean periostin level (ng/mL) (n=23, range=10.3-405.5, mean±SEM= 186.7±23.2) was significantly higher than reported levels for healthy controls and was higher in patients with signs of fibrosis (esophageal narrowing, mucosal rings, and longitudinal furrows) (n=13, mean±SEM= 204.2±35.69) versus without signs of fibrosis (n=10, mean±SEM= 163.9±26.87).  Mean TARC level (pg/mL) (n=23, range=88.4-1159, mean±SEM= 511.8±64.06) was significantly higher than reported levels for healthy controls and was higher in patients with signs of fibrosis (n=11, mean±SEM= 626.3±93.59) versus without signs of fibrosis (n=12, mean±SEM= 407.0±79.63).  In addition, changes in periostin and TARC levels in individual patients’ sera taken at different time points vary with alterations in their clinicopathologic status.

Conclusions:  Our results indicate that periostin and TARC levels are elevated in EoE patients and in the subset presenting with fibrosis.  Changes in these levels also correlate with changes in clinicopathologic status, suggesting they are reflective of disease activity and, therefore, look promising as biomarkers for EoE.