Eosinophil-rich esophagitis pattern in patients with allogenic hematopoietic stem cell transplantation: a multicenter experience.

Eosinophil-rich esophagitis is a pattern of inflammation characterized by increased intraepithelial eosinophils which is associated with a wide range of disorders including eosinophilic esophagitis (EoE). In hematopoietic stem cell transplant (HSCT) patients, eosinophil-rich esophagitis is exceedingly rare and associated in one prior case to transplant-acquired allergy (TAA). The goal of this multicenter study was to characterize the clinical and pathologic features of esophageal biopsies with an eosinophil-rich esophagitis pattern in HSCT patients. 10 cases were identified presenting with a median age of 45 years (range: 10-76), including 7 men. The median time lapsed from HSCT to biopsy was 6 months (range: 0-3). 3 patients presented within 21 days of HSCT, 2 of which showed apoptotic bodies. The median number of eosinophils/HPF was 25 (range: 16-102), 6 cases showed eosinophilic degranulation, 3 cases had eosinophilic abscesses, 5 cases showed apoptotic bodies, and 3 cases had dyskeratotic cells. Of the 5 patients presenting after 21 days of HSCT, features of GVHD were seen in 2 patients (apoptotic bodies and dyskeratotic cells) and 1 patient (apoptotic bodies only), with all of them having extra-gastrointestinal GVHD. 2 patients developed TAA to medications, levofloxacin and diphenhydramine, and 1 patient had an allergic transfusion reaction. Only 1 patient met diagnostic criteria for EoE. Based on these limited cases, HSCT patients presenting with an eosinophilic-rich esophagitis pattern were associated with conditioning regimen-induced injury and GVHD and seen in patients with TAA.