title: Assessment of fractionated exhaled nitric oxide as a biomarker for the treatment of eosinophilic esophagitis.
abstract: Diagnosis of eosinophilic esophagitis (EoE) and determination of response to therapy is based on histological assessment of the esophagus, which requires upper endoscopy. In children, in whom a dietary approach is commonly used, multiple endoscopies are needed, because foods are eliminated and then gradually reintroduced. Ideally, noninvasive methods could supplement or replace upper endoscopy to facilitate management. Fractionated exhaled nitric oxide (FeNO) has been proposed as a useful measure for monitoring disease activity in studies of patients with eosinophil-predominant asthma and in other atopic disorders. Thus, we evaluated whether FeNO levels could be a useful biomarker to assess the response to therapy in EoE patients. This study was designed to determine whether there is a change in FeNO levels during treatment with topical corticosteroids and whether changes correlated with clinical response. This was a prospective, multicenter study that enrolled nonasthmatic patients with established EoE. FeNO levels and symptom scores were measured at baseline, biweekly during 6-week swallowed fluticasone treatment, and 4 weeks posttreatment. Twelve patients completed the trial. We found a statistically significant difference between median pre- and posttreatment FeNO levels [20.3 ppb (16.0 -29.0 ppb) vs 17.6 ppb (11.7 -27.3 ppb), [corrected] p=0.009]. However, neither the pretreatment FeNO level, a change of FeNO level after 2 weeks of treatment, nor the FeNO level at the end of treatment confidently predicted a clinical or histological response. Although our findings suggest nitric oxide possibly has a physiological role in EoE, our observations do not support a role of FeNo determination for management of EoE.
authors: Department of Rheumatology, Immunology and Allergy, Harvard Medical School/Massachusetts General Hospital, Boston, MA 02114, USA. jleung7@partners.org
authors: John
authors: J
authors: Leung
authors: Ann
authors: A
authors: Nguyen-Traxler
authors: Erika M
authors: EM
authors: Lee
authors: Jason S
authors: JS
authors: Yip
authors: Joel V
authors: JV
authors: Weinstock
authors: Walter W
authors: WW
authors: Chan
authors: Peter
authors: P
authors: Ngo
authors: Barbara J
authors: BJ
authors: Weinstein
authors: Peter A
authors: PA
authors: Bonis
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000737:chemistry / Q000378:metabolism; D002648:Child; D057765:Eosinophilic Esophagitis / Q000175:diagnosis / Q000188:drug therapy* / Q000378:metabolism*; D045853:Exhalation; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009569:Nitric Oxide / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000378:metabolism*; D010865:Pilot Projects; D011446:Prospective Studies; D055815:Young Adult
chemical_list: D015415:Biomarkers; D009569:Nitric Oxide
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