The current standard for diagnosis of Eosinophilic Esophagitis (EoE) is endoscopy with esophageal biopsy to determine the eosinophil count. A non-invasive biomarker of eosinophil activation would be helpful in management. A recent study investigated urinary 3-bromotyrosine (3-BT) measurements as a possible biomarker.
An assay called the Eosinophil Quantitated Urine Kinetic was developed. In the EoE patients, median urinary 3-BT level was 93 times higher than the nonatopic (nonallergic) group and 13 times higher than the atopic (allergic) group. Subjects with urine 3-BT level greater than 20pg/400mg of creatinine were 4.8 times more likely to have EoE compared to atopic controls. An atopic disease flare was not associated with any difference in urinary 3-BT.
Urinary 3-BT is an exciting assay that may assist allergists for the diagnosis of EoE.
Author Saraleen Benouni, MD Dr. Benouni specializes in the treatment of asthma, allergies, atopic dermatitis, and immune disorders for both adults and children. She has presented and published research at national allergy meetings and has authored papers on drug allergies and skin conditions. She is a member of the American College and American Academy of Allergy, Asthma, and Immunology, and the Los Angeles Society of Allergy, Asthma, and Clinical Immunology.