Anti–IL-5 (mepolizumab) therapy for eosinophilic esophagitis Miguel L. Stein, MD, Margaret H. Collins, MD, Joyce M. Villanueva, BS, Jonathan P. Kushner, MD, Philip E. Putnam, MD, Bridget K. Buckmeier, BA, Alexandra H. Filipovich, MD, Amal H. Assa'ad, MD, Marc E. Rothenberg, MD, PhD  Journal of Allergy and Clinical Immunology  Volume 118, Issue 6, Pages 1312-1319 (December 2006) DOI: 10.1016/j.jaci.2006.09.007 Copyright © 2006 American Academy of Allergy, Asthma and Immunology Terms and Conditions

Fig 1 Effect of anti–IL-5 on circulating leukocytes. Effect of anti–IL-5 on peripheral blood eosinophil counts (mean ± SD, n = 4). Absolute numbers of eosinophils (A), the percentage of CCR3+ cells in peripheral blood leukocytes (B), and the percentage of eosinophils and total white blood cell counts expressed as ×103 cells (K)/mm3 (WBC; C) during the 28 weeks of the trial. Patients received infusions of anti–IL-5 therapy (mepolizumab) at weeks 8, 12, and 16 (arrows). Blood was taken before the infusion. Percentage of CCR3+ cells (B) was measured before (week 8) and after (week 20) treatment (lines represent mean values). Journal of Allergy and Clinical Immunology 2006 118, 1312-1319DOI: (10.1016/j.jaci.2006.09.007) Copyright © 2006 American Academy of Allergy, Asthma and Immunology Terms and Conditions

Fig 2 Effect of anti–IL-5 on esophageal eosinophil levels. Biopsies were done before (week 8) and after (week 20) anti–IL-5 therapy (mepolizumab). Analysis of each individual (A) shows the median value (line) and actual tissue eosinophil count distribution per hpf. Each point represents a unique hpf counted. Analysis of the entire group (B) shows the mean, median, and maximum eosinophil levels before (week 8) and after (week 20) treatment. Journal of Allergy and Clinical Immunology 2006 118, 1312-1319DOI: (10.1016/j.jaci.2006.09.007) Copyright © 2006 American Academy of Allergy, Asthma and Immunology Terms and Conditions

Fig 3 Photomicrographs of esophageal biopsies before and after anti–IL-5 therapy. Biopsies from the distal esophagus before (A, B) and after (C, D) anti–IL-5 therapy (mepolizumab). The photomicrographs have been selected to demonstrate representative well oriented (A, C) and typical biopsies with maximal tissue pathology (B, D). Note the presence of marked eosinophilic inflammation and epithelial hyperplasia before (week 8) and reduced eosinophilic inflammation and epithelial hyperplasia after (week 20) anti–IL-5. The photomicrographs were taken from patient number 4. Original magnification, ×400. Journal of Allergy and Clinical Immunology 2006 118, 1312-1319DOI: (10.1016/j.jaci.2006.09.007) Copyright © 2006 American Academy of Allergy, Asthma and Immunology Terms and Conditions