OUTLINE Introduction Materials and Methods Patient Selection Tear Sample Collection Saliva Sample Collection Glycan Release Glycan Enrichment Mass Spectrometric Analysis Results Discussion Conclusion GLYCOSYLATION IN TEAR AND SALIVA OF OCULAR ROSACEA

The purpose of this study was to study changes in glycosylation in tear and saliva obtained from control and ocular rosacea patients in order to identify potential biomarkers for rosacea. Tear fluid was collected from 51 subjects (28 healthy controls and 23 patients with ocular rosacea). Saliva was collected from 42 of the same subjects (25 controls and 17 patients). Pooled and individual samples were examined to determine overall glycan profiles and individual variations in glycosylation. O-and Nglycans were released from both patients and control subjects. Released glycans were purified and enriched by solid-phase extraction (SPE) with graphitized carbon. Glycans were eluted based on glycan size and polarity. SPE fractions were then analyzed by high-resolution mass spectrometry. Glycan compositions were assigned by accurate masses. Their structures were further elucidated by tandem mass spectrometric using collision-induced dissociation (CID), and specific linkage information was obtained by exoglycosidase digestion. Nand O-glycans were released from 20-mL samples without protein identification, separation, and purification. Approximately 50 N-glycans and 70 O-glycans were globally profiled Accepted for publication April 2012. From the Department of Ophthalmology, University of California, Davis, CA, Department of Ophthalmology, São Paulo Hospital, Federal University of São Paulo, Brazil, Department of Chemistry, University of California, Davis, CA, Department of Viticulture and Enology, University of California, Davis, CA, and Department of Biochemistry and Molecular Medicine, University of California, Davis, CA, USA. Financial Support: This study was funded in part by Research to Prevent Blindness, Inc., New York, NY, and by CAPES (Brazil) grant to ACV. The sponsor or funding organizations had no role in the design or conduct of this research. The authors have no commercial or proprietary interest in any concept or product discussed in this article. Single-copy reprint requests to Mark Mannis, MD (address below). Corresponding author: Mark J. Mannis, MD, Department of Ophthalmology eUniversity of California, Davis, 4860 Y Street, Suite 2400, Sacramento, CA 95817. Tel: (916)734-6957. Fax: (916)703-5076. E-mail address: mjmannis@ ucdavis.edu © 2012 Elsevier Inc. All rights reserved. The Ocular Surface ISSN: 15420124. Vieira AC, An HJ, Ozcan S, Kim JH, Lebrilla CB, Mannis MJ. Glycomic analysis of tear and saliva in ocular rosacea patients: The search for a biomarker. 2012;10(3):184-192. 184 THE OCULAR SURFACE / JULY 2012, V by mass spectrometry. Most N-glycans were highly fucosylated, while O-glycans were sulfated. Normal tear fluid and saliva contain highly fucosylated glycans. The numbers of sulfated glycans were dramatically increased in tear and saliva of rosacea patients compared to controls. Glycans found in tear and saliva from roseatic patients present highly quantitative similarity. The abundance of highly fucosylated N-glycans in the control samples and sulfated O-glycans in ocular rosacea patient samples may lead to the discovery of an objective diagnostic marker for the disease.