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Gastroenterology Research and Practice
Volume 2013 (2013), Article ID 148086, 9 pages
http://dx.doi.org/10.1155/2013/148086
Review Article

Biomarkers for Gastroesophageal Reflux in Respiratory Diseases

1Faculty of Medicine, University of Iceland, Vatnsmyarvegur 16, 101 Reykjavik, Iceland
2Department of Respiratory Medicine and Sleep, Landspitali University Hospital, 108 Reykjavik, Iceland
3Occupational and Environmental Medicine, Sahlgrenska Academy, Gothenburg University, 413 90 Göteborg, Sweden
4Department of Medical Sciences: Respiratory Medicine and Allergology, Uppsala University, 753 12 Uppsala, Sweden
5Department of Clinical Biochemistry, Landspitali University Hospital, 108 Reykjavik, Iceland

Received 21 January 2013; Accepted 25 February 2013

Academic Editor: P. Marco Fisichella

Copyright © 2013 Össur Ingi Emilsson et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Gastroesophageal reflux (GER) is commonly associated with respiratory symptoms, either through a vagal bronchoconstrictive reflex or through microaspiration of gastric contents. No diagnostic test is available, however, to diagnose when respiratory illnesses are caused by GER and when not, but research in this field has been moving forward. Various biomarkers in different types of biosamples have been studied in this context. The aim of this review is to summarize the present knowledge in this field. GER patients with respiratory diseases seem to have a different biochemical profile from similar patients without GER. Inflammatory biomarkers differ in asthmatics based on GER status, tachykinins are elevated in patients with GER-related cough, and bile acids are elevated in lung transplant patients with GER. However, studies on these biomarkers are often limited by their small size, methods of analysis, and case selections. The two pathogenesis mechanisms are associated with different respiratory illnesses and biochemical profiles. A reliable test to identify GER-induced respiratory disorders needs to be developed. Bronchoalveolar lavage is too invasive to be of use in most patients. Exhaled breath condensate samples need further evaluation and standardization. The newly developed particles in exhaled air measurements remain to be studied further.