H av on emeyer Foundati Havemeyer Foundation Monograph Series No. 9 Proceedings of a Workshop on INFLAMMATORY AIRWAY DISEASE: DEFINING THE SYNDROME 30th September – 3rd October 2002 Boston, USA Editors: A. Hoffman, N. E. Robinson and J. F. Wade H av on emeyer Foundati Havemeyer Foundation Monograph Series No. 9 Proceedings of a Workshop on INFLAMMATORY AIRWAY DISEASE: DEFINING THE SYNDROME 30th September – 3rd October 2002 Boston, USA Editors: A. Hoffman, N. E. Robinson and J. F. Wade © 2003 by R & W Publications (Newmarket) Limited Suites 3 & 4, 8 Kings Court, Willie Snaith Road, Newmarket, Suffolk CB8 7SG, UK No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, without the prior permission of the copyright owner. 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First published 2003 ISSN 1472-3158 Published by R & W Publications (Newmarket) Limited Printed in Great Britain by Quality Print Services (Anglia) Limited Havemeyer Foundation Monograph Series No. 9 CONTENTS EDITORS’ FOREWORD .....................................................................................................................Page v SESSION 1: CLINICAL EVIDENCE Inflammatory airway disease: a clinician’s view from North America B. R. Rush ..........................................................................................................................................Page 3 Inflammatory airway disease: European clinician’s perspective P. M. Dixon, B. C. McGorum and R. S. Pirie ....................................................................................Page 7 Inflammatory airway disease: effect of athletic discipline M. Mazan and A. Hoffman..................................................................................................................Page 9 Mucus, cough, airway obstruction and inflammation N. E. Robinson, C. Berney, H. DeFeijter-Rupp, A. M. Jefcoat, C. Cornelisse, V. Gerber and F. J. Derksen ..............................................................................................................................Page 13 Relationship between coughing and airway inflammation in young racehorses D. R. Hodgson, R. M. Christley, J. L. N. Wood, S. W. J. Reid and J. L. Hodgson ...........................Page 16 Poor performance: the trainer’s perspective (sport horse) C. Platz ............................................................................................................................................Page 19 The diagnostic approach to chronic cough in people A. J. Ghio ..........................................................................................................................................Page 23 SESSION 2: AETIOLOGY Aetiological agents: indoor environment and endotoxin B. C. McGorum and R. S. Pirie .......................................................................................................Page 27 Aetiological agents: outdoor environment and airways A. J. Ghio ........................................................................................................................................Page 29 Aetiological agents: allergy and related mediators J. P. Lavoie .......................................................................................................................................Page 31 Aetiological agents: viruses and inflammatory airway disease J. L. N. Wood, J. R. Newton, K. C. Smith and D. J. Marlin ............................................................Page 33 Natural history of equine influenza H. G. G. Townsend............................................................................................................................Page 37 Aetiological agents: bacteria J. R. Newton, J. L. N. Wood, K. C. Smith, D. J. Marlin and N. Chanter .........................................Page 40 Dysregulation of inflammation F. Bureau and P. Lekeux ...................................................................................................................Page 45 iii Inflammatory Airway Disease SESSION 3: DIAGNOSTIC MEASURES OF INFLAMMATION Significance of tracheal inflammation J. L. Hodgson ....................................................................................................................................Page 49 Significance of bronchoalveolar cytology in inflammatory airway disease of horses L. Viel ................................................................................................................................................Page 52 Cytology of inflammatory airway disease K. C. Smith, J. R. Newton, S. M. Gower, S. M. Cade, D. J. Marlin and C. M. Deaton ...................Page 55 Quantifying and characterising mucus in the airways V. Gerber, A. M. Jefcoat, J. A. Hotchkiss, M. King and N. E. Robinson..........................................Page 59 Breath condensate measures of airway inflammation D. J. Marlin, C. M. Deaton, J. R. Newton and K. C. Smith .............................................................Page 62 SESSION 4: FUNCTIONAL SIGNIFICANCE Lung function for beginners F. J. Derksen .....................................................................................................................................Page 69 Airway obstruction and hyper-reactivity in horses with signs of inflammatory airway disease A. Hoffman and M. Mazan................................................................................................................Page 71 Inflammatory airway disease and gas exchange G. Nyman ..........................................................................................................................................Page 75 Functional imaging of inflammatory airway disease D. Votion ...........................................................................................................................................Page 81 Inflammatory airway disease and clinical exercise testing L. Couëtil ..........................................................................................................................................Page 84 WORKSHOP SUMMARY...................................................................................................................Page 89 LIST OF PARTICIPANTS...................................................................................................................Page 92 AUTHOR INDEX ...............................................................................................................................Page 93 iv Havemeyer Foundation Monograph Series No. 9 EDITORS’ FOREWORD he nomenclature of equine non-infectious reversibility with drugs, ‘recurrent airway obstruction (RAO)’ was also deemed an airway disease is a source of puzzlement appropriate term. By exclusion, all other forms of to many. The terms ‘chronic obstructive T non-infectious airway disease are referred to as pulmonary disease (COPD)’, ‘inflammatory IAD, the topic of this workshop. airway disease (IAD)’, ‘chronic obstructive The Havemeyer Workshop series brings bronchitis (COB)’, ‘reactive airway disease’, together investigators from a range of disciplines ‘allergic bronchitis’, ‘heaves’, ‘broken wind’ and and locations to discuss topic of specific concern ‘small airway disease’ confuse vets and other to the horse industry. IAD is such a topic and we biomedical scientists. The plethora of terminology therefore invited clinicians, epidemiologists, reflects a poor understanding of the pathogenesis pathologists, microbiologists and physiologists to of equine airway disease and leads to confusion as share knowledge with each other. Several to the best way to treat and prevent airway disease. important questions must be addressed before we For years, ‘equine COPD’ was used to describe can provide solid answers about IAD. First, we any accumulation of neutrophils and mucus in the must decide what each of us means by the term airways in the absence of active infection, eg the IAD. Is the syndrome seen in young racehorses mature horse with severe heaves and the younger similar to that of the older ‘cougher without animal with reduced performance, increased airway heaves’? How important is infection? Does the neutrophils and mucus. However, the 2 conditions culture of organisms from the trachea mean that are very different and there is no evidence that the these organisms are causing functional changes in former is a consequence of the latter. A further the airways? Is inflammation regionalised in the source of confusion is the incongruous use of the lung? Does inflammation and mucus in the term in human and veterinary medicine. In human trachea indicate lower airway inflammation? medicine, COPD is a disease of aged smokers and What are the functional consequences of IAD and the term would not be used to describe a young the clinical consequences to the horse? Finally, athlete with a cough, increased