INTRODUCTION G.M. Verleden*, M.G. Demedts*, R. Westhovens}, M. Thomeer*,z *Depts of Respiratory Diseases and } Rheumatology, University Hospitals, Katholieke Universiteit Leuven, Leuven, and z Dept of Respiratory Diseases, Ziekenhuis Oost-Limburg, Genk, Belgium. Pulmonary manifestations of systemic diseases remain very interesting disease entities. However, they are usually not very well known by the treating physician. Several reasons could explain this. First of all, it is a fact that a lot of these systemic diseases are being treated by organ-specific specialists, who may not be very well acquainted with pulmonary signs and symptoms. Secondly, some of these entities are quite uncommon. Therefore, in the present Monograph, the editors have tried to gather a compilation of interesting pulmonary manifestations of very different disease entities, such as collagen vascular diseases and vasculitis syndromes, but also pulmonary involvement in renal, hepatic, gastrointestinal, neuromuscular, endocrine and metabolic, cardiovascular, immunodeficiency, and a1-antitrypsin deficiency diseases. There is also a chapter on non- infectious pulmonary manifestations after organ and bone marrow transplantation (not including heart–lung or lung transplantation) and on acute respiratory distress syndrome (ARDS). An important part of these topics was covered during an international symposium (entitled "Pulmonary manifestations of systemic diseases") that was organised by the Dept of Pulmonary Diseases, University Hospital Gasthuisberg, Katholieke Universiteit Leuven, Belgium (March 17–19, 2005). To that purpose, the editors gathered some 40 specialists from around Europe who, during working group sessions on March 17 and 18, discussed pulmonary involvement in collagen vascular diseases on the one hand and pulmonary vasculitis syndromes on the other hand. These working group discussions finally led to the first five chapters of the present Monograph. This symposium was accredited as a European School of Respiratory Medicine seminar, and was generously sponsored by GlaxoSmithKline (GSK), Belgium, in the framework of the GSK Chair of Respiratory Pharmacology at the Katholieke Universiteit Leuven, attributed to G.M. Verleden. The current editors very much hope that the present European Respiratory Monograph will provide the reader with an interesting overview and update on the possible pulmonary involvement and specific treatment options in different systemic diseases. The editors are very grateful to E.F.M. Wouters for granting us the privilege to act as guest editors for the present European Respiratory Monograph. Eur Respir Mon, 2006, 34, viii. Printed in UK - all rights reserved. Copyright ERS Journals Ltd 2006 European Respiratory Monograph ISSN 1025-448x. ISBN 1-904097-43-X. viii