ERS | monograph Preface John R. Hurst This is an exciting time for those interested in AATD, and for those caring for people affected by AATD. A greater understanding of the science underpinning pathophysiological mechanisms is now directly translating into trials of innovative therapies, whilst our understanding of the role of augmentation therapy is changing with the recent publication of well-conducted trials using novel CT imaging end-points. Consequently, a Monograph addressing AAT is timely, and I congratulate the Guest Editors and authors for their excellent contributions this should be essential reading and the “go to” reference work on the topic for many years to come. AAT is a fascinating condition, affecting people at all ages, from neonates through to the elderly, and with protean manifestations that demand that the AAT specialist be aware not just of the respiratory manifestations of this condition, but also the assessment and management of liver disease and rarer manifestations, such as panniculitis and vasculitis. The diagnosis of AATD is all too often delayed and it is therefore essential that general pulmonologists and the wider multi-professional respiratory community are aware of when to suspect AATD, and how to test for it. Our patients deserve nothing less. Finally, and in addition to thanking the Guest Editors and authors, I’d like to take this opportunity to thank the Monograph staff who work “behind the scenes” at the ERS Publications Office. I warmly recommend this Monograph to you. Disclosures: John R. Hurst reports receiving grants, personal fees and non-financial support from pharmaceutical companies that make medicines to treat respiratory disease. This includes reimbursement for educational activities and advisory work, and support to attend meetings. Copyright ©ERS 2019. Print ISBN: 978-1-84984-108-5. Online ISBN: 978-1-84984-109-2. Print ISSN: 2312-508X. Online ISSN: 2312-5098. https://doi.org/10.1183/2312508X.10026319 v