American Journal of Respiratory and Critical Care Medicine Vol 178. pp. 208-209, (2008)
© 2008 American Thoracic Society
Significance of Bronchiectasis in Patients with  1-Antitrypsin Deficiency
From the Authors:
We read with interest Drs. Chan and Iseman's letter relating to our article on the prevalence and impact of bronchiectasis in  1-antitrypsin deficiency (AATD) (1). They suggest that our study was not directly comparable to Cuvelier and colleagues' study of the prevalence of AATD in subjects with bronchiectasis (2). We acknowledge this, but would like to clarify that such a comparison was not intended. The introduction indicates that our objective was to address key issues identified in the 2003 ATS/ERS official statement on AATD (3), and this was achieved by identifying how radiological bronchiectasis and emphysema, health status, physiology, and clinical manifestations were interrelated. Nevertheless, since there are few published data on this subject and the two largest published studies would appear, on superficial reading, to arrive at opposite conclusions, it was necessary to address the apparent disparity. Although the subject populations are not directly comparable, Cuvelier and coworkers (2) also demonstrated that, in the presence of emphysema, bronchiectasis is associated with an abnormal distribution of AAT alleles, whereas in those subjects without emphysema no such association was evident. This distinction was discussed, since it does suggest agreement (and some comparability) between the two studies.
Chan and Iseman question the true significance of bronchiectasis in our study (1), but in the absence of accepted criteria, they do not indicate what they would consider as "significant." Bronchiectasis is defined as "abnormal chronic dilation of one or more bronchi" (4), and the diagnosis is usually sought in subjects with chronic sputum production using CT imaging. Although 95% of our patients had radiological bronchiectasis, as defined above, approximately 50% reported sputum production on a regular basis, and we therefore did not consider that the diagnosis of "clinically significant bronchiectasis" could be based solely on the radiological definition. We attempted to place our findings into a clinical setting by modifying a previously used arbitrary threshold (5). This pragmatic approach was chosen to generate a conservative, but clinically relevant estimate, also recognizing that sputum production occurs in subjects with chronic obstructive pulmonary disease (COPD) in the absence of bronchiectasis.
We agree that a case-control study with usual COPD is desirable, but our comparison with the study of O'Brien and coworkers (6) may still be informative; the prevalence of bronchiectasis and emphysema was 29% and 53%, respectively, but they were not related. In contrast, bronchiectasis severity related to emphysema severity in AATD, and the distribution of airways disease and emphysema was concordant, and predominantly basal, suggesting some pathogenic commonality, as discussed in the article (1).
David G. Parr
University Hospitals of Coventry and Warwickshire
Coventry, United Kingdom
and
University Hospital Birmingham
Birmingham, United Kingdom
Peter G. Guest
University Hospital Birmingham
Birmingham, United Kingdom
John H. Reynolds
Birmingham Heartlands Hospital
Birmingham, United Kingdom
Lee J. Dowson
Royal Wolverhampton Hospitals NHS Trust
Wolverhampton, United Kingdom
Robert A. Stockley
University Hospital Birmingham
Birmingham, United Kingdom
FOOTNOTES
Conflict of Interest Statement: D.G.P. has received conference attendance expenses from Boehringer Ingelheim in 2006. P.G.G. has no financial relationship with a commercial entity that has an interest in the subject of this manuscript. J.H.R. has no financial relationship with a commercial entity that has an interest in the subject of this manuscript. L.J.D. has no financial relationship with a commercial entity that has an interest in the subject of this manuscript. R.A.S. has received grant funding for the past 3 years from Talecris and AstraZeneca; he sits on advisory boards, including Boehringer Ingelheim, Schering-Plough, GlaxoSmithKline (GSK), and Talecris; and he has lectured on behalf of GSK and Talecris.
REFERENCES
- Parr DG, Reynolds JH, Guest P, Dowson LJ, Stockley RA. Prevalence and impact of bronchiectasis in 1-antitrypsin deficiency. Am J Respir Crit Care Med 2007;176:1215–1221.[Abstract/Free Full Text]
- Cuvelier A, Muir JF, Hellot MF, Benhamou D, Martin JP, Benichou J, Sesboue R. Distribution of alpha(1)-antitrypsin alleles in patients with bronchiectasis. Chest 2000;117:415–419.[CrossRef][Medline]
- American Thoracic Society/European Respiratory Society Statement. Standards for the diagnosis and management of individuals with alpha-1 antitrypsin deficiency. Am J Respir Crit Care Med 2003;168:818–900.[Free Full Text]
- Cole P. Bronchiectasis. In: Brewis RAL, Corrin B, Geddes DM, Gibson GJ, editors. Respiratory medicine, 2nd ed. London: WB Saunders; 1995. pp 1286–1317.
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- O'Brien C, Guest P, Hill S, Stockley R. Physiological and radiological characterisation of patients diagnosed with chronic obstructive pulmonary disease in primary care. Thorax 2000;55:635–642.[Abstract/Free Full Text]
Copyright © 2008 American Thoracic Society
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