Chronic respiratory questionnaire.

AUTHORS' REPLY DrThurlbeck objects to our conclusion that the severity of the lesions of the bronchioles and parenchyma assessed by grading techniques in resected lung specimens do not correlate with lung function measurements obtained in the same subjects. We agree that this conclusion is at variance with much that is in the literature and, indeed, reported it for that reason. The data we presented make two basic points: (1) that rather extensive emphysematous destruction of the lung can be present in patients who have a normal FEVI, and (2) that a reduction in FEV, did not correlate with increased inflammatory changes in the peripheral airways assessed with current grading systems. This does not mean that we think emphysematous destruction is not important, only that its presence does not explain the decline in FEVI. Similarly, we did not mean to imply that the abnormal peripheral airway function may not eventually be explained by the effects of the inflammatory process in these airways-only that current morphological grading systems do not identify the lesions responsible for the abnormalities in function. We agree with his closing statement that airflow obstruction is a complicated matter in which the different lesions ofthe bronchi (not just chronic bronchitis), bronchioles (not just the Cosio score), and parenchyma (not just emphysema) contribute to the decline in function. Specific responses to the otherpoints raised in his letter follow. The criticism concerning our failure to report data on tumour size and stage does not recognise that we have previously reported these data on the first 143 cases entered into our study.' Tumour size, involvement of lymph node by tumour, and staging were included in that report. A more recent analysis of staging also showed no correlation between tumour size, stage, and function. We are well aware that centrally placed tumours might interfere with lung function and did our best to exclude this possibility before a case was entered into the study. His objection to the fact that most of our cases were lobectomy specimens is irrelevant because the manuscript clearly states that the same result was obtained when the data from patients undergoing pneumonectomy were examined separately. The percentage of cases in each FEVy category that were pneu-monectomies (table 2) was not different between groups. Furthermore, we have previously shown that the problem of em-physema distribution can be taken into account when single lobes are evaluated.2 His conclusion that the emphysema …