Bronchial biopsy in chronic bronchitis and asthma.

Chronic bronchitis is responsible for a greater annual mortality in Great Britain than any other single respiratory disease, and its incidence is far higher in this country than anywhere else in the world (Oswald, 1958), yet relatively few comprehensive studies of the pathogenesis of the condition have been published. Considerable attention has been paid recently to the factor of infection in chronic bronchitis, especially with regard to the role of Haemophilus influenzae, since Mulder's work in 1938 (Mulder, 1956; May, 1958). Brumfitt, Willoughby, and Bromley (1957) have emphasized the preponderance of H. influenzae over other organisms when swabs are taken directly from the bronchi in cases of chronic bronchitis. One of us (A. A. G.) has found antibodies to H. influenzae in high titre in two-thirds of patients with the disease. The titres were not significantly affected by intercurrent attacks of acute bionchitis. It has long been recognized clinically that symptoms of chronic bronchitis may persist in the absence of infection, and clinicians have also for many years been aware that a fundamental characteristic of chronic bronchitis is the excessive production of mucus in the respiratory tract. That infection may thereby be facilitated, and that the association of infection and excess mucus production may ultimately cause emphysema, has been suggested by Reid (1954). Evidence of a histological basis for excess mucus production is as yet lacking, and there are few studies of the detailed pathology of chronic bronchitis as distinct from that of emphysema. Rokitansky in 1838 described six cases of chronic bronchitis in which grossly dilated mucous glands were present in the posterior wall of the trachea and in the bronchi. This condition is now recognized as an occasional radiological (Simon and Galbraith, 1953) and pathological (Duprez and Mampuys, 1953) inanifestation of chronic bronchitis. Rokitansky also described less severe degrees of this mucous glandular dilatation in some of his cases. Huber and Koessler (1922) gave a very detailed account of the pathology of " bronchial asthma " based on six patients of their own and 15 culled from the literature. It is clear from their description that an infective element was present in many. Bronchitis was definite or probable in 12 of the 13 in whom they describe mucous gland hypertrophy, while only in one patient with bronchitis was there mucous gland atrophy. Florey, Carleton, and Wells (1932) mentioned that histological examination of the bronchi in a group of 14 patients with chronic bronchitis showed dilated deep glands, the majority of which were mucous in type. Reid, on the basis of post-mortem studies, stated that mucous gland hypertrophy and goblet cell hyperplasia are early changes in chronic bronchitis, and she has stressed the importance of this view in subsequent papers (Reid, 1958). In general, however, the pathological basis of chronic bronchitis is referred to merely in terms of the name as a chronic inflammation of the bronchial wall. We report here the results of a study of bronchial biopsies in 45 patients. They fell clinically into two main groups: those with chronic bronchitis (27 cases) and those with asthma (18 cases). A more detailed classification is given below. From these biopsies from living patients we hoped to establish and describe specific histological changes in chronic bronchitis and in asthma, and to determine if possible their relationship to the severity and to the duration of these disorders. Secondly, in patients with clinical evidence of both asthma and bronchitis we hoped that histological evidence might throw light upon the interrelationship of these two disorders.