Bronchial nerves in chronic obstructive airways disease: a preliminary report

The nerves lying within 300 microns of the basement membrane were studied in the named bronchi of five normal subjects and nine patients with chronic obstructive airways disease (COAD), using S-100 protein as a marker. Two types of change were found. Firstly, there was patchy proliferation of fine nerve twigs, associated with focal increase in fibroelastic tissue. This proliferation was present to a minor degree in two normal subjects, and to a much greater extent in all patients with COAD. The second type of change was most marked in the main and lobar bronchi of the patients with COAD and cor pulmonale, and consisted of enlargement of nerves to a maximum of 150 microns in diameter. The overall mean nerve diameter in these latter patients was 22.3 microns, significantly greater than the mean diameter, 15.8 microns, in the normal subjects (P less than 0.001).