Pulmonary endocrine cells in anthracosilicotic lungs

Abstract

It has been suggested by some studies of human and animal lungs that the products of pulmonary endocrine cells, particularly gastrin-releasing peptide, might play a role in fibrogenesis, but more recent detailed studies of fibrotic human lungs have failed to confirm this. We have made a detailed quantitative examination of a series of fibrotic human lungs to see if we could determine whether there was any relationship between endocrine cells and fibrosis.Using immunocytochemistry, we investigated the morphology, content, distribution and number of pulmonary endocrine cells in 15 pairs of fibrotic lungs from coal miners, and compared their features with those of equivalent cells in agematched controls.Proliferation of endocrine cells was seen in the lungs of just two miners, in which it was focal and associated with acute bronchitis and bronchopneumonia. There was no difference between the miners and controls in the appearance (mostly solitary cells), content (predominantly gastrin-releasing peptide and calcitonin), distribution (mainly in small bronchi and bronchioles), or number (4.5 vs 4.1 cells per 10,000 epithelial cells, respectively) of endocrine cells.It seems unlikely that the substances secreted by these cells play any role in stimulating fibrosis in human lungs, but rather that they have a function in the inflammatory response to pulmonary injury.

Neuroendocrine cell proliferations in lungs explanted for fibrotic interstitial lung disease and emphysema

“…The increase in neuroendocrine cells was also confined to areas of lung affected by acute bronchitis and bronchopneumonia, leading the authors to speculate that inflammation rather than fibrosis is a causative factor of NECH. 24 Aguayo et al reported a ten-fold increase in neuroendocrine cells in eosinophilic granuloma by bombesin-like peptide immunoreactivity compared to smokers and patients with idiopathic pulmonary fibrosis. Normal lung tissue was not examined in the study, however, the frequency of approximately 6-8 cells per 10 cm of airway epithelial length is comparable to the frequency of neuroendocrine cells in normal autopsy lungs as reported by Gosney et al 13,25 A single case report has described NECH as a rare cause of interstitial lung disease in two patients, both of whom were female non-smokers living above sea level.…”