The carotid bodies in bronchial asthma.

A histological study was made of right-sided carotid bodies resected therapeutically from 50 patients with bronchial asthma. Also studied as controls were 10 right-sided carotid bodies from subjects coming to necropsy. Hypoxaemia was considered a contra-indication to glomectomy and only patients with a resting arterial oxygen tension exceeding 65 mm Hg were submitted to operation. It was found that in patients with a short history of bronchial asthma the carotid bodies were not enlarged, but there was hyperplasia of sustentacular cells. In cases with asthma for 5 years or more the sustentacular cell hyperplasia was more pronounced and was associated with many nerve fibrils and slight enlargement of the carotid bodies. The functional significance of the proliferation of sustentacular cells and the abundance of nerve axons is obscure. In the asthma cases there was prominence of the dark variant of chief cells, thought to be related to episodes of hypoxaemia.