Bronchial obstructive reactions after inhalation with endotoxin and precipitinogens of Haemophilus influenzae in patients with chronic non-specific lung disease.

Bronchial obstructive reactions occur after inhalation of Haemophilus influenzae in the absence of proteolytic activity in patients with CNLSD and a lowered histamine threshold in whom specific precipitins are demonstrated. It may be presumed, that the direct bronchial reaction is caused by its content of endotoxin, whereas the late bronchial reaction is the result of a toxic action and a type III allergic reaction. When proteolytic activity is present it lowers the histamine threshold and may influence the endotoxin effect in this way.