A preliminary study of elevated alkaline phosphatase and cathepsin in bronchial aspirates of patients with lung cancer and bronchitis.

The measurement of acid and alkaline phosphatase and cathepsin activities in bronchial aspirates obtained through bronchoscopy from a series of 75 patients suggests a procedure that may have value as a routine diagnostic examination. Using this approach, seven patients with neoplasms in the lung showed elevated levels of alkaline phosphatase and cathepsin in bronchial aspirates without elevation in acid phosphatase activity.