Kallikrein-like activity was evaluated in the bronchoalveolar lavage fluid (BALF) of 43 patients (33 bronchial asthma patients and 10 controls) to study the inflammatory response in the lower respiratory tract of asthma patients. The appearance rate of BALF kallikrein-like activity (BKLA) was 25.0% in asthmatics, and 60.0% in asthmatics after provocation by a specific antigen, whereas it was negative in healthy subjects. The increase in BKLA in asthmatic subjects was significant. BKLA in patients with an immediate asthmatic response after provocation turned negative, whereas it was positive in their ordinary BALF. On the contrary, BKLA after provocation in those with a late asthmatic response turned positive, whereas it was negative in their ordinary BALF.Characterization using three protease inhibitors indicated that BKLA had an enzymatic character similar to plasma kallikrein. These results suggest that the activation of the kallikrein-kinin system may have a possible role during anaphylaxis in asthmatics.
bronchoalveolar lavage fluid
immediate and late asthmatic response