The generation of leukotrienes B4 (LTB4) and C4 (LTC4) by peripheral leukocytes stimulated with Ca ionophore A23187 was examined in 17 patients with pulmonary emphysema. They were divided into three groups according to the mean CT
number; A (<-940 HU), B (-940 ≦, <-930 HU), and C (-930 HU ≦ ).1. The values of FVC (% predicted), FEV1.0% and DLco (% predicted) showed a tendency to decrease as the mean CT number was smaller. The value of % FVC was significantly lower in patients with group A than in those with group C (p<0.05). 2. The generation of both LTB4 and LTC4 was significantly higher in patients with emphysema compared to the generation in healthy subjects (LTB4;p<0.05, LTC4;P<0.05). 3. The generation of LTB4 and LTC4 in patients with emphysema was higher as the mean CT number was larger (severity of the disease become less). The LTC4 production was significantly higher in patients with group C(mild or moderate type of emphysema) than in those with group A(advanced type of emphysema). These results suggest that the generation of LTB4 and LTC4 is higher in patients with mild or moderate type of emphysema than in those with advanced type of the disease.