SERIAL MEASUREMENTS OF PLASMA ELASTASE ALPHA-1-PROTEINASE INHIBITOR COMPLEXES IN PATIENTS RECEIVING CANCER-CHEMOTHERAPY

We monitored the plasma elastase:alpha1-proteinase inhibitor complexes during chemotherapy for cancer and investigated the relationship betw een the elastase burden and the onset of adult respiratory distress sy ndrome (ARDS) in 20 patients with primary lung cancer who received com bination chemotherapy; 15 normal nonsmokers served as controls. Of the 20 patients, 6 developed pneumonia, and 6 developed ARDS. We measured peripheral WBCs, C-reactive protein (CRP), plasma elastase:alpha1-pro teinase inhibitor complex (complex), and the ratio of complex/WBC duri ng chemotherapy for cancer. In patients who did not experience complic ations during combination chemotherapy, WBC counts changed, but levels of complex were normal. In patients who developed pneumonia, levels o f complex were abnormally high during the WBC nadir, and the complex/W BC count increased along with the level of CRP. In patients who develo ped ARDS during chemotherapy for cancer, levels of complex were abnorm ally high immediately after chemotherapy and remained high after the o nset of ARDS. In addition, complex/WBC counts and CRP levels increased at the onset of ARDS. The maximum complex concentration was significa ntly higher in patients with pneumonia (414.3 +/- 57.2 ng/ml) and ARDS (683.2 +/- 72.8 ng/ml), compared with normal nonsmokers (130.2 +/- 5. 5 ng/ml; p<0.01) and patients who did not develop complications (211.5 +/- 23.3 ng/ml; p<0.01). The maximum complex/WBC count was also signi ficantly higher in patients with pneumonia (0.56 +/- 0.12) and ARDS (1 .03 +/- 0.27), compared with normal nonsmokers (0.03 +/- 0.002; p<0.01 ) and patients without complications (0.09 +/- 0.01; p<0.01). These fi ndings suggested a possible correlation between increased levels of co mplex and the onset of ARDS.