The predictive and discriminative value of biologically active products of eosinophils, neutrophils and complement in bronchoalveolar lavage and blood in patients with adult respiratory distress syndrome.

To determine whether biologically active products of eosinophils, neutrophils and complement contribute to the development of adult respiratory distress system (ARDS) we measured eosinophil cationic protein (ECP), lactoferrin (LF) and C3a in bronchoalveolar lavage (BAL) and blood by means of radioimmunoassays. Seventeen patients served as controls. Fifteen patients were studied before and after major surgery to evaluate the influence of the surgical procedure, and 12 patients with ARDS were investigated 4-12 h after the onset of the disease. Major surgery per se significantly increased ECP in BAL, LF in serum and C3a in BAL and plasma. ECP, LF and C3a levels in BAL and blood were all significantly higher in ARDS patients as compared with levels in controls and those observed after major surgery. The higher ECP levels in BAL were associated with the more severe ARDS as was also the case for C3a in BAL and plasma and LF in serum. One out of 15 patients subjected to major surgery developed ARDS postoperatively and had very high levels of ECP, LF and C3a in BAL and blood at sampling 3 h prior to onset of ARDS, and these levels were similar to those observed in ARDS patients. One out of 12 ARDS patients died from the disease and this patient had the highest level of ECP in BAL and serum. Our results strongly support the role of activated polymorphonuclears, and notably the activated eosinophils, in the pathogenesis of ARDS. Evidence is also presented that ECP can be used as a predictor of impending ARDS.