FUNCTIONAL AND METABOLIC-ACTIVITY OF POLYMORPHONUCLEAR LEUKOCYTES FROM PATIENTS WITH ADULT RESPIRATORY-DISTRESS SYNDROME - RESULTS OF A RANDOMIZED DOUBLE-BLIND PLACEBO-CONTROLLED STUDY ON THE ACTIVITY OF PROSTAGLANDIN-E1

Indirect and experimental evidence suggests that polymorphonuclear leukocytes, responding to an activating signal presumably related to the complement cascade activation, are involved in the pathogenesis of the adult respiratory distress syndrome (ARDS). The pathologic changes seem to be result of the polymorphonuclear leukocyte margination within the pulmonary capillary vessels and their activation with subsequent release of vasoactive peptides (thromboxane A2, prostaglandin E2) and toxic intracellular compounds. This study confirms that adherence, chemotaxis, and chemiluminescence are increased in polymorphonuclear leukocytes from patients with ARDS. Enhanced chemotactic and chemiluminescence capacities are likely specific to ARDS, whereas increased polymorphonuclear leukocyte adherence seems to be nonspecific. If increased polymorphonuclear leukocyte activation is important in the pathogenesis of ARDS, the inhibition of this phenomenon could play a therapeutic role. This double-blind prospective study was undertaken to assess if polymorphonuclear leukocyte activity is inhibited in vivo by the iv administration of prostaglandin E1 (PGE1) in patients with ARDS. A continuous infusion of PGE1 at a dose of 30 ng·kg-1 ·min-1 for 7 days did not modify the functional activity of polymorphonuclear leukocytes in patients with ARDS. Because hemodynamic instability was seen during infusion of this dose of PGE1, an increased dose was not tested. At the dose of PGE1 tested, no significant effect upon the function activity of polymorphonuclear leukocytes in patients with ARDS could be demonstrated.