Potential role of neutrophil anti-adhesion therapy in myocardial stunning, myocardial infarction, and organ dysfunction after cardiopulmonary bypass.

When activated neutrophils are recruited and bind to endothelial tissues, they release leukotrienes, proteolytic enzymes, and free radicals. The latter has been implicated in myocardial stunning following periods of ischemia and reperfusion, as may occur following cardiopulmonary bypass (CPB). The neutrophil surface complex CD11/CD18 promotes the neutrophil-endothelial adhesion process. Monoclonal antibodies have been developed that can block neutrophil adhesion to the endothelium by preventing CD11/CD18 binding to adhesion molecules (ICAM-1 or ELAM-1) located on endothelial cells. We used monoclonal IgG antibody 60.3 to block neutrophil adherence and thereby potentially reduce myocardial stunning. Pretreatment of rabbits subjected to myocardial ischemia/reperfusion with either monoclonal 60.3 or saline resulted in only a small increase in the rate of recovery of preload recruitable stroke work index during reperfusion. More severe occlusion may have been needed to see significant results. We also evaluated the effects of anti-neutrophil therapy in animal models of CPB. Rhesus monkeys were subjected to deep hypothermia and CPB, followed by 24 hours of fluid resuscitation. Animals receiving monoclonal 60.3 (N = 3) showed less weight gain, less infused resuscitative fluid, and higher terminal hematocrit and PaO2 than controls (N = 3). Antineutrophil therapy may prevent multiorgan system failure in certain high risk patients.