Pulmonary macrophages are involved in reperfusion injury after lung transplantation

Background. Reperfusion injury is a perplexing cause of early graft failure after lung transplantation. Although recipient neutrophils are thought to have a role in the development of reperfusion injury, some researchers have shown that neutrophils are not involved in its earliest phase. Intrinsic donor pulmonary macrophages may be responsible for this early phase of injury. Using the macrophage inhibitor gadolinium chloride, we attempted to investigate the role of pulmonary macrophages in reperfusion injury after lung transplantation Methods. Using our isolated, ventilated, blood-perfused rabbit lung model, all groups underwent lung harvest followed by 18-hour storage (4 degreesC) and blood reperfusion for 30 minutes. Group I served as a control. Group II received gadolinium chloride at 7 mg/kg 24 hours before harvest. Group III received gadolinium chloride at 14 mg/kg 24 hours before harvest. Results. Group III had significantly improved arterial oxygenation and pulmonary artery pressures compared with groups I and II after 30 minutes of reperfusion. Conclusions. The earliest phase of reperfusion injury after lung transplantation involves donor pulmonary macrophages. (C) 2001 by The Society of Thoracic Surgeons.