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 d onor pulmonary macrophages may be responsible for this early phase of injur y. Using the macrophage inhibitor gadolinium chloride, we attempted to inve stigate 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 pulm onary artery pressures compared with groups I and II after 30 minutes of re perfusion. Conclusions. The earliest phase of reperfusion injury after lung transplant ation involves donor pulmonary macrophages. (C) 2001 by The Society of Thor acic Surgeons.