Hyperacute xenorejection of guinea pig-to-rat lung transplantation can be attenuated by blood which has perfused another xenograft.

In discordant xenotransplantation, the recipientOs blood initiates hyperacute xenorejection (HXR). We hypothesized that HXR-related lung edema may be reduced if a new xenograft is perfused by blood which previously has perfused another xenograft. In a syngeneic control group (n = 6), a rat lung (lung XR) was perfused by rat blood (blood AR), following which the blood was collected (blood BR). After another rat lung (lung YR) was perfused by blood BR, the blood was collected (blood CR). In a xenogeneic experimental group (n = 6), a guinea pig lung (lung XG) was perfused by rat blood (blood AG), and the blood was collected (blood BG). Then, another guinea pig lung (lung YG) was perfused by blood BG, and once more the blood was collected (blood CG). White blood cells (WBC), polymorphonuclear leukocytes (PMN), red blood cells (RBC), hemoglobin, hematocrit, and complement (CH50) in the blood were measured pre- and post-perfusion. The wet/dry weight ratio (W/D) of the lung was calculated after the perfusion. WBC and PMN were higher in blood CR/BR than in blood BR/AR. CH50 was higher in blood CG/BG than in blood BG/AG. RBC, hemoglobin, and hematocrit were not different among the blood AR, BR, CR, AG, BG, and CG. The W/D was not different between lung XR and lung YR. The W/D of lung YG was lower than lung XG. In conclusion, the lung edema associated with HXR is reduced when blood which has perfused another xenograft is used to perfuse the new xenograft without anemia, and complement plays a critical role in reducing lung edema.