Radiological Dissociation of Alveolar and Vascular Phases of Rejection in Allografted Lungs

Twelve dogs with allografted lungs were treated with azathioprine and rabbit antidog thymocyte serum. Chest roentgenography, pulmonary angiography, and lung biopsy revealed a dissociation of the alveolar and vascular components of rejection in 7 of the animals. The vascular phase of rejection was more effectively suppressed than the alveolar phase. This dissociation may produce a functional disturbance with a decreased ventilation to perfusion ratio within the allograft such as has been observed in human lung transplant recipients. The results of this investigation suggest that rejection plays a more important role than previously recognized in the ventilation-perfusion imbalance that occurs with pulmonary allografts.