Diagnosis and Reversal of Rejection in Experimental and Clinical Lung Allografts

Experience in our patients and dogs with lung transplants has provided reliable criteria for diagnosing rejection and distinguishing it from other pathological processes such as pneumonia and ischemic injury. These criteria include fever; dyspnea; malaise; increased sputum production; decreased arterial oxygen tension; and, most importantly, the rapid development (often within hours) of a roentgenographic alveolar infiltrate without any change in the sputum bacteriology. Using these criteria we have identified multiple rejection episodes in 2 patients and in comparably immunosuppressed dogs. In almost every instance all acute manifestations of rejection, including the roentgenographic infiltrates, have been completely reversed by three to seven large intravenous doses of methylprednisolone given at 12- to 24-hour intervals. In the dogs, reversal of rejection has also been confirmed by gross and microscopical examination of the allograft. These findings show that acute rejection in lung allografts can be reliably identified by noninvasive criteria and successfully reversed.