Histologic changes in heart-lung transplant recipients during rejection episodes and at routine biopsy.

In our experience a lung biopsy specimen taken by means of a fiberoptic bronchoscope is a useful, safe technique for the diagnosis of rejection in heart-lung transplant recipients. To determine that the histologic features associated with rejection can be identified in transbronchial biopsy specimens, 35 biopsy specimens (group A) taken when retrospective review confirmed a clinical diagnosis of rejection without evidence of infection were identified from a total of 107 biopsy specimens. These were compared with 14 biopsy specimens (group B) taken when the patients were well. Several foci of dense perivascular mononuclear cell infiltration with pyroninophilic lymphocytes and plasma cells were seen in 79% of group A biopsy specimens. Fewer foci of non-pyroninophilic cells were seen in group B biopsy specimens (p = 0.005). There was also a difference in the histologic features of the mucosa and interstitial lung tissue. We believe that the early confirmation of rejection followed by adequate augmentation of immunosuppression may prove to be an important factor in reducing the incidence of obliterative bronchiolitis in heart-lung transplant recipients.