Cytomegalovirus pneumonitis in heart-lung transplant recipients: histopathology and clinicopathologic considerations.

Three cases of cytomegalovirus (CMV) pneumonitis in heart-lung transplant recipients are presented, and the clinical course and autopsy findings described. The patients survived transplantation for 15, 6, and 2 months, respectively. Cytomegalovirus pneumonitis was diagnosed between 5 and 12 weeks postoperatively, and was still detectable in two of the patients at postmortem examination. In one patient, at autopsy there was no further evidence of CMV pneumonitis 3 months after its onset. Instead we found widespread obliterative bronchiolitis (OB) and signs of acute pulmonary rejection. Early-stage OB was present together with CMV pneumonitis in the patient who had survived transplantation for 2 months. The cause of death in the remaining patient was a bacterial superinfection of the chronic CMV pneumonitis still present more than 1 year after its first manifestation. There were no signs of OB. The marked differences in the clinical course and histologic presentation of CMV pneumonitis in heart-lung transplant recipients and its high, but not uniform, association with OB emphasize the complex interrelations between viral infections and pulmonary rejection.