Pathology of lung allografts in children and young adults

Heart-lung and lung transplantation have become acceptable therapeutic modalities for end-stage lung and heart conditions in children and young adults, but the posttransplantation pulmonary pathology in this age-group is poorly characterized. We present our experience with the pathology of lung transplantation in a cohort of 11 patients with a median age of 12.5 years, and median posttransplantation follow-up of 8.3 months. The findings are based on histological examination of 98 specimens, including five autopsy specimens from patients 20 years of age or younger. Our experience, combined with the data in other pediatric series, suggest that there is not a significant difference in the prevalence or severity of acute rejection or bronchiolitis obliterans (BO) between adult and pediatric lung transplant recipients. Lymphocytic bronchitis/bronchiolitis showed a more prominent association with BO in our series than previously reported in adult studies. Chronic vascular rejection in the pediatric lung transplant recipients can occur earlier than reported in adults and is associated with a grave prognosis. Overwhelming infection was a major cause of death in our experience. In particular, our data combined with the previous reports indicate that adenoviral pneumonia is a relatively common pathogen in the pediatric population and is a major cause of mortality in this age-group.