Pathology of lung transplantation

Lung transplantation may offer longer survival and improved quality of life to patients with end-stage lung disease. Common indications for single lung transplantation include chronic obstructive pulmonary disease, idiopathic pulmonary fibrosis, and interstitial lung disease other than idiopathic pulmonary fibrosis. Bilateral lung transplantation is the norm for cystic fibrosis, but the proportion of bilateral (double) lung transplantation procedures has been rising for other major indications as well. The median overall survival for patients after lung transplantation is currently 6.7 years with a moderate survival advantage for patients with bilateral lung transplantation. Complications of lung transplantation may be related to (1) the operation itself (primary graft dysfunction, anastomotic complications), (2) the host’s immunologic response to the allograft (rejection), and (3) the immunosuppressive therapy used to prevent rejection (infection, posttransplantation lymphoproliferative disorder [PTLD]). Other complications, such as recurrence of the original disease or aspiration, may also occur. Posttransplantation transbronchial biopsy may be performed for a specific clinical indication or for surveillance of acute rejection. The histopathologic findings most commonly encountered in a posttransplantation transbronchial biopsy include acute rejection, infection, airway-centered inflammation, obliterative bronchiolitis, harvest injury, and PTLD.