ABSTRACT
Acute rejection contributes to significant morbidity in lung transplant recipients, and repeated episodes predispose them to the development of chronic rejection. The diagnosis of acute rejection is often made on the basis of routine surveillance transbronchial biopsy. Alternatively, the diagnosis can be based on a patient’s symptoms and worsening pulmonary function test results. The frequency with which surveillance biopsies are performed varies from institution to institution. A biopsy sample is considered adequate for evaluation of rejection if it includes at least one airway and four or five fragments of well-expanded, alveolated lung (each containing 50 to 100 alveoli). Specimens may require gentle agitation in formalin to promote inflation of the fragments. It is recommended that after specimens have been processed, at least five 5-μm levels be cut. Generally, levels 1, 3, and 5 are stained with hematoxylin and eosin (H&E). The remaining unstained slides can be used for special stains or immunostains as described later.
