Introduction

Approximately 10 000 hearts and 2000 lungs are transplanted every year. Rejection remains the most common complication following transplantation and is the major source of morbidity and mortality. Constant vigilance is required to monitor the immune response to the grafted organ in the first 3 months, when acute rejection is most likely to occur. In contrast to the management of kidney transplant recipients, in whom raised levels of serum creatinine and urea can be used to monitor graft function, monitoring the function of transplanted hearts and lungs relies entirely on histological or clinical parameters.

Thus, for patients who have undergone cardiac transplantation, surveillance endomyocardial biopsies are taken at weekly intervals for the first 6 weeks and then at 2-weekly intervals until the end of the third postoperative month. In addition, any positive biopsy is followed up by a repeat biopsy 1 week later to ensure that antirejection therapy has been successful. Patients also undergo further biopsies when clinically indicated. Thus, every heart transplant patient has a minimum of nine biopsy procedures within the first postoperative year. Lung allograft function is monitored daily by the patients themselves by means of a spirometer. Any unexplained persistent fall in the forced expiratory volume will be followed up by transbronchial biopsy to confirm the diagnosis histologically. It is especially important to obtain a differential diagnosis between rejection and infection after lung transplantation. For this reason, the transbronchial biopsy procedure is usually accompanied by bronchoalveolar lavage, which is sent for culture and microbiological analysis.