Special problems after lung transplantation: walking a tightrope between infection and rejection

Between November 1992 and September 1999 84 lungs have been transplanted at University Hospital Zurich. Currently the 1-year survival rate is up to 85 %. However, long-term success is limited by the development of chronic reje ction in the form of bronchiolitis obliterans. The risk factors are repeate d episodes of acute rejection and infections, due to cytomegalovirus in par ticular. Both can occur in asymptomatic patients and are sometimes detected only by transbronchial lung biopsy. At the Zurich Lung Transplant Centre b iopsies are performed as surveillance biopsies in asymptomatic patients in the first 6 months after transplantation, for clinical indications and as f ollow-up biopsies after a pathological result. Open lung biopsies are perfo rmed for special indications only. We evaluated 408 transbronchial biopsies taken between November 1992 and September 1999. Relevant findings were pre sent in 46% of biopsies in symptomatic patients. Relevant acute rejection e pisodes were diagnosed in 15% of surveillance biopsies. Overall, 72% of acu te rejection episodes requiring therapy and 33% of biopsies detecting cytom egalovirus were found in surveillance biopsies. 7 of 11 late (>45 days post operative) and 1 of 5 early (less than or equal to 45 days postoperative) o pen lung biopsies revealed new diagnoses. Transbronchial biopsy after lung transplantation is at present the gold standard for diagnosis of acute reje ction and cytomegalovirus pneumonia of the lung.