SINGLE-LUNG TRANSPLANTATION MORPHOLOGICAL SURVEILLANCE BY TRANSBRONCHIAL BIOPSY

Seven cases of single lung transplantation are reported. The recipient s were all below 60 years of age and severely disabled with end-stage lung disease. Transplantation was performed according to ABO blood gro up compatibility and negative lymphocytotoxic cross-match between dono r and recipient irrespective of HLA mismatch. Recipients' diagnoses we re sarcoidosis (3), alfa-1 antitrypsin deficiency (3), and idiopathic emphysema (1). Mean recipient age was 48 +/- 2.4 years (range 45-52). Donor age was 29.7 +/- 5.6 years (range 16-49). The immunosuppressive regimen included cyclosporin A, azathioprine, steroids and rabbit anti thymocyte globulin. Excellent graft function was achieved. Six patient s survived the postoperative period and are alive 4-18 months posttran splant. One patient died after the operation due to pneumonia with res piratory distress syndrome. Graft function was also monitored by trans bronchial biopsy, and 57 biopsy procedures were performed without fata l complications. Acute cellular rejection was seen in 16 biopsy specim ens from 5 recipients (grade 1 and 2 rejection in 14, grade 3 rejectio n in 2). Neither severe rejection with septal necrosis (grade 4) nor o bliterative bronchiolitis was seen. The rejection rate was 0.03 episod es per patient/month. In contrast to other reports, episodes of cellul ar rejection occurred throughout the observation period, and were not mainly limited to the first 4 months posttransplant. Graft vascular oc clusive disease or chronic vascular rejection was found in 6 biopsy sp ecimens from one recipient. Five patients experienced 7 episodes of cy tomegalovirus infection. The cytomegalovirus infection rate was 0.01 e pisodes per patient/month. The incidence of infection was significantl y lower compared to previous studies of rejection in other lung graft combinations. Both infections and rejection episodes may contribute to the development of obliterative bronchiolitis. Almost one third of th e specimens (30%) showed lymphocytic bronchitis without perivascular i nflammation. The absence of perivascular infiltrates and exclusion of infectious agents leaves in question the aetiology of this inflammatio n. The lymphocytic bronchitis could be ischaemic, related to aspiratio n, or represent recurrent sarcoidosis, or, in fact, express bronchial rejection. All biopsy specimens regarded as rejection with cellular in filtrates in the lung parenchyma also showed a lymphocytic bronchitis. The impact of HLA mismatch on cellular and vascular rejection is uncl ear. Transbronchial biopsy is a reasonably safe and reliable method in the diagnosis of rejection and infection in single lung transplantati on.