Fungal infection in lung transplantation

Fungal infection remains a significant cause of postoperative morbidity and mortality in lung transplant recipients. The lung recipient remains the only solid-organ allograft continuously open to the environment and to the myriad of fungal spores and pathogens. Many factors may predispose to fungal infection in these patients, including: preoperative chronic lung diseases and inherent palliative immunosuppression, intraoperative complications such as abnormalities in the bronchial anastomosis or lung injury, and postoperative complications such as enhanced immunosuppression for early rejection, graft dysfunction, concurrent viral and bacterial infections, and bronchiolitis obliterans syndrome. The risk factors and time course for fungal infection in lung transplant recipients parallel the observations in other solid-organ transplant recipients. Early fungal infections are related to surgical complications, while the period of 1-6 months reflect opportunistic, relapsed, or residual infections; fungal infections greater than 6 months and thereafter are usually associated with treatments for chronic rejection or bronchial airway mechanical abnormalities. The majority of fungal infections in lung transplant recipients involve Aspergillus species, followed by Candida, Pneumocystis, Cryptococcus, geographically-restricted agents, and newly emerging fungal pathogens. The identification of at-risk patients (preoperatively and postoperatively) is essential in implementing prophylaxis or preemptive management. Some anti-fungal strategies and future options for clinical research are discussed.