Aspergillus airway colonization and invasive disease after lung transplantation

Abstract

Background: Invasive Aspergillus is an important cause of morbidity and mortality among lung transplant recipients. The diagnosis can be difficult and treatment is often unsuccessful so many centers preemptively treat all Aspergillus airway isolates to prevent invasive disease. This approach is untested as little is known about the relationship between Aspergillus airway colonization and invasive disease. This study was undertaken to evaluate the incidence of Aspergillus airway colonization after lung transplantation and the risk of invasive disease after colonization.

Design: All cultures and histologic specimens obtained from a consecutive series of 151 lung transplant cases were reviewed for the presence of Aspergillus and compared with clinical data.

Results: Aspergillus was isolated from the airway in 69 (46%) of 151 transplant recipients. Invasive disease occurred in five cases and was uniformly fatal, accounting for 13% of all posttransplant deaths. Results of cytologic examination of BAL fluid were normal in all cases of invasive disease and cultures were positive in only one of five patients prior to invasion. Invasive disease occurred exclusively in patients who died or were colonized with Aspergillus fumigatus within the first 6 months posttransplant. Patients growing A. fumigatus from the airway during the first 6 months were 11 times more likely to develop invasive disease relative to those not colonized.

Conclusion: Aspergillus airway colonization after lung transplantation is common and in most cases, transient. In contrast, invasive Aspergillus disease is less common, but fatal. Bronchoscopy with cytologic examination and fungal culture are not sensitive or timely predictors of invasive disease. Invasive Aspergillus occurred only in patients initially colonized with A. fumigatus within the first 6 months posttransplant. A trial of empiric anti-Aspergillus therapy limited to the first 6 months posttransplant may be warranted.