Effect of infection with transmissible strains of Pseudomonas aeruginosa on lung transplantation outcomes in patients with cystic fibrosis

Background: Compared with patients infected with unique strains of Pseudomonas aeruginosa, patients with cystic fibrosis who are infected with transmissible strains of P aeruginosa, such as the Liverpool epidemic strain, have a 3-fold greater risk of death or lung transplant. We aimed to determine if pre-operative infection with transmissible strains of P aeruginosa was similarly associated with poor health outcomes after lung transplant.

Methods: We had prospectively identified and characterized endobronchial infections in 446 adult cystic fibrosis patients in Ontario, Canada, from September 2005 until December 2009. P aeruginosa isolated from sputum taken at 3-month intervals was genotyped, and patients were characterized as being infected with 1 of 2 transmissible strains or, alternatively, with unique strains of P aeruginosa. We monitored patients until 2013 and collected data on patients from the cohort who subsequently received a lung transplant. The primary outcome was survival after transplantation.

Results: We identified 56 lung transplant recipients from the cohort of 446 patients, including 18 infected with transmissible strains of P aeruginosa and 26 infected with unique P aeruginosa strains. Post-transplant survival at 3 years was 86% in the transmissible group and 84% in the unique group (p = 0.65). No significant differences between groups were found regarding bronchiolitis obliterans-free survival, the frequency of acute rejection episodes, the frequency of post-transplant respiratory tract infection, or the rate of change of post-transplant forced expiratory volume in 1 second.

Conclusions: Pre-operative infection with transmissible strains of P aeruginosa is not associated with poorer post-transplant outcomes compared with patients infected with unique strains of P aeruginosa.