A team led by researchers at St. Michael’s Hospital and the University of Toronto recently revealed that cystic fibrosis (CF) patients in Canada who undergo lung transplantation have good overall survival rates. The study is entitled “Clinical and demographic factors associated with post–lung transplantation survival in individuals with cystic fibrosis” and was published in the Journal of Heart Lung Transplantation.
CF is a rare, life-threatening genetic disease in which a defective gene (cystic fibrosis transmembrane conductance regulatory, CFTR) induces a salt imbalance, causing the body to form unusually thick, sticky mucus that can obstruct the airways and promote dangerous lung infections resulting in serious respiratory and also gastrointestinal manifestations. The majority of the CF patients die due to respiratory failure. There is no cure for the disease and it is estimated that almost 75,000 individuals worldwide suffer from CF. In Canada, CF is the most common fatal genetic disorder in children and young adults.
Lung transplants are an option for CF patients who develop severe lung disease. There are, however, a limited number of studies addressing post-transplant survival in CF patients. In this study, the research group analyzed the overall transplant survival and assessed potential risk factors associated with death after transplantation.
The team used data from the Canadian Cystic Fibrosis Registry, a population-based cohort, to analyze the clinical outcome in terms of survival after lung transplant at a national level in Canada. In total, 580 CF patients who underwent a lung transplant between 1988 and 2012 were considered.
Researchers found that in the cohort of CF patients analyzed, the overall post-transplant survival rates were 87.8% after 1 year, 66.7% after 5 years and 50.2% after 10 years. CF patients infected with the pneumonia-causing bacteria Burkholderia cepacia had a median post-transplant survival of 3.3 years, while it was of 12.36 years in CF patients without the infection. The team found that besides B. cepacia infection, pancreatic sufficiency also had a detrimental impact on survival. The patient’s age at transplant also influenced the survival rate, where the youngest and oldest patients had the poorest survival rates in comparison to patients in the middle age-range. The team also found a trend towards an improved survival in patients transplanted in recent decades, having an estimated median age of survival of 50.9 years (estimated in 1990 to be 31.9 years).
“People think when you have cystic fibrosis and need a transplant it’s a death sentence,” said the study’s lead author Dr. Anne Stephenson in a news release. “But our paper shows that one-, three-, and five-year survival rates following lung transplantation are really quite high.”
Interestingly, factors known to be implicated with a poorer survival in CF patients like being female, malnutrition and CF-related diabetes, did not have a significant impact on post-transplant survival.
The research team concluded that lung transplantation in CF patients has a dramatic positive impact on survival, with half of the patients living beyond 10 years after the transplant. The authors report that the patient’s age at transplant, pancreatic sufficiency and infection with B. cepacia are important determinants of survival after lung transplantation. The team believes that an accurate prediction of post-transplant survival can enable caregivers to properly inform CF patients about the risks and benefits associated with the lung transplant.