End Stage Kidney Disease in Cystic Fibrosis

BackgroundCystic fibrosis (CF) is a multisystem autosomal recessive disease caused by mutations in the cystic fibrosis transduction regulator (CFTR). The CFTR is expressed in all renal tubular segments. Tubular functional abnormalities as well as renal histologic changes are recognized in people with cystic fibrosis (CF). Chronic kidney disease (CKD) occurs in CF at greater frequency than in the non-CF population. The prevalence and characteristics of end stage kidney disease (ESKD) in the cystic fibrosis population have not previously been described. MethodsWe used data supplied by the US Renal Data System (USRDS) to compare persons with ESKD and CF with those with ESKD who did not have a diagnosis of CF. We used linear and logistic regression, propensity score-matched Kaplan-Meier survival curves, and log-rank tests. ResultsThe prevalence of ESKD was approximately thirty times higher than predicted in the general US population. Diabetes was more frequently a diagnosis in people with CF, but was approximately half as frequently the primary cause of ESKD than in those without CF. Complications of transplantation, particularly of lung, were rarely the cause of ESKD in those without CF but were the second most frequent etiology of ESKD in people with CF. Drugs and medications, interstitial nephritis and acute kidney injury (AKI) were more frequent primary causes in those with CF. Hypertension, cystic kidney disease, and glomerulonephritis were less frequent in those with CF. Mortality and survival with ESKD were not significantly different between those with CF and ESKD and those with ESKD who did not have CF. Diabetes mellitus and complications of lung transplantation as the primary cause of ESKD, but not lung transplant status, were associated with significantly shorter survival with ESKD in people with CF. ConclusionsPeople living with CF have a markedly higher prevalence of ESKD than the general United States population. The profile of primary causes of ESKD differed significantly from that of the non-CF population. Diabetes mellitus was approximately half as frequently the primary cause of ESKD in those with CF. Complications of solid organ transplant, particularly lung, were the second most frequent primary cause of ESKD in people with CF. Survival with ESKD was not significantly different between those who did and did not have CF. The diagnosis of diabetes mellitus, and complications of lung transplantation as the primary cause of ESKD, but not lung transplant status, were associated with significantly shorter survival with ESKD in people with CF. It is our aim that these findings will promote awareness of kidney disease in persons living with CF and will encourage prevention of acute kidney injury (AKI), early detection and intervention in CKD, and preemptive referral to nephrology and transplant centers.