Cystic Fibrosis and Survival Beyond 40 Years

Introduction

Cystic fibrosis (CF) is an autosomal recessive condition associated with widespread dysfunction of exocrine glands with particular predilection for the lungs and gastrointestinal tract. In 1938, when CF was first recognized as a distinct pathological process by the pathologist Dorothy Andersen, less than 10% of children survived beyond the first year of life.1 Since then our understanding of the pathophysiology and underlying disease mechanisms have improved vastly but the ultimate aim of a cure is yet to be realized. The recognition by Paul di Sant'Agnese in the 1950s that a high proportion of CF patients were presenting with heat prostration during a New York heat wave, led to the discovery of abnormal sweat composition, which is characterized by high sodium and chloride levels.2 Further investigations identified the basic molecular defect as inadequate chloride secretion in sweat ducts 3 accompanied by sodium hyperabsorption in the airways.4

Abstract

Cystic fibrosis (CF) is the most common life-shortening, genetically inherited condition in the Caucasian population. Despite the lack of a cure for the underlying cellular defect, median survival continues to improve and is currently approximately 38 years—children born today with CF are predicted to live beyond 50 years of age. The demographics are changing with the number of affected adults beginning to outnumber children, and there is an increasing cohort of adults who have survived beyond 40 years of age. The current article provides a summary of the latest research on older CF patients. The aim was to characterize patients with CF who have lived beyond 40 years and discuss factors contributing to survival. Studies show that CF long-term survivors are a heterogeneous group; the majority has features suggestive of the classic disease but a significant proportion (the late diagnosis group) has a specific definable phenotype. Determinants of survival are complex but include maintaining good health in childhood and optimal BMI, FEV, FVC, and no Pseudomonas aeruginosa at the time of transition from pediatric to adult care. It is important to identify the factors contributing to extended life in this cohort of survivors, as we can use this information to improve care for the entire CF population.

Keywords

cystic fibrosis, aging, longevity, survival