CHESTThought Leader BlogCystic Fibrosis: An Adult Pulmonary Disease

Cystic Fibrosis: An Adult Pulmonary Disease

By: Shahid Sheikh, MD

May 29, 2019

Cystic fibrosis (CF) is the most common autosomal recessive disease in the Caucasian population but can be seen in other ethnic groups. Patients with cystic fibrosis (CF) have progressive lung disease because of acute and chronic infections and inflammation.1

Diagnosis of CF in patients with typical disease manifestations need elevated sweat chloride level and the presence of two disease-causing mutations in cystic fibrosis transmembrane conductance regulator (CFTR).2 More than 1,800 mutations have been found in the CFTR gene with varying severity of residual CFTR function ranging from no CFTR function to some function. Mutations in the CFTR gene result in defective chloride transport across epithelial cells in multiple organ systems.3 The F508del mutation is the most commonly identified mutation in the United States, occurring in 90% of patients with CF.3 CFTR channel regulate chloride secretion and water balance of the airway epithelium. Any mutation in genes encoding for CFTR leads to alteration in respiratory secretions,4-5 leading to inadequate hydration and development of viscous mucus and predisposing patients to pathogenic colonization and chronic inflammation.6 This leads to irreversible changes in airways and lung parenchyma, progressive bronchiectasis, and respiratory failure.

Over time, new therapies and medications, including antibiotics, have improved care of patients with CF. Advancements include treatment of infection and inflammation and also thinning, mobilizing, and clearing respiratory secretions. Recent advancements in ameliorating CFTR dysfunction have led to new group of medications called CFTR modulators, which are associated with improvement in lung function and nutrition. Many of these molecules are now FDA approved for specific genetic mutations and many others are undergoing clinical trials.

According to the Cystic Fibrosis Foundation (CFF) annual registry in 2017, there are about 30,000 patients with CF in the United States with about 850-900 newly diagnosed patients every year. Predicted median survival in 2017 is 43.6 years. 6 The number of adults with CF continues to increase. In 2017, adults were 53.5% of the CF population, compared with 29.8% in 1987 and 40% in 2002. 6

Among many, one of the reasons for improvement in CF survival is a multidisciplinary approach with active input from dieticians, social workers, pharmacists, and nurses, among many working with patients and caregivers as a team. New therapies and active research are also keys to success. The role of the Cystic Fibrosis Foundation (CFF) in its evolving guidelines in CF care for every age and the development of cystic fibrosis centers with state-of-the-art care around the country are also of paramount importance.

Early diagnosis and close surveillance with aggressive management of both pulmonary and nonpulmonary complications are important in preserving lung function, improving nutrition, and decreasing CF morbidity over time.

As more patients are becoming adults, adult CF care centers are being developed in collaboration with previously established pediatric centers to have smooth transition. This will help in continuing better control of ongoing progressive lung disease. In adults, CF can lead to many other no-pulmonary issues, such as CF-related diabetes mellitus, osteopenia and osteoporosis, nutritional deficiencies and other GI complications, psychosocial issues, and pregnancy/reproductive health issues, among others that need to be addressed to continue to have better outcomes.

References

  1. Ratjen F, Doring G. Cystic Fibrosis. Lancet. 2003;361:681-689.
  2. Farrell PM, Rosenstein BJ, White TB, et al. Cystic Fibrosis Foundation. Guidelines for diagnosis of cystic fibrosis in newborns through older adults: Cystic Fibrosis Foundation consensus report. J Pediatr. 2008 Aug;153(2):S4-S14.
  3. Rowe SM, Miller S, Sorscher EJ. Mechanisms of disease cystic fibrosis. New Engl J Med. 2005; 352(19):1992-2001.
  4. Cystic Fibrosis Foundation. 2017 patient registry: annual data report. https://www.cff.org/Research/Researcher-Resources/Patient-Registry/2017-Patient-Registry-Annual-Data-Report.pdf. Accessed May 29, 2019.
  1. Welsh MJ. An apical-membrane chloride channel in human tracheal epithelium. Science.1986;232(4758):1648-1650.
  2. Rowe SM, Miller S, Sorscher EJ. Cystic fibrosis. N Engl J Med. 2005;352(19):1992-2001.

Shahid SheikhShahid Sheikh, MD, is a pediatric pulmonologist and allergist immunologist, and Associate Professor of Clinical Pediatrics at Nationwide Children’s Hospital in Columbus, Ohio. Dr. Sheikh is Vice-Chair of the Pediatric NetWork Steering Committee. His areas of specialty are pediatric asthma and cystic fibrosis.

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