HPN 2022 July

Page 64


Cystic Fibrosis

Current Trends in Cystic Fibrosis Interview with Theresa LowryLehnen (PhD), CNS, GPN, RNP, South East Technological University

Cystic fibrosis (CF) is an inherited chronic disease, primarily affecting the lungs and digestive system of over 1,300 children and adults in Ireland and 70,000 people worldwide.1 Between 2008 and 2016, an average of 38 individuals in Ireland were diagnosed with CF each year, with 22 diagnosed in 2016.5 Ireland has the highest incidence per head of population of CF in the world, with three times the rate of the United States and the rest of the European Union.1 We spoke with Theresa Lowry Lehnen, Clinical Nurse Specialist and Associate Lecturer Institute of Technology Carlow to learn more about this lifelong condition.

the first time that the median age for PWCF reached 20 years (half of the population over 20 years and half under) while 8.9% of the PWCF population in Ireland was recorded as over 40 year’s old. There were 1,266 individuals (565 children and 701 adults) with CF on the registry on the last day of 2016, representing 94.5% of people living with CF in Ireland in that year. Theresa told us, “About 2,000 CFTR gene mutations have been identified to date. Genetic testing provides important information to assist the diagnosis and treatment

The symptoms and severity of cystic fibrosis vary from person to person. The majority of people have both respiratory and digestive problems. There is no cure for cystic fibrosis, however, life expectancy has increased steadily over the past 20 years, and today cystic fibrosis is no longer exclusive to childhood. At the beginning of each year, the CF Registry of Ireland (the ‘registry’) conducts a survey of hospitals known to provide care to people with CF in the Republic of Ireland. The registry has gathered information on people with CF since 2002. The annual hospital census carried out by the registry in 2016 showed that 1,339 people were living with cystic fibrosis (PWCF) in Ireland. Most patients attended one hospital for CF care (n=1,107, 82.7%), whereas 17.3% (232) shared care at two or more hospitals. 2016 was also JULY 2022 • HPN | HOSPITALPROFESSIONALNEWS.IE

of cystic fibrosis. F508del is the most commonly detected CFTR mutation in Irish people living with CF. “In 2016, 91.6% of the CF population had at least one copy, 15.2% at least one copy of G551D, and 5.8% at least one copy of R117H. All other CFTR mutations affect less than 5% of the CF population. Fifty-five percent of patients (55.6%) living with CF in Ireland in 2016 had two copies of the F508del mutation (F508del homozygous). This compares with 46.1% in the United States and 50.3% in the United Kingdom in 2015. Thirtysix percent (36.0%) of people had just one copy of the F508del mutation (F508del heterozygous). The F508del homozygous mutation is the most common CFTR gene mutation in people under 40 years. In those over 40, F508del heterozygous mutations are most common.”5 Cystic fibrosis affects multiple organ systems including the lungs, pancreas, upper airways, liver, intestine, and reproductive organs to varying degrees. Early diagnosis provides opportunities for earlier medical intervention. Providing infants with the best possible care results in better nutritional and lung function outcomes later in life, says Theresa. “Optimised treatment prolongs the lives of people with cystic fibrosis, improving their quality of life,” she says.

“Improved diagnosis and symptomatic treatments have increased the survival rates of people with the condition, from a life span of only a few months in the 1950s to a global median age of 40 years today. The predicted median age of survival for a person in Ireland with CF is early to mid-30’s.” Cystic fibrosis is caused by a gene mutation leading to dysfunction of the cystic fibrosis transmembrane conductance regulator (CFTR) protein, a chloride channel of exocrine glands. The defect leads to diminished chloride secretion which, in turn, leads to increased sodium absorption through epithelial sodium channels and removal of water from secretions, which become abnormally viscous. “The effects cause obstruction, inflammation, infection in the lungs and upper airways, tissue reorganisation and loss of function. The severity of the disease in the individual depends on variable organ sensitivity and on the genetically determined residual function of the CFTR protein. 99% of affected male patients are infertile because of obstructive azoospermia, and 87% of patients have exocrine pancreatic insufficiency. Disease severity particularly the degree of pulmonary involvement, also depends on other diseasemodifying genes and a number of factors including socioeconomic background,” says Theresa.2, 3