Cystic Fibrosis Screening

By Dr. Ananya Mandal, MD

Cystic fibrosis screening test results are based on determination of heterogeneous circulating forms of immunoreactive trypsinogen (IRT) and the most common cystic fibrosis mutation that is usually associated with severe cystic fibrosis disease, ∆F508. Newborn screening will not detect all forms of cystic fibrosis; IRT testing may miss patients with pancreatic sufficiency. Because IRT values decrease as a baby ages, IRT results are not reliable after 90 days, so prompt repeat screening is essential. The screening tests are an adjunct to clinical assessment, which is paramount. cystic fibrosis should be considered in infants with any of the signs and symptoms of the disease.

It is essential to confirm or exclude the diagnosis of cystic fibrosis in a timely fashion to avoid unnecessary testing, to provide appropriate interventions, prognostic and genetic counseling, and to ensure access to specialized medical services. In most cases the diagnosis of cystic fibrosis will be confirmed by measurement of chloride concentrations in pharmacologically-stimulated sweat. Because newborns may not produce enough sweat for a reliable diagnosis in the first weeks of life, consultation with a pulmonary specialist is essential. Genetic testing may be performed.

Cystic fibrosis cannot be cured, but many symptoms can be treated. Many newborns with meconium ileus will need surgery shortly after birth. Most children and adults with cystic fibrosis will need to eat a healthy, high-calorie diet and take vitamins to help them grow. Some people may also need medications to help them get more nutrients from the food they eat. To breathe better, many people with cystic fibrosis need help clearing mucus from their lungs each day. Some medications can also prevent infections and help with breathing. The Newborn Screening Program recommends that all babies with cystic fibrosis be treated in an accredited cystic fibrosis Center. Children with cystic fibrosis and their families also benefit from having a primary care physician who helps to coordinate their care with medical specialists and other community-based services.

Further Reading

• All Cystic Fibrosis Content
• Cystic Fibrosis (CF)
• Cystic Fibrosis Causes
• Cystic Fibrosis Symptoms
• Cystic Fibrosis Diagnosis