Cystic Fibrosis

Cystic fibrosis (CF) is a hereditary condition affecting multiple organ systems, primarily the lungs and digestive system. It results from mutations in the CFTR (Cystic Fibrosis Transmembrane Conductance Regulator) gene, which causes the body to produce thick and sticky mucus that can clog airways and lead to respiratory and digestive problems.

The diagnosis of cystic fibrosis involves several steps:

  1. Newborn Screening:
    1. Shortly after birth, a small blood sample is taken from the baby and tested for elevated levels of a pancreatic enzyme called immunoreactive trypsinogen (IRT). Elevated IRT suggests the possibility of CF, but further testing is required for confirmation.
  2. Sweat Chloride Test:
    1. This is the gold standard diagnostic test for CF. Individuals with CF have higher than normal levels of salt (chloride) in their sweat.
    2. In this test, a small area of the skin (usually the forearm) is induced to sweat using an electrode. The sweat is then collected and analyzed for chloride concentration. A high chloride level is indicative of CF.
  3. Genetic Testing:
    1. Identifying mutations in the CFTR gene confirms the diagnosis. There are numerous mutations that can cause CF, with some being more common than others (F508del)
    2. Genetic testing not only helps in diagnosing CF but can also provide information about the potential severity of the disease based on the specific mutation(s) present.
  4. Pulmonary Function Tests (PFTs):
    1. These tests measure how well the lungs are working. They’re not diagnostic for CF by themselves, but in someone with suspected or known CF, they help gauge the severity of lung disease and monitor its progression over time.
  5. Chest X-rays and CT scans:
    1. These imaging tests can identify lung complications related to CF, such as bronchiectasis, infections, or mucus blockages.
  6. Sputum Culture:
    1. Analyzing the mucus from the lungs can identify bacterial infections that are common in people with CF. This can guide treatment decisions.
  7. Pancreatic Function Test:
    1. Since CF can affect the pancreas’s ability to produce digestive enzymes, this test checks the pancreas’s function by measuring the body’s ability to absorb certain fats and other substances.
  8. Other Diagnostic Tests:
    1. For those with gastrointestinal symptoms, tests like stool analysis (to detect malabsorption) or imaging studies of the digestive system might be conducted.

A combination of clinical symptoms (such as chronic lung infections, poor growth, or salty-tasting skin) and the results from these diagnostic tests will help in the confirmation of a CF diagnosis. Once diagnosed, management typically involves multidisciplinary care to address the various aspects and complications of the disease.