Life expectancy among cystic fibrosis patients is making great strides

Cystic fibrosis is an inherited genetic condition. Due to a fault in the CFTR gene, salt transport within the cells doesn’t function properly. “That mutation isn’t the same in every patient, which makes CF a complex disease,” explains Prof Dr De Wachter.

“We distinguish six classes of mutation in total, ranging from missing salt channels to channels that don’t function well enough. When salt transport is disrupted, it affects multiple organs. The lungs struggle with thick mucus that builds up and causes infections, leading to progressive lung damage. Blocked ducts in the liver and pancreas cause digestive issues. Most men with CF are infertile because the sperm cells can’t reach the ejaculate due to blockages.”

The earlier the diagnosis, the sooner treatment can begin and the fewer lasting complications there will be. “That’s why, since 2019, we’ve been screening for cystic fibrosis in Flanders through the heel prick test. (In Wallonia that is the case since 2020.) As this type of screening can result in false positives, a sweat test is ultimately needed to confirm the diagnosis.” This sweat test is carried out at one of the seven recognised cystic fibrosis reference centres in Belgium. UZ Brussels, the hospital of the VUB, is one of them.

“However, there’s a relatively large grey zone between high and low salt concentrations measured during the test. Patients who fall within that zone are examined further and monitored more closely. In children aged six and up, and in adults with an unclear diagnosis, a nasal potential difference test can be performed. UZ Brussels is one of the few centres where this can be done. It allows us to make a more sensitive distinction between having CF or not.”

Until 2016, the focus was on treating symptoms. Patients received aerosol and physiotherapy, took courses of antibiotics, and were given advice on managing digestive issues. Psychologists, nursing staff and social workers supported families in dealing with the impact on daily life.

In 2016, the medication Kalydeco was launched. It marked a breakthrough for a portion of cystic fibrosis patients worldwide. “In short, it restores the function of the defective salt channels. So it doesn’t act on the gene itself, but on the end product.”

In Belgium, around five per cent of the patient population has been able to benefit from this groundbreaking therapy since then. Whether the medication works depends on the specific genetic defect. The vast majority around eighty-five per cent of people with CF carry the F508del mutation, which Kalydeco does not target.

Since 2022, Kaftrio has been reimbursed in Belgium, marking a major turning point. This medication helps patients who carry at least one F508del mutation. As a result, eighty-five of cystic fibrosis patients can now be treated more effectively. "Usually, the first effects are seen after just two weeks: the coughing up of mucus stops, body weight increases, and infections become less frequent."

Many patients even stop using light inhalation therapy and physiotherapy over time. Notably, sweat test results often return to normal under this treatment.

However, not everyone benefits from this medication. Certain mutations are left out. “It’s important to embrace this positive development, but equally important to continue supporting all patients who still don’t have a solution.” For those who do not respond to this therapy, further scientific research is being carried out to tackle the disease through gene therapy or mRNA repair. “The goal is to treat the root cause of cystic fibrosis for every individual.”

Since February 2025, Kaftrio has been approved for patients from the age of two. That’s good news. An early start can help prevent irreversible lung damage. “We expect that many of these children will grow up like other children, without the hospital admissions we used to see.”

It remains important, however, to continue monitoring these children and their families through a CF centre. They receive guidance on their treatment and on what might happen, for instance, if they later decide to reduce or stop their medication.

Thanks to improved understanding, we now know that symptoms can also appear later in life. As a result, the condition is sometimes only diagnosed in adulthood. Often, these individuals had milder symptoms as children.

“Chronic sinusitis or respiratory infections, nasal polyps, pancreatitis or male fertility problems can all be warning signs. If there is any doubt, a sweat test can help provide clarity.”

If the sweat test doesn’t offer a clear result, the Cystic Fibrosis Reference Centre at UZ Brussels can carry out further diagnostic testing.

Thanks to advances in diagnosis and treatment, it’s important to put the image of cystic fibrosis into perspective. “Many people still wrongly associate it with a worst-case scenario.

Most CF patients now have a normal life expectancy, can plan a family and build a career. We hope this success story will soon apply to all people living with cystic fibrosis.”