Cystic fibrosis

Symptoms and cause

Cystic fibrosis is a congenital condition, but its symptoms are not always apparent at birth. They often become noticeable during the first year of life.

The most common symptoms of cystic fibrosis include:

• Persistent respiratory problems (mucous cough, lung infections, etc.)
• Poor weight gain or growth, or weight loss despite a good appetite
• Abnormal stools: frequent, diarrheal, sometimes with visible fat droplets

The brain, nervous system, muscles, and heart are not typically affected. Therefore, individuals with cystic fibrosis do not experience delayed neurological or motor development.

Cause: malfunctioning salt channels

In various parts of the body, mucus production and the hydration of mucous membranes are regulated by multiple salt channels. A genetic mutation in a key salt channel (the CFTR or cystic fibrosis transmembrane conductance regulator) disrupts water transport, drying out the mucus, hence the historical term "mucoviscidosis" (thick mucus).

Diagnosis

At birth

Via neonatal screening

An early diagnosis positively impacts the progression of cystic fibrosis. A few days after birth, a heel prick test is performed on every newborn. This blood analysis detects several congenital conditions, including cystic fibrosis.

If the screening result is abnormal, the baby has an increased risk of cystic fibrosis. In this case, further tests are required, and the infant is referred for a sweat test, which will confirm or rule out the diagnosis.

However, an abnormal screening result does not necessarily mean the baby has cystic fibrosis. This screening can also detect carriers of the genetic mutation in otherwise healthy babies. This is referred to as a false-positive test.

Via clinical symptoms

When no diagnosis is reached via neonatal screening, it can be identified through clinical symptoms.

Persistent respiratory problems (especially persistent productive cough, etc.)
If a child has persistent lower respiratory tract problems, the doctor will consider testing for cystic fibrosis.

Gastrointestinal problems: intestinal blockage at birth (meconium ileus)
When a baby is born, they should pass stool within the first 24 hours. Sometimes this does not happen, and the baby shows signs of severe abdominal pain. Further tests often reveal a plug of meconium in the small intestine, which prevents the colon from developing properly and makes it too narrow. The intestinal contents cannot pass the thickened meconium plug, causing an obstruction. When a baby presents with these symptoms, cystic fibrosis is always considered.

Poor weight gain (failure to thrive) or weight loss despite a good appetite
Parents often report that their child has an insatiable appetite. These children also frequently have abundant, foul-smelling stools. These symptoms raise suspicion for cystic fibrosis, as difficulty absorbing dietary fats is a hallmark feature.

Abnormal stools
Frequent and abundant, diarrheal, sometimes with visible fat droplets.

At a later age

Mild forms of cystic fibrosis may not be diagnosed until later in life. Although cystic fibrosis is typically diagnosed in young children, around 10% of cases are only identified in adulthood.

Vague symptoms

Adults diagnosed with cystic fibrosis often present with vague or mild symptoms, such as:

• Chronic cough
• Sinusitis
• Abdominal pain

General practitioners or pulmonologists often treat these symptoms without further investigating underlying causes if treatment is effective.

In adult men, cystic fibrosis is frequently diagnosed during investigations for fertility issues. In rare cases, the diagnosis is made in severely ill individuals at an adult stage.

Better prognosis

Milder forms of cystic fibrosis have a different disease progression compared to the classic form, which manifests earlier. These milder forms are often linked to different genetic mutations. Patients with these forms tend to have a better life expectancy and retain pancreatic function (pancreatic sufficiency).

Treatments and follow-up

The treatment of cystic fibrosis is a daily task that must be closely monitored, addressing both the lungs and the digestive system.

Check-up examinations

Cystic fibrosis is a slowly progressive disease, making therapy adjustments crucial, even for minor changes.

To make timely adjustments, routine tests are conducted, scheduled at least during quarterly consultations.

Sometimes, additional examinations are required. For these, a day admission or hospitalisation is arranged.

Living with cystic fibrosis

Patients with cystic fibrosis are, first and foremost, individuals with normal physical and intellectual development. Most young patients with cystic fibrosis complete a standard school career, participate in extracurricular activities, and enjoy hobbies like their healthy peers. However, at every stage of life, sufficient time and attention must be dedicated to daily therapy, as it plays a critical preventative role in the treatment of cystic fibrosis.

Daily therapy is the only way to slow down the progression of cystic fibrosis and to stabilise the condition as much as possible.

The disease progression in cystic fibrosis patients varies greatly and can evolve over time. Some patients require frequent hospitalisations, while others are rarely admitted.

Florien, a cystic fibrosis patient, shares her story

Florien, followed up at UZ Leuven, lives with cystic fibrosis. She shares her experience, explaining what cystic fibrosis is and how she manages it in her daily life.

Complications

In various parts of the body, mucus production and mucous membrane hydration are regulated by multiple salt and water channels.

When these channels become obstructed due to thickened mucus, additional problems may arise in other parts of the body.

The most common complications include:

Transition to adult care

For every young adult with cystic fibrosis, there comes a time when paediatric care no longer aligns with their lifestyle. At this point, the transition from paediatrics to adult medicine is made.

At the mucocentre, a dedicated program ensures this transition is as smooth as possible.

About cystic fibrosis

The European Cystic Fibrosis Society Patient Registry (ECFSPR) collects, analyses, and compares data from children and adults with cystic fibrosis across Europe and neighbouring countries, who have consented to the use of their data for this purpose.

Links

• Mucovirus Society asbl
• European Cystic Fibrosis Society
• ERN LUNG