Welcome to the Rare Classroom, a new series from Patient Worthy. Rare Classroom is designed for the curious reader who wants to get informed on some of the rarest, most mysterious diseases and conditions. There are thousands of rare diseases out there, but only a very small number of them have viable treatments and regularly make the news. This series is an opportunity to learn the basics about some of the diseases that almost no one hears much about or that we otherwise haven’t been able to report on very often.
Eyes front and ears open. Class is now in session.
The disease that we will be learning about today is:
Cystic Fibrosis
What is Cystic Fibrosis?
- Cystic Fibrosis (CF) an inherited life-threatening disorder that damages the lungs and digestive system. There is no cure.
- Quality of life is impacted by persistent lung infections and demands of treatment
- There are more than 30,000 people in the US with CF
- Cystic fibrosis occurs at a rate of 1 in 3,400 births in the US
- The average cost of care for a person with CF living in the US in 2006 was just over $48,000
- More than 75 percent of people with CF are diagnosed by age 2
- On average, CF patients spend nearly two hours a day performing therapies in order to maintain their health
- Survival has more than doubled in the past 40 years
How Do You Get It?
- Caused by the inherited genetic defects in the CFTR gene
- The CFTR gene codes for an ABC transporter-class ion channel protein that conducts chloride and thiocyanate ions across epithelial cell membranes. Mutations of the CFTR gene affecting chloride ion channel function lead to dysregulation of epithelial fluid transport in the lung, pancreas and other organs, resulting in cystic fibrosis.
- The gene was identified in 1989
- More than 1000 possible changes can occur in CFTR to cause cystic fibrosis
- Approximately 70% of all patients with cystic fibrosis have the same defect: F508
- Patients who have a complete loss of the CFTR gene have a clinical phenotype representative of pancreatic disease, severe pulmonary disease, gastrointestinal problems, and infertility (in men) or, sometimes, fertility problems (in women)
- Patients who have a partial loss of the gene may have a phenotype that would be less severe
- Gene defects are also classified in 4 or 5 categories depending on the production and function of the gene
- CF gene mutations are divided into classes based on how damaged the CFTR protein function is. Classes I, II, and III are generally more severe causing “classic CF.” Classes IV and V are usually milder.
- Other genes called modifier genes can affect a person’s symptoms and outcome.
- Female patients tend to die earlier than male patients
- Prevalence across racial groups:
- 1 in 3000 Caucasians
- 1 in 9200 Latinos
- 1 in 10,900 Native Americans
- 1 in 15,000 African Americans
- 1 in 30,000 Asian Americans
What Are The Symptoms?
- Respiratory symptoms include:
- Persistent cough that produces thick mucus (sputum)
- Wheezing
- Breathlessness
- Exercise intolerance
- Repeated lung infections
- Inflamed nasal passages or a stuffy nose
- Chest pain
- Gastrointestinal symptoms include:
- Foul-smelling, greasy stools
- Poor weight gain and growth
- Intestinal blockage, particularly in newborns (meconium ileus)
- Constipation
- Abdominal distention
- Recurrent abdominal pain
- GI bleeding
- Urogenital tract symptoms include:
- Undescended testicles or hydrocele
- Delayed secondary sexual development
- Amenorrhea
- Some patients may be infertile or have problems with fertility.
How Is It Treated?
- Treatments are tailored to the type and severity of CF symptoms that a person experiences. Patients typically need daily treatment for respiratory and digestive symptoms.
- Early recognition and aggressive treatment can have a beneficial effect on the course of the disease
- Treatment is very important to prevent or slow down the long-term lung damage from CF
- The goal of treatment is to maintain lung function, maintain adequate growth and manage complications
- Treatments include medications, chest physical therapy, pulmonary rehabilitation and surgical procedures. Treatment is life-long.
- Barriers to treatment can stem from the daily, time consuming nature of treatment.
- The Health Care team can include: pulmonologist, pediatrician, respiratory therapist, dietician, social worker
- Factors impacting prognosis include genotype, environment, pancreatic insufficiency, gender, and pulmonary function
- Medications
- Antibiotics
- Antibiotics are taken by people with CF as part of regular daily treatment
- Antibiotics can be received as inhaled medications, oral, or IV
- Mucus thinners
- Inhaled medications that help thin the mucus in the airways so it can be coughed out of the lungs more easily
- The two main types of mucus thinners are hypertonic saline and dornase alfa (Pulmozyme)
- Anti-inflammatory
- Lessens the swelling in the airways of the lungs
- Bronchodilators
- Help keep your airways open by relaxing the muscles around your bronchial tubes
- Taken through a metered dose inhaler, dry powder inhaler or nebulizer
- Oral pancreatic enzymes
- Help the digestive tract absorb nutrients, help to gain and maintain a healthy weight, help to digest carbohydrates, proteins and fats
- CFTR Modulator therapies
- Designed to correct the function of the defective protein made by the CF gene
- Are effective only in people with specific mutations
- The latest version is a three part combination of elexacaftor, tezacaftor, and ivacaftor, called Trikafta (US) or Kaftrio (EU)
- This treatment can make cystic fibrosis a manageable condition, but only some patients see benefit
- Antibiotics
- Therapies
- Chest physical therapy
- Vest therapy
- Huff coughing
- Breathing techniques
- Hand held expiratory device
- Pulmonary rehabilitation
- Surgery
- Nasal polyp removal
- Oxygen therapy
- Endoscopy and lavage
- Feeding tube
- Bowel surgery
- Lung transplant
- Lifestyle changes
- High-energy and high-fat diet
- People with CF need to consume a very large number of calories to maintain weight and grow, which can be difficult to achieve
- Supplemental vitamins
- Nutritional supplements
- Regular exercise
- Physical activity is important to help keep lungs healthy
- Upper body exercise
- High-energy and high-fat diet
- Children who are born today with CF have a completely different prognosis from those born more than 30 years ago
- In 1962, the predicted median survival for CF patients was about 10 years, with few surviving into their teenage years
- The NIH reports that the current average life expectancy for CF patients in the US who live past childhood is about 40 years. Some live into their 50’s.
- The majority of pediatric CF patients are able to manage symptoms and maintain quality of life such as taking part in school and other activities
- Many young adults with cystic fibrosis manage to finish college and find jobs
- Over time, lung disease tends to worsen which eventually disables the patient
- Months to decades after birth, individuals eventually develop chronic infection of the respiratory tract leading to progressive respiratory insufficiency and eventual respiratory failure. The rate of progression varies widely, depending in part on genotype as well as environmental factors
- Death is most often caused by lung complications
Where Can I Learn More???
- Check out our cornerstone on this disease here.
- Learn more about this disease from the Cystic Fibrosis Research Institute (CFRI).
