Cystic Fibrosis

What is Cystic Fibrosis?

Cystic Fibrosis is a condition characterized by an abnormal increase in thickness and viscosity of mucus secreted by our body. The disease causes progressive breathing impairment and other severe respiratory problems. It can also affect digestion, growth and development. The symptoms result from the buildup of sticky mucus in different organs, such as lungs, pancreas and intestines.

Mucous secretions are mixtures of cells and many different substances that cover the surface of our internal cavities (airways and ducts). Their primary function is to protect and lubricate these passage ways. When mucus becomes too slimy (due to cystic fibrosis, for example), it gradually accumulates and, with time, causes obstruction of different cavities. Obstruction of airways and accumulation of mucus in the lungs leads to respiratory problems, while obstruction of ducts that transport digestive agents from the pancreas and accumulation of the mucus in the intestine results in digestive problems. The symptoms normally appear very early during development and they might include: inability to pass the first stool, diarrhea, extremely salty sweat, abnormal growth pattern, lung infections, wheezing, and persistent cough.

Cystic Fibrosis is a disorder of genetic origin and is caused by the mutation of key regulators of mucus formation and secretion. These abnormalities are genetically inherited and are not repairable with current treatment methods. Despite considerable research efforts, there is no cure for cystic fibrosis. Therapy focuses on managing symptoms and controlling the disease. With recent developments in diagnosis and treatment of cystic fibrosis, people suffering from this disease are living longer and better than ever before.

Cystic fibrosis affects about 30,000 people in the United States and around 70,000 worldwide. Cystic fibrosis is more common in Caucasians usually of Northern European descent. The disease is also common among Latinos and Native Americans and is much less common among African Americans and Asian Americans. Cystic Fibrosis is present from birth and is first seen in early childhood and affects both males and females equally.

What Causes Cystic Fibrosis?

The cause of cystic fibrosis is a gene mutation. This disorder occurs in individuals that inherit the mutated genes from both mother and father. If they only inherit a single mutated gene from either parent they will be carriers of the disease and will not develop cystic fibrosis. Mutation of the cystic fibrosis gene causes malfunction in the cystic fibrosis transmembrane conductance regulator (CFTR), which in turn leads to abnormal production and consistency of mucus. There are more than a thousand different mutations discovered, and this is thought to underlie the broad range of disease severity observed in cystic fibrosis patients.

Symptoms of Cystic Fibrosis

The symptoms of cystic fibrosis vary from one person to another and might change depending on the stage of the disease. The following list presents common symptoms of cystic fibrosis:

• Fatigue
• Foul smelling stools
• Excessive fat in stools (steatorrhea)
• Malnutrition
• Limited exercise tolerance
• Use of accessory muscles
• Severe dysnea
• Cough
• Fever
• Wheezing sound
• Abdominal distention
• Intermittent sinusitis and respiratory infection
• Weight loss
• Delayed growth
• Severe constipation
• Diarrhea
• Skin or sweat is salty
• Infertility in male
• Dehydration
• Increase in heart rate
• Decrease in blood pressure
• Clubbing
• Osteoporosis
• Cyanosis
• Increased anteroposterior diameter of chest
• Respiratory distress with retractions
• Hemoptysis

People that have cystic fibrosis are at an increased risk of developing complications, such as: bronchiectasis, meconium ileus, pneumothorax, gastroesophageal reflux, rectal prolapse, portal hypertension, rickets, nasal polyps, atelectasis, diabetes, cirrhosis, cholecystitis and cholelithiasis, liver failure, pancreatitis, pneumonia, cor pulmonale (right sided heart failure), end-stage lung disease and fatty liver.

Diagnosis of Cystic Fibrosis

Initially, the doctor will ask the patient several questions that include personal information and family history. Then the doctor will perform the physical examination during which he will assess the patient's body to check for any signs and symptoms of cystic fibrosis. Imaging tests such as X-rays, magnetic resonance imaging (MRI), computerized tomography (CT) allow the physician to check for any internal abnormalities. More specific tests are normally performed to confirm the diagnosis of cystic fibrosis. In sweat tests, a sample of the patient's sweat will be taken in order to check for presence of salt content. If the results show an increase in salt, the patient likely has cystic fibrosis. Genetic tests are recommended to confirm mutations in a patient's DNA. A sample of saliva or blood is normally taken for this test. Newborns at risk of developing the disease, or becoming carriers, are immediately screened after birth. A blood test is important to check for pancreas and liver function and elevation in white blood cells. Sputum test is indicated when the patient has lung infection. The doctor will ask the patient to cough up sputum to check for the presence of bacteria. Lung function tests are normally performed to ensure that the lung is still functioning at reasonable levels.

Treatment of Cystic Fibrosis

Management of cystic fibrosis requires daily therapy to provide nutrition, enhance gas exchange and slow down the progression of disease. There is no cure for cystic fibrosis. However, there are new treatments available for people with cystic fibrosis to enhance their life expectancy. The treatment will depend on the severity of the disease and the symptoms the patient is experiencing.

Chest physiotherapy is a manual procedure to eliminate thick mucus from the lungs by clapping with cupped hands from the anterior and posterior of the chest. Mechanical devices such as positive expiratory pressure (PEP) mask and Flutter valve are also available.

Deep breathing exercise or technique also helps in loosening the mucus from the lungs and allows the airway to open. Physical exercise can help loosen mucus and increase the patient's activity tolerance. Aerobic exercise is recommended as it will provide increased benefits for the patient.

Feeding tubes might be necessary when there is poor absorption of vitamins and nutrients. The tubes will help the patient receive nutrition that is needed by the body.

Surgery might be recommended in some cases to slow the progression of the disease or manage its symptoms. When applicable, lung transplant procedures may include a lobe or single lung transplantation as well as double lung transplantation. This is recommended to patients that have advance lung disease. During lung transplantation, the surgeon will remove one or both lungs that are no longer functioning well and replace them with a healthy lung or lungs, respectively. Transplants may cause complications such as bleeding, infection and transplant rejection. Thoracoscopy and chest tube drainage is indicated for disobstruction of pneumothorax or collapsed lung. Bowel surgery might be indicated for patients with digestive problems or obstruction of the bowel. On the other hand, patients suffering from severe sinusitis caused by nasal polyps are candidates to endoscopic sinus surgery.

In addition to surgery, there is a variety of medications that might be applied in the clinical management of cystic fibrosis:

Bronchodilators are drugs used to relax the smooth muscles and allow airway clearance. Albuterol is the most commonly used bronchodilator.

Pancreatic enzymes are agents used to treat the pancreas when it's not functioning properly. Pancrelipase is an example of an available mixture of pancreatic enzymes.

A class of drugs that includes dornase alfa is used to decrease the thickness of mucus. These are mucus-thinning drugs or mucolytics.

Several antibiotics might be needed to fight frequent bacterial infections. Examples include: chloramphenicol, piperacillin, trimethoprim, sulfamethoxazole, gentamicin, cephalexin, ceftazidime, ciprofloxacin, aztreonam inhalation, ciprofloxacin and tobramycin.

Stool softeners are important to manage stool consistency and avoid frequent constipation.

Supplements of vitamin A, D, E, and K are very important to compensate nutritional deficits caused by reduced nutrient absorption of fat-soluble vitamins.

Nonsteroidal anti-inflammatory drugs (NSAIDs) are used to treat recurrent inflammation.

Prognosis of Cystic Fibrosis

The prognosis of cystic fibrosis will depend on the severity of the disease and it varies from one individual to another. Fortunately, there are available treatments that can help patients increase their life expectancy. However, there is still no cure for cystic fibrosis.

Preventing Cystic Fibrosis

Since cystic fibrosis is not curable, it is still important to prevent the disease from causing complications. Genetic tests should be performed early on to confirm the condition and initiate treatment as early as possible. Smoking should be stopped and exposure to second hand smoking avoided. It is important to eat healthy and to eat foods with high-caloric content. Dietary supplements should be taken frequently, as directed by your physician or nutritionist. Immunization is critical to prevent bacterial infections that are common in cystic fibrosis patients. Proper handwashing and other hygiene measures can also help in avoiding infections by bacteria or other infectious agents. Daily exercise and chest physiotherapy can help to clear mucus from the respiratory system.

Living with Cystic Fibrosis

Living with cystic fibrosis might make you feel angry, afraid and depressed, but it is very important to be strong and never lose hope. It is critical for you to understand the risks of the condition and to find information about it. These steps can help you prepare for the treatment choices ahead. Discuss with your family, close friends or partner about your thoughts and feelings. There are also support groups available that you can join. Having many support systems can help you cope with your disease more effectively.  It is very important to have medical surveillance by a multi-disciplinary team of doctors, nurses, and therapists specialized in the treatment of cystic fibrosis. Go to all of your doctor's appointments and follow the recommended lifestyle changes that include eating healthy foods, avoiding tobacco smoke, and washing hands often. It is important to inform the doctor if there is any blood in mucus, fever, decrease in energy or appetite, severe constipation, diarrhea, dark green vomit or abdominal pain.  Follow your vaccination schedule strictly as this will help to prevent potentially serious and life-threatening infections.

Current Research of Cystic Fibrosis

Research focuses on improving quality of life and exploring new approaches that might lead to a cure for this disease. New and more effective ways of correcting vitamin deficiency are being developed. Improvements in entereal tube feeding and non-invasive ventilation techniques are also being developed. New approaches for psychological intervention on patients and their families are under discussion.

New treatments are being explored in clinical trials. These include: premature stop codon (PTC) therapy agents, such as PTC124 and amyloglocosides.

Development of screening techniques is an area of intense research in the field. The hope is that information acquired through these diagnostic techniques will not only identify the disease early, but also assist in design and development of therapeutic approaches. The application of these approaches has had a great impact in the treatment and prevalence of cystic fibrosis. Additional positive effects in the clinical management of the disease are expected.