Mucoviscidosis - Cystic Fibrosis

Cystic fibrosis is a life-threatening, inherited disorder that mainly affects the lungs and pancreas; however it can also affect other organs in the respiratory, digestive and reproductive systems. This disease is also recognized by the following names - mucoviscidosis, cystic fibrosis of the pancreas, pancreas fibrocystic disease or pancreatic cystic fibrosis. The cells that produce saliva, sweat, mucus and digestive juices are damaged in cystic fibrosis. Normally, these secretions are thin and slippery and act as a lubricant. But, in cystic fibrosis, these secretions become thick and sticky, causing blockage of ducts and passageways in the lungs and pancreas. If mucus is accumulated in the lungs, it can cause breathing problems, repeated lung infections and lung damage. Accumulation of mucus in the pancreas can lead to digestive problems, preventing the digestive enzymes produced in the pancreas to reach the small intestine due to blockage in the pancreatic duct. More than 30,000 children and adults are diagnosed with cystic fibrosis in the United States. Let's understand in detail about the causes, symptoms and treatment of mucoviscidosis or cystic fibrosis.

Causes of Cystic Fibrosis

Cystic fibrosis is a genetic disorder caused by a defective gene called cystic fibrosis transmembrane conductance regulator (CFTR). The protein produced by CFTR gene is responsible for regulating the normal movement of salt and water in and out of the cells. This defective gene in cystic fibrosis causes thick, sticky mucus secretions in the digestive and respiratory tracts. It also affects the reproductive system, leading to infertility. There is an increased amount of salt in sweat. If both the parents carry the defective gene, then there are 25% chances that their child will have cystic fibrosis, 50% chances that the child will carry the defective gene and 25% chances that the child will neither be a carrier nor have cystic fibrosis. Family history of cystic fibrosis is the biggest risk factor for CF. People of Northern European ancestry are at higher risk of CF. CF is the most common inherited disorder in Caucasians. This disease is also common in Latinos and native Americans, particularly the Zuni Pueblo.

Signs and Symptoms of Cystic Fibrosis

The severity of symptoms of cystic fibrosis can vary from person to person. Some may either suffer from digestive problems or respiratory problems; while others may suffer from both. Signs and symptoms may vary depending upon the age. In newborns, there may be a blockage in the intestine, causing bulky and greasy stools (steatorrhea). Newborns also suffer from frequent respiratory infections due to accumulation of mucus in the lungs.

In children and young adults, cystic fibrosis causes symptoms such as salty taste to the skin, diarrhea, foul-smelling and greasy stools, thick sputum, delayed growth, frequent coughing or wheezing, chest and sinus infections with recurring bronchitis or pneumonia, dehydration, rectal prolapse and enlargement of fingertips or toes. There are some other medical conditions such as nasal polyps, liver cirrhosis and intussusception, which are related to cystic fibrosis.

Complications of Cystic Fibrosis

Cystic fibrosis can cause some serious respiratory, nutritional and reproductive complications. Respiratory complications include chronic respiratory infections like chronic sinusitis, pneumonia, bronchitis and bronchiectasis (abnormal dilation of the walls of bronchial tubes). A chronic inflammation of the bronchial lining can lead to asthma. Respiratory failure or pneumothorax (collapsed lungs) are life-threatening complications of CF.

Cystic fibrosis can cause chronic diarrhea and severe nutritional deficiencies. The pancreatic ducts are obstructed by thick mucus secretions, which can prevent digestive enzymes from reaching the intestine. These enzymes are essential for the digestion of fats and proteins. This causes malabsorption of fat-soluble vitamins like vitamin A, vitamin D, vitamin E and vitamin K. Since pancreas is affected by CF, it results in increased blood sugar levels, causing CF-related diabetes. Obstruction of bile duct can lead to liver cirrhosis and gallbladder diseases.

Cystic fibrosis also affects organs of the reproductive system. Thick mucus secretions can block Vas deferens (the tube that connects the testes and prostate gland), causing infertility in males. Women with CF may be less fertile; but they can successfully conceive.

Diagnosis of Cystic Fibrosis

Cystic fibrosis can be diagnosed at three stages such as prenatal, postnatal and early childhood. In pregnant women, the amniotic fluid is extracted using the procedure amniocentesis. This fluid is examined for fetal intestinal enzymes. The levels of fetal intestinal enzymes are decreased in a fetus with CF. In newborns, the immunoreactive trypsinogen test (IRT) is carried out. Elevated levels of trypsinogen indicate cystic fibrosis. The sweat electrolyte test is commonly used for the diagnosis of CF in children and young adults. In this test, the amount of electrolytes like sodium, potassium and chloride is determined from the patient's sweat.

Some other tests including lung function test, X-ray, sputum cultures and stool examination are also carried out to confirm the diagnosis of cystic fibrosis. Genetic testing is carried out to detect the cystic fibrosis gene.

Treatment for Cystic Fibrosis

Treatment for CF is aimed at preventing infections, removing thick mucus from the lungs, relieving respiratory and digestive problems and maintaining adequate nutrition. There are different treatment options for respiratory and digestive problems.

Lung problems due to CF can be treated with antibiotics and other medications as well as chest physical therapy and exercises. Respiratory infections are common in people with CF. Antibiotics (oral, inhaled or intravenous) are administered in order to treat infections. Some other medications used for the treatment of CF are anti-inflammatory medications like ibuprofen to decrease the inflammation in the lungs, bronchodilators like albuterol to relax the muscles around the airways and mucus-thinning drugs like hypertonic saline and acetylcysteine saline to help reduce the stickiness of mucus in the airways. Oxygen therapy is administered to increase the levels of oxygen in the blood. If the patient suffers from increasing resistance to antibiotics, severe breathing problems or pulmonary complications, then lung replacement is recommended.

Digestive problems can be managed with the help of nutritional therapy, which constitutes a well-balanced diet that is high in protein and low in fat. Oral pancreatic enzymes are prescribed, which are helpful in digestion of proteins and fats and absorption of vitamins. Vitamin supplements of vitamin A, D, E and K are given to substitute the fat-soluble vitamins. Other treatments for digestive problems in CF are enemas and mucus-thinning drugs to relieve intestinal blockage and use of medications to decrease stomach acid in order to enhance the therapeutic effects of oral pancreatic enzymes.

Cystic fibrosis can be managed with good self-care that includes taking adequate medical treatment, having a nutritious and healthy diet, drinking plenty of fluids and doing regular exercises.