What is Cystic Fibrosis?

Cystic fibrosis is a hereditary exocrine gland disease that mainly affects the gastrointestinal tract and the respiratory system. It is usually characterized by chronic obstructive pulmonary disease, pancreatic exocrine dysfunction, and abnormally elevated sweat electrolytes.

Basic Information

English name: cystic fibrosis, CF
Visiting department: Gastroenterology

Common symptoms: Chronic obstructive pulmonary disease, poor pancreatic exocrine function, abnormally elevated sweat electrolytes
Contagious: no

Causes of cystic fibrosis

Cystic fibrosis is an autosomal recessive disease caused by a mutation in the CF gene on the seventh chromosome pair. The patient is homozygous and his parents are heterozygous. Half of patients' siblings may carry recessive genes, and 1/4 may get sick. Heterozygotes with recessive genes generally account for 2% to 5% of newborns, and one in 2000 to 2500 newborns suffer from the disease. The pathogenesis of cystic fibrosis exocrine gland dysfunction is unknown. Studies have shown that patients with defective epithelial chloride chloride channel regulation have impaired water and electrolyte transmembrane transport in the mucosal epithelium of the respiratory tract, and the acid glycoprotein content in mucus gland secretions has increased, altering the mucosal rheological properties, which may be secretion The reason why things become sticky.

Clinical manifestations of cystic fibrosis

Respiratory system performance

The respiratory system is mainly manifested by repeated bronchial infections and airway obstruction. Symptoms can appear within a few days after birth. There may be a mild cough in the early stage, accompanied by pneumonia and atelectasis, and then the cough intensifies, sticky sputum is not easy to cough, and shortness of breath. If the patient coughs up a lot of purulent sputum or is accompanied by hemoptysis, it may indicate bronchiectasis and lung abscess. On physical examination, clubbing fingers (toes) are common. Lung infections are mostly caused by S. aureus, Pseudomonas aeruginosa, or other Gram-negative bacteria. After extensive fibrosis and emphysema occur in the lungs, there are wheezing, shortness of breath after activity, and often accompanied by spontaneous pneumothorax or mediastinal emphysema. When symptoms of hypoxia and carbon dioxide retention occur, shortness of breath increases and cyanosis eventually leads to respiratory failure and pulmonary heart disease.

2. Digestion and malnutrition

About 10% of neonates have meconium obstruction due to increased intestinal mucus secretion and viscosity, and lack of pancreatic enzymes that affect protein digestion. Bowel obstruction and rectal prolapse can also occur in children. Insufficient secretion of the pancreas causes indigestion symptoms such as abdominal distension, abdominal bulge, discharge of a large amount of foamy stench, and even fatty diarrhea and nitrogen overflow. Vitamin deficiency, especially vitamin A deficiency, can cause dry eye disease. Although the patient has a strong appetite and an adequate diet, he is still malnourished and stunted. Biliary obstruction can occur with jaundice, and concurrent liver cirrhosis can occur with portal hypertension and hypersplenism. If a baby sweats too much, he loses a lot of electrolytes and water, which can easily lead to collapse.

3. Reproductive system performance

Cystic fibrosis can also affect the reproductive system. Because viscous secretions often block the ducts (vas deferens) that connect the testes and prostate, many male cystic fibrosis patients are infertile. Compared with normal women, female cystic fibrosis patients also have reduced fertility.

Cystic fibrosis test

Different stages of disease can be seen on the X-ray as a ring-shaped, small piece of fuzzy inflammation that deepens or scatters the bronchial texture of the two lungs. It can also show signs of limited atrophy (atelectasis), bronchiectasis, lung abscess, and pulmonary heart disease.

Increased sodium chloride content in sweat is characteristic of this disease. Normal children's sweat contains 30-40 mmol / L of chlorine and 60 mmol / L of sodium. The content of chloride in the sweat of sick children can be as high as 105-125 mmol / L, and the sodium content is 120 mmol / L. If the content of chloride in sweat is higher than 60mmol / L (more than 70mmol / L in adults) and sodium is higher than 80mmol / L, and adrenal insufficiency can be ruled out, it has important diagnostic significance. The duodenal fluid is drawn for examination. If the viscosity is increased, and various trypsin, especially trypsin, is reduced or lacking, it is the diagnosis basis. Others, such as rectal mucosal biopsy, see that the glandular duct is full of mucus and expands to form a mucus layer, jejunal mucosal biopsy shows that the intestinal mucosa villi are disappeared, and 5-hydroxyindoleacetic acid in the urine are also valuable for diagnosis.

Cystic fibrosis diagnosis

Because the mutations of the CF gene are so diverse, it is not yet possible to rely on genetic diagnosis, and a diagnosis can be made based on clinical symptoms, combined with laboratory tests to make a diagnosis. If necessary, do a biopsy of the intestinal mucosa. If you can increase vigilance and pay attention to the diagnosis points, it is not difficult to distinguish from other pediatric celiac disease or adult chronic bronchitis.

Cystic Fibrosis Treatment

There are many feasible treatments for the clinical manifestations and complications of cystic fibrosis. The main goals of treatment are to prevent infections, reduce the amount and viscosity of lung secretions, improve breathing, and maintain adequate nutrition. To achieve these goals, treatments for cystic fibrosis include:

Antibiotic

For lung infections in patients with cystic fibrosis, a new generation of antibiotics may be more effective, such as antibiotic sprays, which can deliver drugs directly to the airways to function. One of the biggest problems with long-term use of antibiotics is that the bacteria may develop resistance, which gradually makes the antibiotics ineffective. Therefore, the rational use of antibiotics.

2. Bronchodilator

Bronchodilators (such as salbutamol) can reach the site of action through an inhaler or spray, helping to keep the airway open and clearing viscous secretions.

3. Oral digestive enzymes and strengthening nutrition

Due to cystic fibrosis, pancreatic enzymes required for digestion cannot reach the digestive tract, hinder the digestion and absorption of food, and lead to malnutrition. Therefore, patients should be supplemented with high-energy nutrients, fat-soluble vitamins, and enteric-coated pancreatic enzymes, which can help the body increase nutrition and even increase weight.

4. Lung transplant

If life-threatening pulmonary complications occur and antibiotic treatment fails, lung transplantation is one of the options. However, due to donor difficulties in China, it has not been developed much.

Prognosis of cystic fibrosis

The prognosis depends on early diagnosis and treatment. About half of children die before the age of 10 due to serious complications such as infection or heart and lung failure, and fewer live to adulthood. If early diagnosis, control of respiratory infections, attention to diet therapy, mortality can be reduced during childhood and can survive to adulthood.