Cystic fibrosis
The content of the article:
- Causes and risk factors
- Forms of the disease
- Disease stages
-
Symptoms
- Bronchopulmonary form
- Intestinal form
- Mixed form
- Meconium ileus, or intestinal obstruction
- Other signs
- Features of the course of cystic fibrosis in children
- Diagnostics
- Treatment
- Possible complications and consequences
- Forecast
- Prevention
- Video
Cystic fibrosis is a systemic hereditary disease that affects the glands of external secretion. All body systems are affected, but the respiratory, digestive and sweat glands are the most severe.
Cystic fibrosis is the most common genetic disorder that spreads everywhere, affecting people of all races, but not to the same extent. The most susceptible to it are whites, the least - people of Asian origin (the ratio is 1: 3300 for whites, 1:15 300 for blacks, 1:32 000 for Asians). Not so long ago, cystic fibrosis was considered a disease of children, since patients did not survive to adulthood, at present, thanks to the discovery and improvement of methods of supportive therapy, about half of them survive to adulthood.
Cystic fibrosis affects the entire body, but primarily the pancreas and bronchopulmonary system
In medical reference books, there is another name for the disease - cystic fibrosis.
Causes and risk factors
The cause of cystic fibrosis is the presence of mutations in both alleles of the gene located on the long arm of chromosome 7 (7q31). The gene is responsible for the synthesis of a transmembrane regulatory protein for cystic fibrosis (CFTR, Cystic Fibrosis Transmembrane conductance Regulator). Protein is a channel that transports chlorine and sodium ions through the membranes of epithelial cells lining the respiratory, digestive tract, etc., which is regulated by cyclic adenosine monophosphate (cAMP).
The disease is inherited in an autosomal recessive way, that is, children in whom both parents are carriers of the defective gene become ill.
Disruption of ionic transport through the membrane of epithelial cells leads to the fact that the secretion of exocrine glands is dehydrated and becomes viscous. In the pancreas, a thick secret clogs the excretory ducts, reduces the activity of pancreatic lipase, and reduces the amount of bicarbonates. Metabolic processes in the forming connective tissue are disrupted, the process of sclerosis is started. As early as 2-3 years old, a child with cystic fibrosis may experience complete scarring of the pancreas.
Changes in the bronchial tree concern, first of all, the composition of mucin (mucus), in which the ratio of water and solid part is disturbed, which causes an increase in the viscosity of the secretion. In addition, the amount of leukotrienes and cytokines produced by macrophages, neutrophils and epithelial cells increases, which activates the enzyme elastase. As a result, there is:
- excessive production of pathologically viscous bronchial secretions;
- violation of the mucociliary and cough defense mechanism;
- colonization of the bronchial tree by pathogenic microorganisms;
- the development of secondary inflammation;
- the formation of bronchiectasis (pathological expansion of the bronchi).
Several environmental factors contribute to the worsening of the severity of the disease, these include:
- living in ecologically unfavorable areas;
- respiratory allergens;
- tobacco smoke.
Forms of the disease
The clinic uses a classification of cystic fibrosis based on the prevailing symptoms:
- bronchopulmonary form;
- intestinal;
- mixed intestinal-pulmonary;
- meconium obstruction, or meconium ileus.
A classification is also used based on the degree of damage to the pancreas, according to which they are distinguished:
- cystic fibrosis with pancreatic insufficiency;
- cystic fibrosis without pancreatic insufficiency, including the primary genital form with congenital bilateral aplasia of the vas deferens;
- atypical forms.
Disease stages
On the basis of pathological changes in the respiratory system, 4 stages of cystic fibrosis are distinguished.
| Stage | Characteristic |
| Transient functional changes; manifested by bouts of dry, unproductive cough, mild to moderate shortness of breath during exertion. Duration - up to 10 years. | |
| Chronical bronchitis. Manifestations: productive cough, shortness of breath, aggravated by physical exertion, with auscultation, hard breathing with wet wheezing. Average duration is 2–5 years. | |
|
Development of complications. Respiratory failure appears and grows, which is caused by pneumofibrosis, pneumosclerosis, bronchiectasis, cysts. Right ventricular heart failure (cor pulmonale) is formed. Average duration is 3–5 years. |
|
| Terminal. Manifested by severe cardiopulmonary insufficiency. Lasts several months, ends in death. |
Symptoms
Symptoms of cystic fibrosis can be of varying severity, there are both severe mixed and erased forms of the disease.
Bronchopulmonary form
It is characterized by recurrent protracted bronchitis, bilateral focal pneumonia, which eventually leads to the development of bronchiectasis, pneumofibrosis and pneumosclerosis. Patients suffer from inspiratory dyspnea. The ribcage has a barrel-like shape, the terminal phalanges of the fingers are deformed, thickened (a symptom of drumsticks), the nails have a characteristic convex shape (a symptom of watch glasses), the skin is cyanotic. There are signs of heart failure caused by cor pulmonale, the formation of which is caused by a chronic inflammatory process in the bronchopulmonary system and chronic hypoxia.
Symptom of drumsticks and watch glasses in a patient with cystic fibrosis
Leading symptoms:
- paroxysmal cough with separation of viscous mucous membrane or mucopurulent sputum;
- dyspnea;
- pale or cyanotic skin and mucous membranes;
- weakness, increased fatigue.
Intestinal form
It manifests itself in a violation of digestive processes and intestinal dysfunction. The defeat of the pancreas leads to a violation of the absorption of fats by the body, which is manifested by bloating, oily, poorly shaped stools (the result is muscle hypotension and osteoporosis). The increased viscosity of bile leads to the development of cholelithiasis, cholestatic hepatitis, over time - biliary cirrhosis of the liver (often by the age of 12), various gastric disorders. Often, patients with cystic fibrosis develop gastric ulcer and duodenal ulcer. Leading symptoms:
- paroxysmal pain in the abdomen, cramps;
- bloating;
- nausea, repeated vomiting.
Mixed form
It has signs both from the bronchopulmonary system and from the gastrointestinal tract. It is the most severe of all forms of cystic fibrosis.
Meconium ileus, or intestinal obstruction
It develops in 13-18% of newborns due to a deficiency of the enzyme trypsin, an increased amount of albumin and increased absorption of water from meconium. Because of this, meconium (original feces) becomes excessively viscous and thick and is not excreted, but accumulates in the ileocecal region, forming intestinal obstruction.
Other signs
Patients have excessive sweating, which can lead to dehydration with impaired circulation during fever or summer heat. The skin has a salty taste.
Features of the course of cystic fibrosis in children
It is manifested by the absence of stool, bloating, frequent regurgitation and repeated vomiting, containing an admixture of bile, in newborns in the first days of life.
Prolonged jaundice of newborns is often observed.
If meconium ileus is absent, the first manifestation of the disease may be slow weight gain.
Protein malabsorption can lead to generalized edema, especially in children receiving artificial hypoallergenic nutrition.
Due to dysfunction of the pancreas in children with cystic fibrosis at an early age, bloating, frequent stools of an oily, fetid nature are observed. Against the background of normal or even increased appetite, physical development lags behind - a lack of muscle and adipose tissue is characteristic. Gastroesophageal reflux is not uncommon. Rectal prolapse is observed in 20% of young children.
Dysfunction of the pancreas also leads to the fact that 2% of children and 20% of adolescents have impaired glucose tolerance and, as a result, diabetes.
Leading symptoms in young children:
- paroxysmal cough with viscous sputum;
- pallor, cyanosis;
- shortness of breath, decreased exercise tolerance.
In adolescents with cystic fibrosis, puberty is often delayed.
Children and adolescents are prone to infectious diseases, especially the respiratory tract.
Diagnostics
Neonatal screening is the main method for diagnosing cystic fibrosis in newborns and is the standard in some countries. It is carried out in two stages:
- Determination of the level of immunoreactive trypsinogen in the blood - with cystic fibrosis, it is increased. In this case, the second stage is carried out.
- In one embodiment, a sweat test is tested (the concentration of chlorides is determined), in another, a CFTR gene mutation test is performed, and if a mutation is found, a sweat test is performed.
Neonatal screening makes it possible to diagnose 90% of newborns with cystic fibrosis.
In cases where neonatal screening was not carried out, or for some reason turned out to be insensitive, if cystic fibrosis is suspected, they resort to a sweat test. The method consists in drug stimulation of sweating in the forearm area, after which 50 ml of sweat is collected and sent to the study of the level of chlorides. The diagnosis is considered established if the chloride content is 100 mmol / l or more. A concentration of 60-100 mmol / L indicates the likelihood of cystic fibrosis and requires re-analysis and further examination.
A genetic analysis is carried out - the detection of two characteristic mutations (one on each chromosome) confirms the diagnosis, and the detection of only one mutation is a sign of carriage. The patient's family history is being examined.
In order to obtain a complete picture of the state of the respiratory system, the following are also carried out:
- radiography;
- sputum analysis (as well as clinical analyzes of blood, urine and feces);
- spirography;
- bronchoscopy.
If necessary, resort to additional examination methods.
Treatment
Cystic fibrosis is an incurable disease. However, complex supportive therapy aimed at timely treatment of disorders and prevention of complications allows patients to live longer and maintain an acceptable lifestyle.
The treatment of cystic fibrosis should be handled by a multidisciplinary team of specialists (pulmonologist, gastroenterologist, nutritionist, exercise therapy specialist, and others) under the guidance of a physician with experience in managing patients with this disease. It is important for the patient and his family to receive psychological support.
Basic therapy:
- The diet is high-calorie, enriched with proteins, vitamins and microelements, gentle on the organs of the hepatobiliary system.
- Enzyme replacement therapy (taking pancreatic enzymes).
- Taking choleretic drugs for long, regularly repeated courses.
- Mucolytics and bronchodilators continuously or intermittently.
- Physiotherapy to facilitate sputum discharge (postural drainage, vibration massage, breathing exercises, percussion, exercise therapy).
- Antibiotic therapy. It is prescribed for exacerbation of an infectious and inflammatory process after determining the sensitivity of the pathogen.
- Vitamin therapy. Reception of vitamin-mineral complexes.
- Body weight control. With significant underweight, they resort to anabolic steroids.
Timely and correctly selected treatment allows patients to maintain an acceptable lifestyle
Patients are registered at the dispensary; regularly, at least once every 3 months, they are examined, according to the results of which the doctor can adjust the supportive therapy.
Possible complications and consequences
In the absence of treatment, cystic fibrosis can lead to the development of numerous complications, including life-threatening ones. These include:
- respiratory and heart failure;
- irreversible biliary cirrhosis, accompanied by portal hypertension;
- intestinal intussusception;
- intestinal obstruction;
- parkreatitis;
- cancer of the pancreas and other organs of the digestive system, especially the hepatobiliary tract;
- Crohn's disease;
- male infertility due to obstructive azoospermia; and etc.
Forecast
The prognosis depends on the form, severity of the disease and the age of onset. Currently, thanks to supportive therapy, the situation is improving every year, and in countries with developed medicine, about half of the patients overcome the 40-year mark. The average life expectancy is about 35 years, and this figure is increasing every year.
Prevention
When planning a child in a family where there is a patient with cystic fibrosis, gene diagnosis is necessary.
Neonatal screening allows early diagnosis and treatment.
Children with developmental disabilities who are susceptible to bronchopulmonary disease or digestive disorders should be screened for cystic fibrosis.
All patients with cystic fibrosis should be registered with a dispensary.
Video
We offer for viewing a video on the topic of the article.
Anna Kozlova Medical journalist About the author
Education: Rostov State Medical University, specialty "General Medicine".
The information is generalized and provided for informational purposes only. At the first sign of illness, see your doctor. Self-medication is hazardous to health!
