Pancreatic elastase and analysis of its level
The pancreas produces biologically active substances ─ hormones and enzymes that are actively involved in all digestion processes. One of these substances is pancreatic elastase. The quantitative index of this enzyme determines the functionality of the gland, its physiological state, possible morphological changes in tissues. Stool analysis is an informative diagnostic method for various pathologies of the gastrointestinal tract.
What is pancreatic elastase?
Pancreatic elastase is an enzyme that is produced by the pancreas. It participates in the processes of protein breakdown to amino acids.
Elastase is active in two directions:
- intrasecretory ─ produces insulin and corrects carbohydrate metabolism;
- is an exosecretory ─ involved in digestion processes.
Through the gland ducts, the enzyme in the pancreatic juice, where it is 9%, enters the small intestine. When pathological processes in the duodenum, the elastase values drop. Therefore, the level of the enzyme is a standard marker for determining the insufficiency of the exocrine function of the pancreas.
Passing through the intestinal tract, elastase is not affected and does not change its qualitative or quantitative composition. Her indicators in the study with accuracy inform about internal pathology.
Types of
The pancreatic enzyme, depending on its functions, is divided into two types:
- Elastase-1, or pancreatic .It is produced in the secretory( acinar) cells of the gland and is delivered to the lumen of the intestine along with other enzymes in the form of proelastase. There, when it interacts with trypsin, it is converted into elastase and participates in the cleavage of protein products. This enzyme is specific, it does not appear in other tissues or organs.
- Elastase-2, or serum .An enzyme that, when inflammatory processes from the pancreas penetrates into the blood through the destroyed cell membranes. With an acute pathological process, serum elastase levels are significantly increased. This is determined by a blood test. Concentration begins to increase already after 6 hours from the moment of onset of the disease, reaches its peak on the second day. The enzyme has a long half-life, so it persists in the blood up to 5 days, sometimes more than a week.
When is the analysis assigned?
An analysis for the determination of pancreatic elastase in the stool is prescribed for suspected of the following diseases:
- cystic fibrosis;
- chronic pancreatitis;
- cholelithiasis;
- chronic gland failure;
- Crohn's disease, thermal ileitis( inflammation of the intestine);
- delay in physical development in children;
- pancreatic injury;
- tumor processes in the organ.
As a differential diagnosis, the assay is assigned to detect cystic fibrosis( a hereditary disease that affects the endocrine glands), malabsorption( a violation of the absorption process in the walls of the intestine).
The analysis is also performed with a syndrome that develops after removal of the gallbladder.
This symptomatic complex is characterized by functional impairment:
- failure of the sphynctra Oddi( controls the movement of bile);
- decreased motility of the duodenum;
- pain;
- secretory diarrhea;
- dyspepsia disorder;
- weight loss;
- is a hypovitaminosis.
According to the indications, the study can assign patients after surgical treatment ─ resection of the stomach, intestines. What are the symptoms of the analysis?
Stool examination is prescribed for digestive disorders characterized by certain symptoms:
- Clinical manifestations are directly related to protein deficiency ─ excessive reproduction of conditionally pathogenic intestinal flora. Feces change color, consistency and smell. There are viscous, mushy, with fragments of not digested food. The color of the chair is gray or with a green tint, has a greasy appearance.
- In rare cases, patients have polyphecal ─ intensive diarrhea, the number of feces per day 1000 g and more.
- Dyspeptic signs ─ bloating due to increased gas formation, severity after eating, sometimes nausea and heartburn.
- General( subjective) signs ─ weakness, sluggishness, decreased ability to work, distracted attention, a slight increase in body temperature( not more than 37.5 ° C), dehydration, loss of appetite, body weight, behavioral disorders.
- Because of lack of protein, edema develops. Deficiency of vitamin K provokes the development of anemia, the formation of small subcutaneous hemorrhages.
Preparation and execution of the study
Biological material for examining the patient for pancreatic elastase ─ fecal masses. The recommended volume for the analysis is 5-10 g.
Since the enzyme is associated with food intake, the results of the analysis directly depend on what the person was taking. Therefore, before the delivery of stool, preparation is necessary. Three days before the study you need to stop taking medications on the basis of oils( laxatives), pilocarpine( increases the secretion of the digestive glands, increases the tone of the intestinal wall), belladonna( relaxes the smooth muscles of the gastrointestinal tract).
To obtain accurate indices, it is not possible to make cleansing or medicinal enemas before giving the assay. Contraindicated X-ray studies using contrast medium( barium).
An analysis of feces for pancreatic elastase is best done in the morning. In the morning on the day of the analysis, collect the feces in a clean plastic or glass container with a spatula, sign, indicating their data, and send it to the laboratory. You can collect an evening portion of feces and put it in the refrigerator for the night.
To determine the quantitative content of elastase in the stool, an immunological method is used. It is based on the "antibody-antigen" reaction. A standard coprologic test includes monoclonal bodies that immediately recognize a pancreatic enzyme. This method is a priority, since it has high sensitivity and specificity.
This means that the :
- test unerringly identifies chronic secretory deficiency of elastase;
- in 93% of cases registers chronic pathology of the pancreas;
- identifies the disease at the initial stage with a mild and moderate form of flow.
Changing the activity of pancreatic elastase is a very slow process. Her research is conducted no more than 1-2 times a year, as there will be no significant changes in the indicators for this period.
Norm of elastase in the stool
Normally, in an adult human, the amount of enzyme in the feces is 200-500 μg / g.
With a mild to moderate degree of exocrine gland failure, this value is 100-200 μg / g.
In severe cases, with pronounced exocrine pancreatic insufficiency, the amount of elastase is less than 100 μg / g.
In different laboratories, the quantitative parameters of the enzyme may differ. It depends on the method of immunological research( monoclonal, polyclonal, ELISA), and also from the manufacturer of the test system. Therefore, in order to correctly interpret the results, it is necessary to look at the reference values indicated on the form.
Reasons for abnormality
The main causes that lead to reduced elastase release are:
- Chronic inflammatory lesion of the gland tissues.
- Destruction( destruction) of the exocrine pancreatic parenchyma.
- Congenital dysfunction of the excretory and flow system of the gland with secondary replacement with a connective tissue.
- Disturbance of outflow of pancreatic juice.
Elastase indices are not fundamental in the diagnosis. The analysis is carried out in the complex diagnosis of pancreatic diseases. He is appointed in severe conditions of patients, when the appointment of a treatment regimen requires a careful individual approach.
Author: Natalia Avramenko, doctor,
specially for Moizhivot.ru
