What is an eosinophilic cationic protein? The norm of the eosinophilic cationic protein in adults and children

Before talking about complex things, you need to deal with simple ones. In this case, it’s worth starting not with complex protein structures, the purpose of which for many is just a set of letters, but with a more understandable arrangement of blood cells. Likbez, so to speak.

Blood composition

Everyone knows that blood consists of a liquid part and solid particles - cells. Plasma is a solution of electrolytes, proteins and vitamins. Most of it is water (about 95%). In addition, it contains enzymes, metabolic products, inorganic substances necessary for our body to maintain vital functions.

Blood cells

Now about the cellular component. In an adult, up to half of the total blood volume is formed by shaped elements. They are represented by red blood cells, platelets and white blood cells.

1. Red blood cells. There are so many of them that they give our blood a red color. These are biconcave cells that do not contain a nucleus in mature form. But they have hemoglobin, which allows the transfer of oxygen, dissolved in plasma, to the tissues of the body.
2. Platelets are small white plates. They provide blood coagulation by interacting with plasma proteins. When a vessel is damaged, they first come to the rescue and close the wound, eliminating the damage. The life of a person sometimes depends on how strong this barrier preventing blood loss will be.
3. White blood cells are white bodies. But these are not the same cells, their whole group. Their main function is to protect the body from foreign agents. This is a kind of police in a permanent permanent post. They can detect and kill anything that could be harmful. However, some stereotypic biochemical reactions can lead to a violation of the immune response and damage to the body's own cells.

White blood cells

In the framework of this article, we are exclusively interested in white blood cells and their role in human life. As mentioned above, leukocytes are a general concept assigned to a group of cells. There is such a modern classification of the mentioned blood cells:

1. Granular, or granulocytes. After staining with a marker, a large segmented core and a large number of small inclusions can be seen in them. If possible, white blood cells are divided into eosinophils (pink), basophils (blue) and neutrophils (stained in both colors).

2. Non-granular, or agranulocytes. They have a simple nucleus, do not contain inclusions in the cytoplasm. These include lymphocytes and monocytes.

The blood count indicates the absolute number of leukocytes and the percentage of each fraction in percent.

Eosinophils

So we got to what interests us. These are blood cells responsible for inflammatory reactions. They have for this a number of features provided by nature. Among the latter, one can distinguish the ability to amoeboid movement, that is, independent movement in vessels and tissues, regardless of blood flow; the ability to penetrate through the vascular wall, seeping between cells, and enter tissues and organs, increasing inflammation. In addition, chemotaxis is inherent in eosinophils (this is a directed movement to the source of a chemical substance).

Another interesting property of these cells is phagocytosis, and more precisely - microphagocytosis. They are able to absorb small particles or fragments of cells. But their main property remains representativeness. Thanks to it, the body clearly captures foreign agents and produces immunoglobulins E to eliminate them.

The ability to absorb and release histamine makes eosinophils indispensable in the focus of inflammation. But too many of them can cause anaphylaxis and shock - a deadly condition. Any allergy provokes an increase in the number of this type of white blood cells in the blood. This is one of the diagnostic signs.

ECB (ESR)

ECP is an eosinophilic cationic protein. And do not be surprised that the abbreviation is different, since international names are written mainly in English.

Knowing now what eosinophils are, you can easily understand and accept the phrase that the eosinophilic cationic protein is one of the constituent granules found in these blood cells. It is one of the proteins that are released during the inflammation reaction and affect the surrounding tissues and organs. Since the reactions of the body are mostly stereotyped, proteins can beneficially affect the constancy of the internal environment or destroy it. The activity of this chemical may be associated with helminthiasis, bronchial asthma, dermatitis, rhinitis, autoimmune diseases, chronic fatigue syndrome.

Of the four main proteins of eosinophils, cationic is the most significant indicator when monitoring the activity of the inflammatory process.

Structure

The ECB contains a significant amount of arginine, this allows it to stain more strongly with acidic dyes and give the cell a pink color. The amino acid sequence is unique enough to isolate it from everything else by applying monoclonal antibodies. In addition, the protein is absolutely specific, so the research results show 100% certainty.

The properties of ECB are the stimulation of secretion by the goblet cells of the bronchi, the inhibition of the proliferation of T-lymphocytes, the binding of heparin and the suppression of coagulation. It exhibits toxic properties against parasites, but at the same time it can damage the body's cells: nerve, epithelial, cardiac (muscle).

Rate increase

Normally, the eosinophilic cationic protein in the blood should be no more than 7 μg per liter. Diagnostic sign: in patients with bronchial asthma, it rises to 15-20 micrograms per liter; if the indicator is ten times or more higher than normal, it is helminthiasis or exacerbation of dermatitis. The highest rate - up to 200 micrograms per liter - may indicate myeloproliferative blood cancer.

You should not immediately panic if you saw in the blood test that the eosinophilic cationic protein is elevated. The causes of this condition are not always life threatening. For example, such a result can be obtained with an exacerbation of allergies. It is by the dynamics of changes in the ECP indicator that the quality of treatment and its success are evaluated, the dose of the drug and diet are adjusted.

It is known that eosinophils affect the amount of immunoglobulin E, since they have receptors on their surface that are suitable for this protein molecule. But it also happens that the eosinophilic cationic protein is elevated with normal immunoglobulin E, when the cause is not inflammatory diseases. Sometimes, due to a violation of the response of the protective systems of the body, even a decrease in Ig E can be observed with a significant increase in ECB.

Some diseases that are not associated with allergies, but also occurring with an inflammatory component, increase the eosinophilic cationic protein. Among them, bacterial sinusitis, neoplasms in the kidneys, viral infections.

DRESS syndrome

This is a condition that is characterized by intolerance to any drug substance. It is manifested by a rash on the skin, lesions of internal organs and changes in the blood picture. Most often, this syndrome develops after taking Phenytoin, Phenobarbital, Carbmasepine, Doxycycline, sulfonamides and others. The concentration of eosinophilic cationic protein increases significantly during DRESS syndrome.

Study designation

The doctor may order an ECB test when the patient suspects the development of atopic bronchial asthma, atopic dermatitis, or allergic rhinitis. In addition, even signs of a food allergy or toxic infection, such as swelling, itching, nausea, vomiting, headache and loss of consciousness, can become a serious enough reason to prescribe this analysis.

Analysis Methodology

This is a routine blood test. Eosinophilic cationic protein does not require specific preparation, but the general rules for blood sampling for research should be followed.

1. Take biomaterial in the morning, from 8 to 11 hours, strictly on an empty stomach.
2. A day before the study, exclude alcohol, intense physical. load and medication.
3. A couple of hours before the study, do not smoke, do not drink tea / coffee / juice, exclude emotional and physical stress.
4. Repeated studies are carried out under the same conditions.

Decryption

I must admit that this is a rather rare method of examination - analysis for an eosinophilic cationic protein. What ECB shows in children is not fully understood, its norms are designed for adults. But it can be assumed that an increase in it (more than 15 ng / ml) will indicate an inflammatory process or helminthic invasion.

Despite the high specificity, sometimes an eosinophilic cationic protein test is not enough to establish a diagnosis. The norm in adults varies over a wide range (from 0 to 24 ng / ml), and the analysis can be false positive or false negative, like any other.

Modern doctors try to use non-invasive diagnostic methods for the detection and prevention of diseases as early as possible. Determination of an eosinophilic cationic protein makes it possible to predict the development of serious diseases such as bronchial asthma or blood cancer.