Blood cells are quite diverse. Each of them performs its specific role, aimed at maintaining and maintaining the functions of the body. Platelets are responsible for protecting the body from blood loss.
It is especially important to determine the number of these cells in children, since they are more susceptible to injuries, and blood loss with them can affect the body much more than in an adult. So what are platelets, and what is the norm of platelets in children?
What kind of cells are these?
Platelets are cells that ensure the integrity of the walls of blood vessels. They are formed from a megakaryocyte, a giant cell lacking a nucleus. The formation of blood platelets (the second name for platelets) occurs by detaching them from a giant cell.
About 70 percent of all formed cells circulate in the vessels, and 30 percent remain in the spleen. There is also the destruction of these cells.
Platelets do not have nuclei, and due to this they are not capable of reproduction.
Their cytoplasm contains a certain amount of enzymes, as well as substances that contribute to the formation of blood clots, due to which these cells carry out their functions.
Platelets do not live long - from 7 to 10 days, after which unused cells are destroyed by macrophages.
The platelet norm in children is always somewhat higher than in adults. This is due to the active metabolism of the child's body. What are the normal values for the number of these cells?
Normal performance
What is the number of platelets among the determined blood cells ? The norm in children usually lies in the following limits:
- In newborns, the number of blood platelets usually ranges from 100 to 420 * 10⁹ cells per liter of blood.
- At the age of up to one year, the minimum number of platelets increases slightly - up to 150. The maximum, on the contrary, decreases to 350.
- After a year, the platelet index of the child is the same as that of an adult - 180-320 * 10⁹ per liter of blood.
- At the age of five, a certain phenomenon is sometimes observed - platelets change (the norm in children of 5 years old does not differ from adult indicators, however, the cells become more active, due to which the development of thrombopathies is observed). This phenomenon is explained by the second pediatric cross. Due to the dominance of neutrophils, inflammation processes with false platelet activation can be triggered.
It should be remembered that with a hardware blood test and with manual counting, the platelet norm in a child’s blood may change somewhat. Therefore, when automatically counting, the maximum normal plate values of up to 500 in newborns and up to 400 in a one-year-old child are permissible.
Nevertheless, preference should be given to manual calculation: less likely to make mistakes and more likely to make the correct diagnosis.
How are they formed?
Blood platelet formation occurs in the bone marrow. The progenitor of these cells is a megakaryocyte - a giant cell. It is located between endothelial cells and fibroblasts. Due to the influence of these cells from the outside, particles of a megakaryocyte are separated (its cytoplasm passes between the surrounding cells and thus is unfastened).
When entering the bloodstream, platelets circulate through it until they reach a damaged part of the vessel (damage to the endothelium is important). Settling there, the blood plates trigger some humoral processes, as a result of which a fibrous skeleton is formed at the site of the lesion, on which new platelets settle. Thus, first a white, and then a red blood clot is formed.
The process of cell formation in the bone marrow occurs daily, which helps maintain their normal number. Any damage to the bone marrow helps to reduce or increase the number of plates.
Cell number changes
As you know, all indicators of the internal environment of the human body change under the influence of various reasons. An increase in platelet count is called thrombocytosis. It can be divided into primary and secondary. Primary thrombocytosis develops as a result of direct damage to the bone marrow. Secondary depends on concomitant diseases.
A decrease in platelet count is called leukopenia. Like thrombocytosis, it is divided into primary and secondary.
It should be understood how platelets vary in children. The norm (the table includes normal indicators and deviations according to age) can change in any of the parties and is sometimes regarded incorrectly. That is why it is extremely important to know the possible deviations from the norm in children for the correct diagnosis. the table is as follows.
Platelet count versus age| Indicator | Thrombocytopenia | Norm | Thrombocytosis |
| first 5 days of life | <420 * 10⁹ | 215-420 * 10⁹ | > 420 * 10⁹ |
| 10-14 days | <175 * 10⁹ | 175-420 * 10⁹ | > 420 * 10⁹ |
| 1 year | <150 * 10⁹ | 150-350 * 10⁹ | > 350 * 10⁹ |
So why do these cell levels change? You should understand this problem in more detail.
Reasons for increased platelet count
Why can platelets increase? The norm in children can change due to the following reasons:
- Myeloproliferative diseases (usually tumor lesions of the bone marrow with an increase in its functional activity). An increase in the number of platelets occurs most often with a parallel increase in other cells.
- Inflammatory diseases, usually of a chronic nature - rheumatoid joint damage (juvenile arthritis), tuberculosis.
- Bleeding. Functional hyperproduction of platelets to stop blood loss is observed.
- Use of glucocorticosteroids. These hormones with prolonged use (for example, with severe bronchial asthma) contribute to the fact that almost all natural processes are disturbed, so thrombocytosis can occur.
Platelets above normal in a child can also be observed as a result of diseases of the blood system (for example, with erythremia).
Decreased blood plate count
As was said, the level of coagulation cells may decrease. Why is this happening?
Platelets below normal in a child are most often observed with blood diseases - aplastic anemia and leukemia. The number of cells of the immune system is also reduced.
Inherited diseases. These include Wiskott-Aldrich syndrome, Fanconi, histiocytosis. It is these diseases that lead to the fact that children have reduced platelets. The norm in children is almost never observed, the level of plates is always reduced.
Menses. They are the cause of thrombopenia in girls who have recently had menarche. Prior to normalization of the cycle, a significant decrease in the level of cells can be observed.
Heavy metal poisoning. Most often, lead poisoning occurs (for example, the case is known when a child has had this poisoning as a result of vaporization from new wallpaper).
Features in children
Platelet counts usually normalize by one year, but during the neonatal period, the child ’s blood system undergoes some changes.
When platelets are determined, the norm in children up to a year may vary slightly. For example, during the first five hours of life, a baby has about 215 million platelets in the blood. During the first five days, this amount decreases, and by the end of 5 days their number stops at 175 million. It is on the 5th day that significant changes in the blood take place - the level of not only platelets, but also leukocytes (the so-called “pediatric scissors” - the intersection of lymphocytes and neutrophils) changes. From about the tenth day, the platelet count stabilizes - at least 100 million cells (100-420 * 10⁹).
As they grow older, their number increases slightly and about a year becomes equal to 180-320 * 10⁹.
How to determine platelets?
A blood test is used to determine the number of blood platelets. It can be carried out in any clinic or laboratory equipped with the necessary equipment.
When conducting an analysis, the age of the child must be taken into account. It should be remembered that if platelets are determined, the norm in children under one year of age, namely its lower border, is quite low. It’s worth panicking only if the lower indicator is less than 100.
Indications for the determination of cells are prolonged bleeding or, conversely, an excessively rapid formation of blood clots.
As mentioned above, if platelets are determined, the norm in children may fluctuate slightly depending on the calculation method. If automated counting is used, the upper limit of the norm is slightly higher than with manual counting. This is due to the fact that the apparatus perceives even small blood clots as several blood clots, and a person, when counting, as one cell.
In addition to determining the number of cells, one can evaluate their functional activity. For this, another study is prescribed - a coagulogram. It can detect abnormalities in the work of the plates, even if the platelet norm in the child’s blood has been determined.
What is the danger of changing normal values?
Why is the level of thrombogenic elements of blood determined? Their definition is important in the following cases:
- Low cell counts increase the risk of bleeding. When injured, the likelihood of large blood loss increases significantly (and for a child, the loss of even a small amount of blood can be fatal). Typically, bruises on the skin, even after light contact with it, are signs of a decrease in cell levels. When they appear, a platelet test should be taken.
- An increase in cell level threatens with increased thrombosis, which can adversely affect blood circulation in general (the likelihood of developing thrombosis and subsequent stroke, heart attack or necrosis increases).
That is why it is extremely important to determine these blood elements.