The norm of lymphocytes in the blood in a child: the number for an infant up to a year and more adults, atypical lymphocytes

  • role of lymphocytes
  • Types of lymphocytes
  • normal level of lymphocytes in
  • children how to define lymphocytes in children
  • lymphocytosis
  • Lymphopenia

Every child from time to time have to take a blood test. Someone undergoes a routine examination, for example, at 2 years or 6-7 years. Someone is concerned about the symptoms of the disease, and someone is being treated and it is necessary to find out how much recovery is going on. One of the most important for immunity and disease control of blood cells are lymphocytes. For what do they answer in the child's body, how many such cells should be normal and what should be done if their level deviates?

Lymphocytes - main cells responsible for immunity baby

role lymphocytes

so-called group of blood cells, representing one type of leukocyte. Such cells do not include granules, so they are referred to together with monocytes for agranulocytes. Lymphocytes are important for:

  • Creating local immunity.
  • Protection of the body through the production of antibodies or direct destruction of foreign agents.
  • Control of the cells of the child's body, through which pathological structures are destroyed.
  • Formation of immunity after disease or introduction of vaccines.

See a short video showing the work of lymphocytes:

Types of lymphocytes

Depending on the place of residence and feature all white blood cells are divided into:

  • B cells. They are mainly in the lymph nodes and make up about 8-20% of all lymphocytes. The main task of these cells is to ensure humoral immunity. When B-lymphocytes are independently contacted with antigens or stimulated by T-lymphocytes, the production of antibodies begins. Also allocate B-memory cells. Having met the causative agent of an infection, such cells fix the information about it, thanks to which the children have postinfection and post-vaccination immunity.
  • T cells. Their main location is the thymus, and the main function is the provision of cellular immunity. Such lymphocytes are the most numerous, since they constitute up to 80% of all cells of this species. They are divided into T killer ( main "job" of lymphocytes is to destroy pathogenic cells), T helper ( such lymphocytes help of T-killers and secrete active substance) and T suppressor ( These cells suppress immune responses, So as not to destroy healthy cells).
  • NK cells. Such lymphocytes destroy the child's own cells, which are infected or transformed into tumor cells. They occupy less than 10-20% of all lymphocytes.

normal level of lymphocytes in children

The child, who had just emerged into the light, lymphocytes are not very many, because their immune system has not yet started to work in full force. But by the fourth and fifth day of life the percentage of lymphocytes is compared with the level of neutrophils, after which it grows to 4 years of age, exceeding all other leukocytes. In a child of 4-5 years, the percentage of neutrophils and lymphocytes is almost the same, and then the number of neutrophilic leukocytes becomes larger, respectively, the level of lymphocytes decreases.
The smallest number of lymphocytes is observed in infants in the first 5 days of life

The normal rate for a child at different ages will be such a percentage of lymphocytes:

In a newborn

From 16% to 32%

For a baby with a 4-5 day life

From 30% to 50%

In an infants with 10 days of life

From 40% Up to 60%

For a child under one year older than the 1st month

From 45% to 60%

For children older than the year

From 45% to 65%

For children over 5 years

From 35% to 55%

For children10 years

From 30% to 45%

Exceeding the upper limit is called lymphocytosis , and if the level of lymphocytes does not reach the lower borderOf the norm, this condition is called " lymphopenia " or " lymphocytopenia ".

How to determine lymphocytes in children

First of all, the evaluation of the level of lymphocytes is carried out by a general blood test. In this case, take into account the percentage of other leukocytes( estimate the entire leukogram), as well as the presence of leukocytosis, increased ESR and other changes.

It can also be noted in the form that in the blood there are atypical lymphocytes( they differ in large size and irregular shape).

If there is evidence, the child is referred for a more detailed examination of the immunity system. Special tests count the number of B and T cells individually, determine the level of immunoglobulins, the number of activated B-lymphocytes and other indicators. Such studies help in the diagnosis of immunodeficiency, autoimmune processes and other pathologies.


The increased level of lymphocytes in a child's blood is caused by with an increased number of lymphocytes ( such lymphocytes are called absolute) and with a reduced number of neutrophils ( this lymphocytosis is relative, as in reality the number of lymphocytes does not exceed the norm, but only looksSuch because of another redistribution of different types of white blood cells in the leukogram).

The cause of lymphocytosis in a child is:

  • ARVI, influenza, measles, chicken pox, adenovirus and other viral infections.
  • Toxoplasmosis and other parasitic diseases, as well as infection by protozoa.
  • Tuberculosis.
  • Lymphatic leukemia and other tumors of the hematopoietic organs.
  • Vitamin B12 depletion and deficiency.
  • Poisoning by lead, arsenic and some other poisons.
  • Autoimmune diseases.
  • Hyperfunction of the thyroid gland.
  • Condition after splenectomy.
  • Reception of antiepileptic, hormonal, antimicrobial and other drugs.
lymphocytosis disease often accompanies the child varicella
Suspected lymphocytosis possible for the basic disease symptoms, such as fever, rashes, enlarged lymph nodes and other characteristics. If the baby has an excess of the number of lymphocytes, it is important to immediately consult a doctor.
The pediatrician in the diagnosis will take into account complaints, all indicators of the analysis of blood, transferred diseases, medication and other factors. This will allow the child with lymphocytosis to be treated correctly, as a result of which gradually the level of lymphocytes will return to normal levels.


If lymphocytes are produced in insufficient quantity in the child's body, such lymphopenia is called absolute .In cases where a low percentage of lymphocytes is due to an increased amount of neutrophils, is diagnosed with relative lymphocytopenia.

A decrease in the level of lymphocytes is observed in serious infectious diseases

The reason for the decrease in lymphocyte counts in a child is:

  • Congenital immunodeficiency.
  • Acute surgical pathology.
  • HIV, measles, tuberculosis and some other infectious diseases.
  • Defective food or transferred stress.
  • Aplastic anemia.
  • Chemotherapy or treatment with immunosuppressants.
  • Systemic disease.
  • Extensive burns.
  • Radiation sickness.
  • Thymus pathologies. Injury of lymph nodes.
  • Enteropathy.
  • Lymphoma.
  • Renal failure.

Also, the number of lymphocytes is reduced during recovery from an infectious disease, when the "old" lymphocytes are destroyed, and the "new ones" have not yet entered the blood in sufficient quantity.

We recommend to watch the documentary "Defensive Strengths of the Body: Theory of Immunity"

Specific symptoms of lymphopenia are not detected. At the child with the lowered lymphocytes lymphonoduses can decrease, there are lesions of a mucous mouth. Also, these children often pale or icteric skin color, there are frequent ARVI and enlarged spleen.

Having detected a deficiency of lymphocytes in a child, it is important to find out the cause of such a condition as soon as possible, because such a baby has defensive powers and there is a high risk of infection. After additional tests and consultations of specialists, the child is prescribed a suitable treatment taking into account the cause of lymphopenia. Sometimes you have to inject immunoglobulins or transplant the bone marrow.

For more information about the general analysis of blood see in the transfer of Dr. Komarovsky.