Help the development of the site, sharing the article with friends!

Leukocytes are one of the most important components of the blood. It is these cells that are "soldiers" defending our immunity, fighting against dangerous viruses, bacteria and fungi. Leukocyte level testing is part of the routine morphology test. So what are the norms of the individual leukocyte fractions? What affects high or low white blood cell counts? Check it out!

What are leukocytes?

Leukocytes,otherwise known aswhite blood cells(WBT-white blood cells), they are aftererythrocytesandthrombocytesa large group of blood cells. Unlike erythrocytes, they have a cell nucleus, thanks to which they have their own independentmetabolismand the possibility of division. They are also less numerous (the average number of white blood cells is about 4-10,000 / mm³ of blood).

Why are leukocytes so important in maintaining he alth?

Leukocytes can be compared to the guards guarding ourimmunity . They are the main component of the human immune system. Thanks to this, using a variety of mechanisms,protect against the attack of viruses, bacteria or fungi . Specific immune strategies include:

  • phagocytosis -active absorption and digestion of pathogens inside the cells of the immune system,
  • specific immunity- production of T and B lymphocytes and specific antibodies against specific pathogens,
  • free radical production and degranulation- active release of reactive oxygen species and molecules that are toxic to harmful microorganisms.

The combination of these mechanisms in most cases causesthe destruction of harmful molecules and the maintenance of the body's physiological balance(homeostasis).

Leukocytes: types and their functions

Leukocytes are a heterogeneous group of cells that differ in appearance and function. The first, most general, division divides these cells into:

  • granulocytes(containing special granules inside the cytoplasm, i.e. granules)
  • agranulocytes(containing no grains).

Within agranulocytes we distinguish in turn:

  • Lymphocytes- these are cells6 to 15 μm in diameter, with a large cell nucleus. They constitute about 25-35 percent. population of all white blood cells. Their main role is to recognize,identify and eliminate unknownantigens, that is, hostile cells or specific proteins on their surface. Lymphocytes are formed mainly in the red bone marrow, but also in the thymus, lymph nodes, spleen and lymph nodes on the surface of mucous membranes.

In terms offunctions, lymphocytescan be divided into:

  • T lymphocytes- the most numerous group of lymphocytes (including, among others, sub-types of lymphocytes: Tc, Th, Treg, NKT) responsible forinducing cellular immunity and production of cytokines .
  • B lymphocytes- they recognize the right antigen and produce antibodies, thanks to which we become resistant to the infection. More than half of the number of lymphocytes are found in the lymphoid organs. The remainder, however, travels around the body - in the blood and connective tissue in search of antigens.
  • Monocytes- the largest cells among all leukocytes, measuring from 10 to 40 µm. They are mainly formed in the bone marrow and account for about 3 to 8% of all leukocytes. These cells have a special property: they arephagocytes - phagocytes , so they canactively absorb fragments of dead tissue and pathogens in the blood . They can also crawl quickly, and in the event of inflammation, they can penetrate the endothelium of the blood vessel to the right place of pathogens. They secrete various cytokines: interferon and interleukins, which regulate and mediate various stages of the immune response. Mature monocytes, after getting from blood to tissues, become macrophages.

Granulocytes, in turn, can be divided into:

  • Neutrophils(neutrophils) - this is the most abundant group of granulocytes, making upapproximately 50 to 75 percent.These cells are spherical in shape and have a diameter of 12 to 15 µm. They are the main pillar of non-specific immunity, i.e. the body's first barrier against harmful microorganisms, independent of the production of antibodies. Neutrophils are formed in the bone marrow from where they end up in the blood. In response to pro-inflammatory signalsthey can penetrate through the walls of vessels into tissues , where they phagocytose pathogens when activated. They are the main component of pus produced in the acute phase of inflammation.
  • Eosinophils(eosinophils) - account foron average from 1 to 5 percent. the number of total leukocytes, but this percentage can change with stress, exercise, and even with the time of day or phase of the menstrual cycle in women. They are named after eosin (a dye commonly used in histology), which is acidic in nature and colors the inner granules of eosinophilia red. Like neutrophils, eoosinophils are also formed in the bone marrow, andpasses into the blood after the maturation process. On the surface of eosinophilia, there are many receptor proteins "cooperating" with numerous interleukins and chemokines in the immune cascade. These cells are also phagocytes and their primary role is to destroy parasites and allergens.
  • Basophils(basophils) - are spherical cells with an elongated nucleus about 10 µm in diameter. In terms of numbers, they account for only about 1 percent. all white blood cells. They are produced in the bone marrow. Although neutrophils have the ability to phagocytosis, they are not as efficient as neutrophils.Their main "weapon" is the presence of specific substances contained in granules : heparin, histamine, leukotrienes and interleukin-4, secreted during inflammatory process. It is the histamine released by basophils that causes vasodilation that causes the typical symptoms of allergies that many of us suffer from: swelling, redness and a feeling of heat.

Read also: Blood morphology - what the blood test says

Leukocytes: norms in adults and children

The normal number of leukocytes in the body of a he althy person ranges from 4 to 10,000 / µl. The established norms, however, may differ quite significantly depending on the age, and in young children in the growing period they will be much higher, e.g.

  • newborns:9 - 30 thousand/µl
  • one-year-old children:6 - 20 thousand/µl
  • children aged 4-6:5 - 15.5 thousand/µl
  • children aged 10:4.5- 13.5 thousand/µl

It should be remembered, however, that determining the total number of white blood cells is a very general guideline that tells little about the type of disease or inflammation that is going on. Therefore, appropriate norms have been defined for individual groups of leukocytes.

Importantly, the reference values ​​of leukocytes are determined individually in each laboratory and may depend, for example, on the type of cell counting machine.

Examples of norms of different types of leukocytes:

LeukocytesNorma
Granulocytes1.8-8.9 thousand/µl
Neutrophils (NEUT)1.5-7.4 thousand/µl
Lymphocytes (LYMPH):1.1-3.5 thousand/µl
Basophils (BASO)0-0.13 thousand/µl
Eosinophils (EOS)0.02-0.67 thousand/µl
Monocytes (MONO)0.21-0.91 thousand/µl
B lymphocytes0.06-0.66 thousand/µl
T-lymphocytes0.77- 2.68 thousand / µl

Also Read: Learn How To Recognize The Symptoms Of Leukemia In Children And Adults!

Leukocytes: what are the indications for the test?

The leukocyte count is influenced by many factors, but clear deviations from the norm may be the first symptom of many diseases.

No doubtleukocyte test(being part of the basic blood test) should be done with:

  • suspected inflammatory diseases,
  • suspected autoimmune and systemic diseases (e.g. lupus erythematosus, rheumatoid arthritis),
  • acute infections,
  • allergies and recurrent allergies,
  • suspected diseases related to a decrease in immunity (e.g. AIDS or cancer),
  • regular balances of general he alth.

Leukocytes: norms. What do elevated leukocytes mean?

Occasionally, an excessively highelevated leukocyte countmay be due to your body's normal physiological functions and should not be a cause for concern.

Increased leukocytes (otherwise: leukocytosis) may occur, for example :

  • after intense physical exertion,
  • as a result of severe stress,
  • pregnant (mainly in the third trimester, which is associated with the natural stimulation of the woman's immunity),
  • after childbirth (in the so-called puerperium),
  • as a result of viral, bacterial and fungal infections,
  • after invasive procedures (e.g. surgery),
  • after skin burns.

Low leukocytes: cause for concern?

The state of leukopenia, ora significant decrease in the level of white blood cellsmost often is an alarm signal for abnormalities in the bodyor serious diseases affecting our immune status. Such a situation may be the result of, among others:

  • taking certain groups of drugs (e.g. cytostatics used in chemotherapy, barbiturates, strong antibiotics or anticonvulsants),
  • autoimmune diseases,
  • sepsis (sepsis), i.e. a violent reaction of the body to the ongoing conditionflammable,
  • AIDS,
  • serious malnutrition,
  • bone marrow damage after oncological treatments,
  • diseases of the liver and spleen.

Analyzing the number of individual leukocyte fractions, its genesis and side effects requires a lot of medical knowledge. Therefore, we should always inform the attending physician about all cases that may affect the abnormal levels of these cells, such as trauma, stress or other diseases.

Read also: What are the causes and symptoms of osteomyelitis?

Leukocytes in urine: norm

Leukocytesare present not only in the blood, but also in human urine , where they fulfill their protective function. An acceptable standard of physiologically present leukocytes isabout 8 to 10 cells per mm³ in a fresh sampleor from 3 to even 5 million cells in a daily urine sample.

All values ​​above this number (e.g. 8 to 10 million leukocytes per day) mayindicate urinary tract infection or other diseases,e.g. :

  • nephritis,
  • inflammation of the ovaries,
  • prostatitis,
  • kidney stones,
  • bladder cancer.

A condition in which an increased number of leukocytes in the urine is detected is calledleukocyturia .

Testing your urine for white blood cells is especially important inpregnant women . It is when the bladder is constantly constricted by the growing uterus and cannot be completely emptied that the risk of urinary tract infections increases significantly. If left untreated, urinary tract infections can complicate the form of chronic inflammation that is dangerous for the fetus, and may even result in miscarriage.

Read also: Check how to prevent infection, and when cystitis occurs - how to deal with it quickly!

Leukocytes and diet: is there a connection between them?

So farno direct relationship has been provenbetween a particular diet or the consumption of specific foods and an increase in leukocytes. Nevertheless, in the case of states of reduced immunity and confirmed leukopenia (the so-called reduced amount of leukocytes), it is recommended to supplement the diet with vitamin B12 and folic acid (also known as vitamin B9).

Both of these compounds play an extremely important role in the production of not only leukocytes, but also erythrocytes, as well as their proper maturation and genetic stability. Products rich in B vitamins (including B12 and B9) are, for example :

  • fish,
  • meat,
  • poultry,
  • eggs,
  • milk and dairy products.

In immunodeficient statesyou must also not eat stale, moldy and raw foods(mainly raw meat, eggs or fish), as this can lead to infection. You should also avoid unpasteurized drinks (eg natural beer or milk "from a cow").

Raw fruit or vegetables as a rich source of vitamins and trace elements do not have to be excluded from the diet, but you should always remember to wash them thoroughly.

Leukocytes are undoubtedly the main foundation of the immune shield of our body.Their optimal level contributes to maintaining the balance of he alth. However, their number in the blood should be checked regularly, as too low or too high concentration of leukocytes may be a sign of the disease.

Help the development of the site, sharing the article with friends!

Category:

Research