The causes of increase and decrease in leukocytes
Last reviewed: 19.10.2021
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The number of leukocytes in the blood depends on the rate of inflow of cells from the red bone marrow and the rate at which they exit into the tissue. An increase in the number of leukocytes in peripheral blood above 10 × 10 9 / l is called leukocytosis, a decrease below 4 × 10 9 / l is leukopenia.
The increase or decrease in the number of individual types of leukocytes in the blood can be absolute or relative, depending on the total content of leukocytes - normal, increased or decreased. Determine the absolute content of individual types of leukocytes in a unit of blood volume by the formula: A (%) × WBC (10 9 / l) / 100%, where A is the content of a specific type of white blood cells,%. For example, an increase in the percentage of lymphocytes (60%) with a reduced total number of leukocytes (2 × 10 9 / l) means relative lymphocytosis, since the absolute number of these cells (1.2 × 10 9 / l) is within the normal range (see Fig. Also "leukocyte formula").
The most common leukocytosis is due to acute infections, especially those caused by cocci (staphylococcus, streptococcus, pneumococcus, gonococcus), E. Coli, diphtheria, etc. In these infections, the number of leukocytes is usually 15-25 × 10 9 / l. The expressed leukocytosis of 20-40 × 10 9 / l is typical for patients with pneumococcal pneumonia, scarlet fever, severe burns.
Leukocytosis develops within 1-2 hours after the onset of acute bleeding, it is especially pronounced with hemorrhage into the abdominal cavity, pleural space, joint or in the immediate vicinity of the dura mater. When interrupting tubal pregnancy, the number of leukocytes can be increased to 22 × 10 9 / l, after rupture of the spleen - up to 31 × 10 9 / l. Leukocytosis usually accompanies a sharp attack of gout (up to 31 × 10 9 / L).
In the majority of patients with acute appendicitis, at the very beginning of the disease, an increase in the number of leukocytes in the blood is noted. In the catarrhal form of appendicitis, the leukocyte content in the blood is in the range of 10-12 × 10 9 / l, changes in the leukocyte blood formula are usually not observed. With phlegmonous appendicitis, the number of leukocytes in the blood reaches 12-20 × 10 9 / l, a regenerative shift of neutrophils with a high content of rod-shaped forms (up to 15%) is observed. With gangrenous form of appendicitis, the number of leukocytes is significantly reduced (up to 10-12 × 10 9 / L) or is within the normal range of 6-8 × 10 9 / L, but the inflammatory shift in the leukocyte blood formula can reach a significant degree [the content of stab form 15 -20% or more, there may be the appearance of young neutrophils (4-6%) and even myelocytes (2%)].
When evaluating the results of a blood test for suspected acute appendicitis, it is necessary to adhere to the conclusions made by G. Mondre (1996).
- In cases without suppuration, leukocytosis does not exceed 15 × 10 9 / l.
- If during the first 6-12 hours after an acute attack the leukocytosis does not cease to increase (the blood test is carried out every 2 hours), one should beware of the rapidly spreading heavy infectious process.
- Even if the general symptoms of the disease (pain, fever, etc.) seem to decrease, while leukocytosis continues to increase, the latter is more important, since fluctuations in the expression of leukocytosis at least 24 hours ahead of fluctuations in body temperature.
- In exceptional cases, leukocytosis may be absent; the latter is observed when there is a sudden intoxication of the body or when the patient is severely depleted with a prolonged infection, or when the latter is localized and the abscess is drained and spontaneously sterilized.
A false increase in the number of leukocytes counted with an automatic analyzer is possible in the presence of cryoglobulinemia, clots or aggregation of platelets or in the presence of nuclear forms of red blood cells (erythroblasts) or non-ligated red blood cells, which will be counted as leukocytes.
A number of acute infections (typhus, paratyphoid, salmonella, etc.) can in some cases lead to leukopenia. This is especially characteristic for the depletion of bone marrow reserves of neutrophils as a result of the use of modern chemotherapeutic agents, with nutritional deficiency or general weakening of the organism. Some bacteria and certain viruses (yellow fever, measles, rubella, chicken pox, etc.), rickettsia and protozoa can cause leukopenia in previously completely healthy people.
Diseases and conditions accompanied by a change in the number of leukocytes
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Leukocytosis |
Leukopenia |
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Infections (bacterial, fungal, viral, etc.) Inflammatory conditions Malignant neoplasms Injuries Leukemia Uremia The result of the action of adrenaline and steroid hormones |
Aplasia and hypoplasia of red bone marrow Damage to the bone marrow by chemical means, drugs Ionizing radiation Hyperplenism (primary, secondary) Acute leukemia Myelofibrosis Myelodysplastic syndromes Plasmacytoma Metastasis of neoplasm in bone marrow Addison-Birmer disease Sepsis Typhus and paratyphoid Anaphylactic shock Collagenoses Medicines (sulfonamides and some antibiotics, nonsteroidal anti-inflammatory drugs, thyreostatics, antiepileptic drugs, etc.) |