Leukocyte formula - an important indicator of the state of the body

In clinical practice, a common blood test is most often performed, including the determination of the quantitative and qualitative composition of individual blood cells, the ratio of their forms, and the hemoglobin content.

The leukocyte formula shows the percentage of individual types of leukocytes. It is calculated in stained blood smears. In healthy adults, the number of different types of white blood cells should be as follows:

• Basophils 0-1%;
• Eosinophils 0.5-5%;
• Neutrophils of stab 1-6%;
• Neutrophils segment- nuclear 47-72%;
• Monocytes 3-11%;
• Lymphocytes 19-37%.

As the leukocyte formula shows, the norm of the content of certain types of leukocytes can fluctuate within wide limits. Deviation from these indicators indicates pathological changes in the body.

Leukocyte formula: change in the number of neutrophils

In the leukocyte formula, a change in neutrophils is most common. An increase in the quantity, called neutrophilic leukocytosis, can occur with various infectious diseases, intoxications, malignant tumors, erythrocyte hemolysis and tissue decay. Typical for active synthesis of neutrophils is not only an increase in their number, but also a rejuvenation of their composition. It consists in increasing the number of young forms of neutrophils in the leukocyte formula, and occasionally in the appearance of myelocytes.

The decrease in the number of neutrophils, called neutropenia, develops with the inhibition of hematopoiesis in the bone marrow by various toxins of certain microorganisms, viruses, ionizing radiation, and certain medications.

Leukocyte formula: change in the number of lymphocytes

An increase in the number of lymphocytes or lymphocytosis occurs with a viral infection, in the stage of recovery of an infectious disease. Some patients with whooping cough, infectious lymphocytosis, tuberculosis, chronic lymphatic leukemia determine up to 80% of lymphocytes in the blood.

Reduction of lymphocytes or lymphopenia occurs with inflammatory and purulent-septic diseases, a number of severe infectious diseases. Lymphopenia occurs in malignant diseases of the blood. Pronounced lymphopenia with absolute neutropenia develops with radiation sickness.

Leukocyte formula: change in the number of eosinophils

An increase in the number of eosinophils, called eosinophilia, is observed in allergic reactions, helminthiases, collagenoses, lymphogranulomatosis, complication of myocardial infarction - Dressler's syndrome, chronic myelogenous leukemia, malignant neoplasms, and some infectious diseases. With infectious-septic diseases, eosinophilia with lymphocytosis and a slight shift of the formula to the right is a sign of recovery.

Eosinopenia and aneosinophilia occur in the midst of acute infections with a marked syndrome of intoxication, bone marrow aplasia, hyperproduction of corticosteroids, in the agonal state. Prognostic value they have only in conjunction with other components of a general blood test. An increase in the number of eosinophils without a nuclear shift is an indicator of the non-infectious origin of eosinophilia.

An increase in basophils occurs in chronic leukemia, polycythemia, acute thrombocytopenia and hypothyroidism.

Monocytosis occurs in sepsis, tuberculosis, malaria, leishmaniasis, syphilis, and viral infections. Reducing the number of monocytes always happens in severe septic processes, severe infections.

It should be remembered that the deviation of the percentage of leukocytes in the blood formula from the norm is relative. An increase in the absolute blood content of one type of cell leads to a decrease in the proportion of all other cells and vice versa. The exact information is given not by the leukocyte blood formula, but by absolute values of different leukocytes, expressed in the number of cells in a liter of blood.