The polynuclear are white blood cells (or leukocytes), and therefore the body’s defense cells.

There are several types of white blood cells, including:

• the polynuclear, so named because they appear to have several nuclei
• the mononucléaires, which include the “monocytes” and the “lymphocytes«

Polynuclear cells are cells which circulate in the blood and which in fact have a multilobed nucleus. Inside, they contain “granulations”, which take on different colors when tinted with special dyes. We therefore distinguish:

• neutrophils, whose granulations retain so-called neutral dyes (beige tint)
• eosinophils, whose large granulations turn orange
• polynuclear basophils, which contain large purplish-red granules

These mobile cells travel to sites in the body where there is infection or inflammation. This migration takes place under the influence of chemical molecules emitted by the pathogen or induced by it, which attract them to the “right” place.

Polynuclear neutrophils are the most numerous of polynuclear cells: they represent the majority of white blood cells circulating in the blood (50 to 75%). As an indication, their number varies from 1,8 to 7 billion per liter of blood (i.e. 2000 to 7500 neutrophils per mm³ of blood).

Once in infected tissue, the neutrophils are able to “phagocytize” (that is to say, swallow, in a way) foreign particles.

The measurement of white blood cells in general is recommended in many situations, especially in cases of infection.

Most often, the doctor prescribes a “blood count” (hemogram) which details the concentration of different types of blood cells.

The examination consists of a simple sample of venous blood, usually carried out at the fold of the elbow. It is not necessary to be on an empty stomach.

We can observe the appearance of polymorphonuclear cells under a microscope, from a blood smear.

The concentration of polynuclear neutrophils may be increased (polynucléose neutrophile) or on the contrary lowered compared to the standards (neutropenia).

A moderate or sharp increase in the number of white blood cells, and in particular of polymorphonuclear neutrophils, can be seen in many situations:

• in case of’infection (most bacterial infections)
• a cas de inflammatory disease
• in the case of some c
• about hematological diseases (myeloproliferative syndromes, leukemia, polycythemia, thrombocythemia).

The decrease in neutrophils is possible:

• after some viral infections
• when taking certain medications
• after one chemotherapy
• but also in some spinal diseases (myeloma, lymphoma, leukemia, cancer).

Interpretation of results will depend on other blood values ​​and the patient’s age, symptoms, and history.