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 eosinophils are much less numerous than neutrophils: they represent 1 to 3% of white blood cells circulating in the blood. As an indication, their number varies from 0,04 to 0,4 billion per liter of blood (i.e. 40 to 400 eosinophils per mm³ of blood).

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 venous blood sample, 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 polynuclear under the microscope, from a blood smear.

The concentration of eosinophils may be increased (eosinophilia) or on the contrary lowered compared to the standards (eosinopenia).

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

• in most digestive parasitic diseases
• about allergic reactions
• in certain skin diseases (atopic dermatoses, eczema, chronic pruritus, etc.)
• in certain systemic diseases (connectivitis, Churg and Strauss disease, etc.)
• about digestive diseases (Crohn’s disease, ulcerative colitis, etc.)
• after taking certain medications (antibiotics, anti-tuberculosis drugs, antifungals, antiparasitics, psychotropics, anti-epileptics, oral antidiabetics, anti-inflammatories, etc.)
• in some cancers or lymphomas, especially in Hodgkin’s disease.

The decrease in the number of eosinophils, on the contrary, may be linked:

• when taking treatment with corticosteroids ou ACTH
• to acute stress
• to one hemodialysis
• Has serious viral or bacterial infections

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