Determination of neutrophils in the blood: what is it for?
Polynuclear neutrophils, kezako? Behind these complicated words are simply … white blood cells. Polynuclear neutrophils are cells that belong to the leukocyte family (that is, white blood cells). Their role: to participate in the body’s immune defense – neutrophils are thus “specialized” in the fight against bacterial and fungal infections.
Polynuclear neutrophils (also called “granulocytes” or simply “neutrophils”) circulate in the blood: they eliminate bacteria and fungi in the bloodstream and in wounds. They work in conjunction with lymphocytes, which are also leukocytes. Polynuclear neutrophils are, however, the most common white blood cells in the body.
Polynuclear neutrophils: what are the “normal” blood levels? A “normal” blood level of polynuclear neutrophils is between 1400-1500 and 7000 units per cubic millimeter of blood (mm3).
Blood determination of polynuclear neutrophils: when is it prescribed? The blood test for polynuclear neutrophils is part of the “routine” examinations which are carried out on the occasion of a complete blood count (CBC) or “hemogram”.
The doctor may however prescribe a determination of the neutrophils in the event of suspicion of fungal or bacterial infection. It is therefore a common dosage that can be done at any age. In practice, it is simply a blood test without special precautions – it is not necessary to be fasting for the collection.
Too low or too high Polynuclear neutrophils: what does it mean?
- Too high neutrophils in the blood (neutrophilia)
Too high a blood level of neutrophils (greater than 7000 units / mm3) often reveals the presence of a bacterial or fungal infection – for example: bacterial pneumococcal pneumonia, bronchopulmonary aspergillosis … It may also be a question of inflammatory disease: Crohn’s disease, ulcerative colitis, rheumatoid arthritis …
After a burn, a surgical intervention, a myocardial infarction (heart attack), a pulmonary embolism or in the event of smoking or pregnancy, one can also observe a neutrophilia – that is to say an excess of blood of polynuclear neutrophils .
- Too low levels of neutrophils in the blood (neutropenia)
An excessively low level of polynuclear neutrophils in the blood (less than 1400-1500 units / mm3) is often linked to a defect in the production of these leukocytes by the bone marrow. There are several possible causes of neutropenia:
- a deficiency in vitamin B12 or folic acid,
- a congenital immune defect,
- a disease of the bone marrow: aplasia, hypoplasia or dysplasia of the bone marrow, for example,
- splenomegaly: this is an increase in the volume of the spleen,
- an autoimmune patient: acute systemic lupus erythematosus, for example,
- a viral or bacterial disease: flu, chickenpox, hepatitis, chickenpox, flu, mumps, tuberculosis, typhoid fever …
- a parasitic infection: leishmaniasis, malaria …
And also. ” Consumption of certain medications can lead to neutropenia, explains Pierre Zachary, biologist. This is particularly the case for chloramphenicol, an antibiotic prescribed in particular against meningitis, bubonic plague, cholera and typhoid fever. ”
To know. Severe neutropenia (with a blood level of polynuclear neutrophils of less than 500 units / mm3) exposes to a major bacterial or mycotic infection risk. We also speak of agranulocytosis when polynuclear neutrophils are almost absent. It’s a form of immunosuppression … and a medical emergency!
” If, in the event of infectious signs (with fever, for example), the blood level of polynuclear neutrophils is normal (that is to say: between 1400-1500 and 7000 units / mm3), the doctor may suspect viral infection since polynuclear neutrophils act more against bacteria and fungi. The doctor will then ask for a blood test for lymphocytes, white blood cells rather specialized against viruses “concludes the biologist.
Thanks to Pierre Zachary, biologist at Biogroup in Strasbourg (67).