Basophils are white blood cells that are part of the body’s defense system against viruses and bacteria. What does a low or too high rate reveal?
Definition: what are polymorphonuclear basophils?
Leukocytes (or white blood cells) are cells of the immune system. Among them are the polymorphonuclear basophils, also called basophilic granulocytes. However, the term “polynuclear” is inappropriate because these cells have only one nucleus, and not several, even if the opposite was long believed because of the lobed nature of their nucleus. The other polynuclears are neutrophils and eosinophils. They are called “basophile” because of a characteristic visible in optical microscopy: after addition of the usual vital dyes, these cells stain blue.
What is the role of polymorphonuclear basophils?
Polymorphonuclear basophils activate the inflammatory reaction and are involved in allergic reactions, by releasing histamine, which causes the usual symptoms of allergies. Like all white blood cells, they are involved in the body defenseagainst external aggressions, in particular infections.
When to do the assay for polymorphonuclear basophils?
The dosage of polymorphonuclear basophils, called “basocythemia” or “basocytosis”, is recommended in many situations involving immunity, especially in case of infection or allergy.
The assay consists of performing a venous blood sampling, usually at the bend of the elbow. Fasting is not necessary.
What are the normal values for polymorphonuclear basophils?
Basocytosis should be less than 0.15 G/L, i.e. 0.5 to 1% of all leukocytes, sometimes even 0% in some people.
What are the causes of a low polymorphonuclear basophil count?
A decrease in the number of polymorphonuclear basophils, called “basocytopenia“has no real diagnostic value but can be observed during a acute stress, Cushing’s disease, taking certain medications (corticosteroids, ACTH or estrogen-progestins), a allergic or anaphylactic shock, chronic urticaria, hyperthyroidism or infection.
What are the causes of a high polymorphonuclear basophil count?
► A moderate increase in polymorphonuclear basophils (from 2 to 5%, with or without hyperleukocytosis), is observed mainly duringallergic or inflammatory conditions (dermatoses, asthma, immediate hypersensitivity reactions), or a hypothyroidism, various endocrine diseases, ulcerative colitis, juvenile chronic arthritis, viral infections (chickenpox), administration of estrogens, hyperlipemia, certain cancersor the Hodgkin’s disease.
► A strong increase (more than 5%) or very strong polymorphonuclear basophils is observed rather during the myeloproliferative syndromes or acute leukemia.
When to worry about an abnormal level of polymorphonuclear basophils?
When polymorphonuclear basophils are greater than 5%, you should talk to your doctor about it. In all cases, it is up to him, depending on the other known elements, to make a diagnosis linked to an increase or a decrease in the level of polymorphonuclear basophils in the blood. “Results should be interpreted taking into account clinical observationsother blood count results and variations in results over time.”