To proceed with the removal of pathogenic microorganisms, neutrophils:
- They reach the site of infection with active movements (chemotaxis);
- They make contact and ingest the foreign agent (phagocytosis);
- They proceed with the digestion of what is phagocytosed (microbicidal activity).
These activities are possible thanks to neutrophils
- to the enzymes contained in their primary and secondary granules,
- to the particular structure of the cytoplasmic membrane
- the presence of receptors for immunoglobulins G (IgG antibodies) and for complement proteins.
Under normal conditions, mature neutrophils migrate into the bloodstream, where they remain for a rather short time (6-12 hours), in relation to various needs of the organism (fever, stress, infections, etc.). After this period, these blood cells whites go to confine themselves in the tissues, where they remain for a few days, before dying.
The alterations of the neutrophils can involve numerical modifications in excess or in defect and they can be primitive or acquired.
- Primitive forms can result from genetic mutations that result in a defect in the production, distribution or functionality of neutrophils.
- The acquired or secondary forms can be consequent to infections, parasites, necrosis and tissue damage, allergic manifestations and the intake of certain drugs.
The number of lobes increases with the age of the cell: as soon as it enters the blood it has only two lobes, which can reach five in old age. Due to this particular nuclear conformation, neutrophils are called polymorphonuclear leukocytes.
Produced in the bone marrow like all other blood cells, neutrophils are endowed with a remarkable phage activity, which allows them to incorporate and kill five to twenty bacteria over the course of life (which on average lasts one or two days).
This action, similar to that of tissue macrophages, is carried out above all at the blood level; if the need arises, the neutrophils are in any case able to migrate to the extravascular sites damaged or affected by an infection.
Digestion of cellular or molecular antigens occurs through the release of lytic enzymes contained in their granules. It is therefore no coincidence that the main decaying white blood cells found in pus are precisely the neutrophils.
In addition to engulfing and digesting senescent, infected or transformed microorganisms, debris and cells, neutrophils release particular chemicals, including pyrogens (responsible for fever) and chemical mediators of the inflammatory response.
The neutrophils themselves, thanks to their marked amoeboid activity, are attracted to a series of chemotactic factors at the site of inflammation.
, performed as part of routine examinations to assess the patient's state of health.The count and morphological analysis of neutrophils provide support in the diagnosis of certain types of conditions and diseases, which can affect this type of white blood cell, such as:
- Infections caused by bacteria, viruses, fungi or parasites;
- Inflammations;
- Allergies;
- Neoplasms;
- Conditions that affect its production and survival (immune disorders, autoimmune diseases, drug or chemical poisoning, etc.).
Furthermore, the evaluation of neutrophils allows to:
- Monitor the progression of specific diseases;
- Check the body's response to various treatments, especially if the therapeutic protocol (such as radiotherapy and chemotherapy) tends to damage the white blood cells and / or compromise the function of the bone marrow.
- Surgical interventions;
- Collagenopathies;
- Trauma;
- Tissue necrosis (burns, heart attack);
- Allergies and other inflammatory diseases.
- Myeloproliferative diseases;
- Carcinomas (especially if with bone metastases);
- Lymphomas.
- Acute hemolysis or bleeding;
- Megaloblastic anemias in treatment;
- Post agranulocytosis.
- Hyperazotemia;
- Diabetic acidosis;
- Cigarette smoke;
- Idiopathic (familial) neutrophilia.
In general, the problem can be upstream (reduced or impaired synthesis in the bone marrow) or downstream (increased degeneration).
When neutrophils are low, the body is more susceptible to infections, especially bacterial ones.
Leukopenia and granulocytopenia are often used as synonyms of neutropenia, but strictly speaking they are not exactly equivalent. In fact, leukopenia means a decrease in white blood cells and as such it can also be due to a deficit of other types of leukocytes, in particular lymphocytes; granulocytes, on the other hand, include - in addition to neutrophils - also eosinophils and basophils, even if their contribution to the total count is modest.
Degree of neutropenia
- Mild neutropenia (1000-1500 / mm3): reduced risk of infection.
- Moderate neutropenia (500-1000 / mm3): moderate risk of infection.
- Severe neutropenia (<500mm3): severe risk of infection.
Counting can be done automatically by electronic counters or by observation under an optical microscope (blood smear). and drinks for at least 8-10 hours. The general practitioner who prescribes the tests will still be able to provide useful information for the case.
. The increase in the number of circulating neutrophils may depend on primary (caused by genetic mutations, as in the case, for example, of myeloproliferative diseases) and secondary alterations. The main acquired causes of neutrophilia are represented by bacterial infections. A high value of neutrophils. it can also be found in the course of necrosis and tissue damage (burns, trauma, etc.), intoxications and post-surgical interventions.
Neutrophils
High values = Neutrophilia
Low values = Neutropenia
Possible causes
- Acute infections (bacterial, viral and fungal)
- Acute stress (e.g. heat stroke, anxiety and strenuous physical activity)
- Chronic myeloid leukemia
- Rheumatoid arthritis
- Various neoplasms (gastric and lung cancer, neuroblastoma, etc.)
- Inflammatory diseases and / or tissue necrosis (burns, trauma, surgery, myocardial infarction)
- Collagen diseases
- Acute renal failure
- Ketoacidosics
- Asplenia and hyposplenism
- Anoxia
- Cigarette smoke
- Lead or mercury poisoning
- Pregnancy
- Congenital neutropenia
- Lymphomas and myelodysplastic syndrome
- Diseases of the bone marrow
- Severe infections, including systemic (sepsis)
- Aplastic anemia
- Flu or other viral infections
- Anaphylactic shock
- Taking certain medications (e.g. methotrexate) and chemotherapy
- Radiation therapy or exposure to ionizing radiation
- Autoimmune diseases
Select Blood Tests Blood Tests Uric acid - uricaemia ACTH: adrenocortitotropic hormone Alanine amino transferase, ALT, SGPT Albumin Alcoholism Alphafetoprotein Alphafetoprotein in pregnancy Aldolase Amylase Ammonemia, ammonia in the blood Androstenedione Antibody-endomysial antibodies Anti-gliadicides Nucleus Helicobacter pylori antibodies Embryo carcinoal antigen - CEA Prostate specific antigen PSA Antithrombin III Haptoglobin AST - GOT or aspartate aminotransferase Azotemia Bilirubin (physiology) Direct, indirect and total bilirubin CA 125: tumor antigen 125 CA 15-3: tumor antigen 19-9 as tumor marker Calcemia Ceruloplasmin Cystatin C CK-MB - Creatine kinase MB Cholesterolemia Cholinesterase (pseudcholinesterase) Plasma concentration Creatine kinase Creatinine Creatinine Creatinine clearance Chromogranin A D-dimer Hematocrit Blood culture Hemocrome Hemoglobin Glycated hemoglobin a Blood tests Blood tests, Down syndrome screening Ferritin Rheumatoid factor Fibrin and its degradation products Fibrinogen Leukocyte formula Alkaline phosphatase (ALP) Fructosamine and glycated hemoglobin GGT - Gamma-gt Gastrinemia GCT Glycemia Red blood cells Granulocytes HE4 and Cancer at "Ova" Immunoglobulins INR Insulinemia Lactate dehydrogenase LDH Leukocytes - white blood cells Lymphocytes Lipases Tissue damage markers MCH MCHC MCV Metanephrines MPO - Myeloperoxidase Myoglobin Monocytes MPV - average platelet volume Natremia Neutrophils Homocysteine Thyroid hormones OGTT Osmocyte Plasma protein A associated with pregnancy Peptide C Pepsin and pepsinogen PCT - platelet or platelet hematocrit PDW - distribution width of platelet volumes Platelets Plateletpenia PLT - number of platelets in blood Preparation for blood tests Prist Test Total IgEk Protein C (PC) - Protein C Activated (PCA) C Reactive Protein Rast Protein Test Specific IgE Reticulocytes Renin Reuma-Test Oxygen Saturation Sideremia BAC, BAC TBG - Thyroxine Binding Globulin Prothrombin Time Partial Thromblopastin Time (PTT) Activated Partial Thromboplastin Time (aPTT) Testosterone Testosterone: free and bioavailable fraction Thyroglobulin Thyroxine in the blood - Total T4, free T4 Transaminases High transaminases Transglutaminase Transferrin - TIBC - TIBC - UIBC - saturation of transferrin Transtyretin Triglyceridemia Triiodothyronine in the blood - Total T3, free T3 Troponin TRH and Troponins of s thymol to TRH TSH - Thyrotropin Uremia Liver values ESR VDRL and TPHA: serological tests for syphlis Volemia Conversion of bilirubin from mg / dL to µmol / L Conversion of cholesterol and triglyceridemia from mg / dL to mmol / L Conversion of creatinine from mg / dL to µmol / L Conversion of blood glucose from mg / dL to mmol / L Conversion of testosteronemia from ng / dL - nmol / L Conversion of uricemia from mg / dL to mmol / L
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