White Blood Cells: – Part 1 – Development, function and interpretation of white blood cells (WBC). (2023)

white blood cell sample

1. this happens inEthylenediaminetetraacetic acidBlood.
2. Whole blood in EDTA is stable for 24 hours at 23°C and 48 hours at 4°C.
3. Do not use heparin.

Precautionswhite blood cells

1. this is a routine inspectionCanadian Broadcasting Corporation.
2. TLC distinguishes between acute and chronic infections.
3. TLC diagnoses leukemia.
4. TLC is a follow-up test in patients receiving chemotherapy.
5. This will help allergy sufferers.

Precautions for white blood cells:

1. Physical activity and stress lead to increases in white blood cells and differential values.
2. Pregnancy in recent months can cause an increase in the white blood cell count.
3. White blood cell counts continue to increase slightly in splenectomized patients.
4. Medicines that can increase white blood cell counts include:
   1. aspirin.
   2. Allopurinol.
   3. Steroid.
   4. quinine.
   5. Adrenaline.
   6. Adrenaline.
   7. Chloroform.
   8. heparin.
5. Drugs that lower white blood cell counts:
   1. Antibiotic.
   2. Anticonvulsant.
   3. antimetabolite.
   4. Antithyroid drugs.
   5. diuretics.
   6. Sulfonamides.
   7. Barbiturates.
   8. chemotherapy.

Pathophysiology of white blood cells

Definition of hematopoiesis:

1. This is a dynamic process of production and development of various blood cells.
2. All of these cells develop from totipotent stem cells.
3. This hematopoiesis is characterized by constant renewal of blood cells.
4. The normal hematopoietic system maintains cell populations of erythrocytes, leukocytes, and platelets through an intricate network of tissues, stem cells, organs, and regulatory factors.

Functions of hematopoietic components (cells):

1. It transports oxygen and expels carbon dioxide through red blood cells.
2. It fights infections caused by white blood cells.
3. It exerts immune functions (cellular and humoral immunity) through lymphocytes.
4. It maintains the bleeding and clotting process (hemostasis) through platelets.

Development of bone marrow (myelopoiesis)/red blood cell (erythropoiesis) cells:

1. During the first few weeks of pregnancy, the yolk sac (mesoderm) is the main site of blood formation. The first hematopoietic stem cells were observed in the dorsal aorta, known as the aorta-gonad-mesonephric zone.
2. Common progenitors of these endothelial and hematopoietic cells colonize the bone marrow, liver, and spleen between 6 weeks and 7 months of fetal life.
3. The liver and spleen are the main blood-forming organs and don't produce blood cells until about two weeks after birth.
4. During childhood and adulthood, bone marrow is the only source of new blood cells.
5. In adulthood, bone marrow is made up of approximately 50% fat.
6. From the age of 4, fat cells form in the tubular bones.
7. By age 18 to 20, hematopoiesis is present only in the sternum, ribs, pelvis, vertebrae, and skull.
8. After the age of 40, the sternum, ribs, vertebrae and pelvis are composed of 50% fat and 50% hematopoietic tissue.

fetal hematopoietic function

Bone marrow activity:

1. Bone marrow hematopoietic activity is divided into two pools:
   1. stem cell bank.
   2. bone marrow bank.
2. Eventually, these cells mature and are released into the peripheral blood.

Hematopoietic function:

1. Hematopoiesis originates from pluripotent stem cells.
2. Hematopoietic stem cells are rare; this is one of 20 million nucleated cells.
3. Stem cells regenerate themselves. Thus, in normal, healthy individuals, the cellularity of the bone marrow remains unchanged.
4. Stem cell proliferation, one stem cell can produce about 10⁶Mature blood cells after 20 divisions.
5. There are different types of stem cells, which develop from totipotent cells.
6. totipotent cell, also known as embryonic stem cells and lead to:
   1. Myeloid cells and lymphocytes originate from hematopoietic stem cells.
   2. Epithelial stem cells give rise to organs such as the liver.
   3. Muscle, tendon and cartilage develop from mesenchymal stem cells.
   4. Nervous tissue is formed from neuronal stem cells.

stem cell differentiation

7. These parental stem cells have CD34⁺and CD38^–And has the appearance of small and medium lymphocytes.
8. Combined stem cells are derived from these stem cells, a process that takes place under the influence of CFU (colony forming units).
9. The whole process is shown in the figure below.

Maturation of all bone marrow hematopoietic cells

White blood cells or white blood cells are divided into:

1. Granulocyte lineage.These cells contain granules in their cytoplasm. These are also called polymorphonuclear leukocytes (polys or polys) due to the multilobed nuclei.neutrophils). These are the following types:
   1. neutrophils.
   2. Eosinophils.
   3. Alkaliphiles.
2. Granulocyte seriesThere are no granules in their cytoplasm. These are also called monocytes. all these are :
   1. lymphocytes.
   2. monocytes.
   3. platelets.

maturation of white blood cells

White blood cells can also be divided into:

1. phagocyte:
   2. Neutrophils (polymorphonuclear leukocytes, PMN).
   3. Eosinophils.
   4. Alkaliphiles.
   5. monocytes.
2. Immune Cells:
   1. lymphocytes.
   2. Precursors of lymphocytes.
3. Multicellular and lymphocytes account for 75% to 90% of the totalleukocytecounting.

Polymorphonuclear Leukocytes (PMN):

1. From myeloblasts, neutrophils develop and transform into promyelocytes, myelocytes, metamyelocytes, zona cells, and neutrophils, which are shed into the peripheral blood.

leukocyte maturation cycle

Development of neutrophils:

1. These are also called segmented neutrophils or polymorphonuclear neutrophils (PMNs).
2. There are two types of neutrophils:
3. Segmented neutrophilsOccurs in peripheral blood.
4. tissue neutrophilsHas abundant cytoplasm and irregular, blunt pseudopodia, often multipointed and may have inconspicuous cytoplasmic protrusions.
   1. These cells are not phagocytes and rarely show cytoplasmic vacuoles.
   2. The cytoplasm is pale blue with a fine grid-like structure.
   3. The number and color of the particles vary from red to blue.
   4. These cells have large, round or oval nuclei and coarse chromatin.
   5. Nucleoli are prominent and stained light blue.

The cytokines involved are:

1. The total lifespan of white blood cells is 13 to 20 days, and they are produced by myeloblasts in 7 to 14 days.
2. They live only 7 to 10 hours in the peripheral blood, where they migrate into tissues and are replenished by other cells released from the bone marrow.
3. Polys have a characteristic dense nucleus consisting of 2 to 5 lobes and a pale cytoplasm with many fine powder blue (azurophilic granules) or greyish blue granules. These granules are found in lysosomes.

white blood cell granules Divided into:

1. primary particlesAppears at the promyelocytic stage.
   1. They contain myeloperoxidase, acid phosphatase and other hydrolytic enzymes.
2. Secondary (specific) particlesOccurs at the myeloid cell stage and predominates in mature neutrophils.
   1. These granules contain collagenase, lactoferrin and lysozyme.

The role of lysosomal enzymes in neutrophil-destroying bacteria is to:

1. Bacteria are engulfed inside the cell and fuse with primary lysosomes to form phagosomes.
2. Primary particles attack bacteria.
3. The secondary particle fuses with the phagosome and the secondary enzyme attacks the bacteria.
4. Active oxygen produced by glucose metabolism kills bacteria.
5. Undigested dead residual bacterial products are excreted by exocytosis.

The role of white blood cells in bacterial infection

function ofPoly (PMN)yes:

2. Poly(PMN) confers immunity by fighting infection and responding to foreign bodies in several ways:
   2. Phagocytosis is the killing and digestion of bacteria.
   3. Eosinophils are involved in allergic reactions.
   4. Eosinophils play a role in parasitic infections.
   5. Peripheral blood basophils are also rich in histamine granules; they play a role in allergic reactions.
3. Monocytes have the property of phagocytosis. They kill bacteria and remove dirt.
   1. Monocytes produce interferon.
   2. They live longer than neutrophils.

A summary of the differences between the different types of granulocyte lineage cells (neutrophils):

1. Monocytes develop from monocytes in the bone marrow.
2. These macrophages are 25 to 80 µm in size, have round or reniform nuclei, and contain one or two nucleoli.
   1. There is clumped chromatin, abundant cytoplasm and vacuoles, and numerous azurophilic granules.
3. These monocytes enter the bloodstream for a short time, then migrate into the tissue and transform into tissue macrophages.
   1. Monocytes are also called histiocytes, meaning histio = tissue, cyte = cell.

4. When these monocytes mature, they become too large to pass easily through capillaries, so they lodge in tissues and transform into tissue macrophages in many organs, such as:
   1. In the lungs there are so-called alveolar macrophages.
   2. The peritoneum contains so-called peritoneal macrophages.
   3. The spleen contains so-called splenic macrophages.
   4. In the liver there are so-called Kupffer cells.
   5. So-called tissue macrophages are located in the connective tissue.
5. These are also phagocytes.
6. Monocytes do not enter the bloodstream, but can re-enter the bloodstream in the event of inflammation.
7. Functions of monocytes:
8. Their function as phagocytosis is similar to that of neutrophils.
9. Monocytes can be produced faster than neutrophils and take longer than neutrophils.

1. These cells all go through the same stages as neutrophils.
2. When these are present in tissues, they are also called mast cells.
3. Cells have large basophilic granules.
4. Maturation of basophils in the bone marrow takes more than 7 days.
5. Basophils circulate in the peripheral blood for several hours before migrating to tissue, skin, mucosal, and serosal surfaces.

1. Eosinophils develop in the bone marrow for 3 to 6 days before appearing in the peripheral blood.
2. They are stored in the bone marrow and released into the peripheral bloodstream when needed.
3. The average residence time in the cycle is about 8 hours.
4. Eosinophils migrate from the blood to the bronchial mucosa, skin, gastrointestinal tract, and vagina within approximately 12 days.
5. Eosinophils can return to the blood and bone marrow.
6. Eosinophils are motile and can migrate between endothelial cells into tissues or areas of inflammation.

7. EosinophilsContains hydrolases such as:
   1. peroxidase.
   2. Sol phosphatase.
   3. Arylsulfatase.
   4. beta-glucuronidase.
   5. Phospholipase.
   6. cathepsin.
   7. ribonuclease.
8. But eosinophils bind the following enzymes:
   1. alkaline phosphatase.
   2. Molten body.
   3. cationic protein.
9. Organized eosinophils, these have prominent nucleoli.

LymphocytesThere are two types:

1. B - Lymphocyteslead to antibody-dependent immunity.
2. T - LymphocytesConfers cell-mediated immunity; their subtypes are:
   1. T - Cytotoxic cells. (T-Killer).
   2. T – Suppressorzelle。
   3. T - helper cells.
3. The main function of T cellsIs the fight against chronic bacterial and viral infections.

normal white blood cell count

Those 2

• Adult/Child = 5000 to 10,000/cm3
• Children ≤ 2 years old = 6200 to 17000/cm3.
• Newborn = 9,000 to 30,000 /cm²

other sources

• Adults and Children = 5,000 to 10,000/cm3.
• Children under 2 years = 6200 to 17,000/cm3.
• Newborn = 9,000 to 30,000/cm².

Differential count:

Increased TLC (leukocytosis) observed:

1. TLC>11000/cm²。
2. Mostly an infection, which can be bacterial or viral.
   1. Local infections are:
      1. meningitis.
      2. lung infection.
      3. abscess.
      4. tonsillitis.
   2. systemic infection:
      1. septicemia.
      2. Acute rheumatic fever.
      3. cholera.
3. For leukemia.
4. After strenuous exercise.
5. Pain and anorexia.
6. seizures.
7. emotional response.
8. Mild leukocytosis in pregnancy.
9. acute bleeding.
10. Poisoning such as:
    1. Poisoning from drugs, chemicals and poisons (black widow).
    2. Metabolic diseases include uremia, acidosis, eclampsia, and acute gout.
    3. Parenteral proteins and vaccines.
11. Acute hemolysis of red blood cells.
12. Myeloproliferative disorders.
13. Tissue necrosis:
    1. burn.
    2. Just then.
    3. Tumor necrosis.
    4. Acute myocardial infarction.
    5. Bacterial necrosis.
14. Physiological conditions are:
    1. emotional stress.
    2. an exercise.
    3. obstetrics.
    4. menstruation.

A decrease in leukocytosis (neutropenia) was observed:

1. TLC <4000/cm²。
2. This may manifest as fever, malaise, and chills.
3. Bacterial infections.
   1. bacteria.
   2. septicemia.
   3. Rice tuberculosis.
   4. typhoid.
   5. Subtype
   6. Turami.
   7. Brucellosis.
4. Viral infections are:
   1. hepatitis.
   2. influenza.
   3. infectious monocytes.
   4. Nautilus.
   5. rubella.
   6. measles.
5. blood disease:
   1. leukemia.
   2. pernicious anemia.
   3. Gaucher disease.
   4. Felty syndrome.
   5. Aplastic anemia.
6. Vitamin B12 deficiency.
7. Drugs and chemicals:
   1. Antibiotic.
   2. painkiller.
   3. Sulfonamides.
   4. Antithyroid drugs.
   5. arsenic.
   6. market inhibitors.
8. Malignant infiltration of bone marrow.
9. Bone marrow hypoplasia.
10. Radiation suppresses the bone marrow.
11. Autoimmune diseases such as systemic lupus erythematosus.

TLC goes to NeubauerChamber of Commerce:

• Please always connectTLCwith freshly prepared peripheral blood slides.
• Threshold = <2500 or >30,000 /cm².

Questions and Answers:

• See CBC Part 1 for details.