MTAP HEMA 2

• WBC: colorless, nucleated cell that circulate in the peripheral blood; main line of defense against foreign invaders such as bacteria, viruses and foreign antigens

  Types: Basophil, Eosinophil, Neutrophil, Lymphocyte, Monocyte
• Nuclear chromatin pattern: Most valuable and reliable criterion for deciding whether a cell is mature or immature

  Compartments of leukocytes

  • Bone marrow
  • Peripheral blood
  • Tissues
• According to:

  GRANULARITY- GRANULOCYTES: Baso, eosinophil,neutrophil

  AGRANULOCYTES/NONGRANULOCYTES: Monocytes, Lymphocyte

  NUCLEAR SEGMENTATION:

  POLYMORPHONUCLEAR CELLS: Basophil, eosinophil, neutrophil

  MONONUCLEAR CELLS: monocyte, lymphocyte

  FUNCTION:

  PHAGOCYTES: Basophil, eosinophil, Neutrophil, Monocyte

  IMMUNOCYTES: Lymphocyte
• Leukopoiesis: Formation of WBC

  Chromatin pattern: Identification of WBC

  Obligate end cell: mature cell that is committed to perform a function and die; Neutrophil, Eosinophil, Basophil RBC

  Non obligate cell: Monocyte, Lymphocyte
• Neutrophil: highest numbers in the peripheral blood of adults, common progenitor with monocytes known as granulocyte-monocyte progenitor (GMP) CFU-GM

  : diurnal variation; high level in afternoon; low in morning

  Most common leukocyte in normal peripheral blood

  2 Forms: Segmenters and Band
• Lifespan( myeloblast to death)- several days- several weeks

  9-10 days (steininger)

  10-14 (cruzada)

  5 days (Brown)
• Ferrata cell- Tissue neutrophil; subacute bacterial endocarditis

  Barr body (sex chromatin)- described as drumstick; 2-3% of the neutrophil in female. NOT FOUND IN MALES

  Neutrophil pool: spends its life in 3 main areas: BM, Peripheral blood and tissue
• Pools of neutrophil in the BM:

  1. Mitotic or proliferating pool- contains myeloblast, promyelocyte,myelocyte; undergoing cell division
  2. Maturation or storage pool or maturation-storage compartment: contains metamyelocytes, bands, segmented neutrophil; no longer undergoing division but progressively maturing; 7-10 days
• In peripheral blood: Circulating pool (50%)

  Adheres to vessel wall: Marginating pool (50%)
• Marrow reserve: refers to segmented neutrophils in the maturation-storage compartment; 4-8 day supply of neutrophil
• Myeloblast: earliest recognizable blast; identified by light microscopy, no visible granules; 15 hrs, 1% of the total nucleated bm cells
• Promyelocyte: known as Programulocyte;

  First appearance of primary granule/azurophilic/nonspecific granules; 24 hrs, 3% of the nucleated bm cell
• Myelocyte: appearance of secondary or specific granules; dawn of neutrophilia (Pinkish arc located in golgi region composed of secondary granules
• Metamyelocyte: called as Juvenile cells; appearance of tertiary granules

  Nucleus: kidney bean/ peanut shaped

  Indention of nucleus < 50% width of nucleus
• Band cell: Stab cell/Staff cell; appearance of secretory granules, Last stage before mature cell, First immature WBC to be released in circulation; Youngest cell in granulocytic appear in peripheral blood

  : >50% width of nucleus
• Primary granules: Azurophilic/ nonspecific granules

  : produced by Promyelocyte

  : LAST GRANULE TO BE RELEASED

  Contents:

  1. Myeloperoxidase
  2. Cathepsins
  3. Acid beta-glycerophosphatase
  4. Defensins
  5. Elastase
  6. Proteinase-3

  Secondary granules: Specific granules

  : produce by: Myelocyte

  :THIRD TO BE RELEASED

  Contains:

  1. Lactoferrin
  2. collagenase
  3. Gelatinase
  4. Beta2-mictoglobulin
  5. Neutrophil gelatinase-associated lipocalin
• Tertiary granules: Produce by Metamyelocyte

  : SECOND TO BE RELEASED

  Contains:

  1. Gelatinase
  2. Collagenase
  3. Lysozyme
  4. Acetyltransferase
  5. Beta2-mictoglobulin

  Secretory granules: Secretory vesicles

  :Produced by Band cell

  :FIRST TO BE RELEASED

  Contains:

  1. Alkaline phosphatase, CD11b/CD18
  2. Vesicle-associated membrane-2
  3. CD10
  4. CD13
  5. CD14
  6. CD16
• Eosinophil: major role in parasitic infections and hypersensitivity reactions

  Products:

  1. Major basic protein (MBP)-arginine rich protein; major role in the eosinophil's ability to damage parasitic invaders
  2. Charcot-Leyden Crystals - composed of lysophospholipase localized in the cell membrane of the eosinophil; hexagonal pyramidal crystals; Found in nasal mucus of px w/ allergic asthma, pleural fluid of px w/ pulmonary eosinophilic infiltrates, stools of px w/ parasitic infections
• Maturation storage lifespan of eosinophil: 2.5 days

  In circulating blood: Few hrs

  In tissues: Several days
• Basophil: LEAST common; resembles mast cell; have specific receptors for immunoglobulin E; immediate hypersensitivity reactions (Type 1 hypersensitivity

  Product: Histamine, Heparin

  Immediate hypersensitivity reaction: Urticaria, bronchial asthma, allergic rhinitis, and anaphylaxis to drugs, insect stings and other antigen

  Mast cells: tissue cells; NOT A LEUKOCYTE

  :effector cells in allergic reactions thru the release of wide variety of lipid mediators

  : NOT OBSERVED in blood of healthy person