Blood

Question 1

Objectives

Answer 1

• Understand the classification and identification of various types bloo cells in peripheral blood
• Understand the clinical sidgnificance of various types blood cells in peripheral blood
• Understand the classification and identification of various types precursor blood cells in peripheral blood
• Understand general changes that occur as blood cells profress through the developmental stages, and what cellular components contribute to staining properties

Question 2

Characteritic of Blood cells

Answer 2

Question 3

Anemia

Answer 3

• Erythrocyte-associated problem
• Reduction in RBC numbers, hemoglobin content, or both
• One of the most frequent hematologic disorders encountered in practice
• Not a disease, but a reflection of a disease state
• Causes:
  
  • Blood loss, hemolysis, decreased RBC production

Question 4

Regenerative Anemia

Answer 4

• Bone marrow responds by releasing more immature RBCs
• Reticulocyte count goes up - best indicator of regeneration, but happens rarely in horses
• Mean corpuscular volume (MCV) goes up because reticulocytes have greater volume
• Mean corpuscular hemoglovin concentration (MCHC) goes down because reticulocytes have less oncentrated hemoglobin

Question 5

Lymphocytes

Answer 5

• One subtypes of WBC in a vertebrate’s immune system
• Several subsets:
  
  • B cells (for humoral, antibody-driven adaptive immunity)
  • T cells (for cell-mediated, cytotoxic adaptive immunity)
  • Natural killer cells (function in cell-mediated, cytotoxic innate immunity)
• General Features:
  
  • Size: small 6-15 um
  • Nucleus: heterochromatic
  • Cytoplasm: basophilic and scant
    *

Question 6

Plasma Cell

Answer 6

• Mature B cells
• Antibody Production
• Cytoplasm - abundant, basophilic, round cell
  
  • pale staining area next to nucleus - golgi protein processing
• Nucleus - More euchromatic, but mixture o dark and lightly stained chromatins

Question 7

Antibody production by B cell

Answer 7

1. Antigens (bacteria, virus, etc)
2. Interaction with B cells and APC
3. B cell differentiation to B cell APC and memory B cells
4. Interation with B cells and APC activated helper T cells
5. Activation of B cells
6. B cell differentiation to plasma cell
7. Antigen-specific antibodies

Question 8

B Cell Discovery

Answer 8

• Discovered by a veterinary surgeon at OSU CVM - Dr. Bruce Glick
• Removed the bursa of Fabricius from chickens in 1956
  
  • Used those chickens for antibody production by injecting Salmonella
  • No Antibody production found
• Named it a “Bursa Cell” shortened to B cell

T cells? - Dr.Jacques Miller

Question 9

T Lymphocytes

Answer 9

• Cell-mediated adaptive immune reaction
• Several subsets: all are identical in morphology
  
  • CD4+T cells: helper T cells
  • CD8+T cells: cytotoxic T cells
  • Natrual Killer (NK) T cells: Cytotoxic cells in innate immune system, not for adaptive immune reaction
  • Regulatroy T cells (Treg): Inhibit T cell function
• Nucleus - small, dark, round
• Cytoplasm - scant
• Indentified by immunohistochemistry

Question 10

CAR T Cell Therapy

Answer 10

• Chimeric antigen receptor T cells (CAR T cells)
  
  • Cells genetically engineered to produce an artificial T-cell receptor specific to cancer antigen (with cell proliferation) for use in cancer immunotherapy
  • FDA approved two drugs in 2018
• Benefits:
  
  • Cancer-specific therapy
  • Very effective therapy
  • Applicable to acute lyphoblastic leukemia (ALL), large B cell lymphoma
• Demerits:
  
  • Very expensive $373,000 - $475, 000
  • Need specialized facility

Question 11

Granulocytes

Answer 11

• Catagory of WBC in the innate immune system
• Characterized by the presence of granules in the their cytoplasm
• AKA polymorphonuclear leukocytes (PMN, PML, PMNL) because of the varying shapes of the nucleus, which is usually lobed into 3 segments
• General features:
  
  • size: large 12 - 17 um
  • Nucleus: heterochromatic, segmented
  • Cytoplasm: basophilic-eosinophilic and large

Question 12

Granulocytes: Neutrophils

Answer 12

• PMN’s (polymorphonuclear cells = neutrophils)
  
  • Polymorphonuclear = multilobed nuclei
  • Cytoplasm contains fine eosinophilic granules
    
    • granules contain proteinases Defensins, enzymes
  • Respond to bacterial infections, wound repai
    
    • Phagocytosis
    • Cytokine production
    • Oxidative burst (H2O2, HOCL productions) - kills bacteria

Question 13

Granulocytes: Eosinophils and Basophils

Answer 13

• Eosinophils and Basophils:
  
  • Nucleus is segmented, but not to the same degree as a neutrophil
  • Visible red color (eosinophils) and blue color (basophils) granules in cytoplasm
  • Eosinophils: Response to parasitic infections, production of histamines and peroxidases
  • Basophils: rare cells, prasitic infections, allergic reations by histamine and heparin release
    
    • Similar to Mast cells

Question 14

Canine Mast Cell Tumors

Answer 14

• Mastocytoma
• Often found in skin
• Often benign tumors
• Develop to metastatic multiple tumors (detected in the blood)

Question 15

Monocyte and Macrophage (MPS)

Answer 15

• Monocyte:
  
  • Precursor cells for macrophage
• Macrophage (mononuclear phagocyte system, MPS):
  
  • Found in blood and all connective tissues
  • Phagocytosis
  • Antigen presentation
  • Nucleus - round or indented; vesicular
  • Cytoplasm - usually abundant, large cells

Question 16

Mononuclear Phagocyte System

Answer 16

• Connective tissue (histiocyte)
• Liver (kupffer cells)
• Lung (alveolar macrophage)
• Lymph nodes (free and fixed macrophages)
• Spleen (free and fixed macrophges)
• Bone marrow (fixed macrophage)
• Serous cavities (pleural and peritoneal macrophages)
• Bone (Osteoclasts)
• CNS (microglial cell)
• Cerebrospinal fluid (macrophages)
• Skin (histiocyte)
• Synovia (Type A cell)

Question 17

Clinical significance of precursor cells in peripheral blood

Answer 17

• Needs of hematopoiesis due to:
  
  • Loss of blood
  • Last stage of cancer
  • Infection of blood parasites, such as Babesia, Malaria, Trypanosoma, etc. The fate of these paracite-infected RBC is signifcantly shorter