Plasma Proteins
What is the defining feature of an animo acid?
R Group/Side Chain
What two main plasma proteins are measured?
Albumin + globulin
Describe the location of the thymus in a young animal.
Located in the cranial mediastinum - cranial to the heart. Atrophies with age, responsible for development and maturation of T-Lymphocytes
Define the immune system and its primary functions.
Definition: Network of cells, tissues, and molecules that defend the host from pathogens.
Primary functions:
- Defense against infections/pathogens
- Elimination of damaged/dead cells
- Immune surveillance against tumors
- Distinguishing self vs non-self
What is the feathered edge usually examined for?
"Clumps, critters, and cancer"
What percentage of plasma is water? What percentage is protein?
90% water, 7% protein (albumin, immunoglobulins, fibrinogen, acute phase proteins, etc.)
What is the half-life of plasma albumin in small animals vs. large animals? What is the response time until immunoglobulins are measurable in the blood?
1/2 life albumin = 8 days in dogs, 2-3 weeks in horses, 1-3 weeks on average
Immunoglobulins have a delayed response time of 1-3 weeks after exposure to a pathogen.
Explain why the lymph carried in the thoracic duct often has a milky appearance.
Lacteals carry chyle (fats) from the GI tract
Discuss the relevance of immunology to veterinary practice.
Understanding disease pathogenesis
Designing/using vaccines
Managing immune-mediated diseases
Antimicrobial resistance
List the cell types from most numerous (1) to least numerous (3).
1 RBCs, 2 platelets, 3 WBCs
What types of plasma proteins are produced by hepatocytes? Plasma cells/B-lymphocytes?
Hepatocytes --> ALBUMIN, acute phase proteins, coagulation factors, complement proteins, apolipoproteins (carrier proteins for lipids).
Plasma Cells and B-Lymphocytes --> immunoglobulins (antibodies) : IgM, IgG, IgA, IgE
In what scenario would altered albumin levels lead to edema? Why?
Since albumin is responsible for maintaining oncotic (colloidal osmotic) pressure in vessels, which helps return fluid to vessels, if albumin were low, more fluid would stay in the vessels. The lymphatic system would typically help to reclaim net fluid loss, but if the lymphatic system were altered or a lymph node were blocked, this would lead to edema.
Identify and describe the hilus and capsule of the spleen. What is the function of the spleen?
Where vessels and nerves enter the spleen. Grooved in monogastrics. Indented in ruminants. Responsible for immune response and RBC filtering/storage.
What is the difference between humoral and cell-mediated immunity? What do they include?
Humoral (humors/fuids):
Innate: Complement proteins, acute phase proteins
Adaptive: B cells, plasma cells, antibodies (IgM, IgG, IgA, IgE, IgD), memory B cells (ALL THE B CELLS :))
Cell-mediated (cells do the killing):
Innate: Phagocytes (neutrophils, macrophages), dendritic cells, and NK cells.
Adaptive: Helper T cells, cytotoxic T cells, memory T cells, regulatory T cells (ALL THE T CELLS :))
What are the 5 types of leukocytes (WBCs) found in blood in health?
Neutrophils, Monocytes, Basophils, Eosinophils, and Lymphocytes
What are positive acute phase proteins (+APPs)? Name 4 examples.
What are negative acute phase proteins (-APPs)? Name 2 examples.
+ APPs: Increase with acute inflammation.
Examples: Fibrinogen (coagulation and wound healing), C-reactive protein (promotes complement), Haptoglobin (binds hemoglobin), Serum Amyloid A (SSA) (promotes cytokine production/leukocyte recruitment)
- APPs: Decrease with acute inflammation
Examples: Albumin (protein synthesis, energy production, oncotic pressure), Transferrin (iron transport).
Give both ways that total protein is measured. Which is more accurate? How would a false total protein value affect the globulin value?
Biochemistry analyzer (biuret method): Usually done as part of a chemistry profile. May be done on using serum or plasma. More accurate because it measures peptide bonds.
Refractometer: Performed using plasma from microhematocrit tube from a purple top. Usually done as part of a CBC profile. Less accurate and prone to interference because lipemia or increases in other solids will falsely increase TP!
Since the globulin value is calculated using total protein, a false TP would proportionally lead to a falsely increased or decreased globulin value.
Identify the major lymph nodes in each animal (dog, cat, horse, ruminant) and whether or not they are palpable.
Dog: Parotid (not palpable), mandibular (palpable), prescapular (palpable), axillary (not palpable), superficial inguinal (not palpable, too small), and popliteal (palpable). NO subiliac lymph nodes.
Cat: Parotid (not palpable), mandibular (palpable), prescapular (palpable), axillary (palpable), subiliac (not palpable, too small), superficial inguinal (not palpable, too small), and popliteal (palpable).
Horse: Parotid (not palpable), mandibular (palpable, V-shaped), prescapular (not palpable), axillary (not palpable), subiliac (not palpable), superficial inguinal (not safely palpable), and popliteal (not safely palpable).
Ruminant: Parotid (palpable), mandibular (palpable), prescapular (palpable), axillary (not palpable), subiliac (palpable), superficial inguinal (not palpable), and popliteal (not palpable).
Differentiate between innate and adaptive immunity.
Innate: Fast, non-specific, no memory. Present at birth. Includes: Barriers such as skin, mucous membranes, and normal flora. Cells such as phagocytes (neutrophils, macrophages, dendritic cells), NK cells, basophils, eosinophils, mast cells, complement, and acute phase proteins
Adaptive: Slower to start, highly specific, has memory. Includes: T lymphocytes (helper and cytotoxic) and B lymphocytes (and plasma cells).
What is the main advantage of an automated hematology analyzer WBC differential?
Looks at more cells and is therefore more accurate. Also, more efficient than a manual.
What is the difference between plasma and serum? Include the type of blood tubes, the type of blood, and the difference in what proteins each sample contains.
Plasma = fluid portion of unclotted blood, collected in a purple top tube that contains EDTA, and contains the following proteins: albumin, globulins, clotting factors, and fibrinogen.
Serum = fluid obtained from clotted blood, collected in a red top tube, and contains the following proteins: albumin and globulins. NO fibrinogen or clotting proteins.
Draw out the peaks on a standard serum protein electrophoresis diagram (4 most important/discussed). Which protein will migrate the furthest and why? Explain why the albumin and IgG peaks appear different.
4 plasma protein peaks from left to right: Albumin (smallest protein, tallest peak), alpha 2 (haptoglobin), beta 2 (IgM, IgA immunoglobulins), gamma (IgG immunoglobulin).
Albumin has a higher & narrower peak due to there only being one type of protein being read. This makes albumin the smallest most negative charge. IgG has a smaller & more broad peak due to more than one type of protein being read.
Describe the major lymphocenters of the body (6 main regions, 15 lymphocenters total that we need to know!)
Lymphocenters of the head: The parotid, the mandibular, the retropharyngeal
Lymphocenters of the neck: The superficial cervical (AKA prescapular)
Lymphocenter of the forelimbs: The axillary center
Thoracic lymphocenters: The ventral thoracic center, the mediastinal center, the bronchial center
Abdominal lymphocenters: Lymph nodes of the roof of the abdomen, the celiac center, cranial mesenteric center, caudal mesenteric center
Lymphocenters of the hindlimbs, pelvis, and abdominal wall: The popliteal center, the superficial inguinal center, the iliosacral center
List the primary functions of the following WBCs: Neutrophils, Lymphocytes (B and T), Macrophages, Dendritic cells, Eosinophils, Basophils, Mast Cells, and Natural Killer Cells.
Neutrophils: Involved in early response to infection. Most abundant WBC. Phagocytosis and bactericidal mechanisms.
Lymphocytes (B and T): B lymphocytes develop into plasma cells and secrete antibodies. Helper T cells: Activate B cells, cytotoxic T cells, and macrophages. Cytotoxic T cells: Kill virus-infected or tumor cells. Regulatory T cells: Suppress immune responses, prevent autoimmunity. Memory T cells: Provide long-lasting immunity.
Macrophages: Phagocytosis and bactericidal mechanisms, APCs.
Dendritic cells: APCs (most potent APC) that process antigens and present them to T cells (bridge innate and adaptive).
Eosinophils: Defense against parasitic infections and allergic reactions.
Basophils: Release histamine and involved in inflammatory and allergic responses.
Mast Cells: Release histamine and other chemicals during inflammatory and allergic responses
NK Cells: Kill virus-infected cells and tumor cells without prior sensitization. Use perforin and granzymes to induce apoptosis. Produce cytokines (e.g., IFN-γ) to enhance macrophage and T cell activity.
What is the main disadvantage of an automated hematology analyzer WBC differential?
The analyzer counts nRBCs as WBCs. It also counts band neutrophils as segmented neutrophils and cannot recognize basophils.