Immunology/Hematology Flashcards

1
Q

What is the normal platelet number per HPF in dogs?

A

8-15 platelets/HPF (120 - 225K/uL)

*Each platelet = 15,000/ platelets/uL

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2
Q

What is methemoglobin?

A

A type of hemoglobin that the iron on the heme has been oxidized from ferrous (Fe2+) to ferric (Fe3+)

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3
Q

When there are >30% methemoglobins in the circulation, what does the pulse oximeter usually show? Why?

A

85% (even if PaO2 is high)
Methemoglobins absorb both wavelengths of light very well.

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4
Q

What are the two type of reticulocytes in cats? Which one can be seen up to 10% in healthy cats?

A

Aggregate reticulocytes & Punctate reticulocytes

Punctate reticulocytes can be seen in healthy cats
* Aggregate forms are released from the marrow and, after approximately 12 hours, develop into punctate forms that persist in the circulation for 9–20 days.

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5
Q

Where does ferritin exist and what is its function?

A

Ferritin exists in all cells
It stores iron and acts as a reservoir to prevent excessive intracellular ion causing cell damage.

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6
Q

What is the function of Hepcidin?

A

It is secreted by hepatocytes and inhibits iron export from enterocytes, macrophages, and hepatocytes.

↑ production during iron overload

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7
Q

What is the function of transferrin?

A

Transport iron

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8
Q

For Transferrin and Ferritin, which one is positive acute phase protein and which one is negative acute phase protein?

A

Transferrin: negative acute phase protein
Ferritin: positive acute phase protein

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9
Q

What is the lifespan for canine and feline RBCs?

A

Dog: 120 days
Cat: 80 days

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10
Q

What is the lifespan of platelets?

A

5-7 days

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11
Q

What is the lifespan of neutrophils?

A

< 24 hours

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12
Q

What is the function of haptoglobin?

A

It binds to free hemoglobin in the circulation

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13
Q

True or False: Hemoglobin has 2 𝜶 globins and 2 𝜷 globins, all of which contains heme molecules.

A

True

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14
Q

Which iron can bind to oxygen, ferric or ferrous?

A

Ferrous (Fe2+) can bind to oxygen
Ferric (Fe3+) cannot

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15
Q

What does 2,3-DPG do?

A

It decreases hemoglobin affinity to oxygen.

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16
Q

What is Heinz bodies?

A

Damaged hemoglobins (usually from oxidative damage)

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17
Q

What is phosphofructokinase (PFK) deficiency and what is the treatment?

A

Periodic intravascular hemolysis and hemoglobinuria associated with strenuous exercise or stress-induced hyperventilation causing respiratory alkalosis

Treatment: exercise restriction

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18
Q

What is pyruvate kinase (PK) deficiency?

A

Decreased ATP availability due to lacking of PK → hemolysis
Moderate to severe macrocytic hypochromic anemia with marked reticulocytosis → myelofibrosis → non- regenerative anemia

  • Worse prognosis compared to PFK deficiency
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19
Q

List 10 causes of hemolysis.

A

1) Primary IMHA
2) Mycoplasma haemofelis infection
3) DIC
4) Splenic neoplasia
5) Hypophosphatemia
6) IV hypotonic fluid bolus
7) Phosphofructokinase deficiency
8) Pyruvate kinase deficiency
9) Uremic-hemolytic syndrome
10) Onion ingestion
11) Zinc, copper toxicity

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20
Q

Which type of hypersensitivity is associated with IMHA?

A

Type II

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21
Q

Describe neonatal isoerythrolysis.

A

It happens in kittens - when type B queen mated to a type A male and the kitten is type AB or A.

When kitten is nursed with the queen’s colostrum, the can absorb the antibodies against type A epitope. About 12-24 hours after colostrum ingestion, the antibodies against type A epitope will be in the circulation and attack kitten’s RBCs

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22
Q

What is the equation for corrected reticulocytes?

A

Corrected reticulocytes = Measured reticulocytes x (PCV/N)

*In dogs, N = 45; in cats, N = 37)

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23
Q

After a BM insult, which cell line decrease will be observed first?

A

Granulocytes → Neutropenia (5-6 days later)
Thrombocytopenia (8-10 days)

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24
Q

What is the function of hepcidin?

A

It regulates the iron metabolism and availability.
Increased hepcidin → decreased iron availability
Positive acute phase protein

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25
Q

What is the definitive of RBC regeneration in dogs?

A

Reticulocytes > 60K/uL

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26
Q

What is the common sequela of Pyruvate kinase (PK) deficiency?

A

Myelofibrosis
Osteosclerosis
Hemosiderosis-induced hepatic failure or bone marrow failure

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27
Q

Does canine and feline RBC contain mitochondria?

A

No

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28
Q

What is normal RBC:WBC ratio?

A

500:1

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29
Q

How to calculate HCT?

A

HCT = MCV x RBC/10

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30
Q

Name 3 oxidizing agents in the neutrophils

A

Superoxide (O2−)
Hydrogen peroxide (H2O2)
Hydroxyl ion (OH )

  • one of the lysosomal enzymes, myeloperoxidase, catalyzes the reaction between H2O2 and Cl- to form hypochlorite, which is exceedingly bactericidal.
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31
Q

During inflammation, what is the first line to four line defense mechanism of the body.

A

1) Tissue macrophage
2) Neutrophil Invasion of the Inflamed Area
3) Second Macrophage Invasion Into the Inflamed Tissue
4) Increased Production of Granulocytes and Monocytes by Bone Marrow

32
Q

How many days does it take for the newly formed granulocytes and monocytes reach the stage of leaving the bone marrow?

A

3-4 days

33
Q

What are the 5 factors that are mainly responsible in control of macrophage response (to stimulate BM)?

A

1) TNF-𝜶
2) IL-1
3) GM-CSF
4) G-CSF
5) M-CSF

34
Q

Name two cells that can release eosinophil chemotactic factors.

A

Mast cells
Basophils

35
Q

Name 4 substances mast cells (and basophils) release during inflammation.

A

Heparin
Histamine
Bradykinin
Serotonin

36
Q

Name 4 aspects of innate immunity.

A

1) Phagocytosis of bacteria by neutrophils & lymphocytes
2) Stomach acid and digestive enzymes destroy the swallow organisms
3) Skin as a barrier to invaded organisms
4) Certain chemicals in the blood that attach to foreign organisms or toxins and destroy them (e.g. complement complex, lysosome, basic polypeptides, natural killer lymphocytes)

37
Q

What are the two main types of acquired/adaptive immunity?

A

Humoral immunity (B cell immunity)
Cell-mediated immunity (T cell immunity)

38
Q

Fill out the blank.

A
39
Q

In normal body, how many percentages of immunoglobulins are IgG?

A

75%

40
Q

Name four ways of antibodies destroy antigens directly.

A

1) Agglutination
2) Precipitation
3) Neutralization
4) Lysis

41
Q

Write down the classic pathway of complement.

A
42
Q

Which complement protein cause opsonization of bacteria?

A

C3b

43
Q

What is the complement protein compose the membrane attack complex (MAC)?

A

C5b6789

  • MAC inserts itself into lipid bilayers and makes holes on the cell → cell lysis
44
Q

Which complement protein initiate chemotaxis of neutrophils and macrophages?

A

C5a

45
Q

Name three complement protein fragments that can activate mast cells and basophils.

A

C3a
C4a
C5a

46
Q

What are the three major antigen presenting cells in the body and what is the site where the antigen bind to?

A

Macrophage, B lymphocyte, dendritic cell (accessory cell)

MHC protein (Major histocompatibility complex)

47
Q

What are the two types of MHC protein and what is the main difference?

A

MHC 1 protein - present to cytotoxic T cells

MHC 2 protein - present to T helper cells

48
Q

Which type of T cells is the most abundant in the body?

A

T helper cells

49
Q

Which interleukin has strong positive effect for the proliferation of cytotoxic T cells and regulatory T cells?

A

IL-2

50
Q

Which three interleukins are called B-cell stimulating factors or B-cell growth factors?

A

IL-4, IL-5, IL-6

51
Q

True or False: CD4 T cells are mainly cytokine-secreting helper cells, whereas CD8 T cells are mainly cytotoxic killer cells.

A

True

52
Q

True or False: CD4 T cells can be divided into two major types. Type 1 (Th1) helper T cells secrete interleukin-2 and interferon-𝛄 but not interleukin-4, 5, or 6. Type 2 (Th2) helper T cells secrete interleukin-4, 5, 6, and 10 but not interleukin-2 or interferon-𝛄.

A

True

53
Q

What are the three complement pathways? What is the activator for each pathway?

A

1) Classic pathway - pathogen, antibody-antigen complex to C1
2) Mannan-binding lectin pathway - PAMP recognized by lectin (e.g. mannose-containing carbohydrates on bacteria or viruses)
3) Alternative pathway - spontaneously activated complement component (e.g. pathogens)

54
Q

How many spherocytes/x100 oil immersion field support immune-mediated destruction of RBC?

A

> 5 spherocytes/x100 oil immersion field
(Sen: 63%; Spe 95%)

55
Q

In the ACVIM Consensus Statement of IMHA, what are the 4 evidences of hemolysis?

A

Hyperbilirubinemia
Ghost cells
Hemoglobinemia
Hemoglobinuria

56
Q

True or False: Saline agglutination testing performed by mixing 4 drops of saline with 1 drop of blood has a reported specificity of 100% for IMHA in dogs.

A

True

57
Q

True or False: There is a high level of evidence that immune-mediated destruction of erythrocytes contributes to anemia in dogs infected with B. canis

A

False

B. gibsoni (from fighting)

58
Q

In the ACVIM Consensus Statement of IMHA, it states that the evidence of M. haemofelis causing IMHA in cats is high.

A

True

59
Q

What is the non-associative cause of IMHA? What about associative?

A

Non-associative: primary, cryptogenic
Associative: secondary

60
Q

True or False: According to the ACVIM Consensus Statement of the treatment of IMHA, fresh RBC or at least no older than 7-10 days is recommended for use in dogs with IMHA.

A

True

61
Q

According to the ACVIM Consensus Statement of the treatment of IMHA, what is the recommended dose for prednisone? If the dog is responding to the tx and is on > 2 mg/kg/d, when should you taper it?

A

2-3 mg/kg/d or 50-60 mg/m^/d (for dogs > 25 kg)
* Dex SP 0.2-0.4 mg/kg/d if cannot tolerate oral med

After 1-2 week

62
Q

According to the ACVIM Consensus Statement of the treatment of IMHA, what are the 4 conditions when second immunosuppressant is recommended?

A

1) Severe, life-threatening IMHA
2) First 7 days the HCT decreases ≥ 5% in 24 hours (on pred)
3) Dependent on blood transfusion after 7 days (on pred)
4) Severe side effects from prednisone

63
Q

List 4 drugs as second immunosuppressant for canine IMHA and their dose.

A

Azathioprine - 2 mg/kg or 50 mg/m2 PO q24h
Mycophenolate - 8-12 mg/kg PO q12h
Cyclosporine - 5 mg/kg PO q12h
Leflunomide - 2 mg/kg PO q24h

  • They recommend cyclophosphamide not be administered to dogs with IMHA.
64
Q

According to the ACVIM Consensus Statement of the treatment of IMHA, what is the recommended intervention if the dog does not respond to second immunosuppressant after 7 days?

A

IVIG 0.5-1g/kg single dose

65
Q

According to the ACVIM Consensus Statement of the treatment of IMHA, if dog’s PCV/Hct has remained stable and >30% for 2 weeks after commencing treatment, what is the recommended tapering plan?

A

Taper prednisone by 25%, and by 25% every 3 weeks thereafter

  • If there is a second immunosuppressant → don’t change the dose of that drug
66
Q

According to the ACVIM Consensus Statement of the treatment of IMHA, what is the recommended management for asymptomatic neutropenic patients?

A

If the neutrophil count is between 1000 and 3000 cells/μL → no antibiotics unless other independent risk factors for infection are present

If the neutrophil count is <1000 cells/μL → prophylactic antibiotics

67
Q

What is the relapse rate for IMHA?

A

11-15%

68
Q

List 5 complications of IVIG administration.

A

1) Anaphylaxis
2) Acute kidney injury
3) Hypotension
4) Fluid overload
5) Thromboembolism

69
Q

What is the recommended dose for IVIG?

A

0.5 - 1.5 g/kg IV over 4-8 hours

70
Q

How does hepcidin affect iron?

A

Decreased iron availability
- Decrease GI absorption
- Prevent iron release from hepatocytes and macrophages
- Increase cellular internalization and degradation of ferroportin

71
Q

Is ferritin a positive or negative acute phase protein? What does it do? What about transferrin?

A

Ferritin
- positive acute phase protein
- blood protein that contains iron

Transferrin
- negative acute phase protein
- main protein in blood that binds and transports iron

72
Q

Name 2 poor prognostic indicators for IMHA and ITP.

A

IMHA
HighBUN level
Hyperbilirubinemia

ITP
High BUN level
Melena

73
Q

What is a triad of symptoms for hemolytic-uremic syndrome? What is the cause?

A

Thrombocytopenia
Acute renal impairment (e.g. glomerular necrosis)
Microangiopathic hemolytic anemia

It is caused by Shiga-like toxin produced by E. coli (typical from), other bacteria, medication, immune processes

74
Q

What metal on the pennies minted after 1982 can lead to hemolysis?

A

Copper

75
Q

In cats, nonregenerative anemias with macrocytic normochromic red blood cells may be suggestive of what type of infection?

A

FeLV

76
Q

In patients with IMHA, there are extravascular hemolysis and intravascular hemolysis. What immunoglobulin is associated with each and how does the hemolysis occur?

A

Extravascular hemolysis
- IgG
- IgG-RBC complex is cleared through the reticuloendothelial system

Intravascular hemolysis
- IgM
- IgM-RBC complex activates C3 and membrane attack complexes, induces the classical complement pathway, and results in intravascular hemolysis.