Erythrocyte Flashcards

1
Q

Pathogenesis of Extracellular Hemolytic Anemia

A
  1. Initiating event (immune, metabolic, traumatic, oxidative)
  2. Macrophages recognize and destroy RBCs

——> Anemia

  1. Macrophages degrade Hb to bilirubin

—–> Icterus

——–> Bilirubinuria

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2
Q

Pathogenesis of Hemolytic Icterus

A
  1. Macrophage destructin of RBCs results in unconjugated Bilirubin to enter plasma and bind to albumin
  2. Bu/Alb complex transported to liver

—> Hyperbilirubinemia (Bu) (if incomplete removal)

  1. Bu enters hepatocytes and is conjugated (Bc)
  2. Bc excreted in bile
  3. Bc may be regurgitated to plasma if formation > excretion

—> Hyperbilirubinemia (Bc)

  1. Bc passed through kidneys, excrete

—-> Biliruninuria

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3
Q

If your patient is icteric, what type of anemia will you suspect (intra- or extravascular)

A

Extravascular

The icterus is caused by macrophages destroying RBCs and then degrading Hb to bilirubin

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4
Q

Pathogenesis of intravascular hemolytic anemias

A
  1. Initiating event (immune, metabolic, oxidative)
  2. Marked damage to RBC membrane and lysis of RBCs in blood

—–> Anemia

  1. Hb in plasma

——> Hemoglobinemia

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5
Q

Pathogenesis of hemoglobinemia

A

Starts with intravascular hemolysis. Hb is present in plasma and unstable. 3 things can happen next

  1. Hb binds to haptoglobin (Hpt) —> Hb/Hpt complex removed
  2. Hb binds to hemoplexin (Hpx) —> Hb/Hpx complex removed
  3. Too much Hb released so….

—–> Hemoglobinemia

—–> Hemoglobinuria

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6
Q

Hemoglobinemia and hemoglobinuria are associated with what type of anemia (intra- or extravascular)

A

Intravascular - RBCs lyse and Hb accumulates in blood/passes through urine

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7
Q

Fill out this table

A
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8
Q

Antibodies (especially colostral Abs in horses) are a cause of what type of hemolysis

A

Extravascular

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9
Q
A
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10
Q

Mycoplasma and Anaplasma cause what type of anemia

A

Extravascular hemolytic anemia

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11
Q

Penicillin causes what kind of hemolysis

A

Intravascular (and then extravascular)

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12
Q

Heinz bodies are found in what type of hemolytic anemia

A

Intravascular (and then extravascular)

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13
Q

Your patient has tons of Eccentrocytes. What type of anemia do you suspect

A

Intravascular hemolytic anemia

(extravascular hemolytic anemia will follow)

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14
Q

Hypophosphatemia causes which kind of anemia

A

Extravascular

(PO4 needed for major metabolic pathways. Without PO4 —> reduced ATP –> membrane cant repair –> extravascular hemolysis)

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15
Q

A dairy cow recently gave birth and you now worry she is anemic. Based on this information, what may be causing this and why type of anemia is she suffering from?

A

She may be suffering from post-parturient hypophosphatemia, which would cause extravascular (??) hemolytic anemia

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16
Q

What is a common cause of hypophosphatemia in dogs and how will this effect the dog?

A

Hyperinsulinemia drives PO4 into cells (ie myocytes), resulting in hyphosphatemia and intravascular hemolysis

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17
Q

What does L-sorbose intoxication cause?

A

It cause hypophosphatemia

L-sorbose binds to PO4 and inhibits glycolysis —> Reduced ATP —> Reduced membrane repair

—> Intravascular hemolysis

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18
Q

Agglutinated RBCs will cause artefact to which indice

A

MCV –> agglutination results in increased MCV

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19
Q

What are Wintrobe’s formulas

A
  1. MCV
  2. MCH
  3. MCHC
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20
Q

Can you calculate the hematocrit?

A

Yes: MCV x [RBC] / 10

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21
Q

Which stain is best for reticulocytes

A

Methylene Blue

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22
Q

Whats reticulocyte percentage

A

# reticulocytes / 1000 RBCs

(counted)

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23
Q

Whats Corrected Reticulocyte Percentage (CRP)

A

It compensates for the degree of anemia

RP X (Hct/Average Hct for spp)

Tells you what reticulocyte percentage would be if animal were not anemic (as anemia = fewer RBCS = platelets will seem more plentiful)

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24
Q

Whats a disadvantage of corrected reticulocyte percentage

A

It assumes a normal hematocrit

–> this may not be normal for all animals. (ie greyhounds have higher PCV than other dog breeds)

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25
Q

What is reticulocyte concentration

A

It is used if reliable [RBC] is available

RP x [RBC}

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26
Q

What is appropriate rubricytosis

A
  • Seen in regenerative anemias
  • Regenerative blood cells following blood loss or hemolysis
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27
Q

What is inappropriate rubricytosis

A

Regeneration of RBCs without anemia or in non-regenerative anemia

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28
Q

Causes of inappropriate rubricytosis

A
  • Marrow damage, inflammation, necrosis
  • Lead poisoning in dogs
  • Extramedullary hematopoiesis, splenic contraction (horses), splenectomy
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29
Q
A
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30
Q

RBC lifespan for cats, dogs, cows, horses

A

Cats: 70d

Dogs: 100d

Cows: 280d

Horses: 450d

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31
Q

Which species have a sinusoidal spleen? What’s the clinical significance?

A

Dogs, horses

    • Pools of blood can be released quickly*
    • More efficient removal of old, damaged RBCs (by macrophages outside spleen)*
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32
Q

What’s a morphological sign of regenerative anemia in cows?

A

Basophillic stripping (Ribosomal RNA that isnt degraded)

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33
Q

All acquired anemias are initially what (-chromic, -cytic, -generative)

A

Normochromic

Normocytic

Non-regenerative

*Because it takes 3-4 days for EPO to kick in and for new RBCs to be released

34
Q

When does reticulocytosis start after onset of anemia? When is peak reticulocytosis

A

Start: 3-4 days

Peak: 7-10 days

35
Q

What is macrocytosis and who has it

A

Large cells - its seen in horses during regenerative anemia instead of reticulocytosis

36
Q

How do you classify non-regenerative anemias

A

Normocytic

Normochromic

  • No reticulocytosis!
  • No rubricytosis!
37
Q

Principle causes of non-regenerative anemia

A

AID

Renal failure (chronic)

38
Q

Fill in the blanks

A
39
Q

Your patient has normocytic, normochromic anemia. What is cause

A
  • Initial status of regenerative (ie just got HBC)
  • Non-regenerative
40
Q

Your patient is macrocytic and hypochromic. What type of anemia

A

Regenerative

41
Q

Your patient is macrocytic and normochromic - what type of anemia

A

Regenerative

42
Q

Your patient is microcytic and hypochromic - what kind of anemia

A

Fe deficiency (due to nutrition, AID..)

43
Q

Your patient is microcytic and normochromic. What type of anemia

A

Fe deficiency

Liver failure (microcytes)

44
Q

What does hyperchromic indicate

A

Usually an artefact!

45
Q

What is this? What is its signficance/cause?

A

Rouleax formation

Significance

  • Hyperglobinemia
  • Hyperfibrinogenemia

Cause

  • Inflammation
  • Dehydration

*normal in horses!

46
Q

You’re evaluating a blood stain from your equine patient. Should you be concerned?

A

No - roleaux is common in horses

47
Q

What’s this? Significance? Cause?

A

Agglutination

Significance

  • Formed by antibody bridges between cells

Causes

  • Cold antibody
  • Heparin induced (horses)
48
Q

What kind of artefacts would you expect from this smear?

A

Clumps will be seen as large RBCs so:

- Decreased [RBC]

- Increased MCV

Could suggest a regenerative anemia (macrocytic..)

49
Q

You’re unsure whether your patient’s blood is roleaux or agglutinated. How do you test?

A

Saline dilution test

  • Add saline (1 blood: 9 drops saline)

- If clumps disperse —> Roleaux

- If clumps dont disperse –> Agglutination

50
Q

How does central palor vary in species (dogs, cats, cows, horses)

A

Dogs: prominent

Cats: mild

Cows: mild-moderate

Horses: none-mild

51
Q

How will your RBC indices be effected by Fe deficiency

A

MCV: decreased

MCHC: decreased

MCH: decreased

Marked central pallor

52
Q

How will your RBC indices be effected by regenerative anemia

A

MCV: increased

MCHC: decreaed

MCH: increased

  • Reticulocytes*
  • Polychromatic*
53
Q

What are howell-jolly bodies caused by

A

Extra chromatic after mitosis of RBC

Indicate increased erythropoiesis and decreased splenic function

54
Q

What are heinz bodies caused by

A

Oxidative damage

Defective RBC metabolism

55
Q

Your horse is anemic and has recently been seen eating red maple leaves. What will you seen

A

Heinz bodies!

56
Q

Your cat has hepatic lipidosis. How will RBCs appear

A

Elliptocytes

57
Q

RBCs in a patient with intravascular coaguation will be?

A

Keratocytes

58
Q

Which RBC morphology is indicative of a drying artefact

A

Echinocyte

59
Q

Which RBC morphologies would you see with microangiopathy

A

Shizocyte (triangular fragments)

Keratocyte (horn projections)

60
Q

How do impedence cell counters identify RBCs

A

By volume

61
Q

How do optical/laser flow cytometers identify RBCs

A

By light scatter

62
Q

How do conductivity methods identify RBCs

A

By electrical resistance

63
Q

How does cetnrigufation analysis identify RBCs

A

By microhematocrit and buffy coat analysis

64
Q

In which species is it normal to hve orange plasma. Can it indicate pathology?

A

Healthy in herbivores (plant pigments)

Pathology: icterus (bilirubin)

65
Q

Pink/red plasma indicates

A

Hemoglobin

66
Q

White/hazy plasma indicates

A

Presence of lipids

67
Q

A thickened buffy coat indicates increase of two types of cells

A

WBCs

Platelets

68
Q

Calculated hematocrit (cHct) and spun hematocrit (sHct) should be within what percentage of each other

A

3%

If not, something is wrong (usually with cHct)

69
Q

Whats erythrocytosis

A

Increased RBC mass

Increased Hct

Increased Hgb

Increased [RBC]

70
Q

What is hemoconcentration

A

Increased concentration of blood components due to decreased plasma volume –> DEHYDRATION

71
Q

What is polycythemia vera

A

Clonal myeloproliferative disease causing:

  • erythrocytosis
  • leukocytosis
  • thrombocytosis
72
Q

Common causes of erythrocytosis

A
  1. Hemoconcentration (dehydration due to diarrhea, voliting, polyuria)
  2. Splenic contractions (exercise, fright/excitement)

*dogs, horses*

  1. Hypoxia
  2. Neoplasm
73
Q

How can you calculate erythrocytosis using spleen and peripheral Hct

A

Add peripheral Hct to splenic Hct –> if higher than 100%, thats how much erythrocytosis you have

74
Q

What are two secondary causes of erythrocytosis (appropriate and inappropriate)

A
  1. Hypoxia –> stimulates EPO —> increased RBC release
    - Appropriate (= due to hypoxia)
  2. Neoplasm in liver, kidney stimulating EPO
    - Inappropriate
75
Q

Whats hypoferremia and whats the analyte

A

Decreased [Fe] in serum/plasma

Analyte = Serum Fe

76
Q

Whats hypoferritinemia and what is the analyte

A

Decreased [ferritin] in serum/plasma

Analyte = Serum ferritin

77
Q

What’s hyerferritinemia and what is the analyte

A

Increased ferrtin in serum/plasma

Analyte = serum ferriitn

78
Q

What is TIBIC?

A

Total iron binding capacty – total amount that can be bound in serum transferrin

79
Q

T/F TIBC is an important diagnostic tool

A

False, it is of little diagnostic value

80
Q

Which assay is useful for Fe storage?

A

Serum ferritin

81
Q

How can you differentiate if hypoferemia is due to Fe deficiency or inflammation

A

Stainable Fe test – Fe stained in spleen or bone marrowx

  • Inflammation: will be increased (mac sequestratio)
  • Fe deficiency: will be decreased (less avaialbe and what is available is being used up to make new RBCs)
82
Q

You suspect IMHA. Which two antibdy tests can you use and which antibody are you testing for

A

Detecting for ESAIg (erythrocyte surface associated immunoglobulin)

1) Coomb’s test

2) Flow cytometry for ESAIg