Pathology exam-anemia

Question 1

Describe the erythropoietin mechanism for regulating erythropoiesis rate

Answer 1

Stimulus: hypoxia
Reduced O2 levels in blood causes kidney to release EPO
EPO stimulates red BM to enhance erythropoiesis
More RBC is produced= increased O2 carrying ability of blood

Question 2

What is anemia?

Answer 2

“Lack of blood”
Reduction below normal in:
- total RBC count
-PCV
-Haemoglobin concentration
Leading to decrease in oxygen carrying capacity

Question 3

Clinical signs of anemia

Answer 3

Cardiac-work overload
Respiratory-Tachypnoea, hypoxia
Urinary-Hematuria (renal damage)
Systemic-Jaundice, tissue hypoxia

Question 4

What are the causes of anemia?

Answer 4

• loss due to hemorrhage
• destruction of RBCs
• Lack of production

Question 5

What is Non-regenerative anemia?

Answer 5

Low production of RBCs

• primary BM disorder
• secondary BM disorder (nutritional or hypoproliferative)

Question 6

What is regenerative anemia?

Answer 6

Exit/turnover exceeds production

• haemolysis (high destruction), intravascular or extravascular
• hemorrhage, internal or external

Question 7

What is MCV?

Answer 7

Mean Corpuscular Volume
The average volume of a red blood cell
Tells about age of RBC, younger are bigger

Question 8

What is MCH?

Answer 8

Mean Corpuscular Haemoglobin

The average amount of Hb per RBC

Question 9

What is MCHC?

Answer 9

Mean Corpuscular Haemoglobin Concentration
The average concentration of Hb per unit volume of RBCs
Low is sign of regenerative anemia

Question 10

What are signs of regeneration?

Answer 10

• macrocytosis/anisocytosis
• polychromasia (immature red blood cells)
• RBC inclusions

Question 11

What is an acantocyte?

Answer 11

• Picked cell membrane, abnormal thorny projections
• excess of cholesterol relative to phospholipids in cell membrane
• severe hepatic disease

Question 12

What is a target cell?

Answer 12

• cell with dark center surrounded by white ring and dark peripheral ring
• iron deficiency anemia
• liver disease (increased cholesterol to phospholipid ratio)
• post splenectomy

Question 13

What are types of abnormal aggregation of RBCs?

Answer 13

• agglutination=immunomediated or staphylococcus infection

- rouleaux formation= “stacks of coins”, normal in cats+horses, occurs in inflammations, tumours, infection

Question 14

What are the types of RBC inclusions?

Answer 14

• nucleated RBCs=metarubricytes or late rubricytes
• Howell-jolly bodies= basophilic nuclear remnants in erythrocytes
• basophilic stippling= spots of nuclear remnants

Question 15

When do we see reticulocytes in peripheral blood?

Answer 15

• in cats, dogs and pigs they can be present in healthy animals
• in ruminants only present in regenerative response
• horses have no reticulocytes, they mature in BM

Question 16

What is Reticulocytosis?

Answer 16

• Absolute increase in reticulocyte count
• shows effective erythropoiesis
• takes several days to be evident on RBC cell count

Question 17

What are clinical signs of anemia?

Answer 17

Main signs:
- weakness
-exercise intolerance
-pale mucous membranes
Other signs:
-jaundice, hematuria, haemoglobinuria
- tachycardia, cardiac murmur, cardiomegaly
-lymph node enlargement
-hepatomegaly, splenomegaly

Question 18

How do you asses acute hemorrhagic anemia?

Answer 18

1. Loss of whole blood=PCV May be unchanged
2. After 24 hours blood is replaced w interstitial fluid= Drop in PCV, low serum total protein (esp. in external loss)
   Reticulocytes in blood smear:
   - increased nr. After 3 days
   - maximal nr. after 7 days
   - normal after 14 days
   Anisocytosis remain far longer

Question 19

What are haemolytic aniemia?

Answer 19

Destruction of RBCs
Extravascular- RBC prematurely removed by mononuclear macrophage can system. Outside of blood vessels
Intravascular- rupture of RBCs inside vessels
Signs= bilirubinaemia, sometimes haemoglobinuria

Question 20

How do you asses haemolytic anemia?

Answer 20

• low PCV
• high bilirubin
• normal or high total protein
• increased reticulocytes, more than in haemorrhagic
• RBC shape change (spherocytes) and presence of parasites may be identified

Question 21

What is IMHA?

Answer 21

Immune-mediated haemolytic anaemia

• immunemediated destruvtion of RBCs
• primary=idiopathic
• secondary=immunologic response to non self antigens, could be infections, neoplasia, drugs or vaccination, incompatibility reactions, oxidative stress etc

Question 22

What is microangiopathic haemolytic anaemia?

Answer 22

RBCs being fragmented due to damaged blood vessels
Leads to intravascular haemolysis
-Schistocytes

Question 23

What is oxidative stress anemia?

Answer 23

-Due to paracetamol, diabetes mellitus, ingestion of toxic substances
- lead to irreversible erythrocyte damage
- methaemoglobin (hemegroup contains Fe3+, cannot bind oxygen)
- Heinz bodies (Hb precipitates over RBC inner surface)
-eccentrocytes ( Hb displaced to one part of the cell)
Cats very sensible