RBCs

Question 1

what is EPO? where is it produced?

Answer 1

a glycoprotein hormone produced manily in the kidney

Question 2

when is EPO secreted?

Answer 2

in response to cellular hypoxia, via HIF (hypoxia inducible factor)

Question 3

what does EPO do?

Answer 3

stimulates RBC production in the bone marrow

Question 4

What are reticulocytes?

Answer 4

late-stage immature RBCs

Question 5

What % of blood do retics make up?

Answer 5

about 1% of peripheral blood

Question 6

An increase in reticulocytes signifies

Answer 6

a regenerative response

Question 7

What species do you not see reticulocytes in?

Answer 7

Horses

Question 8

what are some reasons you would see a nRBC in peripheral blood?

Answer 8

• a regenerative response (look for retics)
• splenic disorder (decreased clearance)
• marrow injury
• hematopoietic neoplasia

Question 9

RBC function

Answer 9

• transportation of O2 and CO2
• Buffer (HCO3-)
• bind cell-free DNA in circulation during sepsis
• Hb synthesized within developing RBCs

Question 10

More affinity of Hb for O2 during….

Answer 10

decreased CO2, decreased temp, increased pH

Question 11

Less afinity of Hb for O2 during…

Answer 11

Increased CO2, increased temp, decreased pH

Question 12

What is hepcidin? where is it produced?

Answer 12

a key negative regulator of iron (increased hepcidin -> decreased serum iron).

produced in the liver

Question 13

when is hepcidin increased?

Answer 13

with inflammation

Question 14

Explain a serum iron test

Answer 14

measures iron bound to the carrier protein transferrin

Question 15

explain a TIBC (total iron binding capacity)

Answer 15

amount of iron transferrin can bind when totally saturated with iron. (an indirect measurement of serum transferrin)

Question 16

what is the % saturation of transferrin measuring?

Answer 16

% of iron binding sites that are occupied

Question 17

How do you measure iron storage?

Answer 17

serum ferritin, hemosiderin

Question 18

what values signify a true iron deficiency?

Answer 18

• decreased serum iron
• decreased serum ferritin
• normal or increased TIBC
• decreased % saturation of transferrin
• microcytosis

Question 19

define anisocytosis
what species is this normal in?

Answer 19

variation in RBC size
normal in cats

Question 20

define poikilocytosis

Answer 20

variation in RBC shape

Question 21

What is a howell jolly body?

Answer 21

A RBC with a remnant of nucleus - can see with regeneration

Question 22

What is a Heinz body?

Answer 22

an aggregate denatured Hb on a RBC

Question 23

What do Heinz bodies indicate?

Answer 23

Oxygen injury

Question 24

what is a coomb’s test

Answer 24

tests for Ab against RBC

Question 25

define Absolute anemia

Answer 25

a decrease in the total body red blood cell mass

Question 26

define a relative anemia

Answer 26

normal red cell mass but increased plasma volume

Question 27

causes of regenerative anemia

Answer 27

hemorrhage or hemolysis

Question 28

how long does it take for regeneration to occur?

Answer 28

3-5 days

Question 29

An increase in nRBC without reticulocytosis (does/does not) indicate a regenerative response

Answer 29

does not

Question 30

PCV and TP decreased - what type of anemia?

Answer 30

hemorrhagic

Question 31

PCV decreased, TP normal, icterus, +/- hemoglobinemia - what type of anemia?

Answer 31

hemolytic

Question 32

iron, protein and RBCs lost - internal or external hemorrhage?

Answer 32

external

Question 33

protein and iron reabsorbed, some RBC may also be reabsorbed - internal or external hemorrhage?

Answer 33

internal

Question 34

causes of blood loss

Answer 34

trauma, parasitism, hemostasis disorders, ulcers, vascular neoplasms

Question 35

causes of hemolysis

Answer 35

* immune-mediated * toxins/chemicals * RBC parasites * mechanical injury * inherited RBC defects * oxidants * hypophosphatemia

Question 36

Proper function of bone marrow requires:

Answer 36

* normal stem cells and hematapoietic precursors * normal stimulation/growth factors * normal nutrients * normal hematopoietic environment

Question 37

when the # of erythroid precursor cells or stimulation to the erythroid cells is inadequate, the erythroid marrow is (hypocellular/hypercellular)

Answer 37

hypocellular

Question 38

when abnormal maturation occurs due to nutritional deficiences, the erythroid marrow may be (hypocellular/hypercellular)

Answer 38

hypercellular

Question 39

Normocytic/normochromic anemias with normal or increased neutrophils and platelets

Answer 39

* anemia due to lack of EPO * anemia of inflammation * Anemia of endocrine Dz and neoplasia * infectious causes of anemia * immune-mediated anemia

Question 40

Normocytic/normochromic anemias with decreased neutrophils and/or platelets

Answer 40

Aplastic anemia (infectious, drugs/toxins, irradiation, idiopathic) Myelophthisic anemia (means you have neoplastic cells in the bone marrow)

Question 41

microcytic, hypochromic, anemias with variable neutrophils and platelets

Answer 41

* iron deficiency * anemia of chronic inflammation * portosystemic shunts * B6 deficiency * Cu deficiency

Question 42

How to Dx a non-regenerative anemia?

Answer 42

Tricky! Start wutg CBC/Chem, UA... consider bone marrow evaluation, iron testing, infectious Dz testing