CBC and Other Studies

Question 1

What are the components of a CBC?

Answer 1

Hb, Hct, RBC count
RBC indices
WBC count w/ differential
Platelet count
Evaluation of blood morphology

Question 2

Define anemia.

Answer 2

Decreased Hb, Hct, or RBC concentration

Question 3

Detail O2 content in a patient with anemia.

Answer 3

O2 content includes Hb concentration, SaO2, PaO2. The latter 2 variables are normal, Hb concentration is decreased, therefore, O2 content is decreased.

Question 4

Is anemia a diagnosis?

Answer 4

No- anemia is a sign of underlying disease

Question 5

What are the general clinical symptoms of anemia?

Answer 5

Fatigue, dyspnea with exertion, inability to concentrate, dizziness

Question 6

What are the general clinical signs of anemia?

Answer 6

Pallor of skin/conjunctivae

Question 7

What are the RBC indices?

Answer 7

MCV, MCHC, RDW

Question 8

Define MCV.

Answer 8

Average volume of RBCs

Question 9

Define microcytic and macrocytic RBCs.

Answer 9

Microcytic is less than 80.

Macrocytic is greater than 100.

Question 10

Define MCHC.

Answer 10

Average Hb concentration in RBCs.

Question 11

What does decreased MCHC indicate?

Answer 11

Decreased synthesis of Hb

Question 12

With a decrease in MCHC, the central area of pallor is greater than normal. What is this called?

Answer 12

Hypochromasia

Question 13

What does increased MCHC indicate?

Answer 13

Spherical RBCs

Question 14

What term refers to a lack of central pallor?

Answer 14

Hyperchromasia

Question 15

Define RDW.

Answer 15

Reflects variation in size of RBCs

Question 16

The RDW is useful in distinguishing iron deficiency from other causes of microcytic anemias, why?

Answer 16

Iron deficiency is the most common microcytic anemia with an increased RDW.

Question 17

What organelles do RBCs lack?

Answer 17

Mitochondria

Nucleus

Question 18

What is the end product of anaerobic glycolysis?

Answer 18

Lactic acid

Question 19

Briefly describe the Cori cycle.

Answer 19

RBCs turn glucose into lactic acid. Lactic acid enters liver and is used in gluconeogenesis. Glucose is used by RBCs.

Question 20

The pentose phosphate pathway produces what antioxidant?

Answer 20

GSH- glutathione

Question 21

What is the function of glutathione?

Answer 21

Neutralizes FRs

Question 22

What is the function of the metHb reductase pathway used by RBCs?

Answer 22

Reductase system converts ferric (3+) iron to ferrous (2+) iron

Question 23

What is the function of the Luebering-Rapoport pathway?

Answer 23

Synthesizes 2,3-BPG- shifts oxygen binding curve to the right

Question 24

What is the normal life span of a RBC?

Answer 24

4 months

Question 25

Where are senescent RBCs phagocytosed?

Answer 25

Cords of Billroth by splenic macrophages

Question 26

What product is formed by splenic macrophage breakdown of heme?

Answer 26

Unconjugated bilirubin

Question 27

What are the components of the iron studies?

Answer 27

Serum ferritin Serum iron TIBC % saturation

Question 28

Define serum ferritin.

Answer 28

Iron binding storage protein

Question 29

What cells synthesize ferritin.

Answer 29

Bone marrow macrophages | Hepatocytes

Question 30

Macrophages are the primary storage site for ferritin (iron), where does most macrophage iron come from?

Answer 30

Phagocytosis of senescent RBCs

Question 31

Detail ferritin synthesis in inflammation.

Answer 31

Ferritin synthesis increases - release of IL-6

Question 32

What condition is diagnosed by decreased serum ferritin?

Answer 32

Iron deficiency

Question 33

Define hemosiderin.

Answer 33

Insoluble product of ferritin degradation in lysosomes

Question 34

Define serum iron.

Answer 34

Iron that is bound to transferrin

Question 35

Define serum total iron binding capacity.

Answer 35

Correlates with concentration of transferrin

Question 36

What is a normal serum iron and TIBC?

Answer 36

Serum iron ~100 | TIBC ~300

Question 37

When is serum iron increased?

Answer 37

Iron overload diseases

Question 38

When is serum iron decreased?

Answer 38

Iron deficiency | Anemia of chronic disease

Question 39

Detail the relationship of transferrin synthesis with ferritin stores in macrophages.

Answer 39

Increased ferritin leads to decreased liver synthesis of transferrin Decreased ferritin leads to increased liver synthesis of transferrin

Question 40

Define iron saturation.

Answer 40

The percentage of binding sites on transferrin occupied by iron

Question 41

What formula is used to calculate iron saturation?

Answer 41

Iron saturation = serum iron/TIBC *100

Question 42

When is iron saturation decreased?

Answer 42

Iron deficiency | Anemia of chronic disease

Question 43

What test is used to detect hemoglobinopathies?

Answer 43

Hb electrophoresis

Question 44

What are normal Hb detected in adults?

Answer 44

HbA has 2α/2β globin chains (97% in adults) HbA2 has 2α/2δ globin chains (2% in adults) HbF has 2α/2γ globin chains (1% in adults)

Question 45

What are abnormal Hbs?

Answer 45

Sickle Hb, HbH, Hb Bart