Anemia: Therapeutics

Question 1

Complete Blood Count (CBC)

• Comprised of:

Answer 1

⮚ RBC count
⮚ WBC count
⮚ Hemoglobin
⮚ Hematocrit
⮚ RBC indices (MCV, MCH, MCHC)
⮚ Red cell distribution width
⮚ Platelets
• CBC “with differential” – various types of WBCs are analyzed

120 days turnover?

Question 2

Regulation of RBC production: review

Key Points: Synthesis of hemoglobin (Hgb)

Answer 2

• Hgb is a protein in RBCs that carries oxygen
• Iron is an essential part of Hgb
• Plasma transport protein (transferrin) delivers
iron to the bone marrow for incorporation into
Hgb
• Circulating transferring normally about 30%
saturated with iron
• Transferrin delivers extra iron to other body
storage sites (liver, marrow, spleen) for later use
• Ferritin – reflects total body iron storage

Question 3

Anemias
• Definition:
pathophys

Answer 3

– Decrease in number of red blood cells or
concentration of hemoglobin (Hgb)
– Sign of underlying disease
• Pathophysiology:
– ⇓ red cell production
– ⇑ red cell destruction
– ⇑ red cell loss

Question 4

Signs and Symptoms of Anemia

Answer 4

Symptoms
• Fatigue
• Weakness
• Lightheadedness
• Shortness of breath
• Decreased exercie
toleranc
Signs
• Pallor of:
– Conjunctivae
– Nail beds
– Palmar creases
– Face

Question 5

Goals of Therapy

Answer 5

• Alleviate signs and symptoms of anemia
• Normalize or ensure adequate hemoglobin
level
• Improve quality of life
• Prolong survival

Question 6

Interpreting Lab Values for Anemia

Answer 6

• Lab values can be helpful to differentiate possible
causes of anemia
• Erythrocyte morphology can be used to categorize
anemias
– Additional tests/work-up may be required to
confirm the cause
• Peripheral smear may provide additional information
– formed elements of blood (erythrocyte,
leukocytes, and platelets) are examined for
abnormal size, morphology, or inclusion

Question 7

what is an immature rbc called?

Answer 7

reticulocytes

they will continue to increase in anemia as long as bone marrow active

Question 8

RBC indices and reticulocyte

```
Hemoglobin
Hgb
Red Blood Cell
(RBC)
Hematocrit
(Hct)
~~~

Answer 8

Hemoglobin
- Indirect measure of O2 carrying
capacity of the blood

Red Blood Cell
4.0 - 5.7 x 1012/L - Varies with age, sex and geographic
location
- Primary function – transport O2/CO2

Hematocrit (Hct)
(M) 0.42-0.52
(F) 0.37-0.48
- Packed cell volume
- Actual volume of RBCs in a unit volume expressed as %

Question 9

MCV
MCHC
RDW
Reticulocyts

Answer 9

MCV 82-100 fL -size of average RBC
MCHC 320-360 g/L - Hgb divided by Hct
mean corpuscular
Hgb conc

RDW 0.110-0.160 (11-16%) - Measure of variation in red blood cell volume
Reticulocytes 0.5-2.5% - Immature RBCs

Question 10

Iron studies/ B12/folate

ferritin is usually the best one test to get

Answer 10

Serum iron - concentration of iron bound to transferrin
Normally transferrin is 1/3 bound to iron

Total iron binding capacity - Indirect measurement of
serum transferrin

Percent transferrin saturation or saturation index
~15-55% Ratio of serum iron to TIBC expressed as a %

Serum ferritin
- Indicator of iron body stores

Question 11

Iron studies/ B12/folate

Folate
B12

Answer 11

Folate > 7 nmol/L -Decreased levels indicate
deficiency
Vit B12 155-800 pmol/L - Low levels indicate
deficiency

Question 12

macrocytic
normochromic, normocytic
microcytic

Answer 12

MCV > 100 fL
Macrocytic Anemia
Possible causes: Vitamin B12 deficiency Folic acid deficiency Drug-induced BM toxicity liver disease, hypothyroidism, myelodysplasia
Helpful lab tests:
Vitamin B12/folate, LFTs, retics, TSH, Protein electrophoresis

MCV 82-100 fL
Normochromic, normocytic Anemia
Possible causes:
Bleeding, early iron deficiency, hemolysis, CKD, anemia of inflammation & chronic disease, primary marrow
disease
Helpful lab tests:
Retics, CRP, LFTs, Scr 

MCV < 82 fL
Microcytic anemia
Possible causes: Iron deficiency anemia of inflammation & chronic disease, Thalassemias
Helpful lab tests:
Ferritin, CRP

Question 13

Interpreting MCV

Answer 13

• MCV is a measurement of the size of average
RBCs
• Increased reticulocytes in circulation may
increase MCV as reticulocytes have larger size
than mature erythrocytes
• “Mixed anemias” may result in normal MCV
• RDW (and peripheral smear) useful to
evaluate in conjunction with MCV

Size of RBCs can be misleading
be aware of mixed anemias

Question 14

Microcytic Anemia

Answer 14

Iron deficiency is most frequent cause
• anemia develops when there is insufficient iron available to support red blood cell production
– Most common causes of iron deficiency anemia (IDA):
• inadequate dietary intake
• inadequate absorption
• increased demands (e.g. pregnancy and breast feeding)
• increased loss of iron (e.g. menstrual bleeding and blood donation)
– Other causes of microcytic anemia: thalassemias,
anemia of chronic disease (some)