RBC Labs and Anemia Classifications

Question 1

What is normocytic anemia?

Answer 1

decreased RBC mass due to peripheral destruction (hemolysis) or underproduction

normal RBC size

MCV: 80-100

Question 2

How are hemolytic and underproduction normocytic anemias differentiated?

Answer 2

Reticulocyte

• young RBC in blood
• bluish tint due to residual RNA in cytoplasm
• ~1-2% of RBCs in circulation normally

Reticulocyte count is falsely elevated in anemia; correcction must be done to get true value = RC * Hct/45

underproduction, corrected reticulocyte % is <3%

hemolytic, corrected reticulocyte % is >3%

Question 3

What are the types of hemolytic anemia?

Answer 3

• extravascular hemolysis
• intravascular hemolysis

Question 4

What is extravascular hemolysis?

What findings will it have?

Answer 4

Predominant breakdown of RBCs by reticuloendothelial system (macrophages) of the liver, spleen, and lymph nodes (occurs outside the vasculature in these organs). Hemoglobin broken down into bilirubin and iron is recycled.

• anemia
• splenomegaly
• increased unconjugated bilirubin/jaundice

Question 5

What is intravascular hemolysis?

What findings will it have?

Answer 5

Predominant breakdown of RBCs within vasculature. RBC contents spill directly into blood where they can be found and are excreted by the kidney.

• hemoglobinemia
• hemoglobinuria**
• hemosiderinuria** (renal tubular cells trap and degrade HGB to hemosiderin, release it days later into the urine)
• decreased serum haptoglobin (depleted by binding free hemoglobin to recycle)

Question 6

What is microcytic anemia?

(pathophys and lab finding)

Answer 6

decreased RBC mass due to lack of hemoglobin components (iron, protoporphyrin, or globin)

decreased RBC size

MCV: <80 (norm 80-100)

Question 7

What are the main types of microcytic anemia?

Answer 7

• iron deficiency anemia
• anemia of chronic disease
• sideroblastic anemia
• thalassemia

Question 8

What is macrocytic anemia?

(pathophys and lab finding)

Answer 8

decreased RBC mass frequently due to impaired DNA synthesis/ineffective hematopoiesis

increased RBC size

MCV: >100 (norm 80-100)

Typically accompanied by megaloblastic anemia:

• ovalocytes (large, oval-shaped RBCs)
• nuetrophil hypersegmentation

Question 9

What is anisocytosis?

Answer 9

Increased variance in RBC size = increased RDW

Think:

• iron deficiency
• sickle cell
• folate/B₁₂ deficiency
• autoimmune hemolytic

Question 10

What is poikilocytosis?

Answer 10

pressence of abnormally shaped RBCs (teardrop cells, target cells, etc.)

Question 11

What are target cells and when are they seen?

Answer 11

Cells with a dark, hemoglobin filled spot in the the central pallor.

occurs when there is low amounts of hemoglobin in the cell

• thalassemia
• iron deficiecny
• sickle cell (autospleenectomy)
• splenectomy/hypoplasia (removes target cells)

Question 12

What do ferritin levels represent?

Answer 12

stored iron

Question 13

What does an elevated LDH represent?

Answer 13

hemolysis