Anemias

Question 1

What is considered a normal reticulocyte count?

Answer 1

Less than 2% of RBCs per high powered field

more is pathologic

Question 2

Two best labs for detecting hemolysis.

Answer 2

1. LDH

2. Haptoglobin

Question 3

What is the Mean Corpuscular Volume for RBCs in microcytic anemia?

Answer 3

MCV Less than 80fL (femtoliters)

Question 4

What is the Mean Corpuscular Volume for RBCs in macrocytic anemia?

Answer 4

MCV greater than 100fL

Question 5

Main cause of Iron deficiency anemia.

Answer 5

Blood loss

• also caused by metabolic alterations (pregnancy)
• also caused by absorption disorders (celiac)

Question 6

Tx for iron deficiency anemia.

Answer 6

Ferrous Sulfate

IV meds if absorption disorder exists

Question 7

What are the four conditions caused by alpha globin mutations?

Answer 7

Alpha thalassemias
1 mutation: silent carrier
2 mutations: Alpha Thal Trait
3 mutations: Hb H disease
4 mutations: hydrops fetalis

Question 8

Tx for the 4 types of alpha thalassemia.

Answer 8

Silent Carrier: observation
Alpha Trait: genetic counseling
Hb H: occasional transfusion with exerting circumstances
Hydrops Fetalis: transfusion until transplant can occur

Question 9

What is Frontal Bossing?

Answer 9

Characteristic skull bone hypertrophy due to increased hematopoiesis in the flat bones of the skull in patients with untreated Beta Thalassemia.

Question 10

Why does beta thalassemia cause hepatomegaly and splenomegaly?

Answer 10

Deficiency adult Hb forces the body to revert back to a fetal mechanism of oxygen transport by making fetal Hb. This occurs in the spleen and liver causing hypertrophy.

Question 11

What is the Tx for the 3 types of beta thalassemia?

Answer 11

Beta Trait: counseling
Beta Intermedia: occasional transfusion
Beta Major: transfused until transplant can be done

Question 12

Complicaiton of blood transfusion in patients with Beta thalassemia.

Answer 12

Iron overload can cause heart failure.

Question 13

Pathology of Sickle Cell Disease.

Answer 13

Mutation in the beta globin chain at position 6. Amino acid switch to valine from glutamate

Question 14

Complications of Sickle Cell Disease.

Answer 14

Pain, polyarthralgia, stroke

HbS crystalizes when the pH drops or the Hb becomes deoxygenated. This occurs in the peripheral or near the venous end of circulation.

Question 15

How is stroke prevented in Sickle Cell patients? 1 test and 2 treatments.

Answer 15

Transcranial Doppler to check cranial blood flow
1. Hypertransfusions to wash out sickled blood cells.

2. Hydroxyurea: chemotherapy tablet that targets histones in gamma globlin genes forcing adults with sickle cell disease to make HbF which doesn’t use the beta globin protein

Question 16

Major complication of Splenic Sequestration Crisis caused by Sickle Cell Disease and a result of the complication.

Answer 16

Autosplenectomy due to occlusion of splenic vasculature.

Loss of spleen results in increased susceptibility to encapsulated bacteria. Also MRSA in the clavicle joints.

Question 17

Cause of Warm autoimmune hemolytic anemia.

Answer 17

Cause is unknown but linked to blood malignancies. CLL, lymphoma.
Results in IgG mediated RBC lysis.

Question 18

Tx of Warm AIHA.

Answer 18

Remove offending agent or cancer

Prednisone or IVIG

Question 19

Cause of Cold AIHA.

Answer 19

Often after Mycoplasma pneumoniae infection. Production of IgM autoantibodies lyse RBCs.

Question 20

Tx for Cold AIHA.

Answer 20

Plasmaphoresis to wash out IgM

Warm the patient

Question 21

Pathology of Glucose-Phosphate-6 Dehydrogenase deficiency.

Answer 21

RBCs unable to produce NADPH to fight ROS and oxidative stress leads to early RBC lysis.

Question 22

Characteristic of G6PD def. on blood smear.

Answer 22

Heinz Body

Question 23

Pathology of Pyruvate Kinase Deficiency.

Answer 23

Failure of adequate ATP production in RBC. Leads to RBC lysis and jaundice in young children. Production of gall stones.

Question 24

Why does Macrocytic anemia caused by B12 deficiency cause ataxia or dementia?

Answer 24

Metabolism of methylmalonic Acid in the myelin sheath requires B12. Otherwise the myelin becomes fragile and neurons cannot send signals.

(MMA requires methylation by B12 to form a functional dimethylmalonic acid lipid polymer of myelin)

Question 25

How can you distinguish B12 def. anemia from Folate def. anemia?

Answer 25

Check B12 levels, folate levels
-these aren’t as reliable.

Homocysteine is high in both

MMA levels rise in B12 def.
MMA is normal in folate def.

Question 26

Pathology of Hereditary Spherocytosis.

Answer 26

Defective spectrin, ankyrin, or Band 3.1 proteins causing rounded RBCs.

Question 27

Best test for diagnosis of Hereditary Spherocytosis.

Answer 27

Osmotic Fragility

-cells can’t withstand much osmotic gradient and lyse easily

Question 28

Tx for hereditary spherocytosis.

Answer 28

Pre-splenectomy: folic acid, transfusion

Splenectomy

Question 29

What are Howell-Jolly Bodies?

Answer 29

Remnants of RBC nuclei inside mature RBCs due to decreased splenic activity or asplenia. Most common after splenectomy due to hereditary spherocytosis treatment.