GenMed - Hemato

Question 1

MAHA

• List causes (10).

Answer 1

1. DIC.
2. TTP - ADAMTS13 deficiency.
3. HUS (eg E-coli SHiga Toxin).
4. Heart valves (stenotic / mechanical / periprosthetic leak).
5. Infection.
6. Drugs.
7. Malignancy.
8. Malignant hypertension.
9. Pre-eclampsia.
10. Autoimmune diseases.

Question 2

MAHA

• Define
• Characteristics.
• Example.

Answer 2

*MAHA (Microangiopathic Hemolytic Anemia)

• Anemia caused by fragmentation and destruction of erythrocytes due to intravascular physical shearing as a result of passage through small vessels occluded by microthrombi / fibrin.
• Characteristically:

1. Thrombocytopenia.
2. Normal coag.
3. Peripheral smear: schistocytes.

Example:

1. Shiga toxin by E. coli strain 0157:H7, causing HUS:

• Shiga toxin damages endothelial cells, resulting in platelet aggregation and thus deposition of microthrombi.