Hemolytic Anemia Flashcards
What’s the average lifespan of an RBC?
100-120 days
Where does extravascular hemolysis occur?
It’s caused by phagocytic cells and it can happen in the bone marrow, liver or the spleen
What’s the most common congenital red cell membrane disorder?
Hereditary spherocytosis
What are examples of common symptoms seen in patients with HS? (4)
- Intermittent jaundice
- Red cell aplastic episodes associated with viral infections
- Splenomegaly
- Cholelithiasis
Which RBC membrane is affected in HS?
Spectrin protein which is one of the skeletal membrane protein.
Why does splenomegaly occur in patients with HS?
The splenic sinusoids prevent the passage nondeformable spherocytic red cells.
Which is why splenectomy can be a therapeutic option in HS.
Which red cell indices can be a clue for HS on a CBC?
There is a higher MCHC (characteristically higher than 36%)
RDW can be elevated too due to the presence of microspherocytes and reticulocytes
What’s the confirmatory test for HS?
Band 3 protein reduction in RBC. The test is done through flow cytometery through the binding of EMA to Band 3 protein
Which conditions can give a false positive EMA flow cytometry test? (3)
- Congenital dyserythropoietic anemia type 2
- Southeast Asian ovalocytosis
- Hereditary pyropoikilocytosis
Which viral infection predisposes to aplastic crises?
Parvo virus (B19). It causes fifth disease (erythema infectiosum).
The virus selectively invades erythroid progenitor cells and may result in transient arrest in red cell proliferation.
When does recovery from an aplastic crises secondary to viral infection (B19) begin?
Recovery begins in 7-10 days and is usually completed by 4-6 weeks.
How to manage post splenectomy thrombocytosis in patients with HS?
No therapeutic intervention is needed
What dietary supplementation should patients with HS be on?
They should be on folic acid due to the higher turn over or red cells.
What are the three key features of PNH? (3)
- Acquired Hemolytic Anemia
- Risk of venous thrombosis
- Association with aplastic anemia.
Which CD deficiencies can be seen in patients with PNH? what’s the impact of this deficiency?
Deficiency in CD55 or CD59
There is deficiency in GPI antigen which leads to complement activation secondary to CD55 or CD 59 deficiency
