5.5 Normocytic Anemia with Extravascular Hemolysis Flashcards
Hereditary Spherocytosis
Inherited defect of RBC tethering proteins
What are the common protein defects in hereditary spherocytosis?
- Spectrin
- Ankyrin
- Band 3.1
What are the lab findings of hereditary spherocytosis?
Increased RDW and MCHC
- RDW is due to the nonuniform size of RBCs and MCHC is due to increased relative Hb concentration in the RBCs.
What kind of bilirubin builds up in hereditary spherocytosis?
Unconjugated Bilirubin
What is the response of a spherocytic RBC to the osmotic fragility test?
It will burst as it cannot accommodate a hypotonic solution entering the cell due to it being “filled” already
Why do Howell-Jolly bodies appear with splenectomy?
They are nuclear fragments in RBCs that are normally removed by the spleen
What is an effect of hydroxyurea on blood?
Increases HbF
What is the appearance of RBCs on blood smear in sickle cell anemia?
- Sickled cells
- Target cells
What is a common presentation of sickle cell anemia in infants?
Dactylitis
How can SCA affect the spleen?
It can lead to autosplenectomy
What is the most common cause of osteomyelitis in SCA patients?
Salmonella paratyphi
What is the most common cause of death in adults with SCA?
Acute Chest Syndrome
What is the most common cause of death in children with SCA?
Infection with encapsulated organisms
Where can sickling of RBCs occur in the patients with sickle cell train (NOT SCA)?
Renal Medulla - lead to eventual inability to concentrate urine
Metabisulfite Screen
It will cause HbS to sickle in BOTH patients with sickle cell anemia and trait
