Hemolytic Anemia 9/27 Flashcards
(16 cards)
What molecule does free Hgb bind to in intravascular hemolysis?
Free Hgb binds to HAPTOGLOBIN
When binding capacity exceeds, plasma turns PINK
How do you determine intravascular hemolysis? 3 indications.
- Reduced serum haptoglobin
- Presence of plasma (pink) or urine (red dipstick) hemoglobin
- Detection of hemosiderin in renal tubular cells in urinary sediment
What are the 3 disorders intrinsic to RBCs that cause hemolytic anemia?
- Abnormal Hbg
- Enzyme defect: G6PD deficiency
- Membrane abnormality: spherocytosis
What are the 5 disorders extrinsic to RBCs that cause hemolytic anemia?
- Autoimmune
- Mechanical factors (burns)
- Infections & toxins (snake venom)
- Liver disease
- Hypersplenism
What should you test to determine hemolytic anemia? 5 tests
- CBC
- Blood smears
- Reticulocyte count
- EPO
- BM biopsy
What test is used to distinguish immune from non-immune mediated hemolysis?
Coomb’s antiglobulin test
How does Coombs test work?
Detects Ag/Ab complexes on RBC membrane.
Coombs reagents are antibodies that recognize the Fc portion of Ig or C3d.
What are features of hemolytic anemia diagnosis?
- Compensatory production of Reticulocytes
- Reticulocyte index >3
- Absolute count of rtcytes >100k
- Bilirubin elevated
- LDH elevated
- Serum haptoglobin diminished
what 2 tests are performed to diagnose extra vascular hemolytic anemia?
- Coombs
2. Hgb electrophoresis
What 2 tests determine intravascular hemolytic anemia?
- Hgb in urine and plasma
2. Iron stains of urinary sediment
What are the 3 heriditary/intrinsic erythrocyte defects of hemolytic anemia?
- Hereditary spherocytosis
- Heriditary elliptocytosis
- G6PD deficiency
How is hereditary spherocytosis inherited and what is the characteristic?
Autosomal.
Intrinsic defects in RBC membrane - SPHEROCYTES.
Reduced membrane stability.
Which erythrocyte membrane proteins lead to heriditary spherocytosis when defective? (4)
- Ankyrin
- Spectrin (most common)
- Band 3
- Band 4.2
What are symptoms of spherocytosis? (3)
- Anemia
- Splenomegaly
- Jaundice
How do you diagnose hereditary spherocytosis? (2)
- Osmotic fragility test
2. Molecular studies to confirm
What is the pathogenesis of g6dp deficiency?
- O2 oxidation
- Denaturation of globin chains
- Heinz bodies
- Cell rigidity
- Hemolysis