10.09.18 Hemolysis Flashcards
A group of disorders characterized by decreased red cell lifespan
Hemolytic anemia
What are the clinical features of hemolytic anemia?
- Jaundice
- Dark urine (tea/red)
- Pigmented gallstones
- Ankle ulcers
- Sphenomegaly
- Aplastic crises (assoc. with Parovirus B19)
- Increased req. for folate
Yellowing sclera
More generalized yellow discoloration of tissues
scleral icterus
Jaundice
When are splenectomies generally done?
To treat disorders where there is uncontrolled splenic destruction of RBC/platelets
small round blue DNA remnants in periphery of RBCs
Howell-Jolly bodies
What kid of RBC abnormalities would you find after a splenectomy?
- Target cells
- Acanthocytes
- Schistocytes
- Nucleated Red Cells
- Howell Jolly bodies
Non-encapsulate DNA virus; destroys RBC precursors
Normal individuals have no significant effet but in those with hemolytic anemia loss of RBC production can reduce reticulocyte count
Parovirus B19
Parovirus B19 can cause a loss of RBC production, reducing reticulocyte count and Hb values causing what?
Aplastic crisis
How are hemolytic anemias classified?
- Sites of RBC destruction
- Acquired vs. Congenital
- Mechanism of RBC damage
Macrophages in spleen, liver, and marrow remove damaged or antibody-coated RBC
Extravascular Hemolysis
RBC rupture within the vasculature, releasing free hemoglobin into the circulation
Intravascular Hemolysis
What is the laboratory evidence for hemolysis?
- Increased RBC production
- elevated reticulocyte count in the blood
- erythroid hyperplasia in the bone marrow
- Deforming changes in skull/long bones - Increased RBC destruction
- Elevated LDH
- Elevated unconjugated bilirubin
- Reduced serum haptoglobin (binds free Hb)
Expansion of the eythroid lineage that should be myeloid: erythroid 3:1 but is now 1:10
Erythroid hyperplasia
Results from increased erythropoietic activity and marrow space expansion
Frontal Bossing
This type of hemolytic anemia is classified by defects in membrane skeleton proteins, defects in enzymes involved in energy production, and hemoglobin defects
Congenital
The type of hemolytic anemia is classified by immune-mediated and non-immune mediated pathways
Acquired
Most common defect leading to anemia
Defect in protein of membrane skeleton (ankyrin)
Causes decreased MCV
Heridtary Spherocytosis
What is the genetic pattern for hereditary spherocytosis?
What will MCHC levels look like?
How do you diagnose?
How do you treat?
Autosomal Dominant
Elevated
Increased osmotic fragility
Folate supplementation; splenectomy
In this disease oxidizing agents convert Hb to methemoglobin and causes it to precipitate as Heinz bodies which the spleen pinches off leaving a bite/blister cell
G6PD Deficiency
How is G6PD deficiency genetically passed on?
What population is this found in?
Why does it matter if someone has G6PD deficiency?
X linked
Mediterreanean (more extreme) and Africans (unstable; loses activity with age)
Need to avoid oxidative drugs (quinine in malaria)
What triggers hemolysis in G6PD deficiency?
How does G6PD levels differ after a hemolytic episode in African and Mediterranean populations?
Drugs/infections
Africans can have normal level since mature cells are lysed and young cells are normal; not happening in Med pop.
What are the different types of immune hemolysis?
- Warm antibody-mediated (AIHA)
- Cold antibody-mediated
- Drug-related hemolysis
- Paroxysmal Nocturnal Hemoglobinuria
Hallmark of this disease is a positive Coomb’s test
Autoimmune Hemolytic Anemia
This type of anemia reacts with RBCs best at 37 degrees and don’t agglutinate RBC
IgG aginst RBC surface molecules form and coat with or without C3 complement causing engulfment by spleen and forming spherocytes
Warm antibody-mediated
This type of anemia reacts best below 32 degrees and causes RBC agglutination
Pathogenic antibody is IgM
Digital ischemia
Cold antibody-mediated
Tests for IgG or C3 which are bound DIRECTLY on the RBC
Direct Antiglobulin Test (DAT) = Direct Coomb’s test
What are important clinical features with warm-antibody hemolytic anemia?
- Positive Coomb’s test
2. Spherocytes on peripheral smear
How do you treat AIHA?
Immunosuppression
- Corticosteroids
- Splenectomy or Rituximab (works against CD20 on B cells)
May require transfusion if symptomatic with anemia
What kind of infection is associated with Cold Agglutinin Disease?
What other kind of disease is associated with it?
Can you use steroids/splenectomy?
Mycoplasma or Monoculeosis
Lymphoproliferative disease
No, its ineffective; use immunosuppression
Hallmark of this disease is the presence of schistocytes on the peripheral smear and can be cause by TTP/HUS and DIC
Microangiopathic Hemolytic Anemia
