Hemolytic Anemias Flashcards
hemolytic anemia
intravascular rupture of RBC or increased uptake by phagocytes
plasma
liquid portion of blood
serum
liquid left over if you let blood clot
CANNOT asses blood coagulation
hemolytic anemia lab findings
- free hemoglobin increased
- LDH increased
- haptoglobin reduced (infection/inflammation can artificially increase)
- unconjugated bilirubin
spherocytosis
genetic hemolytic anemia
defects membrane anchors, spectrin, or ankyrin
Dx: osmotic fragility test
hemoglobinopathies
genetic hemolytic anemia: crystallization of hemoglobin
missense mutation
Hgb S, HgB C, HgB SC, Hgb E
Dx: hemoglobin electrophoresis
pyruvate kinase deficiency
genetic hemolytic anemia
decreases in ATP inhibits the Na/K ATPase, sodium leaks into the cell, water follows and cell bursts
polychromes counted as reticulocytes
Dx: enzyme activity test
hereditary spherocytosis
genetic hemolytic anemia
defects membrane anchors, spectrin, or ankyrin
Dx: osmotic fragility test
pyropoikilocytosis
genetic hemolytic anemia
defects membrane anchors, spectrin, or ankyrin
Dx: osmotic fragility test
hereditary eliptocytosis
genetic hemolytic anemia
defects membrane anchors, spectrin, or ankyrin
Dx: osmotic fragility test
G6PD deficiency
genetic hemolytic anemia
X-linked
defect in anti-oxidant system: can’t produce NADPH via the pentose phosphate pathway to reduce glutathione needed to reduce peroxide
Heinz bodies, methemoglobinemia
induced by: fava beans, bactrim (sulfamethoxazole), anti-malarials, lots of drugs
Dx: enzyme activity
methemoglobinemia
extensive oxidation of heme iron (now Fe3+)
Drugs that should be avoided in G6PD deficiency
- dapsone
- methylthioninium chloride (methylene blue)
- nitrofurantoin
- phenazopyridine
- primaquine
- rasburicae
- tolonium chloride (toluidine blue)
* Many used to treat malaria and G6PD is prevalent in same region
paroxysmal nocturnal hemoglobinuria
neoplastic/ acquired genetic
unimpaired complement fixation: MAC destroys RBC (no phosphotidylinosital glycan: no DAF)
Dx: flow cytometry
Tx: allogenic bone marrow transplant and ecluzimab
malaria
infectious hemolytic anemia
intracellular protozoal parasite
travel to tropical/ subtropical areas: anopheles mosquito
high fever, dark urine, jaundice
thick smear needed if parasite load isn’t high
merozoites
early form of plasmodium
plasmodium falciparum
parasite that causes malaria
most lethal form
Africa
plasmodium vivax
parasite that causes malaria
Caribbean
babesia
infectious hemolytic anemia
protozoal intracellulair parasite
ticks
NE U.S.
Bartonella baciliformis
infectious hemolytic anemia (sever in acute phase)
rash in chronic phase
fever, splenomegaly
sand flies
northern Andes (Peru, Ecuador, Colombia)
other names: Carrions disease, Oroya fever
C. perfringens (welchii)
infectious hemolytic anemia
normal skin flora
gas gangrene or sever anemia
trauma, septic abortions, rare complication of cholecystitis, or cancer
warm autoimmune hemolytic anemia
Ab against RBC antigens: cleared by phagocytes
extravascular and intravascular hemolysis
microspherocytes, nucleated red cells, basophilic stippling, polychromasia, hemolysis lab tests
DAT positive at 37 F for complement and Ab
NO blasts or myelocytes
Associated with: lymphoma, malignancies, autoimmune
Tx: steroids, splenectomy
Prognosis: poor
extravascular hemolysis
macrophages clear RBC marked with C3b
intravascular hemolysis
MAC complex destroy RBCs
direct antiglobulin test (DAT)
direct Coombs test
Why would you add exogenous RBCs to a DAT?
RBC with Ab bound may get lysed/cleared rapidly and undetectable to DAT
What is a problem with DAT?
nonspecific: up to 8% of hospitalized patients have a positive DAT
cold autoimmune hemolytic anemia
cold agglutinins with broad thermal amplitude (up to 37 F) or high concentration: IgM Ab
raynaud’s phenomenon, hemolysis by serum tests, RBC agglutination, polychromasia, basophilic stippling, nucleated RBC
Clumping: may get inaccurately low red cell count and hematocrit: have to warm up for accurate count
DAT: + at room temp for IgM, + at 37 F for C3
Ab screen: + at room temp, - at 37 F
NO blasts or myleocytes
associated with: viral syndromes, Mycoplasma
Tx: steroids, splenectomy
Prognosis: chronic, seasonal
thrombotic thrombocytopenia purpura (TTP)
Ab against adamTS13
thromboses, thrombocytopenia, hemorrhage
microangiopathic hemolytic anemia: scistocytes
fever, renal failure, CNS symptoms in absence of sepsis
Tx: plasmapheresis
AdamTS13
cleaves vWF to the appropriate size
vWF
link platelets to damaged endothelium
blood transfusion: major antigen mismatch
acute hemolysis immediately or within hours
blood transfusion: minor antigen mismatch
delayed hemolytic reactions (1-7 days)
