Hemolytic Anemias

Front 1

What 6 features are commonly seen in patients with a hemolytic anemia?

Back 1

Splenomegaly, tea-colored or red urine, jaundice, pigmented gallstones, ankle ulcers, increased folate requirement.

Front 2

By what 3 categories can hemolytic anemias be classified?

Back 2

site of RBC destruction, congenital or acquired, and mechanism of cell damage.

Front 3

What are the two types of hemolytic anemias when classified by site of destruction.

Back 3

Extravascular hemolysis: macrophages in liver, spleen, and marrow destroy RBCs.

Intravascular hemolysis: red cells rupture inside the vasculature.

Front 4

What are the two broad pieces of evidence for hemolytic anemia?

Back 4

Evidence of increased RBC production, and evidence of increased RBC destruction.

Front 5

What are the pieces of evidence for increased red cell production?

Back 5

elevated reticulocyte count (polychromasia), MCV and RDW elevated, erythroid hyperplasia, and frontal bossing.

Front 6

What are the pieces of evidence for increased red cell destruction?

Back 6

High LDH, elevated unconjugated bilirubin, schistocytes, spherocytes, bite cells.

Front 7

How would serum haptoglobin change with intravascular hemolysis?

Back 7

Lower levels of serum haptoglobin.

Front 8

What are schistocytes indicative of?

Back 8

MAHA: microangiopathic hemolytic anemia.

Front 9

What type of cell damage are spherocytes indicative of?

Back 9

membrane loss

Front 10

In what hemolytic condition do you especially see bite cells (evidence of Heinz bodies).

Back 10

G6PD deficiency

Front 11

what are the 3 broad causes of congenital hemolytic anemias?

Back 11

defects in:
membrane skeleton proteins, enzymes of energy production, hemoglobin synthesis or structure.

Front 12

What are the 2 general categories of congenital hemolytic anemias caused by membrane skeleton defects? What is the inheritance pattern?

Back 12

Hereditary spherocytosis, and hereditary elliptocytosis. They are both autosomal dominant

Front 13

What are the two frequent proteins that are mutated in hereditary spherocytosis?

Back 13

spectrin or ankyrin

Front 14

What is a central feature of the RBCs in a patient with hereditary spherocytosis?

Back 14

increased osmotic fragility. The cells will lyse at lower degrees of osmotic pressure.

Front 15

What are the treatment options for hereditary spherocytosis?

Back 15

Folate, and maybe splenectomy to correct the hemolysis.

Front 16

What is glucose-6-phosphate dehydrogenase involved in?

Back 16

RBC aerobic metabolism via the pentose-phosphate shunt.

Front 17

In an RBC, why is NADPH important?

Back 17

anti-oxidant and reduces methemoglobin.

Front 18

What does low G6PD lead to?

Back 18

Low levels of NADPH-->low levels of glutathione-->no antioxidant effects.

Front 19

In patients with G6PD deficiency, where do Heinz bodies come from?

Back 19

They are precipitated methemoglobin in the RBCs.

Front 20

What is the most common variant of normal G6PD? What is the most common mutant G6PD?

Back 20

Type B is the most common normal variant. The most common mutant is Type A-

Front 21

What is the heredity of G6PD deficiency?

Back 21

X-linked

Front 22

What triggers hemolysis in patients with G6PD deficiency?

Back 22

drugs or infections

Front 23

When is anemia maximal for a patient with G6PD def.?

Back 23

7-10 days after drug exposure.

Front 24

What four drugs/chemicals cause hemolysis in G6PD patients?

Back 24

sulfa drugs, dapsone, anti-malarials, and vitamin K

Front 25

What are the two categories of antibodies that cause hemolysis?

Back 25

warm and cold.

Front 26

Which type of antibodies cause red cell agglutination?

Back 26

Cold antibodies

Front 27

What is the hallmark of Auto-Immune Hemolytic Anemias?

Back 27

positive Coomb's test

Front 28

What does the direct Coomb's test (DAT) look for?

Back 28

It looks for IgG or C3 directly bound to surface of patient's RBCs.

Front 29

What class of antibody causes warm AIHA and what are they targeting?

Back 29

IgG anti-Rh protein

Front 30

What is the conjunction of warm AIHA and ITP called?

Back 30

Evan's Syndrome

Front 31

What are the two key lab findings for warm AIHA?

Back 31

positive Coomb's test (both indirect and direct), and spherocytes.

Front 32

What is the treatment for warm AIHA?

Back 32

Immunosuppression, and transfusion if condition is severe enough (angina, CHF, rales, etc).

Front 33

What is the first line of treatment for warm AIHA?

Back 33

corticosteroids

Front 34

What are the 3 general mechanisms of drug-induced hemolytic anemia?

Back 34

1. Innocent bystander mechanism
2. Hapten mechanism (drug binds to RBC surface).
3. True autoimmunoe mechanism: drug induces allo-immunization.

Front 35

What class of antibodies are involved in cold AIHA?

Back 35

IgM antibodies against the "i" or "I" RBC antigens.

Front 36

What do IgM-coated red cells do?

Back 36

They agglutinate and clog the microvasculature in cold extremities. The IgM falls off when the red cells return to the central circulation and the C3 stays on.

Front 37

What will the Coombs test be positive for in cold AIHA?

Back 37

Positive for C3 but not for IgG.

Front 38

In what two ways can complement-coated red cells be destroyed?

Back 38

Intravascular: MAC complex attacks the cell.

Extravascular: Phagocytosis by macrophages in liver, spleen, marrow.

Front 39

What are two pathogens known to provoke cold AIHA?

Back 39

Mycoplasma pneumoniae and Epstein-Barr virus

Front 40

What are some bodily symptoms of cold AIHA?

Back 40

shock, rigors, back pain, renal failure, as the body tries to cope with large amounts of free hemoglobin.

Front 41

For which type of AIHA are steroids and splenectomy ineffective?

Back 41

cold AIHA