Hemolytic Anemia Flashcards Preview

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Flashcards in Hemolytic Anemia Deck (37):
1

what is released upon RBC hemolysis?

lactate dehydrogenase (LDH) & hemoglobin

2

haptoglobin

binds to free hemoglobin in circulation. decreased free levels in intravascular hemolysis.

3

bilirubin conjugated vs unconjugated

breakdown of heme. conjugated form when released from liver, **unconjugated when released by hemolysis

4

clinical manifestations specific to hemolysis

jaundice, hemoglobinuria (specifically intravascular hemolysis), pigmented gallstone disease

5

notable causes of intravascular hemolysis

microangiopathy (MAHA), paroxysmal nocturnal hemoglobinuria (PNH), infections

6

causes of extravascular hemolysis

herediatry spherocytosis, G6PD deficiency, autoimmune, drug induced, infections

7

proteins defective in hereditary spherocytosis

band 3, spectrin, or ankyrin

8

diagnostic test for HS?

osmotic fragility test (HS cells lyse earlier)

9

treatment for HS?

splenectomy

10

G6PD deficiency

renders RBCs more susceptible to free radical damage due to inability to synthesize glutathione

11

morphological consequence of G6PD deficiency?

Heinz bodies (denatured hemoglobin aggregates in these within RBCs) with bite cells (macrophages nibble on the cells)

12

G6PD A-

decreased G6PD activity in aged RBCs (African Americans)

13

G6PD B

decreased G6PD activity in all RBCs (Mediterranean & Asians)

14

clinical manifestations of G6PD deficiency

precipitated by oxidative stress (acute illness, drugs, fava beans)

15

diagnosis of G6PD deficiency

G6PD biochemical assay (months after event)

16

treatment of G6PD deficiency

avoid triggers, RBC transfusion

17

AutoImmune Hemolytic Anemia (AIHA) types

IgG mediated (warm) & IgM mediated (cold)

18

Warm AIHA

IgG binds to RBC at body temp, splenic macrophages activated by Fc receptor binding. Nibbling results in microspherocytes

19

where is clearance of warm AIHA cells?

spleen

20

Cold AIHA

IgM binds to antigens below body temp, attracts and binds complement to RBC, after which the cells are cleared by Kuppfer cells.

21

where is clearance of cold AIHA cells?

liver

22

what happens to cold AIHA RBCs at room temp?

agglutination

23

diagnostic test for AIHA

Direct Coombs test (incubate RBCs with reagent that binds complement or IgG)

24

common causes of warm AIHA

autoimmune disorders, lymphoproliferative diseases

25

common causes of cold AIHA

infection (EBV), lymphoproliferative diseases

26

treatment for warm AIHA

corticosteroids (downregulate Fc receptors on macrophages), splenectomy

27

treatment for cold AIHA

avoid cold, treat underlying infection, rituximab, plasma exchange

28

drug induced immune hemolytic anemia

clinical presentation like warm AIHA but history of drug exposure. treat via drug withdrawal

29

three potential mechanisms of drug induced hemolytic anemia

hapten mediated (drug serves as bound antigen), neo-antigen mediated (drug causes conformational change in cell that become antigenic), alteration of antigen without binding

30

microangiopathy (MAHA)

some sort of issue in vessel that causes destruction of RBCs.

31

hallmark finding of microangiopathy

schistocytes in blood smear

32

causes of microangiopathy

TTP, HUS, super hypertension, vasculitis, DIC

33

paroxysmal nocturnal hemoglobinuria (PNH)

acquired somatic mutation in PIG-A, which causes deficiency of CD55 & CD59 GPI anchoring proteins. RBC becomes very susceptible to complement mediated intravascular hemolysis

34

diagnosis of PNH

flow cytometry of CD55/59 in neutrophils or monocytes (NOT IN RBCs)

35

treatment of PNH

iron/folate supplementation, blood transfusion, eculizumab (C5 inhibitor)

36

clinical manifestations of PNH

increased risk of venous thrombosis and aplastic anemia

37

hemolysis due to infection

toxins destroy membrane, infestation causes RES clearance, antigen mimicry