5.6 and 5.7 Intravascular hemolysis and underproduction Flashcards Preview

All the things continued > 5.6 and 5.7 Intravascular hemolysis and underproduction > Flashcards

Flashcards in 5.6 and 5.7 Intravascular hemolysis and underproduction Deck (56):
1

What are the two components on RBCs that inhibit complement activation?

MIRL
DAF (CD55)

2

What is the function of DAF?

Accelerates the decay of C3 convertase

3

What is the anchoring protein found on RBCs that allow for DAF and MIRL to stick?

GpI

4

What is the cause of PNH?

Acquired defect in myeloid stem cells, that deletes the GpI anchor on RBCs, allowing RBCs to be destroyed by complement

5

What accounts for the paroxysmal part of PNH?

Shallow breathing at night causes a mild respiratory acidosis, leading to the activation of complement

6

What type of hemolysis occurs with PNH? What, then, are the common s/sx?

Intravascular:
-Hemoglobinemia
-Hemoglobinuria
-Hemosiderinuria

7

What is the screening test for PNH, and how does it work?

Introduce sucrose into the serum, which activates complement

8

What is the confirmatory test for PNH?

Acidified serum test or flow cytometry for a lack of CD55

9

What is the main cause of death in patients with PNH? How does this occur?

Thrombosis (e.g. of hepatic, portal, or cerebral veins)

-Destroyed platelets release cytoplasmic contents into circulation, inducing thrombosis

10

What causes the Fe deficiency anemia that occurs with PNH?

Loss of Fe in urine

11

What is the cancer that occurs with PNH?

AML due to mutation in myeloid stem cell

12

What is the inheritance pattern with G6PD deficiency?

XLR

13

What is the molecule that reduces the H2O2 and other free radicals in RBCs?

Glutathione

14

What is the pathophysiology behind G6PD deficiency?

Reduced half life of G6PD prevent the reduction of NADP to NADPH, meaning that glutathione cannot be reduced to prevent RBCs from being damaged from oxidative stress

15

What are the two variants of G6PD deficiency?

-African = mildly reduced half life of G6PD

-Mediterranean = markedly reduced half life of G6PD

16

What is the thinking behind the preponderance of G6PD deficiency?

Protective effect against falciparum malaria

17

What are the causes of oxidative stress that classically precipitate G6PD episodes?

-Fava beans
-Sulfa drugs
-Primaquine
-Dapsone

18

What is the classic PBS finding in G6PD deficiency? Why?

Bite cells from removal of Heinz bodies

19

What type of hemolysis occurs with G6PD deficiency?

Intravascular

20

What happens to Hb when it is exposed to oxidative stress?

Precipitates as a Heinz body

21

What are the classic s/sx of G6PD deficiency?

Hemoglobinuria and back pain hours after exposure to an oxidative stress

22

What is the screening and confirmatory test for G6PD deficiency?

-Screen = Heinz prep
-Confirmatory = enzyme studies

23

What are the antibody classes that cause immune hemolytic anemia?

IgG or IgM

24

IgG mediated immune hemolytic anemia usually results in intra or extravascular hemolysis? Why?

Extravascular, since

25

Why should you never perform an enzyme test for immune hemolytic anemia during an acute attack?

Cells that lack the enzyme will be destroyed, and thus will result in a false negative test

26

IgG binds to RBCs centrally or peripherally in immune hemolytic anemia? IgM?

IgG = centrally
IgM = peripherally

27

What happen to RBCs with immune hemolytic anemia? Why?

Spherocytosis due to a slow loss of membrane

28

What are the two major diseases in which warm agglutinins occurs?

SLE
CLL

29

How does PCN lead to immune hemolytic anemia?

Drug attaches to RBC membrane, allowing for IgG to attach to and destroy RBCs

30

How does methyldopa lead to immune hemolytic anemia?

Drug induces immune antibodies itself

31

What is the treatment for immune hemolytic anemia? (4)

-Cessation of drug
-Steroid
-IVIG
-Splenectomy

32

Cold agglutinins (IgM mediated immune hemolytic anemia) is associated with what infectious diseases?

-Mycoplasma pneumoniae
-EBV

33

What is the diagnostic test for immune hemolytic anemia?

Coombs test

34

What is the direct coombs test?

Patient's RBCs added to anti-IgG antibody. Will agglutinate if RBCs are already coated with IgG

35

What is the indirect coombs test?

Take normal RBCs and add to patient's serum.

Anti-IgG is then added to test for the presence of ab-RBC complexes

36

What are the thrombi composed of with TTP?

Platelets

37

What is the enzyme that is deficient in TTP? What does this cause?

ADAMTS13- prevents vWF polymer from being broken down into monomers, resulting in

38

What are the thrombi composed of in DIC?

Platelet and fibrin

39

What is the characteristic PBS finding of microangiopathic anemia?

Schistocytes

40

What are the heart pathologies that may lead to schistocyte formation?

-Prosthetic heart valves
-Aortic stenosis

41

What is the characteristic PBS findings of plasmodium falciparum?

Banana

42

What is the characteristic PBS finding of babesiosis?

Maltese cross

43

What is the vector for malaria?

Anopheles mosquito

44

What causes the s/sx of malaria?

Intravascular hemolysis of RBC that occurs as a part of plasmodium life cycle

45

What is the species of plasmodium that causes daily fevers?

Falciparum

46

What is the species of plasmodium that causes fevers every other day? What is the treatment?

Vivax and ovale
Praziquantel

47

What is the diagnostic finding of anemia 2/2 underproduction?

Low corrected reticulocyte count

48

What are the three major etiologies of anemia 2/2 underproduction?

-Macro or microcytic causes
-Renal failure
-Bone marrow precursor cell damage

49

What is the treatment for underproduction anemia 2/2 parvovirus B19 infection?

Supportive

50

What is the cause of aplastic anemia?

Damage to HSC, resulting in a pancytopenia

51

What is the CD marker for hematopoietic cells?

CD34

52

What antipsychotic drug classically causes agranulocytosis?

Clozapine

53

What are the common etiologies of aplastic anemia?

Drugs
Viruses
Autoimmune damage

54

What is the classic bone marrow aspirate finding of aplastic anemia?

dry tap--fat in bone

55

What is the treatment for aplastic anemia, besides obviously d/c drugs that cause it? (4)

-Transfusions
-Marrow stimulating factors
-Immunosuppression
-BMT

56

What is a myelophthisic process?

Pathologic process that replaces bone marrow. This impairs hematopoiesis, and resulting in a pancytopenia