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Flashcards in Hemolytic Anemia Deck (67)
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1
Q

The basic pathophysiology of HS is that spectrin, ankyrin, or band 3 defects weaken the _____ and destabilize the ______.

A

cytoskeleton; lipid bilayer

2
Q

______ are more susceptible in vitro to osmotic stress, the basis for a common test for the disorder.

A

Spherocytes

2
Q

What happens when the cold antibodies and RBC move centrally to areas of higher temperature?

A

the Ab dissociates b/c of low affinity and complement destroys the RBC (intravascular hemolysis)

3
Q

The basic pathophysiology of HS is that ____, _____, or _____ weaken the cytoskeleton and destabilize the lipid bilayer.

A

spectrin; ankyrin; band 3 defects

3
Q

By definition, autoimmune hemolytic anemia should have a _____.

A

positive DAT

3
Q

What does the AIHA smear look like?

A

spherocytes, teardrop cells, bite cells

4
Q

The tetramer form of _____ is unstable and dissociates into αβ dimers which may immediately bind to haptoglobin.

A

hemoglobin

4
Q

What are 2 complications of HS?

A

1) aplastic crisis 2) bilirubin stones

4
Q

What is the treatment for G6PD?

A

none- just avoid oxidant drugs and foods; treat anemia as needed

5
Q

How is G6PD inherited?

A

X-linked recessive

6
Q

Cold antibodies bound to the RBC activate ______ through the C5-C9 attack complex, which creates holes in the plasma membrane.

A

complement

7
Q

In ______, phosphoenolpyruvate cannot be converted to pyruvate, so ATP is decreased, 2,3-DPG is increased, membrane plasticity is reduced, and the spleen destroys the RBCs

A

pyruvate kinase (PK) deficiency

8
Q

How do you prevent sepsis in pts with a splenectomy?

A

immunizations against the flu and pneumonia; prophylactic antibiotics

9
Q

What is the method of inheritance of HS?

A

75% auto dominant; 25% recessive

9
Q

Defects in the RBC _____ and associated ____ pathways may present with hemolytic anemia.

A

glycolytic; enzyme

10
Q

The tetramer form of hemoglobin is unstable and dissociates into αβ dimers which may immediately bind to _____.

A

haptoglobin

10
Q

What does G6PD protect against?

A

oxidant stress

11
Q

The unconjugated bilirubin fraction will be _____ in hemolytic anemia.

A

elevated

11
Q

By definition, _____ should have a positive DAT.

A

autoimmune hemolytic anemia

12
Q

What morphologic features of RBCs are seen in G6PD?

A

bite cells, microspherocytes

13
Q

Defects in the RBC glycolytic and associated enzyme pathways may present with ______.

A

hemolytic anemia

13
Q

At what temperature is maximal effect of warm hemolytic anemia seen?

A

37 deg C

14
Q

Why is splenectomy contraindicated in children under 5?

A

it is important for development of the adaptive humoral response and is the origin of IgM agglutinins, especially for encapsulated organisms

15
Q

_____ is characterized by the acute or chronic onset of anemia, pallor, jaundice, and dark urine.

A

Autoimmune hemolytic anemia (AIHA)

15
Q

Autoimmune hemolytic anemia (AIHA) is characterized by the acute or chronic onset of ____, ____, ____, and _____.

A

anemia; pallor; jaundice; dark urine

17
Q

How will the metheme or methemalbumin appear in the CBC in hemolytic anemia?

A

increased

17
Q

G6PD is associated with selective resistance to _____.

A

plasmodium vivax/malaria

18
Q

What is the most common glycolytic enzyme defect affecting RBCs?

A

pyruvate kinase (PK) deficiency

19
Q

What is the rate of sepsis in splenectomy pts as compared to the general population?

A

200x

20
Q

What 2 enzymes may be elevated in hemolytic anemia after being spilled by RBCs?

A

SGOT and LDH

21
Q

What tests should be run to check for IgG and/or complement on the RBCs?

A

antiglobulin or Coombs tests

22
Q

How are RBCs bound by warm antibodies destroyed?

A

antibody-mediated phagocytosis via the splenic macs (extravascular hemolysis)

24
Q

The hemoglobin/haptoglobin complex is removed from circulation by the ____.

A

liver

25
Q

Cold antibodies bound to the RBC activate complement through the ______, which creates holes in the plasma membrane.

A

C5-C9 attack complex

26
Q

What kind of antibodies are seen in warm hemolytic anemia?

A

IgG

28
Q

What cells in the spleen remove the fragile RBCs?

A

macs

29
Q

Red cells undergoing _____ release hemoglobin into the circulation.

A

intravascular hemolysis

29
Q

What are the 2 kinds of autoimmune hemolytic anemia?

A

cold and warm

31
Q

The tetramer form of hemoglobin is unstable and dissociates into ____ which may immediately bind to haptoglobin.

A

αβ dimers

32
Q

Red cells undergoing intravascular hemolysis release _____ into the circulation.

A

hemoglobin

33
Q

The symptoms of HS can be variable, so what is the hallmark of the disorder?

A

loss of PM and formation of the microspherocyte

35
Q

With _____, the red cell is ingested by macrophages of the reticuloendothelial (RE) system.

A

extravascular hemolysis

37
Q

Hereditary spherocytosis (HS) is a familial disorder characterized by ____, _____, _____, and _____.

A

anemia, intermittent jaundice, splenomegaly, responsiveness to splenectomy

38
Q

____ is associated with selective resistance to plasmodium vivax/malaria.

A

G6PD

38
Q

What happens in pyruvate kinase (PK) deficiency?

A

phosphoenolpyruvate cannot be converted to pyruvate, so ATP is decreased, 2,3-DPG is increased, membrane plasticity is reduced, and the spleen destroys the RBCs

39
Q

What are the treatments for HS?

A

supportive care, transfusions, splenectomy

41
Q

What are milder syndromes assoc. with defects in the RBC cytoskeleton?

A

1) hereditary elliptocytosis 2) stomatocytosis 3) acanthocytosis 4) echinocytosis

42
Q

The _____ is removed from circulation by the liver.

A

hemoglobin/haptoglobin complex

44
Q

What is aplastic crisis?

A

when a viral infection causes severe anemia bc of suppressed erythropoiesis coupled to short RBC lifespan

45
Q

Spherocytes are more susceptible in vitro to ____, the basis for a common test for the disorder.

A

osmotic stress

46
Q

With extravascular hemolysis, the RBC is ingested by _____ of the reticuloendothelial (RE) system.

A

macrophages

47
Q

Loss of membrane and formation of the spherocyte leads to decreased _____ and ______.

A

deformability; entrapment in the spleen

48
Q

What intracellular disorders can result in shortened RBC lifespans?

A

defects in the plasma membrane/cytoskeleton, enzyme disorders, and hemoglobinopathies

50
Q

How will the serum haptoglobin levels appear on the CBC in hemolytic anemia?

A

decreased

51
Q

What kind of antibodies are seen in cold hemolytic anemia?

A

IgG and IgM

53
Q

Hemoglobin in the plasma or urine indicates _____.

A

intravascular hemolysis

56
Q

What happens in G6PD deficient RBCs?

A

they are unable to restore reduced glutathione, which deforms the membrane

57
Q

On the CBC, what bilirubin test will be elevated in hemolytic anemia?

A

the unconjugated bilirubin fraction

58
Q

At what temperature is maximal effect of cold hemolytic anemia seen?

A

4 deg C

60
Q

With extravascular hemolysis, the red cell is ingested by macrophages of the _____.

A

reticuloendothelial (RE) system

61
Q

What cell morphology will be seen in PKD?

A

nothing specific

62
Q

What is the most common infection seen in pts post splenectomy?

A

S. pneumoniae

63
Q

How are RBCs bound by cold antibodies destroyed?

A

intravascular hemolysis

64
Q

Why are bilirubin stones common in HS?

A

large amounts of bilirubin circulates

65
Q

_____ bound to the RBC activate complement through the C5-C9 attack complex, which creates holes in the plasma membrane.

A

Cold antibodies

66
Q

_____ is a familial disorder characterized by anemia, intermittent jaundice, splenomegaly, and responsiveness to splenectomy.

A

Hereditary spherocytosis (HS)

67
Q

What are the 2 mechanisms of RBC destruction?

A

1) intravascular 2) extravascular