Hemolytic Anemias Flashcards
1
Q
definition of hemolytic anemias
A
- a group of disorders characterized by decreased red cell lifespan
2
Q
normal red cell lifespan
A
- 120 days
3
Q
severity of anemia depends on
A
- ability of bone marrow to compensate
4
Q
clinical features of hemolytic anemia
A
- jaundice
- dark urine
- pigmented gallstones
- chronic ankle ulcers
- splenomegaly
- requirement for folate
FAP DJS - He (hemolytic) a DJ who Faps
5
Q
yellowing of sclera called
A
- scleral icterus
6
Q
jaundice is
A
- more generalized yellow discoloration of tissues
7
Q
what do you want to make sure to do before a splenectomy?
A
- vaccinate against encapsulated organisms
- spleen required to kill off encapsulated organisms
8
Q
post-splenectomy blood findings
A
- Howell-jolly bodies
9
Q
parvovirus B19 affect on blood cels
A
- infects and lyses and destroys RBCs in marrow
- causes 7-10 day halt to erythropoiesis
10
Q
parvovirus B19 in patients with hemolytic anemias
A
- loss of red cell production causes reticulocyte count and hemoglobin to plummet dramatically
- aplastic crisis
11
Q
hemolytic anemias classification schemes
A
- sites of red cell destruction
- acquired vs. congenital
- mechanism of red cell damage
12
Q
sites of RBC destruction
A
- extravascular hemolysis
- intravascular hemolysis
13
Q
extravascular hemolysis
A
- macrophages in spleen, liver, and marrow removed damaged or antibody-coated red cells
14
Q
intravascular hemolysis
A
- red cells rupture within the vasculature, releasing free hemoglobin into the circulation
15
Q
laboratory evidence for hemolysis
A
- evidence for increased RBC production
- evidence for increased RBC destruction
16
Q
evidence for increased RBC production in the blood
A
- elevated reticulocyte count
17
Q
evidence for increased RBC production in the bone marrow
A
- erythroid hyperplasia
18
Q
evidence for increased RBC production in the bone
A
- deforming changes in the skull and long bones
- frontal bossing
19
Q
erythroid hyperplasia
A
- reduced myeloid/erythroid ratio
- WAY more erythroids
20
Q
frontal bossing caused by
A
- increased erythropoietic activity
- marrow space expansion
21
Q
evidence for increased RBC destruction
A
- biochemical consequences of hemolysis
- morphological evidence of RBC damage
- reduced red cell lifespan
22
Q
biochemical consequence of hemolysis in general
A
- elevated LDH levels
- elevated bilirubin
23
Q
LDH levels high due to
A
- lysis of any cells
24
Q
bilirubin is a byproduct of
A
- heme breakdown
25
when bilirubin is fractionated, the portion that is elevated is the
- unconjugated bilirubin
26
biochemical consequences of intravascular hemolysis
- reduced serum haptoglobin
27
most common hemolytic anemia due to membrane skeleton defects
- hereditary spherocytosis
28
hereditary spherocytosis defect in
- tethering proteins of membrane skeleton
| - ankyrin
29
lipid microvesicles in heredity spherocytosis
- pinched off in the spleen
- causes decreased MCV
- and spherocytic change (spherocytes are engulfed by macrophages which causes the anemia)
30
hereditary spherocytosis genetic pattern
- autosomal dominant
31
hereditary spherocytosis patients with trivial infections will develop
- increased hemolysis
| - abdominal pain
32
hereditary spherocytosis and MCHC
- MCHC will be elevated
| - ONLY TIME WE CARE ABOUT THIS
33
hereditary spherocytosis diagnosed by
- osmotic fragility - lysis occurs at higher tonicities
34
hereditary spherocytosis and parvovirus B19
- causes aplastic crises
35
hereditary spherocytosis treatment
- folate supplementation
| - splenectomy to resolve anemia
36
what cells remain after splenectomy in hereditary spherocytosis
- spherocytes because the cell will still bleb
37
what do RBCs require to maintain biconcave disc shape and hemoglobin in reduced form?
- constant energy
38
what happens if RBC don't have energy
- they lyse
| - or deform
39
two sources of energy for RBCs
- anaerobic glycolysis (Embden-Myerhof pathway)
| - aerobic pathway (PPP - G-6-PD)
40
purpose of G-6-PD
- make NADPH and glutathione
41
role of NADPH and glutathione
- detox metabolites of oxidative stress
- elimination of methemoglobin
- glutathione neutralizes oxidative metabolites
- NADPH regenerates glutathione
42
in absence of adequate reducing ability, what will happen to hemoglobin
- will be converted to methemoglobin by oxidizing agents
| - then denatured to precipitate as Heinz bodies
43
the spleen's role on Heinz bodies
- leaves a bite cell or blister cell
44
G6PD deficiency genetic inheritance
- X-linked
45
things to avoid in G6PD deficiency
- oxidizing agents
46
examples of oxidizing agents to avoid
- anti-malarial (quinines)
- SULFA DRUGS
- dapsone
- vit K
- fava beans
- naphtha compounds (mothballs)
47
hemolysis in G6PD deficiency is often triggered by
- drugs or infections
48
African American patients G6PD levels immediately after a hemolytic episode
- may be normal since mature cells are lysed
| - only younger cell with normal G6PD survive
49
G6PD deficiency symptoms
- jaundice
50
G6PD deficiency reticulocyte count
- elevated
51
G6PD deficiency bilirubin
- elevated
52
G6PD deficiency LDH
- elevated
53
G6PD deficiency haptoglobin
- low
54
G6PD deficiency seen on peripheral smear
- bite and blister cells
55
pathophysiology of acquired hemolytic anemias
- antibodies bind to red cell antigens
| - lead to RBC destruction
56
acquired hemolytic anemias - IgG coated RBCs
- interact with Fc receptors on macrophages
- complete or partial phagocytosis
- spherocyte formation (extravascular hemolysis)
57
acquired hemolytic anemias - C3-coated red cells
- extravascular hemolysis
| - complement mediated RBC lysis (intravascular hemolysis)
58
Immune hemolysis classifications
- autoimmune
- drug related
- PNH
59
two types of autoimmune hemolytic anemias
- warm antibody mediated
| - cold antibody mediated
60
hallmark of autoimmune hemolytic anemia
- positive Coomb's test
61
warm antibodies react with RBCs best at
- 37 degrees
| - body temp
62
warm antibodies and agglutination of RBC
- do not agglutinate RBCs
63
warm antibody mostly composed of which antibody
- IgG
64
cold antibodies react best at
- below 32 degrees
65
cold antibodies and RBC agglutination - seen on peripheral blood smear
- cause RBC agglutination
| - IgM is pentameric
66
cold antibodies composed mostly of which antibodies
- IgM which fix complement
67
Direct Coomb's test tests for
- IgG or C3
| - DIRECTLY ON RED CELLS
68
Coomb's reagent contains
- anti-IgG and anti-C3 antibodies
| - will cause agglutination
69
if Coomb's test is positive
- EITHER IgG or C3 on red cells
| - follow up with more specific test for anti-IgG or anti-C3
70
warm-antibody hemolytic anemias etiology
- primary or secondary to hematologic malignancy or another autoimmune disease
- induced by drugs
71
warm-antibody hemolytic anemias symptoms
- splenomegaly
- jaundice
- can be VERY symptomatic or not
72
warm-antibody hemolytic anemias - reticulocyte count
- elevated
73
warm-antibody hemolytic anemias - bilirubin
- elevated
74
warm-antibody hemolytic anemias - LDH
- elevated
75
warm-antibody hemolytic anemias - haptoglobin
- low
76
warm-antibody hemolytic anemias - diagnostic test
- positive Coomb's test
77
warm-antibody hemolytic anemias - seen on peripheral smear
- spherocytes
78
treatment of warm-antibody hemolytic anemias
- may require transfusion
| - immunosuppression is mainstay of therapy
79
first line of drugs for warm-antibody hemolytic anemias therapy
- corticostertoids
80
if steroids fail to work in warm-antibody hemolytic anemias
- splenectomy
| - rituximab (CD20 - B cell)
81
distal problems with cold agglutinin disease
- distal ischemia
| - red cell clumps cannot pass through microvasculature, leading to cyanosis and ischemia in extremities
82
cold agglutinin disease associated with these infections/diseases
- IGM SO ASSOCIATED WITH MMMMM
- mycoplasma pneumoniae
- mononucleosis
- lymphoproliferative diseases
83
cold agglutinin disease treatment
- keep patient warm
84
cold agglutinin disease steroids and splenectomy
- not effective
85
warm antibody hemolytic anemias pathophysiology
- IgG antibodies against RBC surface molecules are formed
- coat RBC with or without complement
- IgG coated fragment engulfed by macrophages
- spherocytes form
86
cold agglutinin disease pathophysiology
- IgM binds to red cells in cooler extremities
- fix complement
- lysed directly in vessel
- or engulfed by complement receptors on macrophages in liver
87
non-immune hemolytic anemias
- MAHA
- March Hemoglobinuria
- Infections
- Drugs, chemicals, and venoms
