Hemoglobinopathies Flashcards
1
Q
- result due to differences in the arrangement of amino acids in the polypeptide chains
- alphabetically designated
- qualitative
A
Hemoglobinopathies
2
Q
prevalence of hemoglobinopathies (worldwide)
A
Hb S, Hb E, Hb C
3
Q
Severity of hemoglobinopathies
A
HbSS, Hb SC, Hb CC
4
Q
hemoglobinopathies are differentiated from one another by:
A
- solubility
- mobility in an electrophoretic field
5
Q
- screening test for detection of sickling hemoglobin
- not specific for HbS
A
Sodium Dithionite (Hydrosulfite) Tube test
6
Q
principle of sodium dithionite tube test
A
- red cells are lysed by saponin
- sodium dithionite binds & removes oxygen from the test environment
7
Q
False (+) result of sodium dithionite tube test
A
- hyperlipidemia
- rare hemoglobinopathies
- too much blood added to solution
8
Q
false (-) result of sodium dithionite tube test
A
- infants less than 6 months of age
- decreases hematocrit/RBC
9
Q
under deoxygenated state, Hb S causes formation of ____
A
sickle cells
10
Q
found in sickle cell trait, reported as positive
A
“holly leaf”
11
Q
a reducing agent that deoxygenates hemoglobin
A
sodium metabilsufite
12
Q
negative result of 2% sodium metabisulfite test
A
normal RBCs/slightly crenated
13
Q
hemoglobin molecules have a net negative charge at____
A
alkaline pH
14
Q
hemoglobin migrate towards the _____
A
anode (positive)
15
Q
fastest in cellulose acetate
A
Hb H & Hb I
16
Q
slowest in cellulose acetate
A
Hb C, E, O & A2
17
Q
pH of cellulose acetate
A
8.4-8.6
18
Q
buffer used in cellulose acetate membrane
A
tris-EDTA-boric acid (TEB)
19
Q
stain in cellulose acetate membrane
A
ponceaus
20
Q
- used as a compliment to cellulose acetate electrophoresis
A
Citrate agar
21
Q
- differentiates some Hb variants that migrate together on cellulose acetate
A
citrate agar hemoglobin electrophoresis
22
Q
negative in CAHE
A
Hb F
23
Q
positive in CAHE
A
Hb C
24
Q
pH of citrate agar electrophoresis
A
6.0-6.2
25
Hb A becomes Hb S when glutamic acid on the 6th position of the beta chain is replaced by ____
valine
26
hgb S state that causes sickle cell anemia
homozygous state (SS)
27
hb S state that causes sickle cell trait
heterozygous state (AS)
28
clinical features of sickle cell disease
1. vasooclusive
2. sequestration
3. chronic hemolytic anemia
4. megaloblastic
5. aplastic
6. acute chest syndrom
7. acute infections
29
recurring pain
crises
30
hallmark of sickle cell disease
vasooclusive
31
gradual loss of splenic function
autosplenectomy
32
there is a presence of _____ & _____ in autosplenectomy
Howell Jolly bodies & Pappenheimer bodies
33
- shortened RBC survival
Chronic hemolytic anemia
34
in chronic hemolytic anemia there is an
- increased ____ & ____
- decreased _____ & ____
- retics & jaundice
| - Hemoglobn & hematocrit
35
result from sudden arrest of RBC production due to folate depletion
Megaloblastic anemia
36
- most common life threatening hemolytic complication
Aplastic anemia (bone marrow failure)
37
- aplastic anemia is associated with ____
parvovirus infection
38
leading cause of death among adults (crises)
Acute chest syndrome
39
- bacterial infections
| - most frquent cause of death esp first 3 years of life
Acute infections
40
hallmark of sickle cell disease
sickle cell & target cell
41
lab findings of sickle cell disease
severe normochromic/ normocytic hemolytic anemia w/ polychromasia
42
pbs of sickle cell disease
sickle cell, target cells, ovalocytes, schistocytes, RBC, Pappenheimer bodies & Howell Jolly Bodies
43
in scd there is an increased ___ & decreased ___
bilirubin & haptoglobin
44
the death of scd is usually because of ____ or ____
infection or congestive heart failure
45
- defect is inherited from one parent
- one normal beta chain can produce some HbA
- no clinical symptoms
sickle cell trait
46
sickle cell trait has apparent immunity to
Plasmodium falciparum
47
occurs in African-American populations
| - no Hb A is produced: Approximately
Hb C disease (CC)
48
- rhomboid, tetragonal or rod shaped crystals of dense staining hemoglobin that often destrort the cell.
- found un patients with CC or SC disease, particularly after splenectomy
Hemoglobin C crystals
49
laboratory findings for hemoglobin c
normochromic/normocytic anemia w/ target cells
50
____________ are seen in CC disease only
typical hexagonal crystal
51
electrophoresis: Hb C migrates with ___, ____, & ___ on ______ electrophoresis
HbA2, Hb E & Hb O
| alkaline
52
heterozygous form of HbC disease but no symptoms
Hb AC
53
- a double heterozygous condition where S & C are inherited
- most common compound heterozygous
- no HbA is produced
Hb SC Disease
54
other name of Hb SC
Washington monument
55
frequency of Hb SC
West africa
56
symptoms of Hb SC
less severe than sickle cell anemia but more severe than Hb C disease
57
laboratory findings of Hb SC
- moderate to severe normocytic/normochromic anemia w/ target cells
58
- protrude from RBC membrane
- longer than Hb C
- shorter & thicker than HbS
- often branched
SC crystals
59
- lysine replaces glutaic acid at position 26 on beta chain
| - mild anemia w/ microcytes
Hemoglobin E
60
Hb E migrates w/ ____ in ____
Hb A2, C & O
| alkaline
61
Hb EE resembles _____
thalassemia trait
62
Hb E gene has highest incidence in ____
Thailand
63
- malaria prevalent
Hb E gene
64
P. falciparum multiplies more slowly in ____
Hb EE
65
variants of Hgb D & G
- Hb D-Punjab
- Hb D-Los Angeles
- Hb G-Philadelphia
66
homozygous w/ 95% HbD, normal Hb A2 & HbF
Hb DD
67
hetero form, asymptomatic
Hb D & Hb C
68
- caused by a variety of mutation in alpha, beta & gamma globin genes
- substitution of tyrosine amino acid to histidine amino acids
Hemoglobin M
69
iron form of Hb M
ferric form
70
- result from genetic mutation to globin gene creating Hb products that precipitate in vivo
Unstable Hemoglobin
71
anemias with unstable hemoglobin
- congenital nonspherocytic anemia
- congenital heinz body anemia
- unstable hemoglobin disease
72
laboratory test for unstable hemoglobin
- isopropanol precipitation test
| - heat denaturation test
73
result for isopropanol precipitation test
unstable hemoglobin
74
5 mins result of isopropanol precipitation test
rapid ppt
75
after 20 mins result of isopropanol precipitation test
heavy flocculation
76
normal hemoglobin result of isopropanol precipitation test
more than 40 mins=Hb precipitate
77
result of unstable Hb in heat denaturation test
heat sensitive, flocculent ppt
78
result of normal hb in heat denaturation test
little or no ppt
