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45 Cards in this Set
- Front
- Back
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What is the normal Hb distrib in a healthy adult?
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HbA = 97%
HbA2 = 2% HbF = 1% |
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What percentage can HbA2 never be?
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more than 7-10% - there's just not that many delta chains.
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What is the definition of Hbopathy?
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Condition where Hb synthesis is abnormal; Either inherited or genetic mutations.
Result = structural instability or nonfunction of Hb molecule. |
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What are 5 ways of having a Hbopathy condition?
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1. Single or double AminoAcid substitution.
2. Amino acid deletion 3. Decr. Hb chain production 4. Cross-linked or fused Hb 5. Longated subunits |
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What are the formal names of
-Decr. Hb chain production -Cross-linked or fused Hb -Longated subunits |
-Thalassemia
-Hb Lepore -Hb Constant Spring |
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What are the 2 types of Hb electrophoresis?
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Cellulose acetate, pH = 8.4
Citrate gel, pH = 6.2 |
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What is the sequence of migration of Hb in alkaline medium? (moving toward pos)
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C S F A B H
E D A G O Can santa fly away before halloween? |
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What is the sequence of migration of Hb in acid medium?
(moving toward positive, so opposite direction of Alk) |
F A S C
D G E Fast As She Can |
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What bands do you seen for Normal patients on
-Alkaline -Acid |
Alk: Majority is A, small amt A2 on the C band
Acid: All is A |
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What bands are seen for a ptnt with Sickle cell Disease?
-Alkaline -Acid |
Alk: majority at S, some A2 and F
Acid: majority is S, some F |
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what is the Hb pattern in S trait?
-Alk -Acid |
Alk: 60% A, 40% S -> biggest bands are A and S, some at C for A2.
Acid: Smaller A band, most S. |
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what type of inheritance pattern of sickle cell disease and trait?
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Autosomal co-dominant inheritnc
Disease = homozygous Trait = heterozygous |
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What chromosomes are the Hb genes on?
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11 and 16
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What Hb genes are on
-Chromosome 11 -Chromosome 16 |
11: 1 Beta, 2 Gamma, 1 epsilon, 1 delta.
16: 2 zeta, 2 epsilon |
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what gene/s is/are altered in sickle cell anemia?
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the beta gene on chrom 11
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why is there a 60/40 ratio of normal to abnormal Hb in Sickle cell trait?
Why doesn't Disease? |
because normal has a higher Hb affinity
b/c all the Hb in disease is HbS and there are no normal B chains. |
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What occurs in Sickling phenom?
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1. Due to decreased O2 affinity, deoxygenation -> incr. viscosity
2. RBCs less pliable; plug up circulation. 3. Plug causes more deoxygen. 4. Tactoid bars form - 15 Hb molecules per bar. 5. Tactoid bars sickle cells and block vessels. 6. Ischemic infarct results 7. Result: pain, tissue death |
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What is a thrombotic sickle crisis?
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an Aplastic crisis due to viral infections (they change pH), causing hemolysis of the sickled cells.
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What is the occurence of SS dis?
-Worldwide -Us |
Worldwide is 1/500
U.s. is 1/1875 Afric.Americans |
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what causes sickling to be irreversible?
How does sickling alter lifespan of RBC? |
if cells are sickled 7 to 8 x.
Life = 14-17 days inst. of 120 |
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What are 5 clinical features of SS disease?
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FAJAS
1. Fatigue, jaundice, leg ulcer 2. Autosplenectomy 3. Joint pain 4. Aplastic crisis 5. sickling crisis - bact. inf |
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What are the 4 major lab findings in SS disease?
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1. Severe hemolytic N/N anemia
2. Aniso/poik 3. Erythroid hyperplasia 4. Evidence of free Hb and Red cell destruction |
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Waht are 5 steps in diagnosing SS disease?
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1. Physical symptoms/PBS
2. Hb Solubility test 3. Urea solubility test 4. Hb Electrophoresis - BEST 5. Sickle cell prep |
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what is the normal electroph pattern of a 6 mo old or younger?
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Some HbA but still a lot of HbF - it is the FETAL Hb.
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What 6 ways can one treat SS disease?
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1. Administer O2 - prevent sckl
2. Hydroxyurea 3. Transfuse - esp infants. 4. Support - iron chelate/pain 5. Prevent sickling inducement 6. Bone marrow transplant - only cure |
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What happens w/ the iron in SS disease patients?
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They get hemociderosis -> iron overload b/c they're not using it.
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What are some complications of SS disease, sickle cell anemia?
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1. Adapt to Anemia -> it's hard on the heart and decr. lifespan.
2. Crisis causes organ failure, thrombosis/hemorrhage, and death. |
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in what population is sickle cell trait found?
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9% of Afr. Americans
Asian indians, Turks, Arabs, Greeks, Italians. Malarial belt |
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What are the clinical features of SS trait - how does it compare anemia-wise to SS dis?
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Asymptomatic and benign, with rare crises.
Not detected unless screen for HbS. |
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What type of patient alterations does SS trait cause?
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NOT MUCH!
-Wil have a Normal lifespan. -May have a few sickle crises. |
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What does the PBS show in SS trait?
What other lab tests diagnose? |
-Moderate target cells
-Solubility test positive -60% A1, 40% S, 3% HbA2 |
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What type of inheritance pattern is seen in HbC disease?
What's an interesting feature? |
Non-sex linked Incomplete dominant.
Male:Female is 3:1 |
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What nationalities is HbC disease seen in most?
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Afr.Americans - 2,3%
Native W. Africans - 20-30% |
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How does HbC disease anemia compare to HbS?
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It's less common
Milder anemia, but might have marked splenomegaly. |
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Why does splenomegaly develop in HbC disease?
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HbC crystals are made, and the spleen attempts to keep them.
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What lab information indicates HbC disease?
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PBS: N/N mild anemia
Mkd Target cells, Spherocytes, Folded cells, HbC crystals. Polychromasia |
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What is necessary for forming HbC crystals?
What causes it? |
40% HbC in the cell.
caused by Dehydration |
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What is the electroph. pattern of Hb C disease?
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90% HbC
8-10% HbF No HbA2 HAVE TO USE ACID to seperate the C from EAO on alkaline. |
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What is the treatment/therapy for HbC disease?
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-Know the limitations - prevent dehydration, excess heat/vomit.
-Careful in pregnancy/stress. Relatively normal lifespan. |
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What are te lab findings of HbC trait?
What type of anemia? |
Benign anemia, maybe absent.
Mkd Targets |
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What is the electroph pattern of HbC trait?
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35-45% HbC
55-65 HbA1 (higher affinity) <1% HbF |
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Regarding Hb SC disease:
-How common? -Anemia severity? -3 clinical features/problems |
As common as HbS disease
Mild anemia, less severe than HbC disease 1. Hemolytic Crisis 2. Splenomegaly 3. Pregnancy problems |
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What are lab findings in HbSC disease?
-PBS -Bone marrow |
PBS shows MARKED Targets
FEW sickles, SC crystals -polychromasia and nRBCs. BM: hyperplasia |
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what's the electroph pattern of Hb SC disease?
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-Half/half HbS & HbC
-maybe a little HbF -NO HbA -make sure to do acid so C seperates out. |
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what Hbopathy/Thalassemia combos should you know about?
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HbS/Beta thal
HbS/Alpha thal |
