Thalassemias and Hemoglobinopathies Flashcards
Which protein increases as a compensatory response to chronic anemia?
A. Hepcidin
B. 2,3 Diphosphoglycerate
C. Transferrin
D. Cubilin
B. 2,3 Diphosphoglycerate
Where is Vitamin B12 absorbed into blood?
A.Stomach
B. Duodenum
C. Jejunum
D. Terminal Ileum
D. Terminal Ileum
Contrast thalassemias and hemoglobinopathies
Thalassemias >> synthesis prob (deficient synthesis of globin chain)
Hemoglobinopathies >> structural prob (Hb chain structural abnormalities)
Contrast alpha thalassemia in AAs and in SE asians (what mutation does each population carry and are the patients symptomatic?
In African americans, a-thalassemia will manifest as a silent carrier scenario in which one copy is dysfunctional. The patients are usually asymptomatic
It can also manifest as thalassemia minor, in which a trans alpha deletion (2 copies from two separate chromosomes deleted; pt will have small RBcs but otherwise normal)
In SE asians, thalassemia minor is the same as that in AA’s except the deletiion is a cis-deletion
In SE asian children, a-thalassemia can present as thalassemia major (all the alpha copies are deleted) >> increased risk for hydrops fetalis >> death in utero
In alpha thalassemia major with hydrops fetalis, the children have Hb that has excess gamma chains, called ___, or Hb H that has excess ___
In alpha thalassemia major with hydrops fetalis, the children have Hb that has excess gamma chains, called Hb Barts, or Hb H that has excess beta chains
How does hemoglobin H disease arise? Pts with this disease have marked ___ and ___. Morphologically, the rbcs have ___ which are precipitates of ___
Hemoglobin H disease arises from 3 dysfunctional copies of alpha. Pts with this disease have marked anemia and microcytosis. Morphologically, the rbcs have Heinz bodies which are precipitates of beta globins
What are the various combinations of Beta thalassemia?
In beta thalassemia minor, you see basophilic stippling, which results from ___?
Excess alpha is precipitated coz ratio is skewed towards alpha – causes basophilic stippling >> leads to red cell killing in the spleen >> anemia
In what other conditions do you see basophilic stippling? (Baste the ox TAIL)
Thalassemia
ACD
iron deficiency
lead toxicity
In beta thalassemia intermedia and major, the RBCs exhibit ___ (varying size and shape of cells). Symptoms start to arise after ___ when fetal Hb levels start to fall
What are some complications that can arise from B-thalassemia?
In beta thalassemia intermedia and major, the RBCs exhibit anisopoikolocytosis (varying size and shape of cells). Symptoms start to arise after 6 months when fetal Hb levels start to fall
Ineffective erythropoiesis
Iron overload
Extravscular hemolysis
Skeletal deformities
Which lab finding would you expect in a patient with beta-thalassemia?
A.Increased RBC count
B. Low MCV
C. Decreased Hb A2
D. A&B
E. A,B,C
Both A and B
Sickle cell anemia arises from a __ to __ mutation (adenine to thymine substitution)
How do the sickle cells form?
What are the 3 drivers of sickling?
Sickle cell anemia arises from a Glu to Val mutation (adenine to thymine substitution)
Deoxyhemoglobin S forms fibers that become very rigid and are held together by the valine that’s not supposed to be there
Low pH>>O2 tension
Intracellular dehydration
Decreased transit times thru vascular beds
Sickle cell anemia can lead to ___ anemia (specifically __ hemolysis). Infection with ___ can also cause aplastic crisis. Because the spleen eventually involutes due to trapping of RBCs, patients become more susceptible to bacterial infections, namely ___ and ___
Sickle cell anemia can lead to hemolytic anemia (specifically intravascular hemolysis). Infection with parvovirus can also cause aplastic crisis. Because the spleen eventually involutes due to trapping of RBCs, patients become more susceptible to bacterial infections, namely Pneumoccocal and Salmonella infections (also Neisseria)
Sickle cell anemia patients can also get ___, which is the most common cause of death, as well brain infarctions that can lead to stroke
Sickle cell anemia patients can also get pulmonary infarctions, which is the most common cause of death, as well brain infarctions that can lead to stroke
How would you treat sickle cell anemia? (state 5 things)
RBC exchange
Stem cell transplant
Give vacccines for Pneumoccoci and Neisseria
Keep hydrated
Give hydroxyurea (increases HbF and reduces frequency of painful episodes)