1.2 + 1.3 highlights pt 1B

Question 1

1) Beta Thalassemias are usually caused by _______ mutations (rather than deletions) in beta globin genes
2) Result in _________ (beta+) or _________ (beta0) beta-globin chain synthesis

Answer 1

1) point
2) reduced (beta+) or absent (beta0)

Question 2

Beta thalassemia:
In the presence of reduced beta chains, the excess _______ chains are unstable and precipitate, leading to damage of RBC membranes; this leads to both intramedullary (bone marrow) and peripheral blood _________

Answer 2

alpha; hemolysis

Question 3

Beta thalassemia:
1) The __________ marrow demonstrates _________ hyperplasia (under the stimuli of anemia) and ineffective erythropoiesis (intramedullary destruction of the developing erythroid cells)
2) In cases of severe beta­ thalassemia: marked expansion of this may cause what 4 things?

Answer 3

1) bone; erythroid
2) Severe bony deformities
Osteopenia
Pathologic bone fractures
Extramedullary hematopoiesis

Question 4

Describe which forms of beta thalassemia req. transfusions

Answer 4

1) Thalassemia intermedia: occasional
2) Thalassemia major* (Cooley anemia): dependent (bc no hemoglobin A)

Question 5

Beta thalassemia minor is ___________ for beta­ thalassemia (beta/beta0 or beta/beta+); 1 mutated gene

Answer 5

heterozygous

Question 6

Beta Thalassemia Minor (Trait): Key Lab Finding
In contrast to alpha-thalassemia (and iron deficiency), __________ stippling is present on peripheral blood smear.

Answer 6

basophilic

Question 7

Beta thalassemia major: After first ___ months of life (when Hgb synthesis switches from Hgb F to Hgb A), they develop severe anemia requiring _____________

Answer 7

6; transfusions

Question 8

True or false: pts with beta thalassemia major require regular blood transfusions

Answer 8

True

Question 9

Beta thalassemia major:
1) What is a complication of transfusions?
2) __________ stem cell transplantation is the treatment of choice and the only available cure

Answer 9

1) Iron overload; Iron chelation
2) Allogeneic

Question 10

In beta thalassemia major, the predominant Hgb is _______ on hemoglobin electrophoresis

Answer 10

Hgb F

Question 11

Compared to iron deficiency anemia*, patients with thalassemia have what? [lab values]

(starred slide)

Answer 11

-Lower MCV
-Normal or elevated RBC count (rather than low)
-More abnormal peripheral smear at modest levels of anemia
-Usually a reticulocytosis
-Iron studies are normal or have elevated transferrin saturation and/or ferritin

Question 12

1) Beta-thalassemia: What are the typical findings?
2) How is alpha thalassemia Dx’d?

(starred slide)

Answer 12

1) Regular thalassemia findings plus Hgb electrophoresis showing elevated levels of Hgb A2 and F (if no concurrent Fe deficiency) or beta-globin gene sequencing
2) Diagnosis made by exclusion (Hgb electrophoresis may have no change in proportion of normal adult Hgb species) or confirmed by alpha gene deletion studies

Question 13

Patients with __________ thalassemia are maintained on a regular transfusion schedule (in part to suppress endogenous erythropoiesis and therefore bone marrow expansion) and receive _________ acid supplementation (1 mg/day orally).

Answer 13

severe; folic

Question 14

Thalassemias: ______________ is performed if ____________ causes a marked increase in the transfusion requirement or refractory symptoms.

(starred)

Answer 14

Splenectomy; hypersplenism

Question 15

Thalassemias: Patients with regular transfusion requirements should be treated with_____________ (oral or parenteral) in order to prevent or delay life-limiting organ damage from ______ overload.

(starred)

Answer 15

iron chelation; iron