Hem Test 1: Hemoglobinopathies

Front 1

Hb is made up of what?

Back 1

2 alpha chains and 2 beta chains with a central iron

Front 2

Left shifts in Hb dissociation curve means what? What causes?

Back 2

Holds onto longer
dec temp, dec 2,3 DPG, inc pH

Front 3

alpha2 + gamma2 = ?

Back 3

HbF

Front 4

alpha2 + delta2 = ?

Back 4

HbA2 (minor adult Hb)

Front 5

alpha2 + beta2 = ?

Back 5

HbA (major adult Hb)

Front 6

Which hemoglobinapathy is a quantitative deficiency?

Back 6

thalassemia (alpha or beta)

Front 7

genetically heterogenous conditions resulting from globin chain imbalance

Back 7

thalassemia (corresponds to distribution of falciparum malaria)

Front 8

Thalassemia major have what going on?

Back 8

two knock outs (transfusion dependent)

Front 9

three levels of thalassemia?

Back 9

minor (very mild)
major (transfusion dependent)
intermedia (not transfusion dependent)

Front 10

Beta thalassemias most common where?

Back 10

Italians/Greeks or countries around Mediterranean

B0 thalassemia if lacking beta globin synthesis
B+ thalassemia have dec beta globin synthesis

Front 11

Excess globin chain instability leads to? (imbalance)

Back 11

ineffective erythropoiesis
destruction of produced RBCs

Front 12

Potential responses within body of thalassemias

Back 12

splenomegaly (worsens anemia)
skeletal deformities from overactive RBCs
Iron overload develops

Front 13

Where are alpha thalassemias seen?

Back 13

SE Asia and W Africa

Front 14

Two examples of alpha thalassemias

Back 14

one alpha gene deletion (normal Hg electrophoresis)
two gene deletions (normal Hg electrophoresis)

Front 15

When is HbA2 more prevalent?

Back 15

during B thal to make more delta for Hb cover.

Front 16

How does alpha thalassemia gene deletion present in African/AA? Compare to Asian?

Back 16

a-/a-; for aa/--

Front 17

If you have no alphas what so ever, what is this?

Back 17

Hydrops fetalis; intrauterine death; predominant chain is Hb Barts

Front 18

Hb S characterized by what?

Back 18

6th aa in B chain changes from glu (charged) to val (hydrophobic)

Front 19

Hb C characterized by what?

Back 19

6th aa changed from glu to lysine (leads to inc cel dehydration)

Front 20

Pathophys of sickle cell disease

Back 20

HbS polymerizes
multiple cycles lead to cell dehydration
Can become irreversibly sickled and obstruct
Abnormal Hb/membrane activate Gardos Channel
Can suffer hemolysis
Sickle cells have abnormal adhesion to endothelial cells

Front 21

Which disease genotype is sickle cell disease?

Back 21

SS

Front 22

Presentation of sickle cell anemia

Back 22

chronic hemolysis
leukocytosis
thrombocytosis

Front 23

3 potential causes of other Anemic changes in SCD

Back 23

parvovirus B19
splenic/hepatic sequestration
acute chest syndrome

Front 24

How does spleen present in SS sickle cell?

Back 24

small, autoinfarcted

Front 25

4 components of sickle cell crises

Back 25

hemolytic crisis (rare)
splenic sequestration crisis (needs transfusion)
aplastic crisis (parvovirus B19 leads to marrow suppression w/ rapid development of anemia)
painful (vaso-occlusive) crisis

Front 26

Triggers of SCC

Back 26

exercise, dehydration, infection, cold, stress, menstruation, surgery/trauma, pregnancy

Front 27

Why are SCD pts immunocompromised?

Back 27

autosplenectomy leading to inc susceptibility to encapsulated organisms

Front 28

What can cause oseto issues in SCD pts?

Back 28

salmonella osteomyelitis

Front 29

Most common cause of death of SCD pts

Back 29

acute chest syndrome

Front 30

4 components of acute chest syndrome

Back 30

hypoxemia
NEW infiltrate on CXR
NEW fever, chest pain, dyspnea, or cough
acute worsening of anemia

Front 31

Possible etiologies of Acute chest syndrome

Back 31

infection, fat embolism
sequestration of sickled red cells
pulmonary infarct
hypoventilation
pulmonary edema

Front 32

Tx of Acute chest syndrome

Back 32

antibiotics, oxygen, transfusion to lower HbS conc

Front 33

How frequently does pulmonary hypertension occur?

Back 33

1/3 of SCD pts

Front 34

Median age of stroke in SCD pts

Back 34

5 yo

Front 35

How can transcranial dopplers help SCD children?

Back 35

ID stenosis, then have chronic regular transfusions to prevent stroke

Front 36

Complications of transfusion in SCD

Back 36

iron overload (organ damage and chelation)
Allo-immunization (request negative for C,E,Kell)

Front 37

Additional complications of SCD

Back 37

renal
leg ulcers
avascular necrosis
priapism
proliferative retinopathy

Front 38

Main tx for SCD pts; effect?

Back 38

hydroxyurea; inc amount of HbF and dec conc of HbS (helps everything)

Front 39

Side effect of hydroxyurea

Back 39

bone marrow suppression

Front 40

What can present with sickle cell trait?

Back 40

Renal manifestations
-isothenuria
-microscopic hematuria

Front 41

Pregnancy circumstances with SCD

Back 41

inc risk, causes SCC, perinatal mortality still 5-6%

manage dehydration and avoid hydroxyurea

Front 42

What can surgery lead to in pts with SCD?

Back 42

SCC, acute chest (can just simple transfusion, or exchange transfusion)

Front 43

Presentation of HbC disease

Back 43

mild hemolysis
microcytosis & target cells
splenomegaly