RBC and Bleeding Disorders II

Question 1

hexose monophosphate shunt and glutathione metabolism

Answer 1

abnormal in G6PD deficiency

Question 2

G6PD deficiency

Answer 2

RBCs cannot protect against oxidative damage

leads to hemolysis
-both intravascular and extravascular

Question 3

episodic hemolysis

Answer 3

characteristic of G6PD deficiency

-exposures that cause oxidative stress

infections - viral hepatitis, pneumonia, typhoid

drugs - antimalarials

foods - fava beans

Question 4

G6PD

Answer 4

glucose 6 phosphate DH

-reduces NADP to NADPH while oxidizing glucose-6P

NADPH - provides reducing equivalents for glutathione metabolism that protects against oxidative damage
-like H2O2

Question 5

genetics of G6PD

Answer 5

X-linked trait

-males higher risk

Question 6

heinz bodies

Answer 6

in G6PD deficiency

seen in RBCs

also bite cells

Question 7

bite cells

Answer 7

G6PD deficiency

Question 8

G6PD-

Answer 8

in blacks

Question 9

G6PD mediterranean

Answer 9

protective against plasmodium falciprum malaria

greater hemolysis in this variant

only older red cells at risk for lysis

recovery phase - reticulocytosis

Question 10

G6PD clinical

Answer 10

no spenomegaly or cholelithiasis

-bc is intermittent - no chronic hemolysis

Question 11

sickle cell

Answer 11

beta chain point mutation codon 6

-glutamate to valine

Question 12

HbA

Answer 12

alpha2beta2

Question 13

HbA2

Answer 13

alpha2delta2

Question 14

HbF

Answer 14

alpha2gamma2

Question 15

beta-globin chain

Answer 15

one gene

Question 16

alpha-globin chain

Answer 16

two genes

Question 17

PBS of sickle cell

Answer 17

anisocytosis and poikilocytosis and sickled cells

Question 18

sickle cell trait

Answer 18

heterozygote for HbS

offspring of hetero - 1/4 chance

Question 19

protective effect HbS

Answer 19

against falciprum malaria

parasites promote sickling - get cleared rapidly - keep parasite load down

Question 20

pfEMP-1

Answer 20

knob formation
-impaired by sickling

-knob formation on membranes

basis of cerebral malaria

Question 21

sickle cell clinical

Answer 21

moderately severe hemolytic anemia
-Hct 20-30%

reticulocytosis, hyperbilirubinemia, and sickled cells

Question 22

vaso-occlusive crisis

Answer 22

in sickle cell

-aka pain crisis

bones, lung, liver, brain, spleen, penis

Question 23

hand-foot syndrome

Answer 23

painful bones in children with sickle cell

Question 24

dactylitis

Answer 24

of bones in hands and feet

with sickle cell

Question 25

acute chest syndrome

Answer 25

vaso-occlusive crisis in sickle cell

fever cough, chest pain, pulmonary infiltrates

blood flow - sluggish
-further hypoxemia - more sickling - bad cycle

requires prompt treatment and exchange tranfusions

Question 26

priapism

Answer 26

in sickle cell

45% males after puberty

Question 27

stroke and retinopathy to blindness

Answer 27

with sickle cell

Question 28

depletion of NO

Answer 28

no vasodilation

-predisposition for stroke in sickle cell disease

Question 29

sequestration crisis

Answer 29

in children with sickle cell
-entrapment of sickled RBCs in spleen

rapid splenic enlargement, hypovolemia, shock

requires prompt treatment and exchange tranfusions

Question 30

aplastic crisis in sickle cell

Answer 30

with parvovirus B19 infection

cessation of erythropoiesis and anemia

Question 31

chronic hypoxia with sickle cell

Answer 31

impaired growth and development and organ damage

Question 32

hyposthenuria

Answer 32

sickling in kidney - damage

inability to concentrate urine

Question 33

infections in sickle cell

Answer 33

pneumococcus pneumonia and haem influenza

because of altered splenic functions

Question 34

diagnosis of sickle cell

Answer 34

clinical findings and presence of irreversibly sickled cells

-test - mix blood sample with metabisulfite - induces sickling

Question 35

metabisulfite

Answer 35

for dx of sickle cell

will cause sickling in HgS patients

Question 36

Hg electrophoresis

Answer 36

can demonstrate presence of HbS and other sickle syndromes

Question 37

prenatal sickle cell diagnosis

Answer 37

analyze fetal DNA

-amniocentesis and chorionic biopsy