normocytic hemolytic anemia

Question 1

RBC hemolyisis → ↑ Hb in blood
↓ serum haptoglobin: binds free Hb in blood so it can be recycled, prevents breakdown to bilirubin
RBC hemolyisis → ↑ LDH in blood
↑ LDH (lactate dehydrogenase, lot in RBCs): pyruvate → lactate

Answer 1

intravascular hemolysis

Question 2

↑ unconjugated bilirubin → jaundice

↑ LDH (lactate dehydrogenase, lot in RBCs): pyruvate → lactate

Answer 2

extravascular hemolysis

Question 3

defect of proteins that interact with RBC membrane + cytoskeleton: ankyrin, spectrin (gives biconcave shape + flexibility) → RBC spheres
spleen recognizes + removes abnormal RBCs → splenomegaly

Answer 3

hereditary spherocytosis

Question 4

↓ G6PD → ↓ glutathione → RBC sensitive to oxidative damage → hemolysis
back pain + hemoglobinuria few days after start DRUG
extravascular + intravascular hemolysis
resistant to malaria

Answer 4

G6PD deficiency

Question 5

no central pallor
↑ MCHC: contain same absolute amount of Hb but smaller cell
↑ RDW

Answer 5

hereditary spherocytosis

Question 6

complication of hereditary spherocytosis

Answer 6

aplastic crises due to parvovirus B19 infection (suppresses BM)

Question 7

diagnostic test for hereditary spherocytosis

Answer 7

osmotic fragility test: put RBC in hypoosmotic solution → high % lysis of RBCs at any given concentration of NaCl (no normal spectrin)

Question 8

treatment for hereditary spherocytosis

Answer 8

splenectomy: prevent removal of RBCs

Question 9

post-splenectomy for hereditary spherocytosis

Answer 9

Howell Jolly Bodies: basophilic nuclear remnants in RBC (not removed by spleen)

Question 10

Heinz bodies: oxidation of iron, denaturation of Hb

Bite cells: spleen remove Heinz bodies

Answer 10

G6PD deficiency

Question 11

glycolytic enzyme deficiency → no ATP in RBC → can’t maintain Na/K ATPase → RBC swelling + hemolysis

Answer 11

pyruvate kinase deficiency

Question 12

RBC missing surface markers: CD55 + CD59

complement attacks → lyses RBC

Answer 12

paroxysmal nocturnal hemoglobinuria

Question 13

diagnostic test for PNH

Answer 13

Ham’s test:
add pH → activates complement → lysis of RBC
flow cytometry (used now)

Question 14

HbS: glutamic acid → valine in ß chain at position 6
allows Hb to polymerize in RBC
triggers of sickling = sickle crisis:
hypoxemia
dehydration
acidosis
8% AA heterozygotes (HbS trait): resistant to malaria
0.2% AA homozygous

Answer 14

sickle cell disease

Question 15

infant: asymptomatic (HbF)
infant + toddler: symptoms (HbF → HbS)
splenic sequestration crisis →↓ H/H, wedge-shaped infarcts on CT
autosplenectomy: complete infarction by 3-4 yo, ↑ risk infections by encapsulated organisms (vaccinate for meningococcus, pneumococcal, flu vaccine too)
aplastic crisis post-parvovirus B19
pain crises: vasoocclusion → ischemia
renal papillary necrosis due to hypoxemia in kidneys

Answer 15

sickle cell disease

Question 16

osteomyelitis in sickle cell disease

Answer 16

salmonella

Question 17

causes of aplastic crisis post-parvovirus B19

Answer 17

sickle cell disease

hereditary spherocytosis

Question 18

types of pain crises: vasooclusion

Answer 18

dactylitis: painful hand swelling

acute chest syndrome

Question 19

“hair-on-end” appearance from marrow hyperplasia (↑ RBC production)

Answer 19

sickle cell disease

ß thalassemias

Question 20

treatment of sickle cell disease

Answer 20

hydroxyurea: ↑ production of HbF
definitive: BMT (stem cells without HbS mutation)

Question 21

glutamic acid → lysine on ß globin chain on position 6
HbC form crystals in cell instead of long polymers in sickle cell disease
heterozygous for HbC: asymptomatic
homozygous for HbC: milder than sickle cell disease
SC disease = heterozygote with HbS + HbC mutation: milder than SCD
mild hemolysis, splenomegaly

Answer 21

hemoglobin C disease

Question 22

RBC mechanically damaged as they pass through lumen of obstructed or narrowed vessel → RBC sheared by fibrin strand or shear force of HTN:
DIC
TTP/HUS
lupus
malignant HTN

Answer 22

microangiopathic anemia

Question 23

shistocytes

Answer 23

microangiopathic anemia or macroangiopathic anemia

Question 24

damage to RBC by prosthetic heart valve, aortic stenosis

Answer 24

macroangiopathic anemia

Question 25

RBC infection → hemolysis

Answer 25

malaria

babesiosis

Question 26

autoantibodies bind to RBC → hemolysis

either warm or cold agglutinins

Answer 26

autoimmune hemolytic anemia

Question 27

IgG antibodies attach to RBC antigen at BODY TEMP → RBC agglutination (clump together) → chronic anemia
EBV/HIV
lupus
CLL, non-hodgkin lymphoma
congenital immune abnormalities
drugs

Answer 27

warm agglutinins in autoimmune hemolytic anemia

Question 28

IgM antibodies attach to RBC antigen ONLY IN COLD→ complement fixation → MAC lysis (and opsonization → phagocytosis) → acute anemia
EBV infection
Mycoplasma infection
CLL

Answer 28

cold agglutinins in autoimmune hemolytic anemia

Question 29

most autoimmune hemolytic anemias have a positive

Answer 29

+ coombs test: RBC agglutination with addition of anti-human antibody because RBCs are coated with Ig or complement proteins (C3)

Question 30

prepared Abs (coombs reagant) are added to a patient’s washed RBCs to detect the PRESENCE of Igs ALREADY on RBC (using antibody to detect an antibody) → RBCs agglutinate

Answer 30

direct coombs test

Question 31

+ direct coombs test

Answer 31

hemolytic disease of newborn
drug-induced autoimmune hemolytic anemia
hemolytic transfusion reactions

Question 32

patient’s SERUM incubated with normal RBC to detect for presence of ABs in serum → if Abs bind to RBCs →
RBCs agglutinate when anti-Ig antibodies (coombs reagant) added

Answer 32

indirect coombs test

Question 33

+ indirect coombs test

Answer 33

Abs to foreign RBCs/blood are present:
test blood prior to transfusion (type and screen: donor blood screened for Abs)
screen for maternal Abs to a fetus’s blood

Question 34

anemia
jaundice: extravascular hemolysis in spleen
pigmented gallstones: ↑ bilirubin
splenomegaly
spherocytes
\+ osmotic fragility test

Answer 34

hereditary spherocytosis