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Flashcards in Heme-coag Deck (54)
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1

Contents of platelet alpha granules

Protein molecules:

Fibrinogen

PDGF

vWF

P-selectin

PF4

2

Contents of platelet dense bodies

Nonprotein molecules ADP ATP serotonin (5-HT) Calcium

3

GPIb/XI/V complex (CD42)

mediates platelt adhesion

Receptor for vWF

4

GPIIb/IIIa complex (CD41&CD61)

Mediates platelet aggregation,

fibrinogen receptor

 

5

GPIaIIa

Mediates platlet adhesion

Collagen receptors

6

GPIc/IIa complex

Fibronectin receptor

7

Composition of Heinz body

Clumps precipitated hemoglobin

8

Hermansky-Pudlak Syndrome

-abnormal dense granules (normally secrete ADP, ATP, 5-HT and calcium) -Epistaxis, oculocutaneous albinism, pulmonary fibrosis, granulomatous colitis -ceroid-like material within tissue macrophages -common in Puerto rico

9

hereditary spherocytosis

AD inheritance, ANK1 (ankyrin) gene -increased MCHC, and reticulocyte count -PB: spherocytes -sx of extravascular hemolysis Abnormal osmotic fragility and autohemolysis tests (DAT is neg vs AIHA)

10

hereditary elliptocytosis/ovalocytosis

AD, spectrin alpha chain gene mutations -PB: elliptocytes (twice as long as wide) >25% -*hereditary pyropoikilocytosis (HPP): most common in AA, RBCs sensitive to heat *Stomatocytic type (aka southeast asian ovalocytosis): protects against P. vivax

11

G6PD deficiency

*G6PD needed to produce NADPH adn reduced glutathione for protection from oxidants; X-linked recessive inheritance -RBCs hypersensitive to oxidant stress (sulfa drugs, nitrofurantoin, primaquine, fava beans, infection) resulting in episodic hemolysis -p/w extravascular hemolysis -PB: bite cells*, Heniz bodies, poikilocytosis, blister cells

12

Pyruvate kinase (PK) deficiency

-PK catalyzes rate limiting step in glycolysis pathway

AR inheritance

-echinocytes ("burr cells")

13

major adult hgb

HbA alpha2 beta2

14

minor adult hgb

HBA2 alpha2 delta2

15

Variant beta chain "S"

AA6 Glu-->Val

16

Variant beta chain "C"

AA6 Glu-->Lys

17

Relative proportion of Hgb types in sickle cell trait

SA 35-45% HbS 50-65% HbA <3% HbA2

18

Relative proportion of Hgb types in sickle cell disease

homozygous SS RBC lifespan of 17 days

>80% HbS 1-20% HbF 1-4% HbA2 0% HbA

19

screening tests for sickle cell

metabisulfite dithionate

20

Right shift O2 binding curve

Decreased affinity hb acidosis, increased temp, hyperthermia, increased 2,3 DPG,

21

Left shift O2 binding curve

Increased affinity hb alkalosis, hypothermia, decreased 2,3 DPG

22

What is Methemoglobin?

Hb with iron in ferric (Fe+++) state instead of usual ferrous (Fe++) state -normal low levels of Hi maintained by NADH dependent methemoglobin reductase system -treatment is methylene blue (reduces Hi to Hb)

23

Elevated zinc protoporphyrin

Iron deficiency anemia Anemia of chronic disease Lead poisoning

24

Elevated free erythrocyte protoporphyrin

Iron def anemia Anemia of chronic dx Lead poisoning

25

Conditions associated with arterial thrombosis

Lupus anticoagulant, HIT and hyperhomocysteinemia

26

What molecule is inappropriately high in anemia of chronic disease?

Hepcidin, this inhibits iron export from macrophages and enterocytes resulting in functional iron deficiency

27

What supports a diagnosis of anemia of chronic disease versus iron deficiency anemia

Elevated serum ferritin

28

Causes of intravascular hemolysis

Microangiopathic hemolytic anemia (DIC, HUS, TTP, HELLP) Complement fixation in RBC surface (ABO incompatibility, PNH, PCH) Mechanical heart valves Snake venom Infection (malaria, Vanessa, clostridium)

29

Heinz body composition

Insoluble hemoglobin inclusion

30

Pentad of TTP

Thrombocytopenia, microangiopathic hemolytic anemia, neurological abnormalities, renal dysfunction and fever