Bleeding and Bruising Scheme

Question 1

What is ITP and how does it work?

Answer 1

iatrogenic thrombocytopenia that is autoimmune mediated
Abs against GP IIb/IIIA -> no aggregation
complex removed by the spleen

Question 2

what is DIC and how does it work?

Answer 2

thrombohemorrhagic act. by TF
usually preceded by an illness/trauma
leads to inc. thrombin

Question 3

2 mechanisms for DIC?

Answer 3

thrombotic disorders-> clots

consumption of platelets and clotting factors-> bleeding

Question 4

what lab tests do you expect with DIC>

Answer 4

inc. PT, aPTT, D-dimer,
dec. fibrinogen, platelets
schistocytes

Question 5

what does an inhibitor mixing study tell you with PT, aPTT?

Answer 5

if it normalizes- factor def.

if it remains prolonged, inhibitor present (autoimmune)

Question 6

what common drug can lead to a qualitative platelet disorder?

Answer 6

ASA

Question 7

hemophilia A is a def. in which coag factor?

Answer 7

factor VIII

Question 8

hemophilia B is a def. in which coag factor?

Answer 8

factor IX

Question 9

what is the inheritance pattern of hemophilia?

Answer 9

x linked recessive

Question 10

what is the mutation of TTP?

Answer 10

ADAMTS-13 ->vWF inc. (no breakdown)

Question 11

what drugs cause thrombocytopenia?

Answer 11

penicillin, sulfonamides, phenytoin

Question 12

pathophys of HIT?

Answer 12

heparin binds PF4 -> Ab binding to Fab region -> complex binding Fc region -> platelet activation -> thrombosis

Question 13

what does lupus anticoagulant do?

Answer 13

interferes with clotting by inc. PTT

Question 14

where is vWF stored?

Answer 14

weibel palade bodies

Question 15

what coagulation factor is bound to vWF?

Answer 15

factor VIII

Question 16

what gene codes for factor VIII

Answer 16

FA gene

Question 17

what chr is responsible for vWF

Answer 17

Chr 12

Question 18

what does SNP do in regards to vWF?

Answer 18

cleave vWF -> bleeding

Question 19

which blood group has the highest vWF?

Answer 19

AB

Question 20

genetics of Type 1 vWF def.

Answer 20

autosomal dominant
may not have family hx as incomplete penetrance
most common
point mutations -> red. secretion, and inc. clearance
haploinsufficiency

Question 21

genetics of Type 2a vWF dz?

Answer 21

dominant missense mutation

full penetrance

Question 22

genetics of Type 2b vWF dz?

Answer 22

gain of function ; autosomal dominant
full penetrance
vWF binds without collagen interaction

Question 23

genetics Type 2M vWF dz?

Answer 23

autosomal dominant
fully penetrant
mutation in A3 domain
less platelet vWF interaction

Question 24

genetics of type 2N vWF dz?\

Answer 24

autosomal recessive
red. VIII and so less vWF and VIII binding
hemophilia A

Question 25

genetics of Type 3 vWF dz?

Answer 25

autosomal recessive

absence of vWF and dec. FVIII

Question 26

what is used to treat vWF dz

Answer 26

desmopressin

stim. vWF release

Question 27

which types of vWF dz do not respond to desmopressin

Answer 27

type 3, 2B, 2M, 2N

Question 28

what cleaves/act FVIII

Answer 28

thrombin

Question 29

FVIII is a cofactor for the cleavage of?

Answer 29

FX via IX

Question 30

FIX is cleaved/act by?

Answer 30

FXI

Question 31

what does FIX do?

Answer 31

cleaves/act. FX via FVIII

Question 32

what inhibits FIX?

Answer 32

antithrombin

Question 33

what test is useful for DIC?

Answer 33

D dimer

Question 34

what is the first test you order when you have a prolonged PT or PTT

Answer 34

inhibitor mixing study