RBC and Bleeding Disorders VI

Question 1

prothrombin time

Answer 1

PT

extrinsic and common pathways

V, VII, X, PT, fibrinogen

Question 2

partial thromboplastin time

Answer 2

PTT

intrinsic and common pathways

V, VIII, IX, X, XI, XII, PT, fibrinogen

Question 3

platelet count

Answer 3

best confirmed by PBS inspection

Question 4

petechia and purpura in skin or mucous membranes

Answer 4

bleeding disorders caused by vessel wall abnormalities

normal PT, PTT and platelet count

Question 5

infection causing bleeding disorders with vessel wall abnormalities

Answer 5

meningococcemia
infective endocarditis
rickettsioses

vasculitis and DIC

Question 6

leukocytoclastic vasculitis

Answer 6

hypersensitivity

with drug rxns

immune complex deposition in vessel walls

Question 7

scurvy

Answer 7

microvascular bleeding resulting from collagen defect weakening vessel wall

vit C deficiency

Question 8

ehler danlos syndrome

Answer 8

microvascular bleeding resulting from collagen defect weakening vessel wall

Question 9

cushing syndrome

Answer 9

excess corticosteroid causes loss of vascular supporting tissue

bleeding disorder

Question 10

henoch schonlein purpura

Answer 10

systemic immune disorder

purpuric rash, colicky pain, polyarthralgia and acute glomerulonephritis

deposition of immune complexes of IgA throughout body and within glomerular mesangial region

Question 11

purpuric rash, colicky pain, polyarthralgia and acute glomerulonephritis

Answer 11

henoch schonlein purpura

Question 12

weber osler rendu syndrome

Answer 12

hereditary hemorrhagic telangiectasia

auto dominant

mutation in genes regulating TGF-beta signaling

dilated, turtous blood vessels with thin walls - serious bleeding

nose, tongue, month, eye, GI bleeds

Question 13

perivascular amyloidosis

Answer 13

weak blood vessels

bleeding disorder

most common with amyloid light chain

often mucocutaneous petechiae

Question 14

severe bleeding

Answer 14

hereditary hemorrhagic telangiectasia

-weber osler rendu syndrome

Question 15

thrombocytopenia

Answer 15

platelets < 100,000

Question 16

posttraumatic bleeding

Answer 16

20-50,000 platelets

Question 17

spontaneous bleeding

Answer 17

<20,000 platelets

Question 18

bleeding from thrombocytopenia

Answer 18

normal PT and PTT

Question 19

most feared with low platelets

Answer 19

intracranial bleeds

Question 20

causes of thrombocytopenia

Answer 20

1 decreased platelet production
2 decreased platelet survival
3 sequestration
4 dilution

Question 21

decreased platelet production

Answer 21

drugs and alcohol

HIV - infect megakaryocytes

Question 22

decreased platelet survival

Answer 22

immunologic and nonimmunologic

Question 23

immune thrombocytopenia

Answer 23

deposition of Abs or immune complexes on platelets

Question 24

fetus thrombocytopenia

Answer 24

alloantibodies

IgG antibodies made in mother can cause thrombocytopenia in fetus

Question 25

nonimmunologic destruction of platelets

Answer 25

mechanical injury - metal prosthetic heart valves

Question 26

splenomegaly

Answer 26

platelets can be sequestered

thrombocytopenia occurs

Question 27

massive transfusions

Answer 27

can lead to dilutional thrombocytopenia

Question 28

chronic ITP

Answer 28

caused by autoAb mediated destruction of platelets

can be idiopathic or secondary

secondary - SLE, HIV, B cell neoplasms

can be improved by splenectomy - major site of removal of opsonized platelets and removal of source of antoAbs - plasma cells

Question 29

autoAbs in chronic ITP

Answer 29

against platelet membrane glycoproteins IIb-IIIa, or Ib-IX

IgG class

Question 30

increased megakaryocytes in BM

Answer 30

seen in chronic ITP

also see large platelets on peripheral blood - megathrombocytes

and normal sized spleen

Question 31

chronic ITP clinical

Answer 31

adult women < 40yo
boeeding into skin and mucosal surfaces
petechiae - pinpoint
easy bruising, nosebleeds, bleeding from gums, melena, hematuria, excessive menstruation

intracranial bleeds fatal - rare in treated pts

normal PT and PTT

dx of exclusion**

Question 32

chronic ITP and splenomegaly

Answer 32

probably not primary - idiopathic

look at B cell neoplasm secondary cause

Question 33

acute ITP

Answer 33

disease of children

equal frequency both sexes

1-2 weeks after viral infection

resolves spontaneously within 6 months

Question 34

tx of ITP

Answer 34

glucocorticoid

• in chronic
• and in acute if severe

Question 35

acute ITP without viral prodrome

Answer 35

worse prognosis

Question 36

drug induced thrombocytopenia

Answer 36

quinine, quinidine, vancomycin

Question 37

HIT

Answer 37

heparin induced thrombocytopenia

type I - rapidly after start heparin therapy and goes away
type II - 2 weeks after heparin - severe arterial/venous thrombosis

Question 38

type I HIT

Answer 38

rapidly after start heparin therapy and goes away

Question 39

type II HIT

Answer 39

2 weeks after heparin - severe arterial/venous thrombosis

Abs for heparin and platelet factor 4

DVT, PE, vascular insufficiency

Question 40

HIV thrombocytopenia

Answer 40

common heme manifestation of HIV

CD4 and CXCR4 - on megakaryocytes
-HIV receptors

these cells apoptose and don’t produce platelets

Question 41

thrombotic microangiopathy

Answer 41

includes TTP and HUS

excessive platelet activation - deposit as thrombi in small blood vessels

Question 42

fever, thrombocytopenia, microangiopathic hemolytic anemia, transient neuro deficits, renal failure

Answer 42

pentad of TTP

Question 43

TTP vs. HUS

Answer 43

TTP - neuro sx
HUS - no neuro sx

both have normal PT and PTT

Question 44

microangiopathic hemolytic anemia, thrombocytopenia, acute renal failure, children

Answer 44

HUS

Question 45

deficiency of ADAMTS13

Answer 45

TTP

tx plasmaphaesis

Question 46

E.Coli 0157:H7 infection

Answer 46

typical HUS

Question 47

deficiency of complement factor H, CD46, or factor I

Answer 47

atypical HUS

inhibitors of alternate complement pathways