111 - Disorders of Platelet & Vessel Wall

Question 1

Platelets are activated by attaching to __ and __ found in the sub-__ which has been exposed due to injury or shear force. The activated platelets activate the production of __

Answer 1

vWV
collagen
epithelium
fibrin

Question 2

Platelets are released from __ in response to stimulation by __ which is produced in the __

Answer 2

megakaryocytes
TPO
liver

Question 3

What are the main reasons or thrombocytopenia?

Answer 3

decreased production (do BM biopsy)
splenic aggregation
increase in destruction (HUS/vasculitis/TTP/DIC/ITP)
pseudothrombocytopenia

Question 4

Why and how should we approach to a 60 years old patient with thrombocytopenia?

Answer 4

Looking for MDS, performing BM biopsy

Question 5

What is the most common non-iatrogenic factor leading to thrombocytopenia?

Answer 5

infection:
DIC in G(-) systemic infection
ITP in viral infection and HIV

Question 6

HIT= __

Answer 6

heparin induced thrombocytopenia

Question 7

HIT does not increase the risk for __ as much as it does for __

Answer 7

bleeding

thrombosis

Question 8

HIT is caused as antibodies against the __/__ complex are produced. It can also happen due to treatment with __, but is much more common when treating with __.

Answer 8

PF4/heparin
LMWH
UFH

Question 9

What are the 5T for HIT?

Answer 9

thrombocytopenia
Timing
Thrombosis
oTher
Type of heparin

Question 10

How do you treat HIT?

Answer 10

early diagnosing
stop heparin->switch to different anti coagulant (e.g. coumadin)
perform imaging to rule out thrombosis (lower limbs doppler)

Question 11

Why coumadin should be administrated to patients with HIT only after platelets are back to normal level?

Answer 11

It decrease the level of protein C&S which may lead to skin necrosis

Question 12

ITP= ___. It is an __ disorder, leading to immune mediated destruction of platelets.

Answer 12

Immune Thrombocytopenic Purpura

acquired

Question 13

ITP tends to be __ in children, and secondary after: 4

Answer 13

acute
SLE
HIV
HCV
HP

Question 14

When considering ITP, what may suggest a life threatening bleeding?

Answer 14

Wet purpura and retinal bleeding, together with low platelets and otherwise normal CBC

Question 15

What is the typical clinical presentation of ITP? 3

Answer 15

cutaneous bleeding (ecchymoses / petechia)
membranous bleeding- wet purpura
other (retinal, GI, menorrhagia, CNS)

Question 16

What are the 4 tools in diagnosing ITP?

Answer 16

• serology for HIV/HCV/SLE
• serum protein electrophoresis + immunoglobulin levels (hypogammaglobulinemia + IgA deficiency )
• coombs (looking for hemolysis- EVANS syndrome)
• BM examination

Question 17

What is Evans syndrome?

Answer 17

autoimmune hemolysis + ITP

Question 18

What is the goal of treating ITP?

Answer 18

reduce platelets destruction and reduce antibodies production

Question 19

What is the indication to start treatment ITP?

Answer 19

when platelets < 30K

Question 20

What are the 3 lines of treating ITP?

Answer 20

prednisone
anti RhD
IVIg

Question 21

Only ITP patients with __ can be treated with anti RhD

Answer 21

positive

Rh +

Question 22

__ is more efficient than other lines for treating ITP

Answer 22

IVIg

Question 23

Name two S/E for IVIg when treating ITP (remember those are rare S/E)

Answer 23

RF

aseptic meningitis

Question 24

If the patient with ITP is experiencing severe __, extreme thrombocytopenia ( __ is required

Answer 24

bleeding
5K
illness
hospitalization

Question 25

Hospitalized ITP patients should be treated with: __+__ /__. Sometimes other__ drugs are used. If refractory- add __. If glucocorticoids do not help- perform

Answer 25

steroids + IVIg/ anti RhD rituximab (anti CD20) splenectomy

Question 26

TTP= __

Answer 26

thrombotic thrombocytopenic purpura

Question 27

What is the TTP pentad?

Answer 27

``` thrombocytopenia microangiopathic hemolytic anemia RF neurological signs fever ```

Question 28

TTP can be __ or __

Answer 28

idiopathic | inherited

Question 29

Idiopathic TTP is when antibodies for __ are produced. They slice __ after it is secreted which leads to the platelets attaching to the __ wall. More common in 3

Answer 29

ADAMTS13 vWF blood vessels women/HIV/pregnancy

Question 30

Give 2 drugs which can cause TTP

Answer 30

cyclosporine | ticlopidine

Question 31

What lab results will suggest TTP?

Answer 31

``` elevated LDH elevated unconjugated bilirubin elevated reticulocytes decreased haptoglobin In peripheral blood look for schistocytes and polychromasia ```

Question 32

How should you treat TTP?

Answer 32

plasma exchange for 2 days, possibly with steroids. If refractory- rituximab/cyclophosphamide/splenectomy

Question 33

HUS= __

Answer 33

hemolytic uremic syndrome

Question 34

What is the HUS triad?

Answer 34

ARF microangiopathic hemolytic anemia thrombocytopenia

Question 35

HUS is more common in __, usually after __ due to __ infection

Answer 35

children hemorrhagic diarrhea E. Coli O157P:H7

Question 36

Atypical HUS appears without __. Treatment is with-

Answer 36

diarrhea | eculizumab

Question 37

Unlike TTS, in HUS __ levels are normal

Answer 37

ADAMTS13

Question 38

Treating HUS is usually __, but __ can also be required

Answer 38

supportive | dialysis

Question 39

What is the most common bleeding disease?

Answer 39

Von Willebrand disease

Question 40

How many Von Willebrand disease types are there?

Answer 40

Type I Type II Type III

Question 41

Type I VWD is the most common type (_%). The factor level's are __ together with factor __. Bleedings will appear in late __. __ blood types are less affected.

Answer 41

``` 80 decreased VIII childhood O ```

Question 42

Type II VWD is more __ than quantitative. There are 4 subtypes: 2A- over sensitivity to __ by __ 2B- mutation leading to increased __ attachment to platelets 2M- faulty __ 2N- faulty binding to factor __

Answer 42

``` qualitative cleavage ADAMTS13 vWF function VII ```

Question 43

Type III VWD is considered __. Patients will experience multiple __, low levels of factor __ and low __. Higher chances to developed infused vWF

Answer 43

severe bleeding VIII vWF

Question 44

How will you treat type I vWD? what are the S/E?

Answer 44

nasal/IV DDAVP | hyponatremia- add water for 24 hours

Question 45

How will you treat vWD II-III?

Answer 45

vWF replacement + antifibrinolytic treatment (epsilon aminocaproic acid) before dental procedures and mucosal bleeding.

Question 46

When epsilon aminocaproic acid is C/I?

Answer 46

patients with upper UT bleeding- risk for ureter blockage