Platelet Disorders

Question 1

What two drugs are most commonly causing ITP?

Answer 1

Quinine or quinidine

Question 2

What family of drugs can also cause ITP acutely and give an example?

Answer 2

2b3a inhibitors like abciximab

Question 3

What are the 3 clinical settings we see ITP?

Answer 3

Response to a drug, within another disease, and idiopathic

Question 4

3 clinical diseases where we might see low platelet?

Answer 4

HIV, LUPUS, and in older patients, lymphoproliferative malignancy

Question 5

2 clinical symptoms of ITP and what makes for a more probable diagnosis? What should blood smear show and bone marrow aspirate?

Answer 5

Petechial rash and easy bruising.
ITP is more probable in an isolated setting. Everything else should be normal. Maybe a little anemia with larger blood loss that is secondary.
Blood smear shows decreased platelets and can be large. Bone marrow should show increased megakaryocytes.

Question 6

2 first line treatments for ITP and 2 second line treatments and 1 last line?

Answer 6

Steroids and IVIG
Anti rho d if patient is rho d positive and anti 20 rituximab
Take spleen out

Question 7

What kind of heparin and what type of patient have a higher incidence of getting HIT?

Answer 7

Unfractionated vs. low molecular weight

Open heart surgery patients get it more

Question 8

What drug is not a good alternative to heparin in the present of HIT and what drug is?

Answer 8

No warfarin but direct thrombin inhibitors are

Question 9

What are the 4 Ts for diagnosing HIT?

Answer 9

Thrombocytopenia level
Timing of the platelet count fall
Thrombosis or other problems
Other causes of thrombocytopenia present

Question 10

What is the 0,1,2 points for thrombocytopenia level?

Answer 10

0 - platelet count fall is less than 30% and a low count less than 10k
1 - platelet count falls 30-50% and a low of 10-19k
2 - platelet count falls more than 50% and a low of greater than 20k

Question 11

0,1,2 points for timing of platelet drop?

Answer 11

0- platelet count fall is less than 4 days without recent exposure
1- looks like it fell 5-10 days but not documented or after 10 days or less than a day with exposure within 1-3 months
2- clear onset of 5-10 days or less than 1 day with exposure within the last month

Question 12

0,1,2 points for thrombosis?

Answer 12

0 - no thrombosis
1 - suspected thrombosis that has not been proven
2 - confirmed skin necrosis or thrombosis

Question 13

0,1,2 points for other causes of thrombocytopenia present?

Answer 13

0 - definite
1 - possible
2 - none apparent

Question 14

Once you add all 4 categories up, what does 0-3, 4-5 and 6-8 mean?

Answer 14

Low probability
Medium probability
High probability

Question 15

What 3 patient populations are at higher risk for TTP-HUS?

Answer 15

Pregnant women, HIV infected patients, and patients receiving cancer chemo or immunosuppressive

Question 16

4 lab findings suggestive of TTP-HUS?

Answer 16

Schistocytes of blood smear
Decreased haptoglobin
LDH is up
Low platelets

Question 17

Because it is hard to diagnose TTP-HUS from other microangiopathic diseases, what 4 clinical signs will help us direct towards TTP-HUS?

Answer 17

Platelets are low, kidney problems, fever, and neuro deficits

Question 18

2 things to treat TTP-HUS?

Answer 18

Plasma exchange and glucocorticoids

Question 19

How is Essential Thrombocythemia usually diagnosed and what 3 clinical symptoms may patients present with?

Answer 19

Unexpected high platelet levels for no reason

Headache, erythromelalgia, thromboembolic even or acute bleeding

Question 20

What sort of qualifies for a diagnosis of ET? What two other conditions do we see high platelet counts and because of this what do we need to make sure is negative for diagnosis?

Answer 20

Persistent platelet counts over 600k, sometimes these people are over 1mil.
PRV and CML and half of patients with ET have the jak2 mutation, so need to make sure no Philadelphia chromosome to say no CML.

Question 21

How do we treat ET, what is considered a low risk patient and high risk patient and what do we do with each?

Answer 21

Patients less than 60 with counts less than a mil with no prior thromboembolic event have an excellent prognosis and should be watched.
High risk patients, give hydroxyurea first with low dose aspirin. If that doesn’t work give IFN alpha and anagrelide.

Question 22

What is the leading differential in patients suspected of ET and what are the 4 most common causes of it?

Answer 22

Reactive thrombocytosis

Iron deficiency, inflammation, cancer or infection