Thrombocytopenia

Question 1

What is thrombocytopenia?

Answer 1

Low platelets

Question 2

What are the three underlying causes of thrombocytopenia?

Answer 2

Underproduction
Destruction
Sequestration

Question 3

What is the normal ranges of platelets?

Answer 3

150-450k

Question 4

How big are platelets relative to RBCs?

Answer 4

1/3 size

Question 5

What is the cell that produces platelets?

Answer 5

Megakaryocytes

Question 6

What is the chemical that determines the rate and amount of platelet production?

Answer 6

Thrombopoietin

Question 7

What are the receptors on platelets that binds to vWF, and serves as an intracellular signal?

Answer 7

Gp IIb/IIIa

Question 8

Stocking distribution of paresthesias with low pancytopenia =?

Answer 8

Pernicious anemia

Question 9

Where are platelets sequestered, generally?

Answer 9

Spleen

Question 10

What are the viral causes of thrombocytopenia? (2)

Answer 10

HIV

Parvo B19

Question 11

Pts with sickle cell disease are susceptible to what viral infections?

Answer 11

Parvovirus B19

Question 12

What are the two common causes of thrombocytopenia that fall under the medication/drug category?

Answer 12

EtOH

Chemotherapeutic agents

Question 13

What are the three causes of marrow replacement that causes thrombocytopenia?

Answer 13

Granulomatous disease
Myelofibrosis
Malignancies

Question 14

If the MCV is greater than 115, what is the disease?

Answer 14

megaloblastic anemia

Question 15

What are the two platelet dysfunctions with pernicious anemia?

Answer 15

Diminished platelet aggregation

Decreased release of ATP, ADP

Question 16

Elevated methylmalonic acid levels = ?

Answer 16

Pernicious anemia

Question 17

What are the tests to diagnose pernicious anemia? (3)

Answer 17

Anti-parietal cell
Anti IF
EGD

Question 18

What is the treatment for pernicious anemia?

Answer 18

SQ B12 replacement (can’t give PO d/t lack of IF)

Question 19

Why is an EGD indicated for pernicious anemia?

Answer 19

Gastric adenocarcinoma

Question 20

What is pseudothrombocytopenia?

Answer 20

Platelet aggregation or clumping in the test tube (in vitro)

Question 21

What is the solution to pseudothrombocytopenia?

Answer 21

Use a blue top tube with heparinized blood

Question 22

thrombocytopenia with o/w normal CBC + bleeding from gums + mucocutaneous petechial rash = ?

Answer 22

ITP (immune thrombocytopenia purpura)

Question 23

What is ITP?

Answer 23

Accelerated destruction of platelets by immune destruction

Question 24

How do you diagnose ITP?

Answer 24

Diagnosis of exclusion

Question 25

What are the results of a bone marrow biopsy with ITP?

Answer 25

Normal to increased number of megakaryocytes

Question 26

The incidence of ITP increases or decreases with age

Answer 26

Increases

Question 27

What are the antiplatelet abs that are involved in ITP targeted against?

Answer 27

IgG to GPII/IIIa receptor

Question 28

True or false: transfusions to pts with ITP still result in destruction of platelets

Answer 28

True

Question 29

What are the usual symptoms of ITP?

Answer 29

Purpura/petechiae Epistaxis/bleeding gums Menorrhagia

Question 30

What is the first line of drug treatment for ITP? Second? Third?

Answer 30

IV corticosteroids IVIG Rituximab

Question 31

What is the last resort for ITP treatment?

Answer 31

Splenectomy

Question 32

What is antiphospholipid antibody syndrome?

Answer 32

Abs to GPIIa/IIIb

Question 33

Is HUS/TTP immune mediated?

Answer 33

no

Question 34

HELLP syndrome is indicated by what? (3)

Answer 34

Low platelet HTN elevated LFTs

Question 35

HIT is caused by what?

Answer 35

Immune mediated destruction of platelets after exposure to heparin

Question 36

What do abs in HIT attach to?

Answer 36

heparin and PF4 complex

Question 37

What type of heparin has a lower risk of HIT?

Answer 37

Low molecular weight heparin

Question 38

What happens to HIT pts when they are left untreated?

Answer 38

Thromboses form

Question 39

How do you manage HIT?

Answer 39

Stop heparin | Change anticoag

Question 40

True or false: you can administer heparin in pts who have had HIT before?

Answer 40

True, but needs to be more than 6 months

Question 41

Jaundice everywhere but the sclera is what?

Answer 41

NOT hyperbilirubinemia--Hyperbetacarontenamia

Question 42

Thrombocytopenia d/t to sequestration generally results in what PE findings?

Answer 42

Splenomegaly

Question 43

What are the four causes of splenic sequestration?

Answer 43

1/ Hereditary spherocytosis 2. CML 3. Hairy cell leukemia 4. MALT lymphoma

Question 44

True or false: DM is a common cause of liver cirrhosis

Answer 44

True

Question 45

What are the three components of thrombocytopenia?

Answer 45

1. Careful H&P 2. Lab eval 3. Bone marrow biopsy

Question 46

What are the three things to look for in a PE of thrombocytopenia?

Answer 46

Mucocutaneous exam Lymphadenopathy Splenomegaly

Question 47

What are the two diseases that contraindicate platelet transfusion? Why?

Answer 47

ITP HIT May accelerate platelet destruction

Question 48

For every unit of blood, how much increase in platelets should you expect?

Answer 48

5k

Question 49

What are the three things that should be a part of a PE for pts with thromboytopenia?

Answer 49

Mucocutaneous Lymph Spleen

Question 50

When is a bone marrow biopsy indicated?

Answer 50

2 or more cell lines affected

Question 51

What is the more common cause of underproduction thrombocytopenia?

Answer 51

Drugs

Question 52

What is the tube that should be used to r/o pseudothrombocytopenia?

Answer 52

Blue top