Pre-5: Quantitative Disorders

Question 1

Normal platelet count

Answer 1

150-400 x 10^9/L

Question 2

Thrombocytopenia

Answer 2

50-100 x 10^9/L

Question 3

Thrombocytopenia results from three distinct mechanisms:

Answer 3

1. Deficient Platelet Production
2. Abnormal Distribution of Platelets
3. Increased Platelet Destruction

Question 4

Deficient platelet production

Answer 4

1. Myelophthisis
2. Aplasia
3. Ineffective erythropoiesis
4. Congenital Disorders

Question 5

Abnormal platelet distribution

Answer 5

Hypersplenism
Hemangiomas

Question 6

Increased platelet destruction

Answer 6

Immune origin - primary
Immune origin - secondary
Microangiopathic thrombocytoepnia
Pregnancy-associated thrombocytopenia

Question 7

Caused by an auto-Ab to the patient’s plts

Answer 7

Idiopathic Thrombocytopenic Purpura (ITP)

Question 8

Most common disorder causing severe isolated thrombocytopenia

Answer 8

Idiopathic Thrombocytopenic Purpura (ITP)

Question 9

In chronic ITP, the target for the autoantiplatelet antibodies is platelet membranes which are

Answer 9

GP IIb/IIIa
GP Ib/IX
GP Ia/IIa
GP VI

Question 10

Treatment for Idiopathic Thrombocytopenic Purpura (ITP)

Answer 10

Splenectomy
Corticosteroid (Prednisone)
IVIG

Question 11

Caused by an alloantibody to HPA-1a (Human Platelet Antibody-1a)

Answer 11

Post-Transfusion Purpura (PTP)

Question 12

The recipient’s plasma is found to contain alloantibodies to antigens on the platelets or platelet membrane of the transfused blood product, directed against antigen the recipient does not have

Answer 12

Post-Transfusion Purpura (PTP)

Question 13

Treatment for Post-Transfusion Purpura (PTP)

Answer 13

Plasmapheresis

Question 14

Rare hemolytic disease of newborn

Answer 14

Isoimmune Neonatal Thrombocytopenia

Question 15

Fetal-maternal incompatibility of platelet antigens, and destruction of fetal platelets by a transplacental transfer of maternal antibody

Answer 15

Isoimmune Neonatal Thrombocytopenia

Question 16

recognized as the most common cause of Drug-Induced Immune Thrombocytopenia (DIIT)

Answer 16

Quinine

Question 17

develops secondary to antibody produced to Platelet factor 4 - Heparin complex

Answer 17

Heparin-Induced Thrombocytopenia and Thrombosis (HITT)

Question 18

Heparin-Induced Thrombocytopenia and Thrombosis (HITT)

• Appears 4-7 days after treatment
• As low as 20x10^9/L
• Severe thrombocytopenia and thrombotic episodes

Answer 18

TYPE 2

Question 19

Heparin-Induced Thrombocytopenia and Thrombosis (HITT)

• Appears early in treatment
• Rarely falls below 100x10^9 /L
• NO resultant bleeding or thrombotic complications

Answer 19

TYPE 1

Question 20

directly related to the accumulation of ultra large von Willebrand factor (ULVWF) multimers in the plasma due to deficiency of the von Willebrand factor cleaving protease known as a disintegrin and metalloproteinase with a thrombospondin type 1 motif, member 13 (ADAMTS-13)

Answer 20

Thrombotic Thrombocytopenic Purpura (TTP)

Question 21

Mutations in ADAMTS-13 gene

Answer 21

Congenital/Familial TTP

Question 22

Antibodies anti-ADAMTS13

Answer 22

Idiopathic TTP

Question 23

Classic PENTAD of TTP

Answer 23

FAT RN

1. Fever
2. Anemia
3. Thrombocytopenia
4. Renal failure
5. Neurologic findings

Question 24

Shiga-toxin-producing organisms

Answer 24

Hemolytic Uremic Syndrome (HUS)

Question 25

Bacteria responsible for HUS

Answer 25

Escherichia coli 0157:H7

Question 26

Types of HUS:

• usually involves diarrhea
• primarily affects infants, small children
• associated with shiga toxin
• often resolves with supportive care, with recovery of renal function

Answer 26

Typical HUS (90%)

Question 27

Types of HUS:

• may or may not involve diarrhea
• can affect children or adults
• may be familiar or sporadic
• requires immediate attention to avoid fatality and optimize outcomes

Answer 27

Atypical HUS (10%)

Question 28

TRIAD for HUS

Answer 28

RAT:
- Renal injury
- Anemia
- Thrombocytopenia

Question 29

A complication or intermediary phase of many diseases such as liver disease, renal disease, and lymphoproliferative disorders

Answer 29

Disseminated Intravascular Coagulation (DIC)

Question 30

Positive for D-Dimer assay (most specific test)

Answer 30

Disseminated Intravascular Coagulation (DIC)

Question 31

● Thrombocytopenia
● The PT, PTT, and thrombin time are prolonged
● The fibrinogen level is reduced to less than 100 mg/dL
● Fibrin degradation products, inducing D-dimers, are significantly increased

Answer 31

Acute, uncompensated DIC

Question 32

● Normal or Elevated
● The only elevated result may be the D-dimer assay

Answer 32

Chronic, compensated DIC

Question 33

HELLP syndrome;

Answer 33

Hemolysis
Elevated Liver enzymes
Low Platelet count

Question 34

Defined as platelet count above normal range

Answer 34

THRombocytosis

Question 35

<1,000 x 10^9/L
Normal platelet function

Answer 35

Secondary Thrombocytosis
(REACTIVE)

Question 36

> 1,000 x 10^9/L
Defective platelet function

Answer 36

Primary Thrombocytosis
(AUTONOMOUS)