Thrombotic Microangiopathies

Question 1

How can you clinically differentiate TTP from HUS?

Question 2

True or false: The treatment of choice for TTP is plasma exchange.

Answer 2

True

Question 3

True or false: Platelet transfusion is the treatment of choice for TTP.

Answer 3

False

Question 4

What type of anaemia is the hallmark in TMA?

Answer 4

MAHA

Question 5

True or false: Iron deficiency anaemia is the hallmark in TMA.

Answer 5

False

Question 6

What is the most correct statement regarding TTP and HUS?

Answer 6

HUS is a more common cause of ARF than TTP

Question 7

What are the classic pentad features of TTP?

Answer 7

• Microangiopathic haemolytic anaemia
• Thrombocytopenia
• Renal insufficiency or abnormalities
• Neurologic abnormalities
• Fever

Question 8

What accounts for >99% of adolescent and adult cases of TTP?

Answer 8

Acquired TTP

Question 9

What autoimmune condition is associated with TTP?

Answer 9

Anti-ADAMTS-13 antibodies

Question 10

What does decreased ADAMTS13 activity lead to?

Answer 10

Accumulation of UL vWF multimers

Question 11

TTP is a _______ diagnosis.

Answer 11

clinicopathological

Question 12

What is considered pathologic in terms of schistocytes on a blood film?

Answer 12

More than two schistocytes per high-power field or > 1.0% schistocytes

Question 13

What is the cornerstone of current management of TTP?

Answer 13

Therapeutic Plasma Exchange (TPE)

Question 14

What is the recommended dosage of prednisone for TTP treatment?

Answer 14

1 mg/kg/day orally followed by a rapid taper

Question 15

Without therapy, the mortality rate of TTP exceeds _____%.

Answer 15

90

Question 16

What should be assayed before beginning therapy for TTP?

Answer 16

ADAMTS13 activity

Question 17

What laboratory features are indicative of TTP?

Answer 17

• Anaemia
• Thrombocytopenia
• Schistocytes
• Elevated LDH
• Unconjugated hyperbilirubinaemia
• Reduced haptoglobin

Question 18

What is the major component of the hemostatic system?

Answer 18

• Vascular endothelium
• Platelets
• Coagulation and fibrinolytic systems

Question 19

What is the incidence of TTP in adults?

Answer 19

About 3 per 1,000,000

Question 20

TTP has a higher incidence in which gender?

Answer 20

Female

Question 21

What is the primary cause of ADAMTS13 deficiency in acquired TTP?

Answer 21

Autoantibodies to ADAMTS13

Question 22

What is the role of ADAMTS13?

Answer 22

Cleaves vWF

Question 23

What is a common feature of obstetric TTP?

Answer 23

Occurs during the second half of pregnancy

Question 24

True or false: HIV infection alters the prognosis of TTP.

Answer 24

False

Question 25

What characterizes HUS?

Answer 25

MAHA and thrombocytopenia

Question 26

What is the major clinical manifestation of HUS?

Answer 26

Renal disease

Question 27

What is the most common cause of acute renal failure in children?

Answer 27

HUS

Question 28

What is the inheritance pattern of aHUS?

Answer 28

Autosomal dominant

Question 29

What is the typical treatment for STEC-HUS?

Answer 29

Supportive care

Question 30

What is iculocytosis?

Answer 30

A clinical term related to the presence of schistiocytes in a peripheral blood smear ## Footnote Schistiocytes are fragmented red blood cells often seen in conditions of hemolysis.

Question 31

What are elevated LDH levels indicative of?

Answer 31

Tissue damage, commonly associated with hemolytic conditions ## Footnote LDH (lactate dehydrogenase) is an enzyme released during tissue injury.

Question 32

What clinical findings are associated with hemolytic uremic syndrome (HUS)?

Answer 32

Triad of microangiopathic hemolytic anemia, thrombocytopenia, and acute renal damage

Question 33

What is the primary treatment for STEC-HUS?

Answer 33

Supportive care ## Footnote Volume expansion within the first 4 days is crucial.

Question 34

What should be avoided in the management of STEC-HUS?

Answer 34

Antimotility agents ## Footnote These can worsen the condition.

Question 35

True or False: Antibiotics are routinely recommended for STEC-HUS.

Answer 35

False ## Footnote Use is controversial and only indicated for suspected sepsis or S. dysenteriae infection.

Question 36

What characterizes thrombotic microangiopathies (TMAs)?

Answer 36

MAHA, thrombocytopenia, and microthrombi leading to ischemic tissue injury

Question 37

What is the hallmark of thrombotic microangiopathy?

Answer 37

Microangiopathic hemolytic anemia (MAHA)

Question 38

What is the typical prognosis for patients with STEC-HUS?

Answer 38

Generally favorable, but chronic renal insufficiency may develop over time

Question 39

What is the incidence of atypical HUS (aHUS) in the USA?

Answer 39

Estimated at 2 per million

Question 40

What is a common cause of typical HUS?

Answer 40

Shiga toxin-producing E. coli (STEC) ## Footnote Responsible for 90% of childhood HUS cases.

Question 41

Fill in the blank: The most common serotype associated with STEC-HUS is _______.

Answer 41

E. coli O157:H7

Question 42

What are some potential triggers for atypical HUS?

Answer 42

Varicella, H1N1 influenza

Question 43

What is the primary clinical feature of hemolytic uremic syndrome?

Answer 43

Thrombotic microangiopathy (TMA)

Question 44

What are the main pathological lesions in HUS?

Answer 44

Thickening of arterioles, endothelial swelling, and detachment

Question 45

What is the typical age of onset for pediatric TTP?

Answer 45

Typically occurs during infancy or early childhood (<10 years)

Question 46

What is the role of Eculizumab in aHUS management?

Answer 46

Inhibits C5 activation and prevents TMA process

Question 47

What percentage of children with STEC-HUS require dialysis during the acute phase?

Answer 47

Up to 60%

Question 48

What are alloantibodies?

Answer 48

Antibodies produced against transfused blood cells from another individual

Question 49

What conditions can cause alloantibodies?

Answer 49

* Hemolytic disease of the newborn * Incompatible blood transfusion

Question 50

What distinguishes autoantibodies from alloantibodies?

Answer 50

Autoantibodies are directed against one's own RBCs

Question 51

What are some common causes of autoimmune hemolytic anemia?

Answer 51

* Systemic lupus erythematosus (SLE) * Other autoimmune diseases

Question 52

What is the usual outcome for D(+) HUS?

Answer 52

Self-limiting, but residual renal dysfunction is common

Question 53

What is the significance of DAT in hemolytic anemia?

Answer 53

Direct Antiglobulin Test (DAT) indicates the presence of autoantibodies