Hemolytic uremic syndrome

Question 1

MAHA stands for

Answer 1

Microangiopathic hemolytic anemia (MAHA)

Question 2

MAHA pathophys

Answer 2

• non-immune hemolysis (Coombs-negative) resulting from intravascular RBC fragmentation
• typically due to small arterioles and capillaries but intravascular devices can also cause MAHA

Question 3

what is TMA

Answer 3

TMA describes a specific pathologic lesion in which abnormalities in the vessell wall lead to microvascular thrombosis
- thus path diagnosis made by tissue biopsy

Question 4

What are the primary TMA syndromes?

Answer 4

TTP
Shiga toxin-mediated HUS
Drug-induced TMA
Complement-mediated TMA (atypical HUS)

Question 5

what is atypical HUS?

Answer 5

complement-mediated TMA, so no ADAMTS13 or shiga toxin

Question 6

presentation of HUS

Answer 6

• bloody diarrhea

- renal failure

Question 7

management of HUS

Answer 7

plasmapheresis

Question 8

Problem with plasmapheresis for treatment of HUS

Answer 8

a lot of people don’t respond

Question 9

Atypical HUS pathophys

Answer 9

complement-mediated HUS (20% of population have polymorphisms in complement system–> infection or inflammatory state leads to overactivation of complement system)

Question 10

atypical HUS diagnosis

Answer 10

• diagnosis of exclusion (exclude TTP and HUS)

Question 11

management of atypical HUS

Answer 11

anti-C5 therapy (eculizumab)