A patient with a history of thrombotic events is found to have a deficiency of ADAMTS13. What is the most likely diagnosis?

A Thrombotic thrombocytopenic purpura (TTP) ✓
B Hemolytic uremic syndrome (HUS)
C Disseminated intravascular coagulation (DIC)
D Antiphospholipid syndrome (APS)

Explanation

ADAMTS13 is a metalloprotease that cleaves von Willebrand factor. A deficiency of ADAMTS13 leads to the accumulation of ultra-large von Willebrand factor multimers, which can cause thrombotic thrombocytopenic purpura (TTP).

Source

New England Journal of Medicine article on TTP
Hematology Hematology: Coagulation Disorders Hematology: Coagulation Disorders Hard MEDICAL Confidence: high