ADAMTS13 and anti-ADAMTS13 autoantibodies in thrombotic thrombocytopenic purpura – current perspectives and new treatment strategies

ABSTRACT

A deficiency in ADAMTS13 (A Disintegrin And Metalloprotease with ThromboSpondin type-1 repeats, member 13) is associated with thrombotic thrombocytopenic purpura (TTP). Congenital TTP is caused by a defect in the ADAMTS13 gene resulting in decreased or absent enzyme activity; acquired TTP results from autoantibodies that either inhibit the activity or increase the clearance of ADAMTS13. Despite major progress in recent years in our understanding of the disease, many aspects around the pathophysiology of TTP are still unclear. Newer studies expanded the TTP field from ADAMTS13 and inhibitory antibodies to immune complexes, cloned autoantibodies, and a possible involvement of other proteases. Additionally, several new treatment strategies supplementing plasma-exchange and infusion are under investigation for a better and more specific treatment of TTP patients. In this review, we discuss the recent insights in TTP pathophysiology and describe upcoming therapeutic opportunities.

KEYWORDS:

• ADAMTS13
• thrombotic thrombocytopenic purpura (TTP)
• von Willebrand factor
• congenital TTP
• acquired TTP
• immune complexes
• autoantibodies
• proteases