Thrombotic thrombocytopenic purpura (TTP) is a rare multisystem disorder characterized by single or recurrent episodes of thrombocytopenia, microangiopathic hemolytic anemia and widespread microvascular thrombosis, which causes significant morbidity and mortality unless promptly recognized and treated. The underlying pathogenesis is a defect in von Willebrand factor (vWF) cleaving protease, called `A Disintegrin and Metalloproteinase with Thrombospondin Type 1 Repeats 13 (ADAMTS-13)`. There are 2 forms: congenital TTP (ADAMTS-13 gene mutations) and acquired TTP (autoantibodies and ADAMTS-13 deficiency). We presented two patients who initially presented with thrombotic microangiopathy and were later diagnosed with TTP upon demonstration of the deficiency in ADAMTS-13 activity.

Keywords: ADAMTS-13, Thrombotic thrombocytopenic purpura, microangiopathy