Congenital thrombotic thrombocytopenic purpura simulating alloimmune thrombocytopenia

Abstract

Congenital thrombotic thrombocytopenic purpura (cTTP) is a thrombotic microangiopathic caused by severely reduced activity of the von Willebrand factor-cleaving protease A Disintegrin And Metalloproteinase with a Thrombospondin type 1 Motif, member 13 (ADAMTS-13), which leads to small-vessel platelet-rich thrombi, thrombocytopenia, and microangiopathic hemolytic anemia (MHA) in the absence of neutralizing antibodies. We describe a case of cTTP in a female neonate presenting initially on the 1st day of life with asymptomatic thrombocytopenia thought to be alloimmune thrombocytopenia, then progressed to severe neonatal jaundice, pallor, and MHA, in whom ADAMTS-13 levels <5%, and the anti-ADAMTS-13 antibody titer was negative confirming the diagnosis of cTTP. The patient initially received intravenous immunoglobulin infusion before documenting MHA. She received fresh frozen plasma infusions which successfully reversed the MHA (by supplying ADAMTS-13) and prevented organ damage in this patient.