The characteristics and current treatment status of child-onset thrombotic thrombocytopenic purpura / 中国小儿急救医学

ABSTRACT

Thrombotic thrombocytopenic purpura (TTP) is a rare but fatal entity of thrombotic microangiopathies(TMAs).The pathophysiology of the disease is based on a severe functional deficiency of a disintegrin and metalloprotease with thrombospondin type 1 repeats,member 13 (ADAMTS-13),the specific von Willebrand factor (VWF)-cleavage protease.This deficiency may be either acquired or congenital.The clinical manifestations of TTP include microangiopathic hemolytic anemia,thrombocytopenia and dysfunction of involved organs,which are similar to other TMAs.The differential diagnosis with other TMAs may be challenging.The activity of plasma ADAMTS-13 ＜ 10％ is the only definitive method for diagnosis of TTP.The first-line treatment of the acute phase of TTP is based on plasmatherapy.In congenital TTP,patients benefit from a prophylactic plasmatherapy.In acquired TTP,steroids and B-cells depleting therapies are increasingly used together with plasma exchange.Long-term follow-up including the monitoring of ADAMTS-13 activity is mandatory.A severe decrease in ADAMTS-13 activity (＜ 10％) may predict relapses and preemptive B-cell depletion with rituximab can be used to prevent relapses of acquired TTP.