The features of acquired thrombotic thrombocytopenic purpura occurring at advanced age

Acquired thrombotic thrombocytopenic purpura (aTTP) is a rare life-threatening thrombotic microangiopathy (TMA) affecting more frequently women of 30–50 years of age. There is scarce information on the clinical features of aTTP occurring in the elderly. Our goal was to evaluate the impact of an elderly-onset disease on the expression, severity and management of aTTP. We performed a cross-sectional study of patients enrolled in the Milan TTP Registry (www.ttpdatabase.org) after a first acute episode of aTTP from January 2002 to March 2018. The aTTP diagnosis was suspected on the basis of the presence of thrombocytopenia and microangiopathic hemolytic anemia with no alternative causes, and was confirmed centrally by a severe plasma deficiency of ADAMTS13 activity (