Abstract
Acquired thrombotic thrombocytopenic purpura (TTP) is a rare thrombotic microangiopathy
caused by the immune-mediated severe deficiency of ADAMTS13. We hereby report the
demographic and disease-related data of acquired TTP patients recorded in the Milan
TTP Registry (www.ttpdatabase.org). We performed a cross-sectional study of 302 individuals enrolled in our registry
for an acute episode of acquired TTP occurred between 2002 and 2015 (female 77%; median
age at onset 40 years, interquartile range: 30–50). Twenty per cent of patients had
concomitant autoimmune disorders. Among potential triggers of acute episodes, infections
were the most prevalent (27%), followed by estroprogestinics use and pregnancy (5
and 4% of women, respectively). At presentation, systemic (72%), bleeding (68%) and
neurological (43%) symptoms were the most frequent, whereas a lower prevalence of
renal (18%) and cardiovascular (10%) signs and symptoms was observed. Almost all acute
events were treated by plasma exchange and steroids, and 15% by rituximab. Exacerbation
of acute TTP occurred in 15% of events. The TTP-related mortality was 5%. In survivors,
the median number of plasma exchange procedures to remission was 9 (interquartile
range: 6–14), longer for first events than relapses (median difference 3, 95% confidence
interval: 2–4). Of 251 survivors of the first TTP episode with at least a 6-month
follow-up, 55% had a relapse. In conclusion, acquired TTP is a severe disease with
highly variable clinical presentation, usually requiring a long hospitalization. The
Milan TTP Registry represents a powerful tool to improve our knowledge and management
of acquired TTP.
Keywords
ADAMTS13 - diagnosis management - register - thrombotic microangiopathy - thrombotic
thrombocytopenic purpura
