International Registry for Patients with Hereditary Thrombotic Thrombocytopenic Purpura (TTP) – Upshaw-Schulman Syndrome

Abstract 4654 Background: Hereditary TTP, also known as Upshaw-Schulman syndrome (USS), is a rare disorder and the result of recessively inherited ADAMTS13 gene (located on chromosome 9q34) mutations. The clinical presentation is variable and may vary from mild isolated thrombocytopenia to recurrent severe TTP episodes leading to organ damage or even death. The first acute TTP episode may occur during the neonatal period up to older age. The same variety applies to the treatment requirements as some patients need regular plasma infusion every two to three weeks to prevent recurrent episodes while others only need plasma therapy in situations of increased risk, such as pregnancy or during infections. Due to the rareness of USS evidence based guidelines are lacking as are knowledge of long-term outcome which emphasizes the need of a multicenter cooperation. Aim: We have established a long-term observational study with an electronic database system for hereditary TTP patients (www.ttpregistry.net, ClinicalTrials.gov NCT01257269) to gather as much information as possible about the clinical courses and laboratory investigations performed. We aim at the identification of triggers that set about acute TTP bouts and of factors influencing the clinical course with the goal to possibly elucidated the underlying causes of the variable clinical presentation of this rare monogenic disorder eventually leading to optimization of therapy and evidence based recommendations. The study is open to any patient diagnosed with hereditary TTP and his/her interested family members. Eligibility criteria are as follows: • ADAMTS13 activity ≤10% on two separate occasions at least 1 month apart; and • Absence of a functional ADAMTS13 inhibitor and • ≥2 ADAMTS13 gene mutations and/or full recovery and normal half-life of infused plasma ADAMTS13); or • Being a family members of a confirmed patient Clinical information and laboratory investigations are collected retrospectively up to enrollment as well as prospectively every 12 months following enrollment. Analysis of ADAMTS13 related parameters including molecular analysis of ADAMTS13 gene are offered free of charge to patients and all family members. Conclusion: Our long-term goal is to establish an international network and knowledge platform to exchange information and experience on USS, that helps to improve diagnosis, treatment and prevention of acute episodes with risk of permanent organ damage for affected patients. Physicians treating USS patients are invited to contact us for diagnostics of suspected patients or enroll their confirmed patients. Disclosures: Fujimura: Baxter BioScience: Membership on an entity9s Board of Directors or advisory committees; Alexion Pharma: Membership on an entity9s Board of Directors or advisory committees. George: Baxter, Inc.: Consultancy; Alexion, Inc.: Consultancy; Amgen, Inc.: Consultancy, PI for clinical trial involving romiplostim, PI for clinical trial involving romiplostim Other, Research Funding. Kremer Hovinga Strebel: Baxter: Consultancy, Research Funding.