Thrombotic Thrombocytopenic Purpura Registry - A Prospective Observational Study for Patients Suffering From Hereditary Thrombotic Thrombocytopenic Purpura (Upshaw-Schulman Syndrome)
试验速览
- 阶段
- 不适用
- 状态
- 招募中
- 入组人数
- 450
- 试验地点
- 7
- 主要终点
- Clinical presentation and disease course in hereditary TTP
研究概览
简要总结
Hereditary thrombotic thrombocytopenic purpura (Upshaw-Schulman syndrome) is a rare disorder characterized by thrombocytopenia as a result of platelet consumption, microangiopathic hemolytic anemia, occlusion of the microvasculature with von Willebrand factor-platelet-thrombic and ischemic end organ damage. The underlying patho-mechanism is a severe congenital ADAMTS13 (a disintegrin and metalloproteinase with thrombospondin type 1 motif, 13) deficiency which is the result of compound heterozygous or homozygous ADAMTS13 gene mutations.
Although considered a monogenic disorder the clinical presentation in Upshaw-Schulman syndrome patients varies considerably without an apparent genotype-phenotype correlation. In 2006 we have initiated a registry for patients with Upshaw-Schulman syndrome and their family members to identify possible triggers of acute bouts of TTP, to document individual clinical courses and treatment requirements as well as possible side effects of long standing plasma substitution, e.g. alloantibody formation or viral infections.
详细描述
Background
Thrombocytopenia and microangiopathic hemolytic anemia together with a severely deficient ADAMTS13 activity confirm the diagnosis of acute thrombotic thrombocytopenic purpura (TTP). Today two forms of classical TTP are distinguished. The acquired form is caused by circulating auto-antibodies, mainly Immunoglobulin G (IgG), inhibiting ADAMTS13 (a disintegrin and metalloproteinase with thrombospondin type 1 motif, 13) activity. In contrast, hereditary TTP, also known as Upshaw-Schulman syndrome (USS); #274150 Online Mendelian Inheritance in Man (OMIM), is the result of severe constitutional deficiency of ADAMTS13 due to compound heterozygous or homozygous mutations in the ADAMTS13 gene.
The clinical course of USS is variable with rather mild courses in some of the patients requiring plasma infusions only in special situations (i.e. pregnancy), while in others severe courses with important sequelae and even death in early childhood occur. The reasons for the variable clinical presentation and treatment requirements have not been elucidated. It seems likely, that additional, hitherto unidentified factors besides severe ADAMTS13 deficiency modify the clinical course.
At present, the clinical symptoms and laboratory values on which to base treatment regimens for hereditary TTP are poorly understood. Furthermore, increasing awareness of hereditary TTP results in rising numbers of patients in need of treatment and/or prophylaxis. However, currently very little is known on side effects of long standing plasma substitution. Alloimmunization with the formation of antibodies acting as inhibitors of treatment are well known in other congenital coagulation factor deficiencies (e.g. hemophilia A), but so far no case of treated hereditary TTP with subsequent antibody formation has been reported. It is the aim of the hereditary TTP Registry to provide information on the clinical course of the disease in as many patients as possible and therefore help to establish recommendations on the necessity, modalities, and risks of prophylactic plasma therapy in patients with hereditary TTP. Furthermore, it will help to gain detailed insight into triggers and risk factors of acute bouts of TTP.
Moreover, the hereditary TTP Registry will provide information for family members on their risk to develop TTP-like or TTP-related disorders.
研究设计
- 研究类型
- Observational
- 观察模型
- Case Only
- 时间视角
- Other
入排标准
- 性别
- All
- 接受健康志愿者
- 否
入选标准
- •Severe ADAMTS13 deficiency ( ≤ 10% activity) and no ADAMTS 13 inhibitor on two or more occasions at least one month apart
- •Being a family member of a confirmed or suspected patient
- •Molecular analysis of ADAMTS13 gene with one or more mutations and/or positive infusion trial (full recovered ADAMTS13 activity after infused fresh frozen plasma (FFP) with a plasma half-life of 2-4 days)
排除标准
- 未提供
结局指标
主要结局
Clinical presentation and disease course in hereditary TTP
时间窗: every year until death
次要结局
- Identification of disease-modifying factors, including genotype-phenotype correlation(every year until death)
- Treatment requirements in hereditary TTP patients(every year until death)
- Mortality of hereditary TTP(every year until death)
- Documentation of potential adversary effects of (long-term) plasma treatment(every year until death)
- Clinical course in family members(every year until death)