What is cTTP?

Congenital thrombotic thrombocytopenic purpura (cTTP) is an ultra-rare thrombomicroangiopathy caused by an inherited deficiency of the VWF (von Willebrand Factor)-cleaving metalloprotease, A disintegrin and metalloproteinase with thrombospondin motifs 13 (ADAMTS13), resulting in the abnormal presence of ultra-large VWF multimers and the formation of circulating platelet-rich microthrombi.¹ cTTP results from severe hereditary deficiency (<10% of normal activity) of ADAMTS13, leading to accumulation of ultra-large VWF multimers with high platelet-binding activity.²

The clinical presentation ranges from life-threatening, acute, overt TTP events to milder TTP manifestations, including thrombocytopenia, haemolytic anaemia, abdominal pain, headaches, and neurological symptoms.² End-organ damage due to recurrent overt and non-overt TTP events, such as stroke, chronic kidney disease, or cardiac involvement, can develop.²
 

There are two main types of TTP:³

• The majority of TTP cases are the acquired type and are caused by anti-ADAMTS13 autoantibodies (immune-mediated TTP).
• The remaining cases, which are extremely rare, are congenital TTP (cTTP), also known as Upshaw-Schulman syndrome, and are caused by mutations in the ADAMTS13 gene.
   

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  Did you know?

   The congenital form of the disease was recognised after the immune-mediated form. TTP itself was
                first clinically described in 1924 by Dr. Eli Moschcowitz, as an acute, fatal disorder characterised by
                systemic microvascular thrombosis. Following this, scientists recognised that TTP occurrence could be
                hereditary. In fact, cTTP was first described by Irving Schulman in 1960 in a young girl with haemolytic
                anaemia, recurrent thrombocytopenia and bleeding tendency.^4-6

A study by Mariotte E et al. in The Lancet reported on a cross-sectional analysis of the French national registry for thrombotic microangiopathy, showing a prevalence of adult-onset TTP in approximately 13 individuals per million. Other studies suggest that the exact diagnosed prevalence of cTTP is uncertain, though it is estimated to be 0.5 2 cases per million.^6-8

Although first symptom occurrence of cTTP has classically been described in childhood, presentation can occur at any age, with a notable peak in women during pregnancy.¹