Adamts13

Acronym for "A disintegrin and metalloprotease with thrombospondin-1-like domains". The corresponding ADAMTS 13 gene is located on chromosome 9 q34. The ADAMTS 13 protein is a member of a large family of zinc-containing metalloproteases, of which 20 members have now been described. They are involved in a number of different biological processes, such as connective tissue organization, inflammatory processes, arthritis, angiogenesis and cell migration. ADAMTS 13 cleaves von Willebrand factor (vWF).

ADAMTS-13 cleaves the vWF multimer into smaller segments and thereby prevents the formation of larger aggregates (UL-vWF). Decreased activity of ADAMTS13 (<5-10%) results in high levels of UL-vWF in the blood plasma, leading to spontaneous platelet activation. These thrombi consist of large Von Willebrand factor complexes as well as activated platelets. The thrombotic vascular occlusions result in ischemia of downstream tissues(in the skin, necrotizing purpura).

Severely decreased activity (< 5-10%) of protease is specific for thrombocytic-thrombocytopenic purpura (M31 .1).

In secondary forms, ADAMTS13 is unremarkable or slightly decreased.

In the relatively common autoimmunologically (antibody formation) acquired form, ADAMTS13 antibodies are detectable.

Furthermore, a homologous protein subfamily was identified, the ADAMTS-like proteins, which do not have enzymatic functions. Of these, the ADAMTS-like protein 5 was identified as an autoantigen of melanocytes. It seems to play a role in the pathogenesis of psoriasis.

1. Mariotte E et al (2016) French Reference Center for Thrombotic Microangiopathies. Epidemiology and pathophysiology of adulthood-onset thrombotic microangiopathy with severe ADAMTS13 deficiency (thrombotic thrombocytopenic purpura): a cross-sectional analysis of the French national registry for thrombotic microangiopathy. Lancet Haematol 3:e237-245.
2. Prince JC (2016) Autoimmune reactions in psoriasis. Dermatologist 67: 432-437
3. Tersteeg C et al (2016) ADAMTS13 and anti-ADAMTS13 autoantibodies in thrombocytopenic purpura - current perspectives and new treatment strategies. Expert Rev Hematol 9: 209-221.
4. Thomas MR et al (2015) Pathogenicity of anti-ADAMTS13 autoantibodies in acquired thrombocytopenic purpura. EBioMedicine. 2: 940-950.