ADAMTS13 is a disintegrin and metalloproteinase with a thrombospondin type 1 motif, member 13.

It is also known as von Willebrand factor-cleaving protease (VWFCP).

ADAMTS (short for a disintegrin and metalloproteinase with thrombospondin motifs) 

ADAMST is a family of multidomain extracellular protease enzymes.

19 members of this family have been identified.

ADAMTS proteases functions include processing of procollagens and von Willebrand factor.

ADAMST13 is the plasma metalloproteinases that cleaves ultra large von  Willebrand factor multimers down to physiologic size.

vWF Multimers of physiologic size mediate thrombosis by binding platelets to the sub endothelium were needed.

ADAMST13 is a plasma, protease synthesized in the liver that Cleves von Willebrand factor at his site buried in the core beta sheet of the A2 domain.

when the cleavage does not occur, micro thrombi of platelets form in small vessels at multiple sites causing clinical manifestations of TTP.

Ultra large VWF multipliers in contrast cause excessive binding of platelets throughout the body.

In most cases the deficiency is acquires when antibodies form that either destroy or block the function of ADAMSTS 13.

In rare cases people are born without the ADAMTS 13 protease.

ADAMTS proteases cleave aggrecan, versican, brevican and neurocan, and are  key in remodeling enzymes of the extracellular matrix. 


ADAMTS proteases have roles in connective tissue organization, coagulation, inflammation, arthritis, angiogenesis and cell migration.


Most cases of ((thrombotic thrombocytopenic purpura))arise from autoantibody-mediated inhibition of ADAMTS13.


It is a zinc-containing metalloprotease enzyme that cleaves von Willebrand factor (vWf), a large protein involved in blood clotting. 


ADAMTS13 is secreted into the blood and degrades large vWf multimers, decreasing their activity.

ADAMTS13 mild decrease in activity can be seen with aging, liver, disease, inflammatory, conditions, or pregnancy.

A severe decrease in ADAMTS13 to a level of less than 10% is characteristic of TTP.

In less than 5% of cases such a deficiency is genetic, causing congenital. TTP.

ADAMTS 13 activity levels are usually above 50% and if the activity below falls below 10% the diagnostis is likely TTP, whereas levels exceeding 20% indicate the diagnosis is unlikely.

ADAMTS13 Gene location is Chromosome 9


Thrombotic thrombocytopenic purpura (TTP), one of the microangiopathic hemolytic anemias is characterized in its familial form by the presence in plasma of unusually large von Willebrand factor multimers (ULVWF).


ADAMTS13 has specific epitopes on its surface have been shown to be the target of inhibitory antibodies.

ADAMTS13 Inhibitor assays are available to indicate their presence in acquired disease.

Low levels of ADAMTS13 are also associated with an increased risk of arterial thrombosis, including myocardial infarction and cerebrovascular disease.

The PLASMIC score based on platelet count, combined hemolysis variable, mean corpuscular volume, international normalized ratio, indirect bilirubin, reticulocytes, or haptoglobin,and creatinine in the absence of active cancer or recent transplantation is a clinical tool used to estimate the likelihood of severe ADAMTS 13 deficiency in adults with thrombocytopenia and evidence of micro angiopathic hemolytic anemia on peripheral smear.
ADAMTS 13 activity is measured by means of the fluorescent resonance energy transfer.
Therapeutic plasma exchange allows the transfusion of a high volume of ADAMST13 in donor plasma, but also removes the circulating antibody inhibitor in more than 95% of patients with autoimmune TTP.

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