Laboratory assay of ADAMS 13
ADAMS 13 is a metalloprotease responsible for cleavage of Von Willebrand ultra large multimers. Severe deficiency of this protease, either by auto-antibodies against it or by complement lead to severe thrombotic diseases, such as thrombotic thrombocytopenic purpura or hemolytic uremic syndrome. There are some evidences that less blatant deficiencies of this protease can play a role in other thrombotic diseases, e.g., ischemic stroke and coronary artery disease. The assay of ADAMS13 is usually unavailable at clinical laboratories, and can be done by activity assays or antigen assays. Thrombotic thrombocytopenic purpura has levels lower than 10%, and in thrombotic diseases like ischemic stroke and coronary artery disease, the levels are about 75% higher than normal level. So far, the relevance of this finding is unknown.
Masias C, Cataland SR. The role of ADAMST 13 testing in the diagnosis and management of thrombotic microangiopathies. Blood. 2018;132(9):903-10. https://doi10.1182/blood-2018-02-791533.