Anti-A disintegrin and metalloproteinase with a thrombospondin type 1 motif, member 13 autoantibodies (Anti-ADAMTS13)

Anti-A disintegrin and metalloproteinase with a thrombospondin type 1 motif, member 13 (ADAMTS13) autoantibodies are pathogenic immunoglobulins, primarily of the IgG class, that target the ADAMTS13 enzyme [StatPearls, 2023]. These autoantibodies cause a severe deficiency in ADAMTS13 activity by either directly blocking its proteolytic site or by forming immune complexes that lead to accelerated clearance of the enzyme from circulation [UniProt, P59510]. Under normal physiological conditions, ADAMTS13 cleaves ultra-large von Willebrand factor (ULVWF) multimers; however, its inhibition by autoantibodies leads to the accumulation of these multimers, which induce spontaneous platelet-rich microthrombi [NIH, 2022]. This process results in immune-mediated thrombotic thrombocytopenic purpura (iTTP), a life-threatening condition characterized by microangiopathic hemolytic anemia, severe thrombocytopenia, and potential organ ischemia [ASH, 2020]. Treatment focuses on the rapid removal of these antibodies via therapeutic plasma exchange and the suppression of their production using B-cell depleting agents like rituximab or systemic corticosteroids [JTH, 2017]. Monitoring anti-ADAMTS13 antibody titers and ADAMTS13 activity levels is essential for the diagnosis, management, and prediction of relapse in patients with iTTP [PubMed, 2021].

Other names

ADAMTS13 inhibitorsAnti-ADAMTS13 IgGADAMTS13 autoantibodiesADAMTS13 neutralizing antibodies

Therapeutic interventions target these autoantibodies through physical removal via therapeutic plasma exchange, depletion of antibody-producing B-cells using rituximab, and systemic immunosuppression with corticosteroids to inhibit further autoantibody synthesis.