ADAMTS13 and thrombotic thrombocytopenic purpura: No recurrence of TTP was observed.<h4>Conclusion</h4>In SLE-related TMA, measurement of ADAMTS13 activity and the anti-ADAMTS13 antibody titer are necessary for diagnosis, and for predicting prognosis and recurrence of the disease; however, in the acute phase of immune-mediated TMA, it is important to initiate proper treatments even before knowing the results to improve prognosis.