Patterns of changes of anti‐ADAMTS13 after plasma exchange

An enzyme-linked immunosorbent assay (ELISA) has recently been developed to detect antibodies against the von Willebrand factor-cleaving protease ADAMTS13 in patients with thrombotic thrombocytopenic purpura (TTP). The ELISA is based on incubation of plasma with immobilized recombinant ADAMTS13 followed by visualization of IgG and IgM antibodies by means of secondary enzyme-labeled antibodies [1]. In a recent study, anti-ADAMTS13 IgG antibodies were detected in most patients with TTP (97%) characterized by severe ADAMTS13 deficiency (< 10% of normal) [1]. The ELISA was more sensitive than the standard inhibitor assay based upon ADAMTS13 neutralizing activity, which gave positive results in …