Successful use of recombinant ADAMTS13 in a pregnant patient with immune-mediated thrombotic thrombocytopenic purpura.

We report the first case of immune-mediated thrombotic thrombocytopenic purpura (iTTP) successfully treated with recombinant ADAMTS13 (rhADAMTS13) during pregnancy. A 36-year-old woman with a history of severe iTTP and persistently undetectable ADAMTS13 activity despite multiple immunosuppressive therapies, remained relapse free for 10 years. In the 33rd week of pregnancy, she showed the first signs of relapse, whereupon rhADAMTS13 40 IU/kg was administered twice daily. ADAMTS13 activity and platelet count recovered rapidly, allowing a healthy newborn to be delivered safely by cesarean section. No adverse event was observed. rhADAMTS13 could represent an effective, well-tolerated therapeutic alternative for patients with iTTP and clinical or ADAMTS13 relapse. During pregnancy, where plasma exchange or caplacizumab are undesirable and recommendations are uncertain, this strategy could represent a promising therapeutic alternative in selected cases.