RESUMEN
We report a 23 years old female who presented a second episode of thrombotic thrombocytopenic purpura (TTP). She was treated with fresh frozen plasma infusions and 14 plasma exchange (PE) sessions without response. Therefore a second-line therapy was started, associating a weekly cycle administration of vindesine (Vds) 2 mg/m2 and rituximab (R) 375 mg/m2. Five cycles of this association plus one cycle of R exclusively, were administered. After the third course, biological signs of improvement were observed and complete normalization of blood cell counts and other specific parameters was seen after 8 weeks. From the beginning of her second relapse we detected a severe deficit (<5%) in von Willebrand-cleaving factor (ADAMTS13) associated to the presence of ADAMTS13 inhibitors. The combined treatment induced an improvement in ADAMTS13 values without detectable inhibitors. After 21 months of follow-up the patient was well, without signs of relapse but ADAMTS13 values were still under normal, which may be an unfavorable prognostic factor. PE is the treatment of choice for acquired idiopathic TTP, but for refractory cases or TTP cases with severe ADAMTS13 values/high inhibitor titers, PE associated to an immunosuppressive treatment should be considered.