Unique Presentation of Bortezomib-Associated Thrombotic Microangiopathy Responsive to Therapeutic Plasma Exchange and Eculizumab Therapy.

Thrombotic microangiopathies (TMA) are a rare group of life-threatening hematological conditions characterized by thrombocytopenia and microangiopathic hemolytic anemia. Although our understanding of the pathophysiology and the availability of diagnostic testing has improved for primary TMAs, such as thrombotic thrombocytopenic purpura, the pathophysiology underlying secondary TMAs, including drug-induced TMAs (DITMAs), remains less clear. In this case report, we present the unique case of a patient with a history of multiple myeloma that presented four months after the initiation of bortezomib therapy with a bortezomib-associated TMA that responded to therapeutic plasma exchange (TPE) with plasma replacement and eculizumab therapy. This case demonstrates the possible utility of TPE with plasma replacement and eculizumab therapy in DITMA patients that fail to respond following a trial of holding the suspected medication.