microangiopathy with rituximab

The microangiopathic anaemia with thrombocytopenia—which can occur after haematopoietic stem cell transplant—resembles thrombotic thrombocytopenic purpura but has different pathophysiology and does not respond to plasma exchange. We describe a patient with severe manifestations of this disorder who recovered promptly following treatment with rituximab, an anti-CD20 antibody. Thrombotic thrombocytopenic purpura (TTP) causes microangiopathic haemolytic anaemia with neurological and/or renal dysfunction. Sporadic TTP is due to an antibody against ADAMTS13, a protein required to cleave von Willebrand factor, preventing pathological platelet aggregation. Treatment with plasma exchange removes antibody and replaces ADAMTS13.1 TTP also occurs infrequently post haematopoietic stem cell transplant (transplant-associated microangiopathy, TAM) associated with factors such as endothelial damage from chemoradiotherapy, CMV infection, and use of ciclosporin for graft versus host disease (GvHD) prophylaxis. There is no antibody to ADAMTS13 and plasma exchange is ineffective in patient