Autoimmune Storm Following Alemtuzumab.

Alemtuzumab has been associated with the emergence of secondary autoimmune diseases. We report a case of a patient with relapsing–remitting multiple sclerosis who developed a refractory immune thrombocytopaenia associated with vasculitis, myelofibrosis and later Guillain-Barré syndrome following alemtuzumab. The medical community should be aware of unusual and unexpected adverse events that may be associated with alemtuzumab, especially when occurring simultaneously in the same patient.