D-dimer Increasing After First Alemtuzumab Administration in a Multiple Sclerosis Patient

Alemtuzumab is a humanized anti-CD52 monoclonal antibody used for the treatment of high activity relapsing multiple sclerosis (R-MS). The most common adverse event is an infusion reaction due to cytokine-release. Autoimmunity can arise from months to years after treatment and encompasses Grave’s disease and thrombocytopenia. Recent reports of stroke, heart attack, and arterial dissection after alemtuzumab administration, in some cases within hours of infusion, led the European Medicines Agency’s (EMA's) Pharmacovigilance Risk Assessment Committee (PRAC) to a safety review of treatment with alemtuzumab. We report a D-Dimer increasing with suspected associated pulmonary embolism in an RMS patient after the first alemtuzumab administration. D-dimer test is not mandatory after alemtuzumab treatment, but its possible increase should warn the physician to select the patients with lower cardiovascular and thrombosis risk.