Acquired haemophilia A as a secondary autoimmune disease after alemtuzumab treatment in multiple sclerosis: A case report.

Alemtuzumab is a highly effective monoclonal antibody for the treatment of multiple sclerosis (MS). During the immune reconstitution following the use of this treatment severe secondary autoimmune diseases (SADs) can develop. We present the case of a patient affected by active MS who failed to achieve disease control with several disease-modifying drugs and was thereafter successfully treated with alemtuzumab, obtaining no evidence of disease activity and a high quality of life. Twenty months after the first infusion of alemtuzumab the patient developed acquired haemophilia A (AHA), a treatable but potentially lifethreatening condition that should be considered a possible SADs associated to this drug. In order to allow an early diagnosis and to prevent possible complications of AHA, routine coagulation tests (prothrombin time and activated partial thromboplastin time) should be included in the laboratory serological monitoring of patients treated with alemtuzumab.