Pneumonitis secondary to alemtuzumab in a patient with multiple sclerosis - A non-infectious cause of breathlessness.

The most common adverse events associated with the monoclonal antibody alemtuzumab are infusion associated reactions and secondary autoimmune disease. Respiratory complications are unusual following treatment with alemtuzumab, but can be precipitated by an infectious cause. We describe a case of a sub-acute steroid responsive non-infectious pneumonitis affecting a 51 year old woman, who presented one month after initiation of therapy for multiple sclerosis with alemtuzumab.