Three cases of herpes zoster radiculitis in MS patients treated with natalizumab.

Natalizumab was the first FDA-approved monoclonal antibody for the treatment of multiple sclerosis (MS). We report on 3 natalizumab-treated patients who developed herpes zoster infections. In addition to progressive multifocal leukoencephelopathy, other opportunistic infections have been rarely reported during Natalizumab treatment. We believe that clinicians need heightened awareness of these infections in view of the risks of serious complications.