A 45-year-old Italian woman, affected by
relapsing-remitting multiple sclerosis (RR-MS) starting from 2011, started treatment with
alemtuzumab in July 2016. Nine months after the second infusion, she had an
immune thrombocytopenic purpura (
ITP) with complete recovery after
steroid treatment. Three months after the
ITP, the patient presented with transient
aphasia, cognitive deficits, and
focal epilepsy. Serial brain magnetic resonance imaging showed a pattern compatible with
encephalitis.
Autoantibodies to
glutamate receptor 3
peptide A and B were detected in cerebrospinal fluid and serum, in the absence of any other diagnostic cues. After three courses of
intravenous immunoglobulin (0.4 mg/kg/day for 5 days, 1 month apart), followed by boosters (0.4 mg/kg/day) every 4-6 weeks, her neurological status improved and is currently comparable with that preceding the
encephalitis. Autoimmune complications of the central nervous system during
alemtuzumab therapy are relatively rare: only one previous case of
autoimmune encephalitis following
alemtuzumab treatment has been reported to date.