Evidence of B-cell dysregulation in severe CNS inflammation after alemtuzumab therapy

Cases of severely exacerbated CNS inflammation have been described in patients with MS under treatment with alemtuzumab, a pan-lymphocyte–depleting anti-CD52 monoclonal antibody.1,2 On the basis of the peripheral lymphocyte subset network (higher B-cell and suppressed T-cell counts)2 and marked clinical improvement following plasmapheresis and rituximab treatment (anti-CD20 antibody),1 a B-cell–driven intrathecal autoimmune reaction was hypothesized. Acknowledgment: The authors thank Dr. Lucia Rossi, of the Virology Section of the Department of Molecular Medicine, University of Padua, for EBV DNA testing in blood and CSF.