An interesting variety

This issue of Neurology ® : Neuroimmunology and Neu-roinflammation (N2) includes a wide variety of exciting articles. As usual, I had difficulty selecting the articles to highlight in this Editor's Corner, which is aimed to reflect the range of topics rather than imply a higher quality of the selected manuscripts. One of the treatments frequently used in neuro-myelitis optica (NMO) is rituximab. Nosadini et al. 1 provide interesting information on monitoring and redosing rituximab in 16 pediatric patients with NMO. Overall, the patients received a total of 76 rituximab courses; the mean time from rituximab dosing to last documented B-cell depletion and initial repopulation (defined as CD19 $10 3 10 6 cells/L) was 4.5 and 6.8 months, respectively, with large in-terpatient variability. The authors found a significant reduction between prerituximab and postrituximab annualized relapse rate. Twenty-one relapses occurred in 10 patients (65% during repopulation, 15% during depletion, and 20% as a result of depletion failure). Important causes of repopulation relapses included inadequate monitoring and delayed redos-ing after detecting repopulation. This study shows that in children with NMO, rituximab is effective in relapse prevention and that careful monitoring of B-cell repopulation and appropriate redosing could reduce relapses. In multiple sclerosis (MS), most immunotherapies (interferon-b, glatiramer, steroids) do not appear to increase the prevalence of JC virus (JCV) serology. In contrast, the recent identification of progressive mul-tifocal leukoencephalopathy (PML) among patients treated with natalizumab indicates that studies on the effects of this treatment on JCV are needed. Schwab et al. 2 examined a large cohort of patients with MS treated with natalizumab in order to determine any influence on JCV serology. The study, accompanied by an editorial comment by Drs. Javed and Reder, 3 reveals that treatment with natalizumab was associated with a 15.9% rise in JCV index values in 14.8 months (12.9% per year), suggesting that JCV seroconversion and index values are influenced by natalizumab. The findings emphasize the importance of monitoring patients' JCV serology, and that seroconversion or rising JCV index alter the risk of PML in these patients. Zivadinov et al. 4 hypothesized that in patients with MS dysregulated Epstein-Barr virus (EBV)–infected B cells may induce meningeal inflammation, contributing to cortical pathology. This process was suggested by studies showing that cortical gray matter pathology is associated with subpial cortical lesions, ectopic lymphoid-like structures, and retrograde Wallerian degeneration. Based on these data, the authors investigated a large cohort of patients …