Control of disease activity with large extended-interval dosing of rituximab/ocrelizumab in highly active pediatric multiple sclerosis.

Recent studies in adults suggested that extended-interval dosing of rituximab/ocrelizumab (RTX/OCR) larger than 12 months was safe and could improve safety. This was an observational cohort study of very active pediatric-onset multiple sclerosis (PoMS) (median (range) age, 16 (12-17) years) treated with RTX/OCR with 6 month standard-interval dosing (n = 9) or early extended-interval dosing (n = 12, median (range) interval 18 months (12-25)). Within a median (range) follow-up of 31 (12-63) months after RTX/OCR onset, one patient (standard-interval) experienced relapse and no patient showed disability worsening or new T2-weighted lesions. This study suggests that the effectiveness of RTX/OCR is maintained with a median extended-interval dosing of 18 months in patients with very active PoMS.

Early and Aggressive Treatment May Modify Anti-Hu Associated Encephalitis Prognosis.

Anti-Hu encephalitis is a paraneoplastic syndrome in adults. In children, rare cases of anti-Hu encephalitis were reported mostly without underlying tumors and clinical outcome are usually severe. Here, we describe a 4-year-old girl who developed cerebellar syndrome with abnormal behavior. The brain magnetic resonance imaging showed several T2/fluid-attenuated inversion recovery bilateral brain lesions and autoimmune assessment showed positive anti-Hu antibodies. Computed tomography scan revealed ganglioneuroblastoma which was surgically removed 3 months after onset. Aggressive immunotherapy including dexamethasone, rituximab, and intravenous immunoglobulins were used and a marked neurological improvement soon after 9 months of onset was observed with the child being able to go back to school. The short delay between diagnosis and start of aggressive immunotherapy demonstrate the paramount importance of early diagnosis and early specific therapy after onset of symptoms.

Management and Outcomes of Neonatal Arteriovenous Brain Malformations with Cardiac Failure: A 17 Years' Experience in a Tertiary Referral Center.

OBJECTIVES: To assess the management and outcomes of neonatal arteriovenous brain malformations (mostly vein of Galen malformations) complicated by cardiac failure in the era of prenatal diagnosis and endovascular treatment in a tertiary referral center. STUDY DESIGN: This observational study included 77 living newborn infants with arteriovenous brain malformations with cardiac failure, admitted to our referral center from 2001 to 2017. All infants underwent cardiovascular evaluation including echocardiogram and brain magnetic resonance imaging. Long-term survivors had standard neurocognitive assessments. RESULTS: Infants were admitted to the neonatal intensive care unit at a median of 5 days of age (including 18 inborn patients since 2009). Sixty transarterial shunt embolizations were performed in 46 patients during their first month (at a median age of 7.5 days) or postponed beyond the first month in another 10 long-term survivors. Embolization was not performed in 21 infants, including 19 nonsurvivors with severe brain injury, uncontrolled cardiac failure, or multiple organ failure. Cardiac failure requiring vasopressor infusion occurred in 48 patients (64%) during the hospitalization. Infants who survived the first month underwent a median of 3 embolization sessions. Among the 51 survivors, 21 had a good outcome and 19 had a poor outcome at follow-up (median age, 5.3 years); 11 children were lost to follow-up. CONCLUSIONS: In the era of multidisciplinary prenatal diagnosis, using a standardized care protocol, 47% of liveborn infants with an arteriovenous shunt malformation with cardiac failure experienced a favorable outcome.

Early blood neurofilament light chain and myelin oligodendrocyte glycoprotein antibody levels associate with different disease courses of myelin oligodendrocyte glycoprotein-associated disease in children.

Acquired demyelinating syndrome associated with myelin oligodendrocyte glycoprotein antibodies, named recently myelin oligodendrocyte glycoprotein-associated disease, represents >27% of this paediatric syndrome. Relapses occur in 40% of them, which may be associated with severe outcomes. Aiming to identify biomarker allowing to predict relapse, we measured both myelin oligodendrocyte glycoprotein antibodies and neurofilament light chain levels in blood samples of patients that are known to reflect axonal injuries in neurological diseases including demyelinating autoimmune disorders. Three groups of patients were selected: relapsing myelin oligodendrocyte glycoprotein-associated disease (n = 8), non-relapsing myelin oligodendrocyte glycoprotein-associated disease (n = 7) and control patients with non-inflammatory neurological diseases (n = 12). Neurofilament light chain concentrations were measured in plasma of these three groups of patients using the high-sensitivity single-molecule array method at onset of the disease and 6 months later. At onset of the disease, we found that levels of neurofilament light chain in blood of non-relapsing patients were significantly higher than in control patients (means: 98.36 ± 22.66 versus 12.47 ± 2.47 pg/mL, **P < 0.01, Kruskal-Wallis test). The mean neurofilament light chain value in relapsing patients (82.16 ± 38.41 pg/mL) was not significantly different from that in non-relapsing and in control patients. Plasma myelin oligodendrocyte glycoprotein antibody levels were 2.5-fold higher in relapsing than in non-relapsing patients without reaching significance (means: 15.26 ± 4.87 versus 5.96 ± 1.13; two-tailed Mann-Whitney U-test P = 0.119). Plasma neurofilament light chain correlated significantly with myelin oligodendrocyte glycoprotein antibody levels in relapsing (two-tailed Spearman r = 0.8, P = 0.0218) but not in non-relapsing (two-tailed Spearman r = 0.17, P = 0.71). Interestingly, the ratio of neurofilament light chain-to-myelin oligodendrocyte glycoprotein antibodies was significantly lower in relapsing than in non-relapsing patients (means: 5.19 ± 1.61 versus 21.87 ± 6.13; two-tailed Mann-Whitney U-test P = 0.014). These findings suggest that measuring both neurofilament light chain and myelin oligodendrocyte glycoprotein antibody levels in patients at onset of demyelinating disease could predict relapse of myelin oligodendrocyte glycoprotein-associated disease.

Regulatory T Cells Increase After rh-MOG Stimulation in Non-Relapsing but Decrease in Relapsing MOG Antibody-Associated Disease at Onset in Children.

Background: Myelin oligodendrocytes glycoprotein (MOG) antibody-associated disease (MOGAD) represent 25% of pediatric acquired demyelinating syndrome (ADS); 40% of them may relapse, mimicking multiple sclerosis (MS), a recurrent and neurodegenerative ADS, which is MOG-Abs negative. Aims: To identify MOG antigenic immunological response differences between MOGAD, MS and control patients, and between relapsing versus non-relapsing subgroups of MOGAD. Methods: Three groups of patients were selected: MOGAD (n=12 among which 5 relapsing (MOGR) and 7 non-relapsing (MOGNR)), MS (n=10) and control patients (n=7). Peripheral blood mononuclear cells (PBMC) collected at the time of the first demyelinating event were cultured for 48 h with recombinant human (rh)-MOG protein (10 µg/ml) for a specific stimulation or without stimulation as a negative control. The T cells immunophenotypes were analyzed by flow cytometry. CD4+ T cells, T helper (Th) cells including Th1, Th2, and Th17 were analyzed by intracellular staining of cytokines. Regulatory T cells (Tregs, Foxp3+), CD45RA-Foxp3+ Tregs and subpopulation naive Tregs (CD45RA+Foxp3int), effector Tregs (CD45RA-Foxp3high) and non-suppressive Tregs (CD45RA-Foxp3int) proportions were determined. Results: The mean onset age of each group, ranging from 9.9 to 13.8, and sex ratio, were similar between MOGR, MOGNR, MS and control patients as analyzed by one-way ANOVA and Chi-square test. When comparing unstimulated to rh-MOG stimulated T cells, a significant increase in the proportion of Th2 and Th17 cells was observed in MOGAD. Increase of Th17 cells was significant in MOGNR (means: 0.63 ± 0.15 vs. 1.36 ± 0.43; Wilcoxon-test p = 0.03) but not in MOGR. CD4+ Tregs were significantly increased in MOGNR (means: 3.51 ± 0.7 vs. 4.59 ± 1.33; Wilcoxon-test p = 0.046) while they decreased in MOGR. CD45RA-Foxp3+ Tregs were significantly decreased in MOGR (means: 2.37 ± 0.23 vs. 1.99 ± 0.17; paired t-test p = 0.021), but not in MOGNR. MOGR showed the highest ratio of effector Tregs/non suppressive-Tregs, which was significantly higher than in MOGNR. Conclusions: Our findings suggest that CD4+ Th2 and Th17 cells are involved in the pathophysiology of MOGAD in children. The opposite response of Tregs to rh-MOG in MOGNR, where CD4+ Tregs increased, and in MOGR, where CD45RA-Foxp3+ Tregs decreased, suggests a probable loss of tolerance toward MOG autoantigen in MOGR which may explain relapses in this recurrent pediatric autoimmune disease.