Esther Tantsis

Antibodies to MOG are transient in childhood acute disseminated encephalomyelitis

Objective: To study the longitudinal dynamics of anti–myelin oligodendrocyte glycoprotein (MOG) autoantibodies in childhood demyelinating diseases. Methods: We addressed the kinetics of anti-MOG immunoglobulins in a prospective study comprising 77 pediatric patients. This was supplemented by a cross-sectional study analyzing 126 pediatric patients with acute demyelination and 62 adult patients with multiple sclerosis (MS). MOG-transfected cells were used for detection of antibodies by flow cytometry. Results: Twenty-five children who were anti-MOG immunoglobulin (Ig) positive at disease onset were followed for up to 5 years. Anti-MOG antibodies rapidly and continuously declined in all 16 monophasic patients with acute disseminated encephalomyelitis and in one patient with clinically isolated syndrome. In contrast, in 6 of 8 patients (75%) eventually diagnosed with childhood MS, the antibodies to MOG persisted with fluctuations showing a second increase during an observation period of up to 5 years. Antibodies to MOG were mainly IgG 1 and their binding was largely blocked by pathogenic anti-MOG antibodies derived from a spontaneous animal model of autoimmune encephalitis. The cross-sectional part of our study elaborated that anti-MOG Ig was present in about 25% of children with acute demyelination, but in none of the pediatric or adult controls. Sera from 4/62 (6%) adult patients with MS had anti-MOG IgG at low levels. Conclusions: The persistence or disappearance of antibodies to MOG may have prognostic relevance for acute childhood demyelination.

Antibodies to MOG have a demyelination phenotype and affect oligodendrocyte cytoskeleton

Objective: To examine the clinical features of pediatric CNS demyelination associated with positive myelin oligodendrocyte glycoprotein (MOG) antibodies and to examine the functional effects of MOG antibody on oligodendrocyte cytoskeleton. Methods: We measured MOG antibody using a fluorescence-activated cell sorting live cell-based assay in acute sera of 73 children with CNS demyelination (DEM) (median age 8 years, range 1.3–15.3) followed for a median of 4 years. We used MO3.13 cells to examine immunoglobulin (Ig) G effects on oligodendrocyte cytoskeleton using 3D deconvolution imaging. Results: MOG antibodies were found in 31/73 patients with DEM (42%) but in 0/24 controls. At first presentation, MOG antibody–positive patients were more likely to have bilateral than unilateral optic neuritis (ON) (9/10 vs 1/5, respectively, p = 0.03), less likely to have brainstem findings (2/31 vs 16/42, p = 0.005), more likely to have a raised erythrocyte sedimentation rate >20 mm/h (9/19 vs 3/21, p = 0.05), less likely to have intrathecal oligoclonal bands (0/16 vs 5/27, p = 0.18), and less likely to be homozygous or heterozygous for human leukocyte antigen DRB1*1501 (3/18 vs 7/22, p = 0.46). MOG antibody positivity varied according to clinical phenotype, with ON and relapsing ON most likely to be seropositive. Two relapsing MOG antibody–positive patients treated with mycophenolate mofetil remain in remission and have become MOG antibody seronegative. Oligodendrocytes incubated with purified IgG from MOG antibody–positive patients showed a striking loss of organization of the thin filaments and the microtubule cytoskeleton, as evidenced by F-actin and β-tubulin immunolabelings. Conclusions: MOG antibody may define a separate demyelination syndrome, which has therapeutic implications. MOG antibody has functional effects on oligodendrocyte cytoskeleton.

Infectious and Autoantibody-Associated Encephalitis: Clinical Features and Long-term Outcome

BACKGROUND AND OBJECTIVES: Pediatric encephalitis has a wide range of etiologies, clinical presentations, and outcomes. This study seeks to classify and characterize infectious, immune-mediated/autoantibody-associated and unknown forms of encephalitis, including relative frequencies, clinical and radiologic phenotypes, and long-term outcome. METHODS: By using consensus definitions and a retrospective single-center cohort of 164 Australian children, we performed clinical and radiologic phenotyping blinded to etiology and outcomes, and we tested archived acute sera for autoantibodies to N-methyl-D-aspartate receptor, voltage-gated potassium channel complex, and other neuronal antigens. Through telephone interviews, we defined outcomes by using the Liverpool Outcome Score (for encephalitis). RESULTS: An infectious encephalitis occurred in 30%, infection-associated encephalopathy in 8%, immune-mediated/autoantibody-associated encephalitis in 34%, and unknown encephalitis in 28%. In descending order of frequency, the larger subgroups were acute disseminated encephalomyelitis (21%), enterovirus (12%), Mycoplasma pneumoniae (7%), N-methyl-D-aspartate receptor antibody (6%), herpes simplex virus (5%), and voltage-gated potassium channel complex antibody (4%). Movement disorders, psychiatric symptoms, agitation, speech dysfunction, cerebrospinal fluid oligoclonal bands, MRI limbic encephalitis, and clinical relapse were more common in patients with autoantibodies. An abnormal outcome occurred in 49% of patients after a median follow-up of 5.8 years. Herpes simplex virus and unknown forms had the worst outcomes. According to our multivariate analysis, an abnormal outcome was more common in patients with status epilepticus, magnetic resonance diffusion restriction, and ICU admission. CONCLUSIONS: We have defined clinical and radiologic phenotypes of infectious and immune-mediated/autoantibody-associated encephalitis. In this resource-rich cohort, immune-mediated/autoantibody-associated etiologies are common, and the recognition and treatment of these entities should be a clinical priority.

Radiological differentiation of optic neuritis with myelin oligodendrocyte glycoprotein antibodies, aquaporin-4 antibodies, and multiple sclerosis.

Background: Recognizing the cause of optic neuritis (ON) affects treatment decisions and visual outcomes. Objective: We aimed to define radiological features of first-episode demyelinating ON. Methods: We performed blinded radiological assessment of 50 patients presenting with first-episode myelin oligodendrocyte glycoprotein (MOG) antibody-associated ON (MOG-ON; n=19), aquaporin-4 (AQP4) antibody-associated ON (AQP4-ON; n=11), multiple sclerosis (MS)-associated ON (MS-ON; n=13), and unclassified ON (n=7). Results: Bilateral involvement was more common in MOG-ON and AQP4-ON than MS-ON (84% vs. 82% vs. 23%), optic nerve head swelling was more common in MOG-ON (53% vs. 9% vs. 0%), chiasmal involvement was more common in AQP4-ON (5% vs. 64% vs. 15%), and bilateral optic tract involvement was more common in AQP4-ON (0% vs. 45% vs. 0%). Retrobulbar involvement was more common in MOG-ON, whereas intracranial involvement was more common in AQP4-ON. MOG-ON and AQP4-ON had longer lesion lengths than MS-ON. The combination of two predictors, the absence of magnetic resonance imaging brain abnormalities and a higher lesion extent score, showed a good ability to discriminate between an autoantibody-associated ON (MOG or AQP4) and MS. AQP4-ON more frequently had severe and sustained visual impairment. Conclusion: MOG-ON and AQP4-ON are more commonly bilateral and longitudinally extensive. MOG-ON tends to involve the anterior optic pathway, whereas AQP4-ON the posterior optic pathway.

Clinical course, therapeutic responses and outcomes in relapsing MOG antibody-associated demyelination

Objective We characterised the clinical course, treatment and outcomes in 59 patients with relapsing myelin oligodendrocyte glycoprotein (MOG) antibody-associated demyelination. Methods We evaluated clinical phenotypes, annualised relapse rates (ARR) prior and on immunotherapy and Expanded Disability Status Scale (EDSS), in 218 demyelinating episodes from 33 paediatric and 26 adult patients. Results The most common initial presentation in the cohort was optic neuritis (ON) in 54% (bilateral (BON) 32%, unilateral (UON) 22%), followed by acute disseminated encephalomyelitis (ADEM) (20%), which occurred exclusively in children. ON was the dominant phenotype (UON 35%, BON 19%) of all clinical episodes. 109/226 (48%) MRIs had no brain lesions. Patients were steroid responsive, but 70% of episodes treated with oral prednisone relapsed, particularly at doses <10 mg daily or within 2 months of cessation. Immunotherapy, including maintenance prednisone (P=0.0004), intravenous immunoglobulin, rituximab and mycophenolate, all reduced median ARRs on-treatment. Treatment failure rates were lower in patients on maintenance steroids (5%) compared with non-steroidal maintenance immunotherapy (38%) (P=0.016). 58% of patients experienced residual disability (average follow-up 61 months, visual loss in 24%). Patients with ON were less likely to have sustained disability defined by a final EDSS of ≥2 (OR 0.15, P=0.032), while those who had any myelitis were more likely to have sustained residual deficits (OR 3.56, P=0.077). Conclusion Relapsing MOG antibody-associated demyelination is strongly associated with ON across all age groups and ADEM in children. Patients are highly responsive to steroids, but vulnerable to relapse on steroid reduction and cessation.

Risk of multiple sclerosis after a first demyelinating syndrome in an Australian Paediatric cohort: clinical, radiological features and application of the McDonald 2010 MRI criteria

Background: The risk of multiple sclerosis (MS) is dependent on multiple variables, including geographical location. There is increasing interest in the early recognition and treatment of MS in children. Method: Using univariate and multivariate analysis, we determined the clinical and radiological features that were predictive of MS in 88 children from New South Wales, Australia, with a first acute demyelinating syndrome (ADS) who were followed for a minimum of one year. We tested the McDonald, KIDMUS, Callen and Verhey MRI criteria for paediatric MS. Results: After a mean follow-up of 5.2 years, 13/88 (15%) of children had MS. Using multivariate analysis, preceding infection was protective of MS, and corpus callosal lesions, the combined presence of both well and poorly demarcated lesions, and contrast-enhancing lesions on MRI were predictive of MS. The sensitivity and specificity of the respective radiological criteria were McDonald 2005 (69%, 68%), McDonald 2010 (58%, 95%), KIDMUS (8%, 100%), Callen (69%, 85%) and Verhey (62%, 84%). When McDonald 2010 criteria were applied to baseline and serial scans, the sensitivity and specificity was 91% and 93%. Conclusion: Despite the long follow-up, the risk of MS appears lower in New South Wales children compared to previously reported cohorts. Radiological features are more predictive than clinical features in predicting MS. The McDonald 2010 criteria performed well although the dissemination in time criteria on baseline scans is difficult to apply to children with encephalopathy.

Clinical association of intrathecal and mirrored oligoclonal bands in paediatric neurology

Aim  Biomarkers such as autoantibodies, neopterin, and oligoclonal bands (OCBs) are increasingly used for the diagnosis of treatable inflammatory central nervous system (CNS) disorders. We investigated the correlation between the results of OCB testing and clinical diagnoses in a large contemporary cohort of children with a broad range of neurological conditions.

Utility of CSF Cytokine/Chemokines as Markers of Active Intrathecal Inflammation: Comparison of Demyelinating, Anti-NMDAR and Enteroviral Encephalitis.

Background Despite the discovery of CSF and serum diagnostic autoantibodies in autoimmune encephalitis, there are still very limited CSF biomarkers for diagnostic and monitoring purposes in children with inflammatory or autoimmune brain disease. The cause of encephalitis is unknown in up to a third of encephalitis cohorts, and it is important to differentiate infective from autoimmune encephalitis given the therapeutic implications. Aim To study CSF cytokines and chemokines as diagnostic biomarkers of active neuroinflammation, and assess their role in differentiating demyelinating, autoimmune, and viral encephalitis. Methods We measured and compared 32 cytokine/chemokines using multiplex immunoassay and APRIL and BAFF using ELISA in CSF collected prior to commencing treatment from paediatric patients with confirmed acute disseminated encephalomyelitis (ADEM, n = 16), anti-NMDAR encephalitis (anti-NMDAR E, n = 11), and enteroviral encephalitis (EVE, n = 16). We generated normative data using CSF from 20 non-inflammatory neurological controls. The sensitivity of CSF cytokine/chemokines to diagnose encephalitis cases was calculated using 95th centile of control values as cut off. We correlated CSF cytokine/chemokines with disease severity and follow up outcome based on modified Rankin scale. One-way hierarchical correlational cluster analysis of molecules was performed in different encephalitis and outcome groups. Results In descending order, CSF TNF-α, IL-10, IFN-α, IL-6, CXCL13 and CXCL10 had the best sensitivity (>79.1%) when all encephalitis patients were included. The combination of IL-6 and IFN-α was most predictive of inflammation on multiple logistic regression with area under the ROC curve 0.99 (CI 0.97–1.00). There were no differences in CSF cytokine concentrations between EVE and anti-NMDAR E, whereas ADEM showed more pronounced elevation of Th17 related (IL-17, IL-21) and Th2 (IL-4, CCL17) related cytokine/chemokines. Unlike EVE, heat map analysis showed similar clustering of cytokine/chemokine molecules in immune mediated encephalitis (ADEM and anti-NMDAR E). Th1 and B cell (CXCL13 and CXCL10) molecules clustered together in patients with severe encephalopathy at admission and worse disability at follow up in all encephalitis. There was no correlation between CSF neopterin and IFN-γ or IFN-α. Conclusion A combination panel of cytokine/chemokines consisting of CSF TNF-α, IL-10, IFN-α, IL-6, CXCL13 and CXCL10 measured using multiplex immunoassay may be used to diagnose and monitor intrathecal inflammation in the brain. Given their association with worse outcome, certain key chemokines (CXCL13, CXCL10) could represent potential therapeutic targets in encephalitis.

B Cell, Th17, and Neutrophil Related Cerebrospinal Fluid Cytokine/Chemokines Are Elevated in MOG Antibody Associated Demyelination.

Background Myelin oligodendrocyte glycoprotein antibody (MOG Ab) associated demyelination represents a subgroup of autoimmune demyelination that is separate from multiple sclerosis and aquaporin 4 IgG-positive NMO, and can have a relapsing course. Unlike NMO and MS, there is a paucity of literature on immunopathology and CSF cytokine/chemokines in MOG Ab associated demyelination. Aim To study the differences in immunopathogenesis based on cytokine/chemokine profile in MOG Ab-positive (POS) and -negative (NEG) groups. Methods We measured 34 cytokines/chemokines using multiplex immunoassay in CSF collected from paediatric patients with serum MOG Ab POS [acute disseminated encephalomyelitis (ADEM = 8), transverse myelitis (TM = 2) n = 10] and serum MOG Ab NEG (ADEM = 5, TM = 4, n = 9) demyelination. We generated normative data using CSF from 20 non-inflammatory neurological controls. Results The CSF cytokine and chemokine levels were higher in both MOG Ab POS and MOG Ab NEG demyelination groups compared to controls. The CSF in MOG Ab POS patients showed predominant elevation of B cell related cytokines/chemokines (CXCL13, APRIL, BAFF and CCL19) as well as some of Th17 related cytokines (IL-6 AND G-CSF) compared to MOG Ab NEG group (all p<0.01). In addition, patients with elevated CSF MOG antibodies had higher CSF CXCL13, CXCL12, CCL19, IL-17A and G-CSF than patients without CSF MOG antibodies. Conclusion Our findings suggest that MOG Ab POS patients have a more pronounced CNS inflammatory response with elevation of predominant humoral associated cytokines/chemokines, as well as some Th 17 and neutrophil related cytokines/chemokines suggesting a differential inflammatory pathogenesis associated with MOG antibody seropositivity. This cytokine/chemokine profiling provides new insight into disease pathogenesis, and improves our ability to monitor inflammation and response to treatment. In addition, some of these molecules may represent potential immunomodulatory targets.

Postencephalitic epilepsy and drug‐resistant epilepsy after infectious and antibody‐associated encephalitis in childhood: Clinical and etiologic risk factors

To define the risk factors for postencephalitic epilepsy (PE) and drug‐resistant epilepsy (DRE) in childhood following infectious and autoimmune encephalitis, we included 147 acute encephalitis patients with a median follow‐up of 7.3 years (range 2–15.8 years). PE was defined as the use of antiepileptic drugs (AEDs) for ≥24 months, and DRE was defined as the persistence of seizures despite ≥2 appropriate AEDs at final follow‐up. PE and DRE were diagnosed in 31 (21%) and 15 (10%) of patients, respectively. The features during acute encephalitis predictive of DRE (presented as odds ratio [OR] with confidence intervals [CIs]) were status epilepticus (OR 10.8, CI 3.4–34.3), visual disturbance (6.4, 1.4–29.9), focal seizures (6.2, 1.9–20.6), magnetic resonance imaging (MRI) hippocampal/amygdala involvement (5.0, 1.7–15.4), intensive care admission (4.7, 1.4–15.4), use of >3 AEDs (4.5, 1.2–16.1), MRI gadolinium enhancement (4.1, 1.2–14.2), any seizure (3.9, 1.1–14.4), and electroencephalography (EEG) epileptiform discharges (3.9, 1.3–12.0). On multivariable regression analysis, only status epilepticus remained predictive of DRE in all models. DRE was common in herpes simplex virus (3/9, 33%) and unknown (8/40, 20%) encephalitis, but absent in acute disseminated encephalomyelitis (ADEM) (0/32, 0%), enterovirus (0/18), and anti‐N‐methyl‐d‐aspartate receptor–NMDAR encephalitis (0/9). We have identified risk factors for DRE and demonstrated “high‐risk,” and “low‐risk” etiologies.