Use and Safety of Immunotherapeutic Management of N-Methyl-d-Aspartate Receptor Antibody Encephalitis: A Meta-analysis.

Importance: Overall, immunotherapy has been shown to improve outcomes and reduce relapses in individuals with N-methyl-d-aspartate receptor (NMDAR) antibody encephalitis (NMDARE); however, the superiority of specific treatments and combinations remains unclear. Objective: To map the use and safety of immunotherapies in individuals with NMDARE, identify early predictors of poor functional outcome and relapse, evaluate changes in immunotherapy use and disease outcome over the 14 years since first reports of NMDARE, and assess the Anti-NMDAR Encephalitis One-Year Functional Status (NEOS) score. Data Sources: Systematic search in PubMed from inception to January 1, 2019. Study Selection: Published articles including patients with NMDARE with positive NMDAR antibodies and available individual immunotherapy data. Data Extraction and Synthesis: Individual patient data on immunotherapies, clinical characteristics at presentation, disease course, and final functional outcome (modified Rankin Scale [mRS] score) were entered into multivariable logistic regression models. Main Outcomes and Measures: The planned study outcomes were functional outcome at 12 months from disease onset (good, mRS score of 0 to 2; poor, mRS score greater than 2) and monophasic course (absence of relapse at 24 months or later from onset). Results: Data from 1550 patients from 652 articles were evaluated. Of these, 1105 of 1508 (73.3%) were female and 707 of 1526 (46.3%) were 18 years or younger at disease onset. Factors at first event that were significantly associated with good functional outcome included adolescent age and first-line treatment with therapeutic apheresis, corticosteroids plus intravenous immunoglobulin (IVIG), or corticosteroids plus IVIG plus therapeutic apheresis. Factors significantly associated with poor functional outcome were age younger than 2 years or age of 65 years or older at onset, intensive care unit admission, extreme delta brush pattern on electroencephalography, lack of immunotherapy within the first 30 days of onset, and maintenance IVIG use for 6 months or more. Factors significantly associated with nonrelapsing disease were rituximab use or maintenance IVIG use for 6 months or more. Adolescent age at onset was significantly associated with relapsing disease. Rituximab use increased from 13.5% (52 of 384; 2007 to 2013) to 28.3% (311 of 1100; 2013 to 2019) (P < .001), concurrent with a falling relapse rate over the same period (22% [12 of 55] in 2008 and earlier; 10.9% [35 of 322] in 2017 and later; P = .006). Modified NEOS score (including 4 of 5 original NEOS items) was associated with probability of poor functional status at 1 year (20.1% [40 of 199] for a score of 0 to 1 points; 43.8% [77 of 176] for a score of 3 to 4 points; P = .05). Conclusions and Relevance: Factors influencing functional outcomes and relapse are different and need to be considered independently in development of evidence-based optimal management guidelines of patients with NMDARE.

Pediatric Patients with a Dual Diagnosis of Inflammatory Bowel Disease and Chronic Recurrent Multifocal Osteomyelitis.

ABSTRACT: There is a paucity of information about the epidemiology, pathophysiology, and treatment of patients with a dual diagnosis of inflammatory bowel disease (IBD) and chronic recurrent multifocal osteomyelitis (CRMO). A retrospective chart review was performed of patients at McMaster Children's Hospital with a diagnosis of either IBD or CRMO, to identify those with the dual diagnosis over a 10-year period. A dual diagnosis was identified in seven patients. Most patients (6/7) had a diagnosis of IBD first and were subsequently diagnosed with CRMO. At the time of CRMO diagnosis, IBD treatment regimens included one or more of, sulfasalazine (1/6), infliximab (3/6), adalimumab (1/6), or no treatment (1/6). Although the etiology of the link remains unknown, there does not seem to be an association to a specific IBD subtype, age, or treatment. Our patient population demonstrated a response to biologic agents, specifically tumor necrosis factor-α inhibitors, as treatment for both conditions.

International Consensus Recommendations for the Treatment of Pediatric NMDAR Antibody Encephalitis.

OBJECTIVE: To create an international consensus treatment recommendation for pediatric NMDA receptor antibody encephalitis (NMDARE). METHODS: After selection of a panel of 27 experts with representation from all continents, a 2-step Delphi method was adopted to develop consensus on relevant treatment regimens and statements, along with key definitions in pediatric NMDARE (disease severity, failure to improve, and relapse). Finally, an online face-to-face meeting was held to reach consensus (defined as ≥75% agreement). RESULTS: Corticosteroids are recommended in all children with NMDARE (pulsed IV preferred), with additional IV immunoglobulin or plasma exchange in severe patients. Prolonged first-line immunotherapy can be offered for up to 3-12 months (oral corticosteroids or monthly IV corticosteroids/immunoglobulin), dependent on disease severity. Second-line treatments are recommended for cases refractory to first-line therapies (rituximab preferred over cyclophosphamide) and should be considered about 2 weeks after first-line initiation. Further immunotherapies for refractory disease 1-3 months after second-line initiation include another second-line treatment (such as cyclophosphamide) and escalation to tocilizumab. Maintenance immune suppression beyond 6 months (such as rituximab redosing or mycophenolate mofetil) is generally not required, except for patients with a more severe course or prolonged impairments and hospitalization. For patients with relapsing disease, second-line and prolonged maintenance therapy should be considered. The treatment of NMDARE following herpes simplex encephalitis should be similar to idiopathic NMDARE. Broad guidance is provided for the total treatment duration (first line, second line, and maintenance), which is dictated by the severity and clinical course (i.e., median 3, 9 and 18 months in the best, average, and worst responders, respectively). Recommendations on the timing of oncologic searches are provided. CONCLUSION: These international consensus recommendations for the management of pediatric NMDARE aim to standardize the treatment and provide practical guidance for clinicians, rather than absolute rules. A similar recommendation could be applicable to adult patients.

Consensus Treatment Plans for Chronic Nonbacterial Osteomyelitis Refractory to Nonsteroidal Antiinflammatory Drugs and/or With Active Spinal Lesions.

OBJECTIVE: To develop standardized treatment regimens for chronic nonbacterial osteomyelitis (CNO), also known as chronic recurrent multifocal osteomyelitis (CRMO), to enable comparative effectiveness treatment studies. METHODS: Virtual and face-to-face discussions and meetings were held within the CNO/CRMO subgroup of the Childhood Arthritis and Rheumatology Research Alliance (CARRA). A literature search was conducted, and CARRA membership was surveyed to evaluate available treatment data and identify current treatment practices. Nominal group technique was used to achieve consensus on treatment plans for CNO refractory to nonsteroidal antiinflammatory drug (NSAID) monotherapy and/or with active spinal lesions. RESULTS: Three consensus treatment plans (CTPs) were developed for the first 12 months of therapy for CNO patients refractory to NSAID monotherapy and/or with active spinal lesions. The 3 CTPs are methotrexate or sulfasalazine, tumor necrosis factor inhibitors with optional methotrexate, and bisphosphonates. Short courses of glucocorticoids and continuation of NSAIDs are permitted for all regimens. Consensus was achieved on these CTPs among CARRA members. Consensus was also reached on subject eligibility criteria, initial evaluations that should be conducted prior to the initiation of CTPs, and data items to collect to assess treatment response. CONCLUSION: Three consensus treatment plans were developed for pediatric patients with CNO refractory to NSAIDs and/or with active spinal lesions. Use of these CTPs will provide additional information on efficacy and will generate meaningful data for comparative effectiveness research in CNO.

Overlapping demyelinating syndromes and anti­N-methyl-D-aspartate receptor encephalitis.

OBJECTIVE: To report the clinical, radiological, and immunological association of demyelinating disorders with anti­Nmethyl- D-aspartate receptor (NMDAR) encephalitis. METHODS: Clinical and radiological analysis was done of a cohort of 691 patients with anti-NMDAR encephalitis. Determination of antibodies to NMDAR, aquaporin-4 (AQP4), and myelin oligodendrocyte glycoprotein (MOG) was performed using brain immunohistochemistry and cell-based assays. RESULTS: Twenty-three of 691 patients with anti-NMDAR encephalitis had prominent magnetic resonance imaging (MRI) and/or clinical features of demyelination. Group 1 included 12 patients in whom anti-NMDAR encephalitis was preceded or followed by independent episodes of neuromyelitis optica (NMO) spectrum disorder (5 cases, 4 anti-AQP4 positive) or brainstem or multifocal demyelinating syndromes (7 cases, all anti-MOG positive). Group 2 included 11 patients in whom anti-NMDAR encephalitis occurred simultaneously with MRI and symptoms compatible with demyelination (5 AQ4 positive, 2 MOG positive). Group 3 (136 controls) included 50 randomly selected patients with typical anti-NMDAR encephalitis, 56 with NMO, and 30 with multiple sclerosis; NMDAR antibodies were detected only in the 50 anti-NMDAR patients, MOG antibodies in 3 of 50 anti-NMDAR and 1 of 56 NMO patients, and AQP4 antibodies in 48 of 56 NMO and 1 of 50 anti-NMDAR patients (p<0.0001 for all comparisons with Groups 1 and 2). Most patients improved with immunotherapy, but compared with anti-NMDAR encephalitis the demyelinating episodes required more intensive therapy and resulted in more residual deficits. Only 1 of 23 NMDAR patients with signs of demyelination had ovarian teratoma compared with 18 of 50 anti-NMDAR controls (p50.011). INTERPRETATION: Patients with anti-NMDAR encephalitis may develop concurrent or separate episodes of demyelinating disorders, and conversely patients with NMO or demyelinating disorders with atypical symptoms (eg, dyskinesias, psychosis) may have anti-NMDAR encephalitis.

Distinct phenotype clusters in childhood inflammatory brain diseases: implications for diagnostic evaluation.

OBJECTIVE: To identify distinct clusters of children with inflammatory brain diseases based on clinical, laboratory, and imaging features at presentation, to assess which features contribute strongly to the development of clusters, and to compare additional features between the identified clusters. METHODS: A single-center cohort study was performed with children who had been diagnosed as having an inflammatory brain disease between June 1, 1989 and December 31, 2010. Demographic, clinical, laboratory, neuroimaging, and histologic data at diagnosis were collected. K-means cluster analysis was performed to identify clusters of patients based on their presenting features. Associations between the clusters and patient variables, such as diagnoses, were determined. RESULTS: A total of 147 children (50% female; median age 8.8 years) were identified: 105 with primary central nervous system (CNS) vasculitis, 11 with secondary CNS vasculitis, 8 with neuronal antibody syndromes, 6 with postinfectious syndromes, and 17 with other inflammatory brain diseases. Three distinct clusters were identified. Paresis and speech deficits were the most common presenting features in cluster 1. Children in cluster 2 were likely to present with behavior changes, cognitive dysfunction, and seizures, while those in cluster 3 experienced ataxia, vision abnormalities, and seizures. Lesions seen on T2/fluid-attenuated inversion recovery sequences of magnetic resonance imaging were common in all clusters, but unilateral ischemic lesions were more prominent in cluster 1. The clusters were associated with specific diagnoses and diagnostic test results. CONCLUSION: Children with inflammatory brain diseases presented with distinct phenotypical patterns that are associated with specific diagnoses. This information may inform the development of a diagnostic classification of childhood inflammatory brain diseases and suggest that specific pathways of diagnostic evaluation are warranted.

Encephalitis with refractory seizures, status epilepticus, and antibodies to the GABAA receptor: a case series, characterisation of the antigen, and analysis of the effects of antibodies.

BACKGROUND: Increasing evidence suggests that seizures and status epilepticus can be immune-mediated. We aimed to describe the clinical features of a new epileptic disorder, and to establish the target antigen and the effects of patients' antibodies on neuronal cultures. METHODS: In this observational study, we selected serum and CSF samples for antigen characterisation from 140 patients with encephalitis, seizures or status epilepticus, and antibodies to unknown neuropil antigens. The samples were obtained from worldwide referrals of patients with disorders suspected to be autoimmune between April 28, 2006, and April 25, 2013. We used samples from 75 healthy individuals and 416 patients with a range of neurological diseases as controls. We assessed the samples using immunoprecipitation, mass spectrometry, cell-based assay, and analysis of antibody effects in cultured rat hippocampal neurons with confocal microscopy. FINDINGS: Neuronal cell-membrane immunoprecipitation with serum of two index patients revealed GABAA receptor sequences. Cell-based assay with HEK293 expressing α1/ß3 subunits of the GABAA receptor showed high titre serum antibodies (>1:160) and CSF antibodies in six patients. All six patients (age 3-63 years, median 22 years; five male patients) developed refractory status epilepticus or epilepsia partialis continua along with extensive cortical-subcortical MRI abnormalities; four patients needed pharmacologically induced coma. 12 of 416 control patients with other diseases, but none of the healthy controls, had low-titre GABAA receptor antibodies detectable in only serum samples, five of them also had GAD-65 antibodies. These 12 patients (age 2-74 years, median 26.5 years; seven male patients) developed a broader spectrum of symptoms probably indicative of coexisting autoimmune disorders: six had encephalitis with seizures (one with status epilepticus needing pharmacologically induced coma; one with epilepsia partialis continua), four had stiff-person syndrome (one with seizures and limbic involvement), and two had opsoclonus-myoclonus. Overall, 12 of 15 patients for whom treatment and outcome were assessable had full (three patients) or partial (nine patients) response to immunotherapy or symptomatic treatment, and three died. Patients' antibodies caused a selective reduction of GABAA receptor clusters at synapses, but not along dendrites, without altering NMDA receptors and gephyrin (a protein that anchors the GABAA receptor). INTERPRETATION: High titres of serum and CSF GABAA receptor antibodies are associated with a severe form of encephalitis with seizures, refractory status epilepticus, or both. The antibodies cause a selective reduction of synaptic GABAA receptors. The disorder often occurs with GABAergic and other coexisting autoimmune disorders and is potentially treatable. FUNDING: The National Institutes of Health, the McKnight Neuroscience of Brain Disorders, the Fondo de Investigaciones Sanitarias, Fundació la Marató de TV3, the Netherlands Organisation for Scientific Research (Veni-incentive), the Dutch Epilepsy Foundation.

von Willebrand factor antigen--a possible biomarker of disease activity in childhood central nervous system vasculitis?

OBJECTIVE: The main objective was to develop a trajectory for von Willebrand factor (vWF) antigen in childhood primary CNS vasculitis (cPACNS) after treatment and compare this with disease activity and other inflammatory markers. METHODS: A single-centre cohort study of consecutive children diagnosed with cPACNS was performed. Demographic, clinical, laboratory, imaging and histological data were collected at diagnosis and during standardized clinic visits. Outcome measures included disease activity measured by physician global assessment and serial measures of vWF antigen. Analysis included descriptive statistics and parametric methods. RESULTS: The study cohort consisted of 39 children diagnosed with cPACNS: 25 with angiography-negative cPACNS and 14 with angiography-positive disease. Twenty-one patients were female, median age at diagnosis was 9.8 years, and median follow-up was 18 months. All patients presented with neurological deficits. Disease activity and neurological outcome improved significantly during follow-up. vWF antigen levels were increased at diagnosis in 65% of children with cPACNS and were decreased significantly after treatment. In contrast, levels of CRP and ESR fluctuated over time. Higher vWF antigen levels at diagnosis were associated with lower measures of disease activity at 12 months. CONCLUSION: In our study, all children with cPACNS improved over time. Changes in CRP and ESR, other laboratory tests, and MRI did not consistently reflect altered disease activity. However, vWF antigen may help clinicians to identify changes in disease activity during follow-up and predict treatment response. Controlled studies are necessary to evaluate the sensitivity and specificity of vWF antigen as a biomarker of disease activity.

Childhood primary angiitis of the central nervous system: identifying disease trajectories and early risk factors for persistently higher disease activity.

OBJECTIVE: To compare clinical, laboratory, and imaging characteristics of childhood primary angiitis of the central nervous system (PACNS) subtypes at diagnosis and during followup; to characterize disease activity trajectories in childhood PACNS subtypes; and to identify early risk factors for higher disease activity. METHODS: We performed a single-center cohort study of consecutive children diagnosed as having childhood PACNS. Demographic, clinical, laboratory, and imaging data were collected at diagnosis and during standardized clinic visits. Outcome measures included disease activity measured by physician's global assessment. Descriptive statistics were used to assess characteristics of the study cohort, and longitudinal data were analyzed using linear mixed-effects regression. RESULTS: The study cohort consisted of 45 patients with childhood PACNS; 26 had angiography-negative childhood PACNS and 19 had angiography-positive childhood PACNS. There were 24 females, the median age at diagnosis was 9.8 years, and the median followup period was 1.8 years. Patients with angiography-negative childhood PACNS were more likely to be female and to present with seizures, cognitive dysfunction, vision abnormalities, high levels of inflammatory markers, and bilateral findings on magnetic resonance imaging (MRI). Motor deficits and ischemic MRI lesions were more common in angiography-positive disease. Disease activity decreased significantly after treatment in all patients. Distinct trajectories of disease activity over time were identified for both childhood PACNS subtypes. Patients with angiography-negative childhood PACNS had persistently higher disease activity. Seizures at presentation also predicted higher disease activity over time. CONCLUSION: Distinct subtypes of childhood PACNS have unique disease activity trajectories. Patients with angiography-negative disease and seizures at presentation experience higher disease activity. Early recognition of this high-risk cohort may enable the treating physician to initiate targeted therapies and prevent long-term brain injury.

Central nervous system vasculitis in children.

PURPOSE OF REVIEW: To review the current literature of childhood primary and secondary central nervous system (CNS) vasculitis and to evaluate the growing differential diagnosis of inflammatory and noninflammatory brain diseases. RECENT FINDINGS: Primary angiitis of the central nervous system in children (cPACNS) is a reversible cause of severe neurological deficits and/or psychiatric symptoms. This disease is classified into subtypes based on distinct clinical and radiological features, treatment strategies, and disease trajectories. Also, the increased diagnostic yield from elective brain biopsies in children has improved our ability to diagnose angiography-negative cPACNS. Over the past few years, the differential diagnosis for cPACNS has rapidly expanded due to the characterization of novel inflammatory and noninflammatory brain diseases. Specifically, vasoconstrictive disorders and neuronal antibody-associated conditions have now been described in children and have overlapping clinical features with cPACNS. SUMMARY: This review summarizes the recent data on diagnosis, treatment, and prognosis of cPACNS. It also addresses the evolving differential diagnosis for CNS vasculitis. Our improved understanding of these disorders allows a tailored diagnostic approach leading to rapid diagnosis and initiation of therapy in these potentially reversible conditions.

Diagnosing central nervous system vasculitis in children.

PURPOSE OF REVIEW: To review the current literature of childhood central nervous system vasculitis, and to discuss a tailored approach to diagnosis and treatment based on recent evidence. RECENT FINDINGS: Primary angiitis of the central nervous system in children (cPACNS) is an increasingly recognized inflammatory brain disease with potentially devastating neurological consequences. The diagnostic approach should be tailored to the clinical presentation of the child with suspected cPACNS and should address the expanding spectrum of inflammatory and noninflammatory brain diseases with overlapping clinical features. New evidence has confirmed that elective brain biopsies in children have a higher diagnostic yield than in adults and improve our ability to diagnose angiography-negative cPACNS. Finally, observational studies have shown that early diagnosis and aggressive treatment lead to improved neurological outcomes and lower mortality rates in patients with cPACNS. SUMMARY: This review summarizes the recent data on diagnosis, classification, treatment, and outcomes in cPACNS. Our improved understanding of cPACNS facilitates a tailored diagnostic approach that results in earlier diagnosis and initiation of therapy for this potentially reversible condition.