Irani, Sarosh R

Background N-methyl-D-aspartate receptor antibody encephalitis (NMDAR-Ab-E) can have an onset during, after or prior to a pregnancy. In animal models, transplacental NMDAR immunoglobulin G transfer can affect neurodevelopment. In contrast, clinical reports of mothers affected by NMDAR-Ab-E typically are reassuring. We systematically reviewed maternal, infant and childhood clinical data pertaining to NMDAR-Ab-E with an onset before, during or after pregnancy and compared this to our single autoimmune neurology centre experience. Methods After pre-registration on PROSPERO (CRD42023408447), we searched PubMed and Scopus for NMDAR-Ab-E case reports/series with an onset before, during or after pregnancy (last search 19/10/2023). We extracted maternal, neonatal and childhood outcomes using an idealised checklist to derive summary statistics. Results After quality control, we identified 66 pregnancies in 61 women from 48 reports or series. 72% of women recovered with minimal or no neurological deficits, comparable to non-pregnancy-associated NMDAR-Ab-E. Likewise, 80% of pregnancies resulted in live births with a single neonatal death reported. Data on neonatal outcome measures were frequently unreported, and childhood follow-up was provided in only 60%. Our centre’s experience is consistent: 3/4 mothers recovered with no functional deficits and 7/8 children without evidence of compromise at a median follow-up of 2 years. Conclusions Current evidence does not overall suggest unfavourable maternal, fetal or childhood outcomes after NMDAR-Ab-E. However, the available sample is small, predominantly single case reports with modest follow-up, lacks standardisation, and data are often incomplete. Future approaches should address these caveats: developing multi-centre collaboration towards an international registry.

Cognitive impairment involves alterations to one's cognitive status that affects everyday life. Individuals with CKD, and particularly kidney failure, experience higher rates of cognitive impairment (20%–70%) compared with the general population. The highest prevalence is described in kidney failure such that dialysis-dependent patients have twice the prevalence of age-matched controls. In the past 5 years, the number of investigations examining the “kidney-brain axis,” mechanisms of CKD-related cognitive impairment, and potential therapeutics have exponentially increased. This review article summarizes recent literature on direct and indirect effects of CKD-associated cognitive impairment with emphasis on uremic toxins; brain injury mechanisms; overlap between CKD-associated cognitive impairment, Alzheimer's disease, and other neurodegenerative diseases. Reviewed therapeutic interventions include AST-120 (indoxyl sulfate absorbent), CH-223191 (aryl hydrocarbon receptor antagonist), triarylmethane-34 (Kca3.1-specific inhibitor), anakinra (IL-1R inhibitor), marimastat, exercise, supplements, and kidney transplantation. Special focus is placed on translational studies examining uremic toxin–associated pathogenic processes, including brain oxidative stress, neuroinflammation, and blood-brain barrier dysfunction through in vitro and in vivo models of CKD-associated brain injury. Finally, future research directions are suggested, including targeting of cellular senescence abundance with senotherapeutics and capitalizing on anti-inflammatory effects of regenerative, cell-based therapeutics ( e.g ., mesenchymal stem cells and extracellular vesicles), and use of aged murine models. Collectively, CKD-associated cognitive impairment represents a prevalent condition for which remaining knowledge gaps exist, and scientific advancements are needed to preserve cognitive function and improve the lives of individuals with CKD.

AbstractBackgroundLGI1‐antibody encephalitis (LGI1‐Ab‐E) is a common form of autoimmune encephalitis where most patients demonstrate ‘good’ clinician‐rated outcomes. However, more targeted questionnaires reveal numerous debilitating symptoms for many years. To better quantify these persistent features, we designed the LGI1‐Antibody Encephalitis Rating (LANTERN) scale, a quantified, disease‐specific patient‐reported outcome measure (PROM), adhering to FDA guidelines.MethodsA participant‐driven mixed‐methods approach to develop a clinically valid questionnaire over three stages: (1) Item generation through semi‐structured interviews; (2) Repeated cognitive debriefing rounds to advance comprehensibility, relevance and comprehensiveness; (3) Psychometric survey to condense the most sensitive and valid questions. Analyses incorporated sensitivity testing with multiple internal and external validations.ResultsFrom 73 items across six domains (Stage 1; n = 18), a questionnaire assessing the frequency and severity of 43 symptoms (80 questions), plus nine activities of daily living (ADL), was developed through cognitive debriefing (Stage 2; n = 15). This 89‐question survey was completed (Stage 3; n = 66 patients and 32 relatives) and distilled, using exploratory factor analyses, to a three‐factor symptom‐burden questionnaire comprising 41 questions (19 symptoms and 6 ADL), separated into physical, cognitive/behavioural and ADL domains. These factors demonstrated strong internal reliability (Cronbach alpha: 0.85–0.91), correlations with relative‐completed questionnaires (R = 0.73–0.85; p < 0.001), good‐to‐excellent intraclass re‐testing correlations (0.81–0.98; n = 19) and strong associations with numerous predefined external measures.DiscussionLANTERN represents a PROM for LGI1‐Ab‐E, with initial content, structural and construct validity and test–retest reliability. It can be used as a reliable, tailored, efficient and sensitive method to establish symptom burden in people with LGI1‐Ab‐E, both in clinical practice and trials.

The long‐term clinical outcomes and associated prognostic factors in contactin‐associated protein‐like 2 (CASPR2)‐antibody diseases are unknown. A total of 75 participants with CASPR2 antibodies were longitudinally assessed for disability, quality‐of‐life, and chronic pain. Although most symptoms improved within 6 months of treatment, neuropathic pain and fatigue were the most immunotherapy refractory, and persisted for up to 6 years. Furthermore, these two factors—but not CASPR2 antibody levels or subclasses—independently predicted worse disability and quality‐of‐life at 24 months. Quality‐of‐life varied widely for any given modified Rankin Scale score, indicating a divergence between patient and clinician assessed outcomes. Further work should study the relative importance of these measures, and the immunopathogenesis underlying intractable symptoms. ANN NEUROL 2025;97:521–528

Abstract Autoimmunity affects 10% of the population. Within this umbrella, autoantibody-mediated diseases targeting one autoantigen provide a unique opportunity to comprehensively understand the developmental pathway of disease-causing B cells and autoantibodies. While such autoreactivities are believed to be generated during germinal centre reactions, the roles of earlier immune checkpoints in autoantigen-specific B cell tolerance are poorly understood. We address this concept in patients with CASPR2-autoantibody encephalitis and healthy controls. In both groups, comparable and high (∼0.5%) frequencies of unmutated CASPR2-reactive naïve B cells were identified. By contrast, CASPR2-reactive memory B cells were exclusive to patients, and their B cell receptors demonstrated affinity-enhancing somatic mutations with heterogenous binding kinetics. These effector molecules possessed epitope-dependent pathogenic effects in vitro neuronal cultures and in vivo. The unmutated common ancestors of these memory B cells showed a distinctive balance between strong CASPR2 reactivity and very limited binding across the remaining human proteome. Our results are the first to propose mechanisms underlying autoantigen-specific tolerance in humans. We identify permissive central tolerance, defective peripheral tolerance and heterogenous autoantibody binding properties as sequential pathogenic steps which licence CASPR2-directed pathology. By leveraging the basic immunobiology, we rationally direct tolerance-restoring approaches in CASPR2-antibody diseases. This paradigm is applicable across autoimmune conditions.

Abstract Background The recognition of autoimmune causes of encephalitis has led to epidemiological shifts in the worldwide characteristics of encephalitis. N-methyl-D-aspartate receptor (NMDAR) antibody encephalitis leads to well-established complex neuropsychiatric manifestations. In low- and middle-income countries, including Vietnam, its relative incidence, especially in children, is unknown and most neurologists currently consider infectious encephalitis prior to autoimmune etiologies. Methods The study was prospectively conducted at Children's Hospital 1 in Ho Chi Minh City between March 2020 and December 2022. Any child admitted to the Department of Infectious Diseases and Neurology fulfilling the case definition of encephalitis was eligible to participate. Cerebrospinal fluid samples were collected alongside meta-clinical data for analysis. Results We recruited 164 children with a clinical diagnosis of encephalitis. Etiologies were determined as NMDAR antibody encephalitis in 23 of 164 cases (14.0%), Japanese encephalitis virus in 14 of 164 (8.5%), and herpes simplex virus in 4 of 164 (2.4%). Clinical categorizations suggested idiopathic viral encephalitis in another 71 (43.3%), and autoimmune encephalitis of unknown origin in the remaining 52. Factors including demographics, specific clinical features, cerebrospinal fluid and electroencephalogram findings, and length of hospital stay were significantly different between NMDAR antibody encephalitis and Japanese encephalitis. Conclusions At a tertiary children's hospital in Vietnam, the prevalence of NMDAR antibody encephalitis exceeds that of Japanese encephalitis, the most common infectious encephalitis cause in Southeast Asia. NMDAR antibody encephalitis is associated with long hospital stay and poor outcomes. These findings should change pediatric diagnostics, to earlier consider autoimmune treatments in this clinical setting.

AbstractLymph nodes (LNs) are specialized secondary lymphoid tissues essential to the priming and maintenance of adaptive immune responses, including the B cell germinal center response; thus, they are central to immunity. However, the anatomically restricted and time‐resolved nature of immune priming means that sampling disease‐relevant human LNs requires specialized techniques. This article describes the application of ultrasound‐guided fine‐needle aspiration (FNA) to sample LNs, using cervical LNs of the head and neck as an exemplar. This minimally invasive technique allows collection of both immune cells and cell‐free material that are relevant to both neuroimmune diseases and basic lymphatic functions. Downstream use of cellular material can include multiplexed flow cytometry, single‐cell transcriptome sequencing (RNA‐seq), and B cell cultures. The cell‐free supernatant can be used for proteomics or other similar ‘omics approaches. This unit describes collection of samples by FNA as well as processing and storage of samples for downstream assays. © 2024 The Author(s). Current Protocols published by Wiley Periodicals LLC.Basic Protocol 1: Sampling of human cervical lymph nodes by ultrasound‐guided fine‐needle aspirationAlternate Protocol: Sampling of human lymph nodes by ultrasound‐guided fine‐needle aspiration with negative pressureBasic Protocol 2: Processing and storage of human lymph node samples