Gadolinium-based contrast agents (GBCAs) are essential for improving the diagnostic accuracy of magnetic resonance imaging (MRI) studies. Although traditionally regarded as highly safe, in recent years the marketing authorisation for certain linear GBCAs has been withdrawn, and the use of macrocyclic GBCAs has become subject to regulatory oversight. Current recommendations advocate the use of the lowest effective dose at all times. Central nervous system (CNS) pathology is the most common indication for MRI with GBCAs. However, clinical recommendations and best practices in this setting often lack a comprehensive approach. This document presents recommendations for the use of GBCAs in the main categories of CNS disease-namely neuro-oncological, inflammatory, infectious and vascular conditions-as well as in CNS angiographic studies. These recommendations have been developed by a nationally convened expert committee. It also highlights the importance of ensuring clinical and environmental safety in the use of these contrast media.

Women's neurology and obstetrics/gynecology experts convened to consolidate the best available evidence on multiple sclerosis (MS) management in reproductive-aged women, especially regarding the use of MS disease-modifying therapies (DMTs) surrounding pregnancy and lactation. To update 2014 clinical recommendations, an expert clinical review informed by a systematic literature search of PubMed, LactMed, and ClinicalTrials.gov was conducted utilizing keywords "multiple sclerosis" and "pregnancy." A total of 774 papers were screened for inclusion. To provide updated guidelines, two reviewers prioritized studies according to strength of evidence and relevance to validating/updating our clinical management recommendations. To provide updated information about pregnancy and lactation safety of available MS DMTs, an additional reviewer synthesized all available studies. All authors then reviewed data to craft consensus guidelines. We encourage collaborative care models to optimize symptom control, social support, and maternal wellbeing before, during, and after pregnancy. In most cases, MS is not associated with increased risks of adverse pregnancy outcomes, although some studies have reported slightly elevated risks of lower birthweight, preterm birth, and operative delivery. With appropriate monitoring, MS disease activity can often be minimized throughout the childbearing period by continuation or strategic timing of many DMTs to optimize maternal disease control while minimizing fetal risk. The postpartum period represents a period of increased medical and psychological risk, and close follow-up is recommended. After childbearing is complete, gynecological care can shift to prevention and management of gynecological complications (DMT-associated infections and risk of cervical dysplasia) and of the menopausal transition.

Chronic autoinflammatory diseases such as rheumatoid arthritis and multiple sclerosis lack curative therapies, and current immunosuppressive treatments often cause systemic off-target effects. To address this unmet need, we previously developed an "inverse vaccine" based on anionic phosphatidylglycerol liposomes carrying a disease-specific peptide antigen conjugated to dexamethasone. Here, we assess the therapeutic efficacy and immunomodulatory mechanisms of this platform in two murine models of autoimmunity. In the proteoglycan-induced arthritis model, a single administration of liposomal dexamethasone-human proteoglycan peptide (Dex-K4-hPG) markedly slowed arthritis progression compared to an equivalent dose of free Dex-K4-hPG. Long-term follow-up showed that two injections provided superior protection over a single dose, whereas a third injection yielded no additional benefit. Flow cytometry of paw draining lymph nodes revealed reduced RORγt+CD4+ T cells in mice receiving multiple doses indicating a shift toward less pro-inflammatory T-cell responses. Histological staining of the knees of mice also revealed less damage to the joints of mice receiving 2 or 3 injections of liposomes. To evaluate the versatility of this platform, we generated a novel Dex-peptide conjugate by replacing hPG for myelin oligodendrocyte glycoprotein (MOG). The resulting Dex-K4-MOG conjugate was encapsulated in the liposomes at high encapsulation efficiency (~60%), demonstrating platform modularity. In an experimental autoimmune encephalomyelitis mouse model, two injections of Dex-K4-MOG liposomes (one before disease induction and one after) strongly suppressed disease development compared with controls. Together, these findings demonstrate that antigen-specific inverse vaccination using anionic liposomes offers a modular and broadly applicable strategy for inducing long-term protection in multiple autoimmune disease models. The platform elicits regulatory immune signatures and suppresses pathogenic Th17 responses, supporting its potential as a tolerogenic therapeutic approach.

Despite being the gold-standard therapy for treatment-resistant schizophrenia, clozapine use remains constrained by the risk of rare but serious adverse drug reactions, including severe neutropenia and agranulocytosis. Neutrophil myeloperoxidase (MPO)-mediated bioactivation of clozapine to reactive metabolites has long been implicated in agranulocytosis. Although clozapine is metabolized by MPO, there are numerous other compounds that can also be metabolized by this enzyme. Edaravone is a drug used to treat amyotrophic lateral sclerosis and has potent antioxidant activity; we have previously shown that edaravone is metabolized by MPO. Therefore, we hypothesized that edaravone can attenuate early toxicological events associated with clozapine through MPO modulation. Using purified human MPO, MPO-rich human promyelocytic leukemia (HL-60) cells, and isolated human neutrophils, we evaluated clozapine oxidation, competitive intracellular uptake, protein adduct formation, and cytotoxicity. UV-visible spectroscopy demonstrated concentration-dependent inhibition of MPO-catalyzed clozapine oxidation by edaravone, with 100µM edaravone producing suppression comparable to 100µM 4-aminobenzoic acid hydrazide. LC-MS analysis showed that MPO/H₂O₂ reduced clozapine levels to 26.7 ± 2.9% of control, whereas co-incubation with edaravone preserved clozapine to 67.9 ± 16.2%. Under the same conditions, edaravone was almost completely consumed (0.03 ± 0.02% remaining), consistent with its sacrificial antioxidant activity. In HL-60 cells, edaravone attenuated MPO activity and did not significantly alter clozapine uptake after 30minutes (97.2 ± 7.6% of clozapine alone). Immunoblotting revealed that edaravone reduced clozapine-protein adduct formation in purified MPO, HL-60 cells, and neutrophils. Clozapine (75µM) induced marked HL-60 cytotoxicity after 24hours, whereas edaravone concentration-dependently restored viability, with 200µM fully preventing toxicity. These findings provide proof-of-concept that edaravone mitigates multiple mechanistic events linked to clozapine-induced hematological toxicity and may represent a potential strategy to improve clozapine safety.

Gammaherpesviruses, including human Epstein-Barr Virus (EBV) and Kaposi's Sarcoma-associated Herpesvirus (KSHV), establish lifelong latent infections that contribute to multiple cancers and Multiple Sclerosis. These viruses colonize naïve B cells and drive a robust, polyclonal germinal center response to expand the latent viral reservoir and establish lifelong infection in memory B cells. Despite the clinical burden of these viruses, the host factors that support chronic infection remain poorly defined. Interleukin-22 (IL-22) is a critical cytokine traditionally recognized for its protective roles in bacterial and fungal defense; however, its involvement in gammaherpesvirus pathogenesis has not been explored. Using murine gammaherpesvirus 68 (MHV68) as a tractable in vivo model, we identify IL-22 as a host factor that promotes the establishment of chronic gammaherpesvirus infection. MHV68 infection triggers robust IL-22 production across multiple anatomical sites and immune cell populations. Although IL-22 deficiency did not affect acute viral replication, IL-22-/- mice exhibited a sustained reduction in latent viral burden within both the spleen and peritoneal cavity. This phenotype was accompanied by impaired germinal center B cell and T follicular helper cell responses, reduced plasma-cell expansion, diminished virus-specific antibody responses, and attenuated polyclonal autoreactive antibody production. Furthermore, IL-22 deficiency was associated with reduced systemic BAFF levels, suggesting that IL-22 contributes to the establishment of a germinal center microenvironment that supports chronic infection. Together, these findings identify IL-22 as a previously unrecognized regulator of chronic gammaherpesvirus infection and reveal a role for this cytokine in coordinating germinal center responses, humoral immunity, and latent reservoir establishment, providing new insight into how host immune pathways contribute to lifelong gammaherpesvirus infection.

In multiple sclerosis (MS), spontaneous remyelination occurs in early disease; however, this process becomes inefficient over time, resulting in sustained neurodegeneration and clinical deterioration. It is known that global tumor necrosis factor receptor 2 (TNFR2) deletion in experimental autoimmune encephalomyelitis (EAE), the murine MS model, causes a severe nonremitting disease; however, the underlying mechanism is poorly understood. Here, through bulk and single nucleus RNA sequencing, we identify endothelial TNFR2 deletion as the driver of nonremitting disease, as it is sufficient to drive a severe nonremitting phenotype that closely mirrors global TNFR2 loss. Remyelination failure upon endothelial cell-specific TNFR2 ablation was also detected at the Cuprizone model of remyelination confirming its dominant role in central nervous system (CNS) repair. Notably, this effect was independent of immune cell influx or vascular permeability changes but associated with fibronectin overexpression and accumulation in demyelinating lesions. Fibronectin accumulation led to the sequestering of oligodendrocyte progenitor cells (OPCs) at the demyelination areas and prevented myelin repair. Therapeutically, systemic fibronectin inhibition restored regeneration and clinical remission, as well as prevented OPC accumulation at lesions, providing strong preclinical evidence for fibronectin-targeting therapies in MS and other demyelinating disorders. These findings establish endothelial cells as key regulators of the parenchymal environment permissive to remyelination and open avenues for MS treatment strategies focused on vascular-driven CNS regeneration.

Ketogenic diet (KD) is increasingly considered as an adjunctive therapeutic approach across a range of diseases, but its effects on the pharmacokinetics of concomitantly administered drugs remain unclear. Such interactions may be particularly relevant in multiple sclerosis, where KD is being explored as a complementary strategy alongside disease-modifying therapies, such as ozanimod. We therefore investigated whether KD affects ozanimod metabolism and pharmacokinetics and explored potential factors that may contribute to such effects. Specific pathogen-free female C57BL/6 mice were fed either a control diet containing 10% of calories from fat or a ketogenic diet containing 90% of calories from fat for 4 weeks. Metabolic, inflammatory, and hormonal parameters were determined in plasma. Gut microbiota composition was analyzed by whole-metagenome shotgun sequencing. In parallel, hepatic cytochrome P450 (CYP) enzymes were evaluated by mRNA expression and activity together with ozanimod pharmacokinetics. KD induced the expected metabolic adaptation to ketosis and led to a significant increase in plasma cholesterol accompanied by changes in gut microbiota composition. Other metabolic and inflammatory parameters showed only modest changes. In addition, KD altered the expression and activity of hepatic CYP enzymes, including enzymes involved in ozanimod metabolism: CYP1A activity and mRNA expression were significantly increased in KD-fed mice, whereas lower CYP2C activity was observed in pooled samples and CYP3A activity showed a non-significant trend toward lower values. Ozanimod exposure tended to be higher in KD-fed mice, resulting in an approximately 17% increase in area under the concentration-time curve, although this effect did not reach statistical significance. In conclusion, our findings demonstrate that KD altered the expression and activity of hepatic CYP enzymes and revealed a non-significant trend toward increased ozanimod exposure. These observations highlight the potential importance of considering dietary interventions as a factor contributing to variability in drug response.

Reliable automatic quantification of axon density in histologic sections is important for both research and clinical neuropathology applications - however, it remains a challenge for silver-impregnation stains, such as Bielschowsky. Classical color-deconvolution approaches perform poorly on silver stains, and manual annotation of densely packed axons is time-consuming and subject to inter-rater variability. We developed an automated axon segmentation pipeline in Bielschowsky silver-stained histological brain sections based on an attention U-Net architecture with attention-gated skip connections, trained using Focal Tversky Loss to handle class imbalance and thin structure recovery. Ground truth was manually annotated on 33 image tiles (covering over 25 million pixels) derived from 26 whole-slide images from varying brain regions of four multiple sclerosis patients. Slides were prepared by different laboratory technicians at different time points to capture realistic staining variability. Model performance was evaluated on a held-out test set of unseen tiles. On the test set (eight held-out tiles) the model achieved a mean pixel-wise F1/Dice of 0.717 and an intersection over union (IoU) of 0.584. A dedicated inter-rater experiment on two representative tiles yielded rater-to-rater F1 scores of 0.637 and 0.671, while model-to-rater agreement (F1: 0.681-0.736) met or exceeded that human ceiling. Generated whole-slide density and orientation visualizations accurately reflected regional axon distributions and provided quantitative readouts suitable for downstream analysis. Our attention U-Net provides an open-source solution for axon segmentation from Bielschowsky-stained sections, reducing manual effort and enabling reproducible, slide-level quantitative metrics. This tool can facilitate studies of axonal pathology across research and clinical settings.