Search Results (58)

Cerebrospinal fluid (CSF) oligoclonal band (OCB) analysis remains central to the diagnostic evaluation of neuroinflammatory diseases of the central nervous system (CNS), as it reflects intrathecal immunoglobulin synthesis. However, its reliance on lumbar puncture limits its applicability for screening and repeated longitudinal assessment. Serum metabolomics offers a minimally invasive strategy to explore peripheral biochemical correlates of central immune activity. Building on previous binary OCB comparisons, the present study extends serum metabolomic analysis to encompass all five classical OCB patterns, thereby capturing a broader immunological spectrum. A total of 92 adults undergoing diagnostic evaluation for suspected CNS inflammatory disorders were retrospectively stratified according to OCB type (Types 1–5). Serum samples were analysed using targeted ¹H-NMR spectroscopy on a Bruker Avance Neo 600 MHz platform and processed using Bruker’s IVDr pipeline. Group-wise differences were assessed using non-parametric statistical testing with false discovery rate (FDR) correction, complemented by effect size estimation, exploratory multivariate analyses, and Receiver Operating Characteristic (ROC) modelling. Distributional characteristics were further examined using boxplots and violin plots. Across analytical approaches, several metabolites—most prominently leucine, 2-oxoglutaric acid, histidine, threonine, and glycerol—exhibited nominal variation and moderate effect sizes across OCB patterns. Rather than discrete metabolic separation, these metabolites demonstrated graded shifts in central tendency accompanied by substantial overlap between groups. Unsupervised principal component analysis did not reveal robust clustering, while supervised multivariate models highlighted amino acid- and tricarboxylic acid cycle-related metabolites as contributors to partial differentiation. Post hoc power analysis indicated limited sensitivity to detect small-to-moderate effects under multiple-testing correction, supporting an exploratory interpretation of the findings. Taken together, this first targeted serum ¹H-NMR metabolomic evaluation spanning all classical OCB patterns suggests that peripheral metabolic profiles may reflect graded immunometabolic variation associated with intrathecal immune activity. While not intended for diagnostic classification, these findings provide a spectrum-based framework for integrating serum metabolomics with OCB phenotyping and identify candidate metabolites for future prospectively powered and clinically characterised studies. Full article

Multiple sclerosis (MS) is a chronic autoimmune and neurodegenerative disease characterized by marked clinical heterogeneity. While the genetic architecture underlying disease susceptibility is well established, the role of genetic factors in shaping disease prognosis remains clearly defined. In this structured narrative review, we examine available evidence on genetic contribution to key MS prognostic domains. This includes clinical outcomes, such as age at onset, relapse rate, disability progression, neurological sequelae, and cognitive impairment. We also consider radiological measures like brain and spinal cord lesion burden, gadolinium-enhancing lesions, and atrophy, as well as laboratory biomarkers, such as oligoclonal bands and Immunoglobulin G (IgG) index. Overall, current evidence suggests that genetic influences on prognosis are modest and highly heterogeneous. Only a limited number of associations—primarily from genome-wide association studies (GWAS)—have shown consistent replication, whereas many reported findings come from small candidate-gene studies and remain unconfirmed. Among these, the largest GWAS on age-related Multiple Sclerosis Severity Score (MSSS) identified a locus in the DYSF–ZNF638 region reaching genome-wide significance. The strongest evidence from GWAS relates to relapse rate, magnetic resonance imaging (MRI) measures (e.g., thalamic atrophy) and intrathecal IgG synthesis, the latter also reaching genome-wide significance. Interpretation of genotype–phenotype associations is further limited by small sample sizes, limited replication, heterogeneity in study design with the predominance of candidate-gene approaches, variability in outcome definitions, treatment exposure, and population ancestry. These limitations currently preclude the routine use of genetic markers for prognostic stratification in clinical practice. Larger studies and collaborative genetic consortia efforts are needed to improve statistical power and reproducibility. Additionally, emerging epigenetic studies may provide valuable insights into prognosis and disease management. Understanding which genetic factors can predict diverse MS courses could enhance patient management and enable personalized treatment approaches. Full article

The glymphatic system is a fluid-transport framework in which cerebrospinal fluid (CSF) enters the brain along perivascular routes, exchanges with interstitial fluid (ISF), and exits toward venous, perineural, and meningeal lymphatic pathways enabling waste clearance. Recent studies have clarified the anatomical components that regulate solute movement. The perivascular astrocyte endfeet, which are enriched in polarized aquaporin-4 (AQP4) expression, create a high-permeability water interface that facilitates CSF–ISF exchange. Multiscale physical drivers such as cardiac pulsation, arteriolar vasomotion, and brain-state changes during sleep regulate the timing and efficiency of the glymphatic transport. A broad spectrum of solutes is transported through this pathway, from small metabolites to extracellular proteins including amyloid-β and tau, as well as exogenous tracers and some lipid-associated species. Glymphatic redistribution may interface with other clearance systems, including the brain-to-blood efflux via blood–brain barrier (BBB) transport, intramural periarterial drainage (IPAD) that clears along vascular basement membranes and the meningeal lymphatic pathways that drain macromolecules to deep cervical lymph nodes. These different routes may be interconnected and may represent a waste clearance network with complementary roles assigned to different mechanisms. Moreover, state dependence (notably sleep) and vascular health modulate glymphatic flux, offering plausible links between glymphatic system dysfunction, aging and neurodegeneration. Methodological advances—from intrathecal contrast magnetic resonance imaging (MRI) to in vivo two-photon imaging and tracer-kinetic modeling—have provided new insights into the anatomical scaffold and kinetics of the glymphatic system. Advances in glymphatic anatomy, together with growing evidence implicating glymphatic dysfunction in neurodegeneration, point towards a unifying framework that is urgently needed. Our synthesis spans glymphatic structure, fluid routing, and the repertoire of transported solutes and links to complementary clearance routes, supporting a unified model in which glymphatic clearance represents an important contributor of cerebral homeostasis. Understanding glymphatic dysfunction may guide the establishment of diagnostic imaging biomarkers that have the potential to assist in therapeutic modulation of neurodegenerative diseases. Full article

A multicenter molecular biomarker survey was conducted in Multiple Sclerosis (MS) centers across Central-Eastern European countries, encompassing a population of 107 million. Our aim was to provide a “snapshot” for future studies investigating the use of molecular biomarkers in MS. A self-report questionnaire was distributed via email to MS centers in seven Central-Eastern European countries (Croatia, Czech Republic, Poland, Romania, Serbia, Slovakia, and Slovenia) and to four reference centers (two in Austria, one in Germany, and one in Denmark), focusing on cerebrospinal fluid (CSF) analysis and molecular biomarkers in MS. Responding centers routinely request CSF oligoclonal band (OCB) testing in suspected MS cases, although no consensus exists on the number of CSF-restricted bands required to define OCB positivity, either within or between countries. More than half of the surveyed centers in the Czech Republic, Slovakia, Slovenia, and the reference centers request kappa free light chain (κFLC) testing in patients with suspected MS. Neurofilament light chain (NfL) is frequently used as a molecular biomarker for MS in Romania, Slovakia, and the reference centers. In summary, besides the use of CSF-specific OCB there is no consensus among the surveyed countries regarding the use of molecular biomarkers in MS. Full article

Alzheimer’s disease (AD) is a progressive neurodegenerative disorder characterised by cognitive decline, synaptic loss, and multifaceted pathology involving amyloid-β (Aβ) aggregation, tau hyperphosphorylation, neuroinflammation, and impaired proteostasis. In recent years, biologic therapies, such as monoclonal antibodies, vaccines, antisense oligonucleotides (ASOs), and gene therapies, have gained prominence as promising disease-modifying strategies. In this review, we provide a comprehensive synthesis of current biologic approaches under clinical evaluation for AD. Drawing on data curated from ClinicalTrials.gov (as of 2025), we systematically summarise the molecular targets, therapeutic modalities, mechanisms of action, trial phases, and sponsors of over 60 biologic agents. These include Aβ-directed antibodies targeting distinct conformers such as protofibrils, pyroglutamate-modified species, and soluble oligomers; tau-targeted immunotherapies and RNA-based interventions; and emerging platforms focused on neuroimmune modulation, peptide hormones, and microbiota-based strategies. Gene and RNA therapeutics, particularly ASOs and small interfering RNAs (siRNAs) delivered intrathecally or via lipid nanoparticles, are also reviewed for their potential to modulate intracellular targets with high specificity. We also analyse the historical landscape of biologic candidates that failed to reach approval, discussing key reasons for trial discontinuation, including lack of clinical efficacy, safety concerns (e.g., amyloid-related imaging abnormalities), or inadequate biomarker responses. These cases offer crucial insights for refining future drug design. Looking ahead, we highlight major challenges and evolving perspectives in AD biologic therapy: expanding therapeutic targets beyond Aβ and tau, overcoming delivery barriers to the brain, designing prevention-oriented and genetically stratified trials, and navigating regulatory and ethical considerations. Together, these efforts signal a paradigm shift in AD drug development, from symptomatic treatment to mechanism-based precision biologics. By integrating real-time clinical trial data with mechanistic insight, this review aims to inform both translational research and therapeutic innovation in AD. Full article

Encephalitis is a potentially life-threatening condition with long-term neurological sequelae. However, data on early clinical, demographic, and diagnostic predictors of functional outcomes remain limited. We performed a retrospective monocentric study including 98 patients diagnosed with infectious encephalitis of various etiologies treated in the University Hospital Ulm between January 2014 and December 2024. Ordinal logistic regression models were applied to evaluate associations between admission characteristics and functional outcome at discharge, as measured by the modified Rankin Scale. Three multivariate models incorporating clinical, demographic, and MRI/EEG variables explained up to 53% of the variance in mRS at discharge (p < 0.001), outperforming models based solely on CSF parameters. Key predictors of poor functional outcome included ‘altered consciousness’ (OR 7.08, p < 0.001), higher ‘mRS at admission’ (OR 0.03–0.07 across categories, p < 0.001), ‘focal/generalized EEG slowing’ (OR 9.97, p < 0.001), ‘epileptiform EEG activity’ (OR 17.49, p < 0.001), ‘MRI: myelitis’ (OR 16.44, p = 0.004), and ‘intrathecal IgM synthesis’ (OR 8.93, p = 0.018). Conversely, ‘longer hospitalization’ (OR 0.13–0.17 for different intervals, p < 0.006) and ‘intrathecal IgG synthesis’ (OR 0.05, p = 0.03) were associated with more favorable outcomes. Despite the single-center and retrospective aspects of this study, our findings underscore a multifactorial pattern of outcome determinants in infectious encephalitis, highlighting the prognostic relevance of initial neurological status, electrophysiological abnormalities, and neuroimaging features. Full article

The mineralocorticoid receptor (MR), traditionally associated with renal function, has also been identified in various extrarenal tissues, including the heart, brain, and dorsal root ganglion (DRG) neurons in rodents. Previous studies suggest a role for the MR in modulating peripheral nociception, with MR activation in rat DRG neurons by its endogenous ligand, aldosterone. This study aimed to determine whether MR, its protective enzyme 11β-hydroxysteroid dehydrogenase type 2 (11β-HSD2), its endogenous ligand aldosterone, and the aldosterone-synthesizing enzyme CYP11B2 are expressed in human DRG neurons and whether they colocalize with key pain-associated signaling molecules as potential targets for genomic regulation. To this end, we performed mRNA transcript profiling and immunofluorescence confocal microscopy on human and rat DRG tissues. We detected mRNA transcripts for MR, 11β-HSD2, and CYP11B2 in human DRG, alongside transcripts for key thermosensitive and nociceptive markers such as TRPV1, the TTX-resistant sodium channel Nav1.8, and the neuropeptides CGRP and substance P (Tac1). Immunofluorescence analysis revealed substantial colocalization of MR with 11β-HSD2 and CGRP, a marker of unmyelinated C-fibers and thinly myelinated Aδ-fibers, in human DRG. MR immunoreactivity was primarily restricted to small- and medium-diameter neurons, with lower expression in large neurons (>70 µm). Similarly, aldosterone colocalized with CYP11B2 and MR with nociceptive markers including TRPV1, Nav1.8, and TrkA in human DRG. Importantly, functional studies demonstrated that prolonged intrathecal inhibition of aldosterone synthesis within rat DRG neurons, using an aldosterone synthase inhibitor significantly downregulated pain-associated molecules and led to sustained attenuation of inflammation-induced hyperalgesia. Together, these findings identify a conserved peripheral MR signaling axis in humans and highlight its potential as a novel target for pain modulation therapies. Full article

The combined use of serum and CSF biomarkers for prognostic stratification in multiple sclerosis (MS) remains underexplored. This multicenter observational study investigated associations between serum neurofilament light chain (sNfL), glial fibrillary acidic protein (sGFAP), and CSF lipid-specific IgM oligoclonal bands (LS-OCMB) with different forms of disability worsening, such as relapse-associated worsening (RAW), active progression independent of relapse activity (aPIRA), and non-active PIRA (naPIRA). A total of 535 patients with MS were included, all sampled within one year of disease onset. Biomarkers were quantified using single-molecule array and immunoblotting techniques, and CSF cell subsets were analyzed by flow cytometry. High sNfL z-scores and LS-OCMB positivity were independently associated with increased risk of RAW and aPIRA, collectively termed inflammatory-associated worsening (IAW), while elevated sGFAP levels predicted naPIRA. Patients with both high sNfL and LS-OCMB positivity had the highest risk of IAW. Among LS-OCMB–positive patients, higher regulatory T cell percentages were associated with lower sNfL levels, suggesting a protective role. Conversely, in LS-OCMB–negative patients, sNfL levels correlated with CSF C3 concentrations. These findings support the complementary role of sNfL, sGFAP, and LS-OCMB in identifying distinct mechanisms of disease worsening and may inform early personalized management strategies in MS. Full article

Background: Multiple sclerosis (MS) is a chronic inflammatory disease of the central nervous system (CNS). Oligoclonal bands (OCBs) in cerebrospinal fluid (CSF) are a hallmark of MS and reflect intrathecal IgG synthesis and inflammation. This study aims to analyze the temporal distribution of IgG OCBs in the CSF of patients with a definitive diagnosis of MS. Methods: This retrospective study included 500 patients with diagnosed MS. Patients were divided into four groups according to diagnostic epochs: Group 1 (Pre-2001 or Pre-McDonald), Group 2 (2001–2010 or McDonald 2001-Polman 2010), Group 3 (2010–2018 or Polman 2010), and Group 4 (Post-2018 or Thompson 2017). Statistical analyses examined temporal and sex differences in OCB positivity rates. Results: OCB positivity was lower in Group 4 (69.2%) compared to Group 1 (85.4%) in the overall population (p = 0.0022). A decrease in OCB positivity was observed in Groups 3 (62.5%) and 4 (71.8%) compared to Group 1 (92.5%) among males (p = 0.0117 and p = 0.0198, respectively) and in Group 4 (68.1%) compared to Group 1 (82.5%) among females (p = 0.0274). Conclusions: The present study provides valuable insights into temporal trends in CSF positivity among patients diagnosed with MS. There was an overall decrease in OCB positivity rates over the years, particularly in the post-2018 period. Full article

The aim of this study was to evaluate the usefulness of IgM anti-Tick-Borne Encephalitis (anti-TBE) intrathecal synthesis in the diagnosis and prediction of the clinical course of the disease. Thirty-six patients were included in the study (patients reported symptoms such as fever, headache, fatigue, and nausea/vomiting). CRP, White Blood Cells (WBC), pleocytosis, Cerebrospinal Fluid (CSF) protein concentration, CSF albumin concentration, serum IgM, serum IgG, CSF IgM, CSF IgG, IgM Index, IgG Index, and IgG Index/IgM Index ratio were the parameters which were examined in the individuals. An analysis of correlation presented statistical significance between IgM Index and pleocytosis and protein concentration in CSF in the whole group of individuals. IgM Index and IgG Index/IgM Index ratio may be used in the prediction of severity of TBE. The most probable link between the IgM intrathecal production and severity of TBE may be a result of delayed seroconversion to IgG, and therefore not an adequate response to the virus presence. Full article

The pathophysiology of cognitive impairment (CI) in multiple sclerosis (MS) remains unclear. Meningeal B cell aggregates may contribute to cortical grey matter pathology. Cerebrospinal fluid (CSF), kappa free light chains (KFLC), and KFLCs-Index (kappa-Index) are reliable quantitative markers of intrathecal synthesis, but few data have been presented exploring the association with CI, and no data are present for lambda FLC (LFLC) in MS. We evaluated cognition using the Brief International Cognitive Assessment for MS (BICAMS) battery and collected serum and CSF at diagnosis in newly diagnosed drug-naïve MS patients. We observed that patients with impaired verbal memory and overall CI showed increased CSF KFLCs (respectively p: 0.0003 and p: 0.003) and kappa-Index (respectively p: 0.01 and p: 0.02) compared to those with normal verbal memory and no CI. Patients with CI also displayed lower CSF LFLCs (p: 0.04) and lambda-Index (p: 0.001); however, only CSF KFLC negatively correlated with normalized results of verbal memory (for age, sex, and educational levels), even after correction for EDSS (r: −0.27 p: 0.01). Finally, CSF FKLC and kappa-Index were significant predictors of verbal memory in a multivariate analysis. Our results, suggest that intrathecal B cell activity might contribute to CI development in MS patients. Full article

Intrathecal immunoglobulin A (IgA) synthesis in multiple sclerosis (MS) has long earned little attention, despite a potential significance in disease pathogenesis and prognosis. The presence of IgA-positive plasma cells in MS lesions and along damaged axons suggests a role in disease pathogenesis. Available clinical evidence about a potential positive or negative prognostic role is scarce and inconclusive. Recent observations, however, highlight the migration of immune regulatory IgA-producing plasma cells from the gut to the central nervous system (CNS) in experimental autoimmune encephalitis models. A connection between intrathecal IgA synthesis and the gut–brain axis in MS was further corroborated by the discovery of gut microbiota-specific IgA+ B cells in human CNS during relapse. In this review, we summarize current evidence on the occurrence and immunopathology of intrathecal IgA synthesis in MS, explore its biological implications, and address methodological challenges regarding the detection of IgA as a major limitation and possible source of inconsistencies in clinical studies. By synthesizing these diverse lines of evidence, we highlight the importance of further research and the need for standardized detection methods to clarify the role of IgA in MS pathogenesis, disease progression, and as potential biomarker. Full article

The kappa index is a well-established marker of intrathecal synthesis (IS) of immunoglobulin (Ig). Routinely used for diagnostic aims, IgG IS, which can be assessed quantitatively (ad hoc formulas) or qualitatively (oligoclonal bands, OCBs), may fail in detecting a humoral immune response within the central nervous system (CNS). The main aim of this study was to evaluate the kappa index for its ability to detect the presence of CNS humoral immunity and to associate it with a distinct group of disorders, in the absence of IgG IS/OCBs. Within the kappa index-positive, IgG OCB-negative (Kappa+OCB-) patient group, we also examined whether IgM/IgA IS, determined with the IgM/IgA index and CSF IgM OCBs, could contribute to disease group stratification. Diagnoses were classified as multiple sclerosis (MS), or other inflammatory (INFL), infectious (INFECT), or non-inflammatory (Other) central/peripheral nervous system disorders. Sixty-nine Kappa+OCB- patients and 50 controls (24 Kappa-OCB- and 26 Kappa+OCB+ patients) were included in this study. The most frequent diagnosis in the Kappa+OCB- group was MS (27/69), followed by INFECT (16/69). Additional evidence of IS was demonstrated through an elevated IgG/IgM/IgA index or by the presence of IgM OCBs in 59%, and through only IgM/IgA IS in 52% of cases. In INFECT patients, the median IgM/IgA indexes were higher (p < 0.001) than in other groups, with 18 patients (95%) presenting an elevated IgM index, 11 patients (58%) presenting CSF IgM OCBs, and 10 patients (53%) presenting an elevated IgA index. The vast majority of all INFECT (16/19) belonged to the Kappa+OCB- group. Our data confirm that the kappa index performs at the highest level in assessing intrathecal humoral immunity and supporting the diagnosis of both MS and CNS infectious disorders, which are also characterized by the intrathecal production of IgM and IgA. Full article

Background: Kappa free light chains (KFLCs) are emerging as promising biomarkers for intrathecal B cell activity for diagnosing multiple sclerosis (MS) through cerebrospinal fluid (CSF) analysis. In this study, we evaluated the ability of KFLC formulas to identify the presence of MS and their agreement with the ‘gold standard’ of CSF IgG oligoclonal bands (OCBs). Methods: A total of 233 patients were included in this study: 149, comprising 43 males and 106 females, had MS, and the remainder, 40 males and 44 females, had other neurological diseases (ONDs). We evaluated the potential of KFLCs in terms of sensitivity, specificity, and accordance. All analyses were conducted using a sex-disaggregated approach. Results: KFLCs showed a high sensitivity for both sexes with respect to the diagnosis of MS, with values between 74.42% and 93.03%. The specificity of the various formulas was much lower for females when compared to males, with values between 45.45% and 59.09%, with a significant difference between the two sexes for the K Index > 5.9 (p = 0.0451). Cohen’s kappa showed substantial agreement for men and moderate agreement for women between the KFLC indices and OCB. Conclusions: This study highlights the potential of KFLCs as a biomarker for MS but emphasises the need for sex-specific thresholds to improve diagnostic accuracy. Full article

Background: The presence of intrathecal total IgG production is a hallmark of cerebrospinal fluid (CSF) characteristics in multiple sclerosis (MS). Herein, we systematically analyze how the intensity (instead of mere presence) of intrathecal total IgG production relates to basic CSF parameters in MS. Methods: We retrospectively assessed clinical routine CSF findings from 390 therapy-naïve relapsing-remitting MS patients diagnosed according to 2017 revised McDonald criteria. The intensity of intrathecal total IgG synthesis according to Reiber’s formula was stratified and correlated to demographics, CSF white cell count (WCC), and diversity of MRZ reaction, defined as a polyspecific intrathecal production of IgG reactive against ≥2 of the 3 viruses; measles (M), rubella (R), and varicella zoster (Z) virus. Results: The higher intensity of intrathecal total IgG production significantly correlated with higher CSF WCC (Spearman’s ρ = 0.433, p < 0.001) and with the increasing presence and diversity of positive MRZ reaction (Spearman’s ρ = 0.600, p < 0.001). Female patients showed higher intensity of intrathecal total IgG production and higher prevalence of positive MRZ reaction than males. Conclusions: The intensity of intrathecal total IgG production correlates with the degree of CSF WCC and diversity of MRZ reaction in MS. As yet unidentified female sex-related factors increase the intensity and diversity of intrathecal IgG production in MS. Full article