Can CSF biomarkers predict future MS disease activity and severity?

Effects of voluntary and forced physical exercise on the retinal health of aging Wistar rats

Aging is accompanied by an increased prevalence of degenerative conditions, including those affecting ocular health, which significantly impact quality of life and increase the burden on healthcare systems. Among these, retinal aging is of particular concern due to its direct link to vision impairment, a leading cause of disability in the elderly. Vision loss in the aging population is associated with heightened risks of cognitive decline, social isolation, and morbidity. This study addresses the critical gap in our understanding of modifiable lifestyle factors, such as physical exercise, that may mitigate retinal aging and its related pathologies. We investigated the effects of different exercise regimens-voluntary (recreational-type) and forced (high-intensity)-on the retinal health of aging Wistar rats (18-month-old), serving as a model for studying the translational potential of exercise interventions in humans. Male Wistar rats were divided into four groups: a young control (3-month-old) for baseline comparison, an aged sedentary control, an aged group engaging in voluntary exercise via a running wheel in their cage, and an aged group subjected to forced exercise on a treadmill for six sessions of 20 min each per week. After a 6-month experimental period, we assessed retinal function via electroretinography (ERG), measured retinal thickness histologically, and analyzed protein expression changes relevant to oxidative stress, inflammation, and anti-aging mechanisms. Our findings reveal that voluntary exercise positively impacts retinal function and morphology, reducing oxidative stress and inflammation markers while enhancing anti-aging protein expression. In contrast, forced exercise showed diminished benefits. These insights underscore the importance of exercise intensity and preference in preserving retinal health during aging. The study highlights the potential of recreational physical activity as a non-invasive strategy to counteract retinal aging, advocating for further research into exercise regimens as preventative therapies for age-related ocular degenerations.

Advancements in Cerebrospinal Fluid Biosensors: Bridging the Gap from Early Diagnosis to the Detection of Rare Diseases

Cerebrospinal fluid (CSF) is a body fluid that can be used for the diagnosis of various diseases. However, CSF collection requires an invasive and painful procedure called a lumbar puncture (LP). This procedure is applied to any patient with a known risk of central nervous system (CNS) damage or neurodegenerative disease, regardless of their age range. Hence, this can be a very painful procedure, especially in infants and elderly patients. On the other hand, the detection of disease biomarkers in CSF makes diagnoses as accurate as possible. This review aims to explore novel electrochemical biosensing platforms that have impacted biomedical science. Biosensors have emerged as techniques to accelerate the detection of known biomarkers in body fluids such as CSF. Biosensors can be designed and modified in various ways and shapes according to their ultimate applications to detect and quantify biomarkers of interest. This process can also significantly influence the detection and diagnosis of CSF. Hence, it is important to understand the role of this technology in the rapidly progressing field of biomedical science.

Prognostic relevance of MRI in early relapsing multiple sclerosis: ready to guide treatment decision making?

Magnetic resonance imaging (MRI) of the brain and spinal cord plays a crucial role in the diagnosis and monitoring of multiple sclerosis (MS). There is conclusive evidence that brain and spinal cord MRI findings in early disease stages also provide relevant insight into individual prognosis. This includes prediction of disease activity and disease progression, the accumulation of long-term disability and the conversion to secondary progressive MS. The extent to which these MRI findings should influence treatment decisions remains a subject of ongoing discussion. The aim of this review is to present and discuss the current knowledge and scientific evidence regarding the utility of MRI at early MS disease stages for prognostic classification of individual patients. In addition, we discuss the current evidence regarding the use of MRI in order to predict treatment response. Finally, we propose a potential approach as to how MRI data may be categorized and integrated into early clinical decision making.

Cerebrospinal fluid oligoclonal bands in Chinese patients with multiple sclerosis: the prevalence and its association with clinical features

Background

Cerebrospinal fluid oligoclonal band (CSF-OCB) is an established biomarker in diagnosing multiple sclerosis (MS), however, there are no nationwide data on CSF-OCB prevalence and its diagnostic performance in Chinese MS patients, especially in the virtue of common standard operation procedure (SOP).

Methods

With a consensus SOP and the same isoelectric focusing system, we conducted a nationwide multi-center study on OCB status in consecutively, and recruited 483 MS patients and 880 non-MS patients, including neuro-inflammatory diseases (NID, n = 595) and non-inflammatory neurological diseases (NIND, n=285). Using a standardized case report form (CRF) to collect the clinical, radiological, immunological, and CSF data, we explored the association of CSF-OCB positivity with patient characters and the diagnostic performance of CSF-OCB in Chinese MS patients. Prospective source data collection, and retrospective data acquisition and statistical data analysis were used.

Findings

369 (76.4%) MS patients were OCB-positive, while 109 NID patients (18.3%) and 6 NIND patients (2.1%) were OCB-positive, respectively. Time from symptom onset to diagnosis was significantly shorter in OCB-positive than that in OCB-negative MS patients (13.2 vs 23.7 months, P=0.020). The prevalence of CSF-OCB in Chinese MS patients was significantly higher in high-latitude regions (41°-50°N)(P=0.016), and at high altitudes (>1000m)(P=0.025). The diagnostic performance of CSF-OCB differentiating MS from non-MS patients yielded a sensitivity of 76%, a specificity of 87%.

Interpretation

The nationwide prevalence of CSF-OCB was 76.4% in Chinese MS patients, and demonstrated a good diagnostic performance in differentiating MS from other CNS diseases. The CSF-OCB prevalence showed a correlation with high latitude and altitude in Chinese MS patients.

Dual positivity for anti-MOG and oligoclonal bands: Unveiling unique clinical profiles and implications

BACKGROUND

Distinguishing between MOG-associated disease (MOGAD) and multiple sclerosis (MS) presents a considerable challenge, as there are instances of overlapping clinical presentations. This complexity is further magnified in cases where patients concurrently exhibit both anti-myelin oligodendrocyte glycoprotein (anti-MOG) positivity and detectable oligoclonal bands (OCBs) This retrospective study investigates the clinical and imaging attributes of dual-positive patients, those with both anti-MOG positivity and OCBs, The study aims to show potential areas of overlap between multiple sclerosis (MS) and MOGAD.

METHODS

Utilizing data gathered from three medical centers, we evaluated a cohort of 45 patients, stratifying them into two groups: those exclusively positive for anti-MOG antibodies and those displaying dual positivity. Our analysis encompassed a wide range of clinical and imaging parameters. The statistical techniques employed comprised Fisher's Exact Test along with Benjamini-Hochberg correction to ensure robustness of the findings.

RESULTS

The study involved 45 patients with anti-MOG antibodies; 30 exhibited isolated anti-MOG positivity without OCBs, while 15 were dual-positive. The first group's average age was 10±7 years, compared to 28±17 years in the double-positive group (p = 0.001). CSF analysis showed no significant differences in pleocytosis, protein levels, or opening pressure between the groups. In the exclusive anti-MOG positivity cohort, 9 out of 15 patients received IVIG treatment; a larger subgroup with dual positivity chose anti-CD20 treatment. Notably, papilledema incidence was higher in the single-positive group (p = 0.014). Optic nerve enhancement (p = 0.0038) and nerve thickening (p = 0.0017) were markedly elevated in the single-positive population, with a trend towards pre-chiasmatic lesions (p = 0.06). Double-positive cases exhibited more polyfocal presentation (p = 0.013) and higher attacks per case (p = 0.002, HR=10.2, 95 % CI: 2.19 to 49.23). The double-positive group had more brain lesions (p = 0.0063) but no significant distinctions in other aspects.

CONCLUSION

The results emphasize the challenges inherent in differentiating between MS and a more MOGAD. While the data suggest two plausible scenarios-either falling within the spectrum of MS or representing an intensified MOGAD-we recognize the need for stronger evidence to definitively classify these instances. This study underscores the imperative for thorough investigations to ascertain whether these cases align with the MS spectrum or denote an inflammatory variant of MOGAD.

Distinct myeloid population phenotypes dependent on TREM2 expression levels shape the pathology of traumatic versus demyelinating CNS disorders

Triggering receptor expressed on myeloid cell 2 (TREM2) signaling often drives opposing effects in traumatic versus demyelinating CNS disorders. Here, we identify two distinct phenotypes of microglia and infiltrating myeloid populations dependent on TREM2 expression levels at the acute stage and elucidate how they mediate the opposing effects of TREM2 in spinal cord injury (SCI) versus multiple sclerosis animal models (experimental autoimmune encephalomyelitis [EAE]). High TREM2 levels sustain phagocytic microglia and infiltrating macrophages after SCI. In contrast, moderate TREM2 levels sustain immunomodulatory microglia and infiltrating monocytes in EAE. TREM2-ablated microglia (purine-sensing phenotype in SCI and reduced immunomodulatory phenotype in EAE) drive transient protection at the acute stage of both disorders, whereas reduced phagocytic macrophages and lysosome-activated monocytes lead to contrasting neuroprotective and demyelinating effects in SCI versus EAE, respectively. Our study provides comprehensive insights into the complex roles of TREM2 in myeloid populations across diverse CNS disorders, which has crucial implications in devising TREM2-targeting therapeutics.

Repair what is lost: Neuroprotection through neural stem cells in progressive MS

Genchi et al.¹ report the first phase 1 trial of neural stem cell transplantation in multiple sclerosis showing a reduction in gray matter atrophy. Results give hope for a new era of induced neuroprotection, especially in progressive multiple sclerosis.

Cut-off evaluation of intrathecal oligoclonal bands of IgM in relapsing-remitting multiple sclerosis; a retrospective study

BACKGROUND

Multiple sclerosis (MS) is the most common demyelinating disease and characterized by immunological changes. Oligoclonal bands of IgG in CSF not seen in corresponding serum have been used for many years as part of the diagnostic criteria. However, considerably less is known about the role of IgM, despite several studies showing marked changes to IgM metabolism in MS. Bands of oligoclonal IgM (o-IgM) are more difficult to determine than oligoclonal IgG, thus limiting their study, and there is no agreement as to whether o-IgM in CSF should be part of the clinical work-up of MS. Nevertheless, there is a possibility that such bands might provide a prognostic marker if a cut-off could be established.

MATERIALS AND METHODS

In this pilot study, paired samples of CSF and serum from 37 patients with relapsing-remitting MS (RRMS) and 57 controls with no subsequent signs of neurological disease were analysed for total IgM, and bands of o-IgM were visualised by isoelectric focusing and western blot. Patient records were used to compare mean changes in Expanded Disability Status Scale (EDSS) over a maximum of 17 years.

RESULTS

None of the controls displayed extra o-IgM in CSF compared to corresponding serum, whereas additional o-IgM band(s) were seen in CSF in most patient samples (70%). After five years of disease, there was a significant difference in the EDSS between patients with no extra o-IgM compared to patients with at least one extra o-IgM band. This difference increased over time. If a cut-off of two or more extra bands of o-IgM in CSF was applied, this difference was not found.

CONCLUSION

These exploratory data suggest that o-IgM support the prognostic potential for RRMS, and though tentative, the occurrence of any bands of o-IgM restricted to CSF seems to result in poorer prognosis. Despite the small size of the groups, the data infer that the absence of CSF-restricted o-IgM is good news for the patient. The results need to be reproduced in a more comprehensive study.

The Use of Kappa Free Light Chains to Diagnose Multiple Sclerosis

Background: The positive implications of using free light chains in diagnosing multiple sclerosis have increasingly gained considerable interest in medical research and the scientific community. It is often presumed that free light chains, particularly kappa and lambda free light chains, are of practical use and are associated with a higher probability of obtaining positive results compared to oligoclonal bands. The primary purpose of the current paper was to conduct a systematic review to assess the up-to-date methods for diagnosing multiple sclerosis using kappa and lambda free light chains. Method: An organized literature search was performed across four electronic sources, including Google Scholar, Web of Science, Embase, and MEDLINE. The sources analyzed in this systematic review and meta-analysis comprise randomized clinical trials, prospective cohort studies, retrospective studies, controlled clinical trials, and systematic reviews. Results: The review contains 116 reports that includes 1204 participants. The final selection includes a vast array of preexisting literature concerning the study topic: 35 randomized clinical trials, 21 prospective cohort studies, 19 retrospective studies, 22 controlled clinical trials, and 13 systematic reviews. Discussion: The incorporated literature sources provided integral insights into the benefits of free light chain diagnostics for multiple sclerosis. It was also evident that the use of free light chains in the diagnosis of clinically isolated syndrome (CIS) and multiple sclerosis is relatively fast and inexpensive in comparison to other conventional state-of-the-art diagnostic methods, e.g., using oligoclonal bands (OCBs).

Discordance Between Perceptions and Experience of Lumbar Puncture: A Prospective Study

Background and Objectives

Novel diagnostic techniques and neurologic biomarkers have greatly expanded clinical indications for CSF studies. CSF is most commonly obtained via lumbar puncture (LP). Although it is generally believed that LPs are well tolerated, there is a lack of supportive data for this claim, and patients anticipate LP to be painful. The objective of this study was to prospectively investigate discordance between patient perception and tolerability of LP.

Methods

Adult patients were surveyed before and after LP regarding their perceptions and experience of LP. Physician perceptions were gathered through a web-based survey. Relative risk and Spearman correlation were used to assess the relationship between responses. Paired binomial and paired ordinal responses were compared by McNemar and paired Wilcoxon rank-sum tests.

Results

A total of 178 patients completed the surveys. About half of the patients (58%) reported anxiety pre-LP, at median 3.0 of 10. Physicians overpredicted patients' pre-LP anxiety (median score 5.0, p < 0.001). Experienced pain was significantly less than predicted pain (median scores 0 and 3.0, respectively, p < 0.001). Patients who predicted pain were more likely to report pain from LP (relative risk [RR] 1.3). Predicting pain was also correlated with anxiety before LP (p < 0.001).

Discussion

LP was generally well tolerated. The majority of patients experienced minimal pain. Anticipation of pain was correlated with both feeling anxious and experiencing pain. The results of this study can be used to reassure patients and providers that LP is indeed not as painful as imagined, which may both reduce pre-LP anxiety and improve LP tolerability.

Using personalized prognosis in the treatment of relapsing multiple sclerosis: A practical guide

The clinical course of multiple sclerosis (MS) is highly variable among patients, thus creating important challenges for the neurologist to appropriately treat and monitor patient progress. Despite some patients having apparently similar symptom severity at MS disease onset, their prognoses may differ greatly. To this end, we believe that a proactive disposition on the part of the neurologist to identify prognostic “red flags” early in the disease course can lead to much better long-term outcomes for the patient in terms of reduced disability and improved quality of life. Here, we present a prognosis tool in the form of a checklist of clinical, imaging and biomarker parameters which, based on consensus in the literature and on our own clinical experiences, we have established to be associated with poorer or improved clinical outcomes. The neurologist is encouraged to use this tool to identify the presence or absence of specific variables in individual patients at disease onset and thereby implement sufficiently effective treatment strategies that appropriately address the likely prognosis for each patient.

Basic Analysis of the Cerebrospinal Fluid: An Important Framework for Laboratory Diagnostics of the Impairment of the Central Nervous System

Laboratory analysis of basic cerebrospinal fluid (CSF) parameters is considered as essential for any CSF evaluation. It can provide rapidly very valuable information about the status of the central nervous system (CNS). Our retrospective study evaluated parameters of basic CSF analysis in cases of either infectious or non-infectious CNS involvement. Neutrophils are effector cells of innate immunity. Predominance of neutrophils was found in 98.2% of patients with purulent inflammation in CNS. Lymphocytes are cellular substrate of adaptive immunity. We found their predominance in 94.8% of patients with multiple sclerosis (MS), 66.7% of patients with tick-borne encephalitis (TBE), 92.2% of patients with neuroborreliosis, 83.3% of patients with inflammatory response with oxidative burst of macrophages in CNS and 75.0% of patients with malignant infiltration of meninges (MIM). The simultaneous assessment of aerobic and anaerobic metabolism in CSF using the coefficient of energy balance (KEB) allows us to specify the type of inflammation in CNS. We found predominantly aerobic metabolism (KEB > 28.0) in 100.0% CSF of patients with normal CSF findings and in 92.8% CSF of patients with MS. Predominant faintly anaerobic metabolism (28.0 > KEB > 20.0) in CSF was found in 71.8% patients with TBE and in 64.7% patients with neuroborreliosis. Strong anaerobic metabolism (KEB < 10.0) was found in the CSF of 99.1% patients with purulent inflammation, 100.0% patients with inflammatory response with oxidative burst of macrophages and in 80.6% patients with MIM. Joint evaluation of basic CSF parameters provides sufficient information about the immune response in the CSF compartment for rapid and reliable diagnosis of CNS involvement.

Personalized Disease Monitoring in Pediatric Onset Multiple Sclerosis Using the Saliva Free Light Chain Test

Background

Development of new safe methods of monitoring disease activity in the pediatric onset multiple sclerosis (POMS) is a challenging task, especially when trying to refrain from frequent MRI usage. In our recent study, the saliva immunoglobulin free light chains (FLC) were suggested as biomarkers to discriminate between remission and active MS in adults.

Objectives

To assess utility of saliva FLC measurements for monitoring disease activity in POMS.

Methods

We used semiquantitative Western blot analysis to detect immunoreactive FLC monomers and dimers and to calculate the intensity of their bands. Statistical tests included Firth logistic regression analysis suitable for small sample sizes, and Spearman's non-parametric correlation.

Results

In naive POMS patients, the saliva levels of FLC in relapse were significantly higher than those in remission. Significant correlation was found between FLC levels (monomers, dimers or both) and the load of enhanced lesions in MRI scans. FLC levels may be reduced under treatment, especially as result of corticosteroids therapy. Follow-up of individual patients showed the correspondence of changes in the FLC levels to MRI findings.

Conclusions

Our results show the potential of the non-invasive saliva FLC test, as a new tool for monitoring the disease activity in POMS.

CSF Diagnostics: A Potentially Valuable Tool in Neurodegenerative and Inflammatory Disorders Involving Motor Neurons: A Review

Cerebrospinal fluid (CSF) diagnostics has emerged as a valid tool for a variety of neurological diseases. However, CSF diagnostics has been playing a subordinate role in the diagnosis of many neurological conditions. Thus, in the multitude of neuromuscular diseases in which motor neurons are affected, a CSF sample is rarely taken routinely. However, CSF diagnostics has the potential to specify the diagnosis and monitor the treatment of neuromuscular disorders. In this review, we therefore focused on a variety of neuromuscular diseases, among them amyotrophic lateral sclerosis (ALS), peripheral neuropathies, and spinal muscular atrophy (SMA), for which CSF diagnostics has emerged as a promising option for determining the disease itself and its progression. We focus on potentially valuable biomarkers among different disorders, such as neurofilaments, cytokines, other proteins, and lipids to determine their suitability, differentiating between different neurological disorders and their potential to determine early disease onset, disease progression, and treatment outcome. We further recommend novel approaches, e.g., the use of mass spectrometry as a promising alternative techniques to standard ELISA assays, potentially enhancing biomarker significance in clinical applications.

Serum neurofilament light chain and glial fibrillary acidic protein in AQP4-IgG-seropositive neuromyelitis optica spectrum disorders and multiple sclerosis: A cohort study

We investigated the serum neurofilament light chain (sNfL) and glial fibrillary acidic protein (sGFAP) levels in a cohort of Chinese patients with neuromyelitis optica spectrum disorders (NMOSD) and multiple sclerosis (MS) in relation to clinical disease course and treatment. sNfL and sGFAP levels were determined by ultrasensitive single molecule array (Simoa) assay in patients with NMOSD (n = 102) and MS (n = 98) and healthy controls (HCs; n = 84). Notably, 13 patients with NMOSD and 27 patients with MS were enrolled in the 1-year follow-up cohort. Levels were compared with data such as clinical course, disease duration, Expanded Disability Status Scale (EDSS) score, and lesions on MRI. Higher levels of sNfL and sGFAP were found in subjects with NMOSD and MS than in HCs (sNfL, median 12.11, 17.5 vs. 8.88 pg/ml, p < .05; sGFAP, median 130.2, 160.4 vs. 80.01 pg/ml, p < .05). Moreover, sNfL levels were higher in the relapse phase of MS than in the relapse phase of NMOSD (30.02 vs. 14.57 pg/ml, p < .05); sGFAP levels were higher in the remission phase of MS than in the remission phase of NMOSD (159.8 vs. 124.5 pg/ml, p < .01). A higher sGFAP/sNfL quotient at relapse differentiated NMOSD from MS. Multivariate analyses indicated that sGFAP levels were associated with the EDSS score in NMOSD (p < .05). At the 1-year follow-up, sNfL and sGFAP levels were both decreased in NMOSD patients in remission, while only sNfL levels were decreased in MS patients in remission. sGFAP and sNfL are potential blood biomarkers for diagnosing and monitoring NMOSD and MS.

A Longitudinal, Observational Analysis of Neuronal Injury Biomarkers in a Case Report of a Patient With Paraneoplastic Anti-CRMP5 Antibody-Associated Transverse Myelitis

Biomarkers are needed to guide therapeutic decision making in autoimmune and paraneoplastic neurologic disorders. Here, we describe a case of paraneoplastic collapsing response-mediator protein-5 (CRMP5)-associated transverse myelitis (TM) where plasma neurofilament light (NfL) chain and glial fibrillary protein (GFAP) levels were observed over a 14-month clinical course, correlating with radiographical and clinical outcome measures in response to treatment. Blood and CSF samples obtained at diagnosis as well as 7 and 14 months into treatment. At the time of initial diagnosis, both plasma NfL (782.62 pg/ml) and GFAP (283.26 pg/ml) were significantly elevated. Initial treatment was with IV steroids and plasma exchange (PLEX) followed by neuroendocrine tumor removal, chemotherapy, and radiation. After initial improvement with chemotherapy, the patient experienced clinical worsening and transient elevation of plasma NfL (103.27 pg/ml and GFAP (211.58 pg/ml) levels. Whole body positron emission tomography PET scan did not demonstrate recurrence of malignancy. Repeat PLEX and rituximab induction resulted in improvements in patient function, neurologic exam, and plasma biomarker levels. To our knowledge, this is the first described longitudinal, prospective analysis of neuronal injury biomarkers and association of clinical treatment outcomes in CRMP5 myelitis. Our findings suggest that clinical improvement correlates with NfL and GFAP concentrations.

Early predictors of conversion to secondary progressive multiple sclerosis

BACKGROUND

We conducted this study to estimated the time of conversion from relapsing-remitting MS (RRMS) to SPMS and its early predictor factors.

METHODS

In this retrospective study, demographic, clinical, and imaging data from MS patients at diagnosis were extracted. Cox proportional hazards model was used to assess the association between various baseline characteristics and conversion to SPMS. We also assessed the association brtween escalation and early intensive therapy approaches with transition to progressive phase.

RESULTS

Out of 1903 patients with RRMS at baseline, 293 (15.4%) patients progressed to SPMS during follow-up. The estimated number of patients converted to SPMS was 10% at 10-years, 50% at 20-years, and 93% at 30-years. On multivariate Cox regression analysis older age at onset (HR: 1.067, 95%CI: 1.048-1.085, p < 0.001), smoking (HR: 2.120, 95%CI: 1.203-3.736, p = 0.009), higher EDSS at onset (HR: 1.199, 95%CI: 1.109-1.295, p < 0.001), motor dysfunction (HR: 2.470, 95%CI: 1.605-3.800, p < 0.001), cerebellar dysfunction (HR: 3.096, 95%CI: 1.840-5.211, p < 0.001), and presence of lesions in spinal cord (HR: 0.573, 95%CI: 0.297-0.989, p = 0.042) increased the risk of conversion from RRMS to SPMS. No significant difference between escalation and EIT groups in the risk of transition to progressive phase (weighted HR = 1.438; 95% CI: 0.963, 2.147; p = 0.076) was found.

CONCLUSION

Our data support previous observations that smoking is a modifiable risk factor for secondary progressive MS and confirms that spinal cord involvement, age, and more severe disease at onset are prognostic factors for converting to secondary progressive MS.

[Herpesviruses and biomarkers in disseminated encephalomyelitis and multiple sclerosis in children (part II)]

Recently, the problem of demyelinating diseases in children is still very acute. This occurs, on the one hand, by high access and specificity of diagnostic methods and, on the other hand - by high morbidity of children different neuroinfectious diseases which can lead to demyelinating diseases. This literature review presents the currently available information on the autoantibodies and neurospecific protein role in the development of multiple sclerosis and acute disseminative encephalitis in children. The authors also describe their experience of complex etiopatogenic therapy and cytoflavin use that helps to reduce frequency and expression of demyelinating process and endothelium dysfunction in case of active herpesvirus infection.

Neurofilament light: a narrative review on biomarker utility

Neurofilament light (NfL) is a scaffolding protein that is located primarily within myelinated axons and that provides increased conduction speed and structural support. In recent years, NfL has been used as a disease biomarker on the basis of the observation that axonal injury results in elevated levels of NfL in cerebrospinal fluid or blood. This review focuses on how cerebrospinal fluid and plasma NfL have been studied in various disorders such as Alzheimer’s disease (AD) and multiple sclerosis (MS) in relation to neuroinflammation and cognitive dysfunction. Focusing on the role of NfL as a biomarker for AD and MS, this review aims to further explore the potential of NfL as a promising biomarker with regard to surgery- and anesthesia-based incidents for postoperative cognitive decline and delirium. A search of the PubMed database yielded 36 articles, 31 of which are from within the last 3 years, that show how NfL has been observed and studied under various types of trials and disease cohorts and potential future directions. Higher levels of NfL have frequently been correlated with disease progression and prognosis of AD and MS, and delirium has been found to share a neuroinflammatory pathophysiology that NfL could help to measure. Focusing on NfL as a biomarker for neurodegenerative decline, these studies indicate that the protein could be further tested and related to postoperative aspects that result in cognitive dysfunction, and it has the potential to be an established delirium biomarker, particularly in the realm of the perioperative course.

[Herpesviruses and biomarkers in disseminated encephalomyelitis and multiple sclerosis in children]

The relevance of the study of demyelinating diseases is due to their increasing frequency in children, clarification of the role of infectious agents in their genesis, as well as the possibility of transformation of disseminated encephalomyelitis into multiple sclerosis. The literature review presents the currently available information on the causes of the development of demyelinating diseases, biomarkers of disseminated encephalomyelitis and multiple sclerosis, the causes of an unfavorable course and possible laboratory parameters indicating the transition from one disease to another, which can be used as prognostic factors. The authors also noted the experience of the authors on the importance of adequate etiopathogenetic therapy in changing the nature of the course of the disease, in particular, when confirming the relationship between the frequency of exacerbations of ADEM and MS with the activation of herpesvirus infections, courses of specific antiviral therapy are effective, as well as pathogenetic therapy aimed at correcting endothelial dysfunction using the drug cytoflavin.

CSF parvalbumin levels reflect interneuron loss linked with cortical pathology in multiple sclerosis

Introduction and methods

In order to verify whether parvalbumin (PVALB), a protein specifically expressed by GABAergic interneurons, could be a MS‐specific marker of grey matter neurodegeneration, we performed neuropathology/molecular analysis of PVALB expression in motor cortex of 40 post‐mortem progressive MS cases, with/without meningeal inflammation, and 10 control cases, in combination with cerebrospinal fluid (CSF) assessment. Analysis of CSF PVALB and neurofilaments (Nf‐L) levels combined with physical/cognitive/3TMRI assessment was performed in 110 naïve MS patients and in 32 controls at time of diagnosis.

Results

PVALB gene expression was downregulated in MS (fold change = 3.7 ± 1.2, P < 0.001 compared to controls) reflecting the significant reduction of PVALB+ cell density in cortical lesions, to a greater extent in MS patients with high meningeal inflammation (51.8, P < 0.001). Likewise, post‐mortem CSF‐PVALB levels were higher in MS compared to controls (fold change = 196 ± 36, P < 0.001) and correlated with decreased PVALB+ cell density (r = −0.64, P < 0.001) and increased MHC‐II+ microglia density (r = 0.74, P < 0.01), as well as with early age of onset (r = −0.69, P < 0.05), shorter time to wheelchair (r = −0.49, P < 0.05) and early age of death (r = −0.65, P < 0.01). Increased CSF‐PVALB levels were detected in MS patients at diagnosis compared to controls (P = 0.002). Significant correlation was found between CSF‐PVALB levels and cortical lesion number on MRI (R = 0.28, P = 0.006) and global cortical thickness (R = −0.46, P < 0.001), better than Nf‐L levels. CSF‐PVALB levels increased in MS patients with severe cognitive impairment (mean ± SEM:25.2 ± 7.5 ng/mL) compared to both cognitively normal (10.9 ± 2.4, P = 0.049) and mild cognitive impaired (10.1 ± 2.9, P = 0.024) patients.

Conclusions

CSF‐PVALB levels reflect loss of cortical interneurons in MS patients with more severe disease course and might represent an early, new MS‐specific biomarker of cortical neurodegeneration, atrophy, and cognitive decline.

Prognostication and contemporary management of clinically isolated syndrome

Clinically isolated syndrome (CIS) patients present with a single attack of inflammatory demyelination of the central nervous system. Recent advances in multiple sclerosis (MS) diagnostic criteria have expanded the number of CIS patients eligible for a diagnosis of MS at the onset of the disease, shrinking the prevalence of CIS. MS treatment options are rapidly expanding, which is driving the need to recognise MS at its earliest stages. In CIS patients, finding typical MS white matter lesions on the patient's MRI scan remains the most influential prognostic investigation for predicting subsequent diagnosis with MS. Additional imaging, cerebrospinal fluid and serum testing, information from the clinical history and genetic testing also contribute. For those subsequently diagnosed with MS, there is a wide spectrum of long-term clinical outcomes. Detailed assessment at the point of presentation with CIS provides fewer clues to calculate a personalised risk of long-term severe disability.Clinicians should select suitable CIS cases for steroid treatment to speed neurological recovery. Unfortunately, there are still no neuroprotection or remyelination strategies available. The use of MS disease modifying therapy for CIS varies among clinicians and national guidelines, suggesting a lack of robust evidence to guide practice. Clinicians should focus on confirming MS speedily and accurately with appropriate investigations. Diagnosis with CIS provides an opportune moment to promote a healthy lifestyle, in particular smoking cessation. Patients also need to understand the link between CIS and MS. This review provides clinicians an update on the contemporary evidence guiding prognostication and management of CIS.

Cerebrospinal Fluid Testing for Multiple Sclerosis

Multiple sclerosis is one of the most common autoimmune diseases affecting the central nervous system. Current guidelines characterize multiple sclerosis and related conditions based on clinical, imaging, and body fluid markers. In this review, we describe how laboratory analysis of cerebrospinal fluid is currently performed and discuss new approaches under development for multiple sclerosis diagnostics.

A Multiplex Assay for the Stratification of Patients with Primary Central Nervous System Lymphoma Using Targeted Mass Spectrometry

Primary central nervous system lymphomas (PCNSL) account for approximately 2% to 3% of all primary brain tumors. Until now, neuropathological tumor tissue analysis, most frequently gained by stereotactic biopsy, is still the diagnostic gold standard. Here, we rigorously analyzed two independent patient cohorts comprising the clinical entities PCNSL (n = 47), secondary central nervous system lymphomas (SCNSL; n = 13), multiple sclerosis (MS, n = 23), glioma (n = 10), other tumors (n = 17) and tumor-free controls (n = 21) by proteomic approaches. In total, we identified more than 1220 proteins in the cerebrospinal fluid (CSF) and validated eight candidate biomarkers by a peptide-centric approach in an independent patient cohort (n = 63). Thus, we obtained excellent diagnostic accuracy for the stratification between PCNSL, MS and glioma patients as well as tumor-free controls for three peptides originating from the three proteins VSIG4, GPNMB4 and APOC2. The combination of all three biomarker candidates resulted in diagnostic accuracy with an area under the curve (AUC) of 0.901 (PCNSL vs. MS), AUC of 0.953 (PCNSL vs. glioma) and AUC 0.850 (PCNSL vs. tumor-free control). In summary, the determination of VSIG4, GPNMB4 and APOC2 in CSF as novel biomarkers for supporting the diagnosis of PCNSL is suggested.

Saliva immunoglobulin free light chain analysis for monitoring disease activity and response to treatment in multiple sclerosis

BACKGROUND

Immunoglobulin free light chains (FLC) have recently gained considerable interest as new promising intrathecal biomarkers of multiple sclerosis (MS). However, lumbar puncture is invasive and not practical for monitoring disease course. This study aimed to assess the utility of saliva FLC as a biomarker of disease activity and response to treatment in MS METHODS: Western blotting was used to study saliva FLC monomers and dimers. The intensity of immunoreactive FLC bands was quantified by electrophoresis analysis, and the obtained values were used as FLC indices to account for kappa and lambda FLC monomer and dimer levels. Firth's logistic regression analysis suitable to study small cohorts was applied to compare FLC levels between M.S. patients in relapse, MS patients in remission, and healthy controls. Association between FLC levels and clinical and radiological parameters was analyzed.

RESULTS

55 MS patients and 40 healthy controls were evaluated. Saliva FLC levels were significantly higher in relapse compared to remission. Logistic regression analysis employing a combination of FLC indices confirmed the significant difference between these two groups. The FLC levels were significantly reduced by treatment with corticosteroids. During remission, patients treated with disease-modifying therapies had lower levels of FLC compared to untreated patients. The increased FLC levels were associated with the presence of gadolinium-enhancing lesions, but not with MRI T2 lesion load and EDSS scores. During individual patient follow-up, the changes of the saliva FLC levels were in concordance with the disease activity status.

CONCLUSIONS

Saliva FLC levels may be a useful biomarker for discriminating between stable remission and active disease. The developed test may serve as a new, non-invasive, and inexpensive tool for monitoring disease activity and response to treatment in MS.