Unexpected Low Rate of Amyloid-ß Pathology in Multiple Sclerosis Patients.

The life expectancy of people with multiple sclerosis (MS) has increased, yet we have noted that development of a typical Alzheimer disease dementia syndrome is uncommon. We hypothesized that Alzheimer disease pathology is uncommon in MS patients. In 100 MS patients, the rate of amyloid-ß plasma biomarker positivity was approximately half the rate in 300 non-MS controls matched on age, sex, apolipoprotein E proteotype, and cognitive status. Interestingly, most MS patients who did have amyloid-ß pathology had features atypical for MS at diagnosis. These results support that MS is associated with reduced Alzheimer disease risk, and suggest new avenues of research. ANN NEUROL 2024;96:453-459.

Prognostic relevance of the C-X-C motif chemokine ligand 13 and interleukin-8 in predicting the transition from clinically isolated syndrome to multiple sclerosis.

The initial phase of multiple sclerosis (MS), often known as clinically isolated syndrome (CIS), is a critical period for identifying individuals at high risk of progressing to full-blown MS and initiating timely treatment. In this study, we aimed to evaluate the prognostic value of C-X-C motif chemokine ligand 13 (CXCL13) and interleukin-8 (IL-8) as potential markers for CIS patients' conversion to MS. Our study encompassed patients with CIS, those with relapsing-remitting MS (RRMS), and control subjects, with sample analysis conducted on both cerebrospinal fluid (CSF) and serum. Patients were categorized into four groups: CIS-CIS (no MS development within 2 years), CIS-RRMS (conversion to RRMS within 2 years), RRMS (already diagnosed), and a control group (CG) with noninflammatory central nervous system disorders. Results showed significantly elevated levels of CXCL13 in CSF across all patient groups compared with the CG (p < 0.0001, Kruskal-Wallis test). Although CXCL13 concentrations were slightly higher in the CIS-RRMS group, statistical significance was not reached. Similarly, significantly higher levels of IL-8 were detected in CSF samples from all patient groups compared with the CG (p < 0.0001, Kruskal-Wallis test). Receiver operating characteristic analysis in the CIS-RRMS group identified both CXCL13 (area under receiver operating characteristic curve = .959) and IL-8 (area under receiver operating characteristic curve = .939) in CSF as significant predictors of CIS to RRMS conversion. In conclusion, our study suggests a trend towards elevated CSF IL-8 and CSF CXCL13 levels in CIS patients progressing to RRMS. These findings emphasize the importance of identifying prognostic markers to guide appropriate treatment strategies for individuals in the early stages of MS.

Methylation of Interleukin-1 receptor-associated kinase-3 and the risk of multiple sclerosis relapse/activity.

This study retrospectively investigated the impact of interleukin-1 receptor-associated kinase-3 (IRAK-3/IRAK-M) silencing by methylation on the likelihood of multiple sclerosis (MS) activity. This cross-sectional study included 90 patients with MS: 45 with active disease (Group 1), 45 in remission (Group 2), and 45 healthy controls. The study included quantitation of IRAK-3 methylation index (MI%), IRAK-3 mRNA, and myeloid differentiation factor88 (MyD88) and assessment of NF-κB activity. IRAK-3 MI% was significantly higher in group 1 compared to group 2, accompanied by lower IRAK-3 mRNA expression, elevated circulating MyD88, and increased NF-κB activity. IRAK-3 MI% correlated negatively with its transcript and positively with MyD88 and NF-κB activity. A logistic regression model was created to predict active demyelination. The C-index was 0.924, which indicates a very strong prediction model. Within the limitations of current work, IRAK-3 methylation level seems to be a promising candidate biomarker for identifying MS patients at risk of relapse.

Quantitative and structural changes of blood platelet cytoskeleton proteins in multiple sclerosis (MS).

Epidemiological studies show that cardiovascular events related to platelet hyperactivity remain the leading causes of death among multiple sclerosis (MS) patients. Quantitative or structural changes of platelet cytoskeleton alter their morphology and function. Here, we demonstrated, for the first time, the structural changes in MS platelets that may be related to their hyperactivity. MS platelets were found to form large aggregates compared to control platelets. In contrast to the control, the images of overactivated, irregularly shaped MS platelets show changes in the cytoskeleton architecture, fragmented microtubule rings. Furthermore, MS platelets have long and numerous pseudopodia rich in actin filaments. We showed that MS platelets and megakaryocytes, overexpress ß1-tubulin and ß-actin mRNAs and proteins and have altered post-translational modification patterns. Moreover, we identified two previously undisclosed mutations in the gene encoding ß1-tubulin in MS. We propose that the demonstrated structural changes of platelet cytoskeleton enhance their ability to adhere, aggregate, and degranulate fueling the risk of adverse cardiovascular events in MS.

Reactivity against the BP180 ectodomain in patients with bullous pemphigoid, mucous membrane pemphigoid, multiple sclerosis and Parkinson disease.

The 16th non-collagenous domain (NC16A) of BP180 is the main antigenic target of autoantibodies in bullous pemphigoid (BP) and mucous membrane pemphigoid (MMP). Commercially available assays detect serum autoantibodies against NC16A in the majority of BP (80%-90%) and in approximately 50% of MMP patients. However, a standardized test system for detecting antibodies against other regions of BP180 is still lacking. Moreover, anti-BP180 autoantibodies have been found in neurological conditions such as multiple sclerosis and Parkinson disease. This study aimed at identifying primary epitopes recognized by BP autoantibodies on the BP180 ectodomain. Serum samples of 51 BP and 30 MMP patients both without anti-NC16A reactivity were included along with 44 multiple sclerosis and 75 Parkinson disease sera. Four overlapping His-tagged proteins covering the entire BP180 ectodomain (BP180(ec)1-4) were cloned, expressed, purified and tested for reactivity by immunoblot. IgG antibodies to BP180(ec)3 were detected in 98% of BP, 77% of MMP and 2% of normal human sera. Only weak reactivity was detected for neurological diseases against BP180(ec)1, BP180(ec)2 and BP180(ec)4, in 3%, 11% and 7% of tested multiple sclerosis sera, respectively. 8% of Parkinson disease sera reacted with BP180(ec)2 and 9% with BP180(ec)4. In conclusion, this study successfully identified epitopes recognized by BP autoantibodies outside the NC16A domain in pemphigoid diseases. These findings contribute to a better understanding of the immune response in BP and MMP with potential implications for a future diagnostic assay for NC16A-negative pemphigoid patients.

Increased levels of circulating soluble CD226 in multiple sclerosis.

BACKGROUND: The glycoprotein CD226 plays a key role in regulating immune cell function. Soluble CD226 (sCD226) is increased in sera of patients with several chronic inflammatory diseases but its levels in neuroinflammatory diseases such as multiple sclerosis (MS) are unknown. OBJECTIVE: To investigate the presence and functional implications of sCD226 in persons with multiple sclerosis (pwMS) and other neurological diseases. METHODS: The mechanisms of sCD226 production were first investigated by analyzing CD226 surface expression levels and supernatants of CD3/CD226-coactivated T cells. The role of sCD226 on dendritic cell maturation was evaluated. The concentration of sCD226 in the sera from healthy donors (HD), pwMS, neuromyelitis optica (NMO), and Alzheimer's disease (AD) was measured. RESULTS: CD3/CD226-costimulation induced CD226 shedding. Addition of sCD226 to dendritic cells during their maturation led to an increased production of the pro-inflammatory cytokine interleukin (IL)-23. We observed a significant increase in sCD226 in sera from pwMS and NMO compared to HD and AD. In MS, levels were increased in both relapsing-remitting multiple sclerosis (RRMS) and secondary-progressive multiple sclerosis (SPMS) compared to clinically isolated syndrome (CIS). CONCLUSION: Our data suggest that T-cell activation leads to release of sCD226 that could promote inflammation and raises the possibility of using sCD226 as a biomarker for neuroinflammation.

Analysis of potential microRNA biomarkers for multiple sclerosis.

Multiple sclerosis (MS) is a chronic demyelinating autoimmune neurodegenerative disorder for which no specific blood biomarker is available. MicroRNAs (miRNAs) have been investigated for their diagnostic potential in MS. However, MS-associated miRNAs are rarely replicated in different MS populations, thus impeding their use in clinical testing. Here, we evaluated the fold expression of seven reported MS miRNAs associated with MS incidence and clinical characteristics in 76 MS patients and 75 healthy control plasma samples. We found miR-23a-3p to be upregulated in relapsing-remitting MS (RRMS), while miR-326 was downregulated. MiR-150-5p and -320a-3p were significantly downregulated in secondary progressive MS (SPMS) patients compared to RRMS. High disability was associated with low miR-320a-3p, whereas low BDNF levels were associated with upregulation of miR-150-5p and downregulation of miR-326 expression in the total cohort. MiR-23a-3p and miR-326 showed significant diagnostic sensitivity, specificity, and accuracy for RRMS diagnosis. In addition, miR-150-5p and miR-320a-3p had comparable significant diagnostic test performance metrics distinguishing SPMS from RRMS. Therefore, there is potential for including miR-23a-3p and miR-326 in an RRMS diagnostic miRNA panel. Moreover, we have shown that miR-150-5p and miR-320a-3p could be novel RRMS conversion to SPMS biomarkers. The use of these miRNAs in MS diagnosis and prognosis warrants further investigation.

Increased level of GATA3-AS1 long non-coding RNA is correlated with the upregulation of GATA3 and IL-4 genes in multiple sclerosis patients.

BACKGROUND: Long non-coding RNAs (lncRNAs) play various roles in gene regulation. GATA3 antisense RNA 1 (GATA3-AS1) is an lncRNA gene neighboring GATA binding protein 3 (GATA3). The current study aims to quantitatively compare the levels of the expression of GATA3-AS1, GATA3, and Interleukin-4 (IL-4) in peripheral blood mononuclear cells (PBMC) samples of MS patients and healthy individuals under the hypothesis of regulation of GATA3 and IL-4 expression orchestrated by GATA3-AS1. METHODS AND RESULTS: In this case-control study, the GATA3-AS1, GATA3 and IL-4 expression profiles were assessed using real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR). Also, we assessed the IL-4 levels in the serum. The median fold changes in MS patients vs. controls were (4.39 ± 0.38 vs. 2.44 ± 0.20) for GATA3-AS1, (5.22 ± 0.51 vs. 2.86 ± 0.30) for GATA3, and (6.16 ± 0.52 vs. 3.57 ± 0.38) for IL-4, (P < 0.001). Furthermore, the mean serum levels of IL-4 were 30.85 ± 1.53 pg/ml in MS patients and 11.15 ± 4.23 pg/ml in healthy controls (P < 0.001). ROC curve analysis showed that the level of GATA3-AS1 might serve as a biomarker for diagnosing MS patients with the area under the curve (AUC = 0.918, P < 0.0001). Based on our results, this GATA3-AS1/GATA3/IL-4 pathway may increase IL-4 expression in MS patients. CONCLUSIONS: Our results indicate a probably regulatory function for GATA3-AS1and the levels of GATA3-AS1 in blood could be important biomarkers for MS diagnosis. To confirm and be more certain of these results, it is necessary to study neuromyelitis optica (NMO) and asthma patients in future studies.

Association of Increased Homocysteine Levels with Impaired Folate Metabolism and Vitamin B Deficiency in Early-Onset Multiple Sclerosis.

The contents of homocysteine (HCy), cyanocobalamin (vitamin B12), folic acid (vitamin B9), and pyridoxine (vitamin B6) were analyzed and the genotypes of the main gene polymorphisms associated with folate metabolism (C677T and A1298C of the MTHFR gene, A2756G of the MTR gene and A66G of the MTRR gene) were determined in children at the onset of multiple sclerosis (MS) (with disease duration of no more than six months), healthy children under 18 years (control group), healthy adults without neurological pathology, adult patients with MS at the onset of disease, and adult patients with long-term MS. A significant increase in the HCy levels was found in children at the MS onset compared to healthy children of the corresponding age. It was established that the content of HCy in children has a high predictive value. At the same time, an increase in the HCy levels was not accompanied by the deficiency of vitamins B6, B9, and B12 in the blood. The lack of correlation between the laboratory signs of vitamin deficiency and HCy levels may be due to the polymorphic variants of folate cycle genes. An increased HCy level should be considered as a marker of functional disorders of folate metabolism accompanying the development of pathological process in pediatric MS. Our finding can be used to develop new approaches to the prevention of demyelination in children and treatment of pediatric MS.

Sunlight exposure exerts immunomodulatory effects to reduce multiple sclerosis severity.

Multiple sclerosis (MS) disease risk is associated with reduced sun-exposure. This study assessed the relationship between measures of sun exposure (vitamin D [vitD], latitude) and MS severity in the setting of two multicenter cohort studies (nNationMS = 946, nBIONAT = 990). Additionally, effect-modification by medication and photosensitivity-associated MC1R variants was assessed. High serum vitD was associated with a reduced MS severity score (MSSS), reduced risk for relapses, and lower disability accumulation over time. Low latitude was associated with higher vitD, lower MSSS, fewer gadolinium-enhancing lesions, and lower disability accumulation. The association of latitude with disability was lacking in IFN-ß-treated patients. In carriers of MC1R:rs1805008(T), who reported increased sensitivity toward sunlight, lower latitude was associated with higher MRI activity, whereas for noncarriers there was less MRI activity at lower latitudes. In a further exploratory approach, the effect of ultraviolet (UV)-phototherapy on the transcriptome of immune cells of MS patients was assessed using samples from an earlier study. Phototherapy induced a vitD and type I IFN signature that was most apparent in monocytes but that could also be detected in B and T cells. In summary, our study suggests beneficial effects of sun exposure on established MS, as demonstrated by a correlative network between the three factors: Latitude, vitD, and disease severity. However, sun exposure might be detrimental for photosensitive patients. Furthermore, a direct induction of type I IFNs through sun exposure could be another mechanism of UV-mediated immune-modulation in MS.

Antipsychotic drugs counteract autophagy and mitophagy in multiple sclerosis.

Multiple sclerosis (MS) is a neuroinflammatory and neurodegenerative disease characterized by myelin damage followed by axonal and ultimately neuronal loss. The etiology and physiopathology of MS are still elusive, and no fully effective therapy is yet available. We investigated the role in MS of autophagy (physiologically, a controlled intracellular pathway regulating the degradation of cellular components) and of mitophagy (a specific form of autophagy that removes dysfunctional mitochondria). We found that the levels of autophagy and mitophagy markers are significantly increased in the biofluids of MS patients during the active phase of the disease, indicating activation of these processes. In keeping with this idea, in vitro and in vivo MS models (induced by proinflammatory cytokines, lysolecithin, and cuprizone) are associated with strongly impaired mitochondrial activity, inducing a lactic acid metabolism and prompting an increase in the autophagic flux and in mitophagy. Multiple structurally and mechanistically unrelated inhibitors of autophagy improved myelin production and normalized axonal myelination, and two such inhibitors, the widely used antipsychotic drugs haloperidol and clozapine, also significantly improved cuprizone-induced motor impairment. These data suggest that autophagy has a causal role in MS; its inhibition strongly attenuates behavioral signs in an experimental model of the disease. Therefore, haloperidol and clozapine may represent additional therapeutic tools against MS.

Liquid chromatography-tandem mass spectrometry for determination of fingolimod and its active metabolite fingolimod phosphate in whole blood of patients with multiple sclerosis.

Fingolimod is an oral drug for the escalation of treatment of relapsing-remitting multiple sclerosis in patients with persistent disease activity on first-line drugs or in patients with rapidly progressive severe relapsing-remitting multiple sclerosis. An ultra-high-performance liquid chromatography-tandem mass spectrometry method for determining the concentrations of fingolimod and its active metabolite fingolimod phosphate in whole blood has been developed and validated. The advantages of this method are the easy, fast and cheap sample preparation using protein precipitation from blood with a mixture of acetonitrile-methanol (40:60, v/v). Chromatographic separation was performed on a ultra-high performance liquid chromatography BEH C18 1.7 µm (100 × 2.1 mm) column. Two modes of ionization, electrospray ionization and atmospheric pressure chemical ionization, were tested and compared. For validation, the electrospray ionization mode was chosen. As internal standard, isotopically labeled fingolimod-D4 was used to quantify the analytes. The method was validated according to the rules of the European Medicines Agency. The coefficients of variation for fingolimod were in the range of 1.13-11.88%, and the recovery was 98.80-106.00%. The coefficients of variation for fingolimod phosphate were in the range of 2.73-9.31%, and the recovery was 90.08-107.00%. The method is quite easy and fast and can be used for routine analysis.

The Role of the Lipid Profile and Oxidative Stress in Fatigue, Sleep Disorders and Cognitive Impairment in Patients with Multiple Sclerosis.

The aim of this study is to investigate the relationship of the lipid profile, dysfunctional high-density lipoprotein, ischaemia-modified albumin and thiol-disulfide homeostasis with cognitive impairment, fatigue and sleep disorders in patients with multiple sclerosis. The cognitive functions of patients were evaluated with the Brief International Cognitive Assessment for Multiple Sclerosis battery. Fatigue was evaluated with the Fatigue Severity Scale and the Fatigue Impact Scale. The Pittsburgh Sleep Quality Index and the Epworth Sleepiness Scale were used to assess patients' sleep disturbance. Peripheral blood samples were collected, and lipid levels and myeloperoxidase and paraoxonase activity were measured. The myeloperoxidase/paraoxonase ratio, which indicates dysfunctional high-density lipoprotein, was calculated. Thiol-disulfide homeostasis and ischaemia-modified albumin were measured.
We did not identify any relationship between dysfunctional high-density lipoprotein and the physical disability, cognitive decline, fatigue and sleep problems of multiple sclerosis. Thiol-disulfide homeostasis was associated with cognitive scores. The shift of the balance towards disulfide was accompanied by a decrease in cognitive scores. On the other hand, we did not detect any relationship between fatigue and sleep disorders and thiol-disulfide homeostasis. Our findings revealed a possible correlation between cognitive dysfunction and thiol-disulfide homeostasis in multiple sclerosis patients.

Laboratory Diagnosis of Intrathecal Synthesis of Immunoglobulins: A Review about the Contribution of OCBs and K-index.

The diagnosis of MS relies on a combination of imaging, clinical examinations, and biological analyses, including blood and cerebrospinal fluid (CSF) assessments. G-Oligoclonal bands (OCBs) are considered a "gold standard" for MS diagnosis due to their high sensitivity and specificity. Recent advancements have involved the introduced of kappa free light chain (k-FLC) assay into cerebrospinal fluid (CSF) and serum (S), along with the albumin quotient, leading to the development of a novel biomarker known as the "K-index" or "k-FLC index". The use of the K-index has been recommended to decrease costs, increase laboratory efficiency, and to skip potential subjective operator-dependent risk that could happen during the identification of OCBs profiles. This review aims to provide a comprehensive overview and analysis of recent scientific articles, focusing on updated methods for MS diagnosis with an emphasis on the utility of the K-index. Numerous studies indicate that the K-index demonstrates high sensitivity and specificity, often comparable to or surpassing the diagnostic accuracy of OCBs evaluation. The integration of the measure of the K-index with OCBs assessment emerges as a more precise method for MS diagnosis. This combined approach not only enhances diagnostic accuracy, but also offers a more efficient and cost-effective alternative.

The Role of Glial Fibrillary Acidic Protein as a Biomarker in Multiple Sclerosis and Neuromyelitis Optica Spectrum Disorder: A Systematic Review and Meta-Analysis.

There is debate on the role of glial fibrillary acidic protein (GFAP) as a reliable biomarker in multiple sclerosis (MS) and neuromyelitis optica spectrum disorder (NMOSD), and its potential to reflect disease progression. This review aimed to investigate the role of GFAP in MS and NMOSD. A systematic search of electronic databases, including PubMed, Embase, Scopus, and Web of Sciences, was conducted up to 20 December 2023 to identify studies that measured GFAP levels in people with MS (PwMS) and people with NMOSD (PwNMOSD). R software version 4.3.3. with the random-effect model was used to pool the effect size with its 95% confidence interval (CI). Of 4109 studies, 49 studies met our inclusion criteria encompassing 3491 PwMS, 849 PwNMOSD, and 1046 healthy controls (HCs). The analyses indicated that the cerebrospinal fluid level of GFAP (cGFAP) and serum level of GFAP (sGFAP) were significantly higher in PwMS than HCs (SMD = 0.7, 95% CI: 0.54 to 0.86, p < 0.001, I2 = 29%, and SMD = 0.54, 95% CI: 0.1 to 0.99, p = 0.02, I2 = 90%, respectively). The sGFAP was significantly higher in PwNMOSD than in HCs (SMD = 0.9, 95% CI: 0.73 to 1.07, p < 0.001, I2 = 10%). Among PwMS, the Expanded Disability Status Scale (EDSS) exhibited significant correlations with cGFAP (r = 0.43, 95% CI: 0.26 to 0.59, p < 0.001, I2 = 91%) and sGFAP (r = 0.36, 95% CI: 0.23 to 0.49, p < 0.001, I2 = 78%). Regarding that GFAP is increased in MS and NMOSD and has correlations with disease features, it can be a potential biomarker in MS and NMOSD and indicate the disease progression and disability in these disorders.

Cytokine profile in multiple sclerosis patients with and without Covid-19.

OBJECTIVE: Aim: To investigate the possible effect of COVID-19 disease on cytokine profile and some circulating growth factors in patients with multiple sclerosis (MS). PATIENTS AND METHODS: Materials and Methods: Serum cytokine levels as well as growth factors content were assessed be means of a solid phase enzyme linked­immunosorbent assay in 97 MS patients of which 41 had and 56 did not have confirmed COVID-19 in the past 4-6-month period, and 30 healthy individuals who were age­, and gender­matched. RESULTS: Results: Some proinflammatory cytokine (such as TNFα, IFNγ) levels were higher while anti-inflammatory cytokine, namely IL­4, was lower in MS patients compared to controls indicating Th1/Th2 imbalance. Our findings revealed that the imbalance of circulating Th1/Th2 cytokines in MS patients after SARS-CoV-2 infection became even more pronounced, thus, might be a reason for the disease deterioration. Furthermore, nuclear factor κB level in MS patients after COVID-19 was found significantly elevated from that with no history of SARS-CoV-2 infection, and could be the cause of proinflammatory cytokines overexpression. CONCLUSION: Conclusions: Our findings revealed that immunopathology of MS is associated with a Th1/Th2 imbalance, furthermore, SARS-CoV-2 infection can lead to the deterioration of this condition in MS patients, causing even more pronounced overexpression of proinflammatory cytokines and decrease in anti-inflammatory cytokines. Our results also indicated that studied growth factors can be involved in MS development but exact mechanism is not clearly understood and requires further research.

Lipid Receptor G2A-Mediated Signal Pathway Plays a Critical Role in Inflammatory Response by Promoting Classical Macrophage Activation.

Macrophage polarization is a dynamic and integral process in tissue inflammation and remodeling. In this study, we describe that lipoprotein-associated phospholipase A2 (Lp-PLA2) plays an important role in controlling inflammatory macrophage (M1) polarization in rodent experimental autoimmune encephalomyelitis (EAE) and in monocytes from multiple sclerosis (MS) patients. Specific inhibition of Lp-PLA2 led to an ameliorated EAE via markedly decreased inflammatory and demyelinating property of M1. The effects of Lp-PLA2 on M1 function were mediated by lysophosphatidylcholine, a bioactive product of oxidized lipids hydrolyzed by Lp-PLA2 through JAK2-independent activation of STAT5 and upregulation of IRF5. This process was directed by the G2A receptor, which was only found in differentiated M1 or monocytes from MS patients. M1 polarization could be inhibited by a G2A neutralizing Ab, which led to an inhibited disease in rat EAE. In addition, G2A-deficient rats showed an ameliorated EAE and an inhibited autoimmune response. This study has revealed a mechanism by which lipid metabolites control macrophage activation and function, modification of which could lead to a new therapeutic approach for MS and other inflammatory disorders.

Assessing the Preanalytical Variability of Plasma and Cerebrospinal Fluid Processing and Its Effects on Inflammation-Related Protein Biomarkers.

Proteomics studies are important for the discovery of new biomarkers as clinical tools for diagnosis and disease monitoring. However, preanalytical variations caused by differences in sample handling protocol pose challenges for assessing biomarker reliability and comparability between studies. The purpose of this study was to examine the effects of delayed centrifuging on measured protein levels in plasma and cerebrospinal fluid (CSF). Blood from healthy individuals and patients with multiple sclerosis along with CSF from patients with suspected neurological disorders were left at room temperature for different periods (blood: 1, 24, 48, 72 h; CSF: 1 and 6 h) prior to centrifuging. Ninety-one inflammation-related proteins were analyzed using a proximity extension assay, a high-sensitivity multiplex immunoassay. Additional metabolic and neurology-related markers were also investigated in CSF. In summary, many proteins, particularly in plasma, had increased levels with longer delays in processing likely due in part to intracellular leakage. Levels of caspase 8, interleukin 8, interleukin 18, sirtuin 2, and sulfotransferase 1A1 increased 2-fold to 10-fold in plasma after 24 h at room temperature. Similarly, levels of cathepsin H, ectonucleoside triphosphate diphosphohydrolase 5, and WW domain containing E3 ubiquitin protein ligase 2 differentiated in CSF with <6 h delay in processing. However, the rate of change for many proteins was relatively consistent; therefore, we were able to characterize biomarkers for detecting sample handling variability. Our findings highlight the importance of timely and consistent sample collection and the need for increased awareness of protein susceptibility to sample handling bias. In addition, suggested biomarkers may be used in certain situations to detect and correct for preanalytical variation in future studies.

Inflammation-related plasma and CSF biomarkers for multiple sclerosis.

Effective biomarkers for multiple sclerosis diagnosis, assessment of prognosis, and treatment responses, in particular those measurable in blood, are largely lacking. We have investigated a broad set of protein biomarkers in cerebrospinal fluid (CSF) and plasma using a highly sensitive proteomic immunoassay. Cases from two independent cohorts were compared with healthy controls and patients with other neurological diseases. We identified and replicated 10 cerebrospinal fluid proteins including IL-12B, CD5, MIP-1a, and CXCL9 which had a combined diagnostic efficacy similar to immunoglobulin G (IgG) index and neurofilament light chain (area under the curve [AUC] = 0.95). Two plasma proteins, OSM and HGF, were also associated with multiple sclerosis in comparison to healthy controls. Sensitivity and specificity of combined CSF and plasma markers for multiple sclerosis were 85.7% and 73.5%, respectively. In the discovery cohort, eotaxin-1 (CCL11) was associated with disease duration particularly in patients who had secondary progressive disease (PCSF < 4 × 10-5, Pplasma < 4 × 10-5), and plasma CCL20 was associated with disease severity (P = 4 × 10-5), although both require further validation. Treatment with natalizumab and fingolimod showed different compartmental changes in protein levels of CSF and peripheral blood, respectively, including many disease-associated markers (e.g., IL12B, CD5) showing potential application for both diagnosing disease and monitoring treatment efficacy. We report a number of multiple sclerosis biomarkers in CSF and plasma for early disease detection and potential indicators for disease activity. Of particular importance is the set of markers discovered in blood, where validated biomarkers are lacking.

IL-12 p40 monomer is different from other IL-12 family members to selectively inhibit IL-12Rß1 internalization and suppress EAE.

Multiple sclerosis (MS) is the most common human demyelinating disease of the central nervous system. The IL-12 family of cytokines has four members, which are IL-12 (p40:p35), IL-23 (p40:p19), the p40 monomer (p40), and the p40 homodimer (p402). Since all four members contain p40 in different forms, it is important to use a specific monoclonal antibody (mAb) to characterize these molecules. Here, by using such mAbs, we describe selective loss of p40 in serum of MS patients as compared to healthy controls. Similarly, we also observed decrease in p40 and increase in IL-12, IL-23, and p402 in serum of mice with experimental autoimmune encephalomyelitis (EAE), an animal model of MS, as compared to control mice. Interestingly, weekly supplementation of mouse and human recombinant p40 ameliorated clinical symptoms and disease progression of EAE. On the other hand, IL-12, IL-23, and p402 did not exhibit such inhibitory effect. In addition to EAE, p40 also suppressed collagen-induced arthritis in mice. Using IL-12Rß1-/-, IL-12Rß2-/-, and IL-12Rß1+/-/IL-12Rß2-/- mice, we observed that p40 required IL-12Rß1, but not IL-12Rß2, to suppress EAE. Interestingly, p40 arrested IL-12-, IL-23-, or p402-mediated internalization of IL-12Rß1, but neither IL-12Rß2 nor IL-23R, protected regulatory T cells, and suppressed Th1 and Th17 biasness. These studies identify p40 as an anti-autoimmune cytokine with a biological role different from IL-12, IL-23, and p402 in which it attenuates autoimmune signaling via suppression of IL-12Rß1 internalization, which may be beneficial in patients with MS and other autoimmune disorders.