NfL and GFAP in serum are associated with microstructural brain damage in progressive multiple sclerosis.

BACKGROUND: The potential of neurofilament light chain (NfL) and glial fibrillary acidic protein (GFAP) as biomarkers of disease activity and severity in progressive forms of multiple sclerosis (MS) is unclear. OBJECTIVE: To investigate the relationship between serum concentrations of NfL, GFAP, and magnetic resonance imaging (MRI) in progressive MS. METHODS: Serum concentrations of NfL and GFAP were measured in 32 healthy controls and 32 patients with progressive MS from whom clinical and MRI data including diffusion tensor imaging (DTI) were obtained during three years of follow-up. RESULTS: Serum concentrations of NfL and GFAP at follow-up were higher in progressive MS patients than in healthy controls and serum NfL correlated with the EDSS score. Decreasing fractional anisotropy (FA) in normal-appearing white matter (NAWM) correlated with worsening EDSS scores and higher serum NfL. Higher serum NfL and increasing T2 lesion volume correlated with worsening paced autitory serial addition test scores. In multivariable regression analyses with serum GFAP and NfL as independent factors and DTI measures of NAWM as dependent factors, we showed that high serum NfL at follow-up was independently associated with decreasing FA and increasing MD in NAWM. Moreover, we found that high serum GFAP was independently associated with decreasing MD in NAWM and with decreasing MD and increasing FA in cortical gray matter. CONCLUSION: Serum concentrations of NfL and GFAP are increased in progressive MS and are associated with distinct microstructural changes in NAWM and CGM.

Immunological effects of dimethyl fumarate treatment in blood and CSF of patients with primary progressive MS.

Dimethyl fumarate is an efficient therapy used widely in patients with relapsing-remitting multiple sclerosis (RRMS). However, lacking effect of treatment has recently been reported in patients with primary progressive MS (PPMS) (Højsgaard Chow et al., 2021). In order to further analyze the immunological treatment response we investigated the systemic and intrathecal immunological effects of dimethyl fumarate (DMF) treatment in 50 patients with PPMS who participated in a 48-week randomized controlled trial with dimethyl fumarate vs placebo. We found substantial systemic immunomodulatory effects of DMF treatment comparable with those observed in patients with RRMS. However, intrathecal effects were limited and restricted to CD4+ T cells presumably resulting in higher concentrations of intrathecal IL-7.

The association of selected multiple sclerosis symptoms with disability and quality of life: a large Danish self-report survey.

BACKGROUND: People with multiple sclerosis (MS) experience a wide range of unpredictable and variable symptoms. The symptomatology of MS has previously been reported in large sample registry studies; however, some symptoms may be underreported in registries based on clinician-reported outcomes and how the symptoms are associated with quality of life (QoL) are often not addressed. The aim of this study was to comprehensively evaluate the frequency of selected MS related symptoms and their associations with disability and QoL in a large self-report study. METHODS: We conducted a cross-sectional questionnaire survey among all patients at the Danish Multiple Sclerosis Center, Copenhagen University Hospital, Denmark. The questionnaire included information on clinical and sociodemographic characteristics, descriptors of QoL and disability, as well as prevalence and severity of the following MS symptoms: impaired ambulation, spasticity, chronic pain, fatigue, bowel and bladder dysfunction, and sleep disturbances. RESULTS: Questionnaires were returned by 2244/3606 (62%). Participants without MS diagnosis or incomplete questionnaires were excluded, n = 235. A total of 2009 questionnaires were included for analysis (mean age 49.4 years; mean disease duration 11.7 years; and 69% were women). The most frequently reported symptoms were bowel and bladder dysfunction (74%), fatigue (66%), sleep disturbances (59%), spasticity (51%) and impaired ambulation (38%). With exception of fatigue and sleep disturbances, all other symptoms increased in severity with higher disability level. Invisible symptoms (also referred to as hidden symptoms) such as fatigue, pain and sleep disturbances had the strongest associations with the overall QoL. CONCLUSION: We found invisible symptoms highly prevalent, even at mild disability levels. Fatigue, pain and sleep disturbances had the strongest associations with the overall QoL and were more frequently reported in our study compared with previous registry-based studies. These symptoms may be underreported in registries based on clinician reported outcomes, which emphasizes the importance of including standardized patient reported outcomes in nationwide registries to better understand the impact of the symptom burden in MS.

Circulating levels of tight junction proteins in multiple sclerosis: Association with inflammation and disease activity before and after disease modifying therapy.

BACKGROUND: Tight junction proteins contribute to maintenance of epithelial and endothelial barriers such as the intestinal barrier and the blood brain barrier (BBB). Increased permeability of these barriers has been linked to disease activity in MS and there is currently a lack of easily accessible biomarkers predicting disease activity in MS. AIM: To investigate whether levels of circulating tight junction proteins occludin and zonula occludens-1 (ZO-1) are associated with biomarkers of inflammation and disease activity; and to determine whether they could serve as clinical biomarkers. METHODS: We prospectively included 72 newly diagnosed patients with relapsing remitting MS or clinically isolated syndrome with no prior disease modifying therapy (DMT) use and 50 healthy controls (HCs). Patients were followed with blood samples, 3 tesla MRI, and clinical evaluation for 12 months. Occludin, ZO-1, calprotectin and soluble urokinase-type plasminogen activator receptor (suPAR) were measured by ELISA; serum neurofilament light (NfL) and IL-6 by single-molecule array (SIMOA). The mRNA expression of IFNG, IL1R1, IL10, IL1B, ARG1 and TNF was measured by quantitative real time polymerase chain reaction (qPCR) in whole blood. RESULTS: Plasma occludin levels were higher in MS patients compared with HCs. After 12 months on DMT, occludin levels were reduced by approximately 25% irrespective of 1st or 2nd line DMT (p<0.001). Furthermore, NfL and calprotectin levels were significantly reduced by 31% and 29%, respectively. Occludin and ZO-1 did not correlate with biomarkers of inflammation and did not predict disease activity at baseline or after 12 months. CONCLUSIONS: Higher levels of occludin suggest an increased permeability of the BBB and/or the intestinal barrier in MS patients. The reduction of occludin after 12 months on DMTs might reflect repair of these barriers upon treatment. However, plasma levels of ZO-1 and occludin could not predict clinical or MRI disease activity as determined by regression and ROC-curve analysis. Our results do not indicate a clear clinically relevant role for circulating tight junction proteins as biomarkers of disease activity in MS and further investigations in larger cohorts are needed to clarify this issue.

Anti-CD20 antibody therapy and risk of infection in patients with demyelinating diseases.

BACKGROUND: Anti-CD20 antibody therapy may be associated with an increased risk of infections. We therefore investigated risk factors for infection in patients with demyelinating diseases treated with anti-CD20 antibody therapy. METHODS: In this retrospective uncontrolled study, patients ever treated with anti-CD20 antibodies at an academic clinic were identified through the Danish Multiple Sclerosis Registry (DMSR). Data were collected from medical charts and the DMSR. We assessed occurrence of severe infections (requiring hospitalization), varicella zoster virus (VZV), major comorbidities and routine laboratory values for lymphocytes, IgG and IgM. RESULTS: A total of 447 patients ever treated with anti-CD20 antibody therapy were identified; of these 416 with 649 patient years of follow-up were still under therapy. In this group, seven patients had VZV infections, and 16 patients had been hospitalized with infections during up to three years of follow-up on anti-CD20 therapy. Comorbidity was recorded in 80 patients. The risk of severe infection was associated with comorbidities, higher age, longer duration of treatment, and higher Expanded Disability Status Scale (EDSS) scores. In multivariable analyses treatment duration, EDSS scores and presence of comorbidity were independently associated with risk of severe infections. Serum concentrations of IgG and IgM decreased with increasing duration of therapy but were not associated with risk of severe infections. Patients with VZV infection had lower lymphocyte counts and lower serum concentrations of IgM. In multivariable analyses only lymphocyte counts were independently associated with risk of VZV infection. CONCLUSIONS: In this retrospective study of patients treated with anti-CD20 antibodies, the risk of infections requiring hospitalization was independently associated with comorbidities, duration of treatment, and higher EDSS scores. Risk of VZV infection was independently associated with lymphopenia. Future studies investigating strategies for mitigating risk of infection in patients treated with anti-CD20 antibodies are warranted, especially for older patients, patients with higher levels of disability and for patients with a longer duration of treatment.

Biomarkers of inflammation and epithelial barrier function in multiple sclerosis.

BACKGROUND: There is a lack of reliable biomarkers predicting disability and disease activity in multiple sclerosis (MS). Recent evidence suggests an involvement of intestinal and pulmonary epithelial barrier function related to immune activation and the pathophysiology of MS. Blood biomarkers of epithelial barrier function have, however, not been widely studied in MS. OBJECTIVE: To examine biomarkers of inflammation and epithelial barrier function in relapsing remitting MS (RRMS) patients compared with healthy controls (HCs), and to assess associations between biomarkers and disease activity. METHODS: A panel of 30 biomarkers were measured in serum or plasma from 49 newly diagnosed, untreated RRMS patients and 58 HCs with electrochemiluminescence or ELISA. Neurofilament light chain (NfL) was measured with single-molecule array. Validation was performed in a second independent cohort of 68 newly diagnosed, treatment naive RRMS patients and 50 HCs. Patients were divided into groups of active and inactive disease based on NfL levels and the presence of gadolinium enhancing magnetic resonance imaging lesions. RESULTS: Patients with active MS showed significantly higher serum levels of calprotectin and soluble urokinase plasminogen activator receptor compared with inactive MS in the exploratory cohort. Validation confirmed higher levels of calprotectin in active compared with inactive MS, and HCs. Biomarkers of intestinal and pulmonary epithelial barrier function did not differ significantly between groups. CONCLUSIONS: The measured biomarkers of epithelial barrier function do not seem to play a major role in the pathophysiology of MS, but serum calprotectin could represent a clinically useful biomarker of innate immune activation and disease activity.

Expression of melanoma cell adhesion molecule-1 (MCAM-1) in natalizumab-treated multiple sclerosis.

The objectives were to study the expression of very late antigen (VLA)-4, melanoma cell adhesion molecule-1 (MCAM-1) and activated leukocyte cell adhesion molecule (ALCAM) on CD4+ T cells during natalizumab treatment and to investigate the association with disease activity. We find that subgroups of autoreactive T cells are retained in peripheral blood, in particular MOG-reactive CD4+ T cells expressing MCAM-1. The expression of MCAM-1 or ALCAM on CD4+ T cells was, however, not clearly associated with disease activity (clinical or MRI) during natalizumab treatment. We confirm upregulation of MCAM-1 on CD4+ T cells during natalizumab treatment while VLA-4 is downregulated.

Illegal cannabis use is common among Danes with multiple sclerosis.

BACKGROUND: Use of cannabis to alleviate multiple sclerosis (MS)-related symptoms is increasing. Due to strict regulations, only a minority of MS patients receive cannabis-based prescription drugs. The extent of recreational and medical cannabis use among Danes with MS is unknown. Our aim was to evaluate the prevalence of illegal and legal use of cannabis in MS patients, as well as reasons for use and perceived adverse effects. METHODS: An anonymous questionnaire was sent to all 3606 patients at the Danish Multiple Sclerosis Center, Rigshospitalet, University of Copenhagen. The questionnaire included questions about sociodemographic factors, clinical characteristics and medical or recreational cannabis use. RESULTS: Questionnaires were completed by 2244/3606 (62%), of which 2009 questionnaires from patients with MS or clinical isolated syndrome (CIS) were valid for analysis. Forty-nine percent (980/2009) had used cannabis at least once. Cannabis was used within the past year (current user) by 21%, and only 21% of those received prescribed cannabis-based medicine. Recreational use was reported by 17%. The primary reasons for use were to alleviate pain (61%), spasticity (52%) and sleep disturbances (46%). The most common adverse effects were drowsiness (30%), feeling quiet/subdued (23%) and dizziness (13%). Almost half (44%) of the non-cannabis users would consider use of cannabis to alleviate MS symptoms if the drug was legalized. CONCLUSION: This study shows that illegal cannabis use is common among Danes with MS as only 21% of the current cannabis users received prescribed cannabis-based medicine. Current cannabis users reported high efficacy in relieving pain, spasticity and sleep disturbances. In addition, only mild to moderate severity of adverse effects were reported. To the best of our knowledge, this is the most comprehensive survey of cannabis use among MS patients.

The neutrophil-to-lymphocyte ratio is associated with multiple sclerosis.

BACKGROUND: Subtypes of white blood cell counts are known biomarkers of systemic inflammation and a high neutrophil-to-lymphocyte ratio (NLR) has been associated with several autoimmune diseases. Few studies have investigated the NLR in multiple sclerosis (MS). OBJECTIVE: To examine the association between NLR, MS and disability measured by the MS severity score (MSSS). METHODS: Patients were included from the Danish Multiple Sclerosis Biobank. Information on patient NLR was obtained just before their first treatment and clinical information was provided by the Danish Multiple Sclerosis Treatment Register. Information on NLR from controls was collected from the Danish Blood Donor Study. Patients and controls were 1:2 propensity score matched by baseline confounders. RESULTS: Propensity score matching left 740 of 743 MS patients and 1420 of 4691 controls for further analyses. Odds-ratio (OR) was 3.64 (95% confidence interval 2.87-4.60, p < 0.001) for MS disease per unit increase of logarithmically transformed NLR (ln-NLR), corresponding to an OR of 2.68 for each doubling of NLR. Mean NLR was 2.12 for patients and 1.72 for controls (p < 0.001). Ln-NLR correlated weakly with patient MSSS (R 2 = 0.019, p = 0.008). CONCLUSION: Patients with early MS had increased levels of NLR compared to healthy controls and NLR was weakly correlated with MSSS.

Disability in progressive MS is associated with T2 lesion changes.

BACKGROUND: Progressive multiple sclerosis (MS) is characterised by diffuse changes on brain magnetic resonance imaging (MRI), which complicates the use of MRI as a diagnostic and prognostic marker. The relationship between MRI measures (conventional and non-conventional) and clinical disability in progressive MS therefore warrants further investigation. OBJECTIVE: To investigate the relationship between clinical disability and MRI measures in patients with progressive MS. METHODS: Data from 93 primary and secondary progressive MS patients who had participated in 3 phase 2 clinical trials were included in this cross-sectional study. From 3T MRI baseline scans we calculated total T2 lesion volume and analysed magnetisation transfer ratio (MTR) and the diffusion tensor imaging indices fractional anisotropy (FA) and mean diffusivity (MD) in T2 lesions, normal-appearing white matter (NAWM) and cortical grey matter. Disability was assessed by the Expanded Disability Status Scale (EDSS) and the MS functional composite. RESULTS: T2 lesion volume was associated with impairment by all clinical measures. MD and MTR in T2 lesions were significantly related to disability, and lower FA values correlated with worse hand function in NAWM. In multivariable analyses, increasing clinical disability was independently correlated with increasing T2 lesion volumes and MTR in T2 lesions. CONCLUSION: In progressive MS, clinical disability is related to lesion volume and microstructure.

Bone microarchitecture and bone mineral density in multiple sclerosis.

BACKGROUND: Multiple sclerosis (MS) patients are at increased risk of reduced bone mineral density (BMD) and fractures. The aetiology of bone loss in MS is unclear. Trabecular bone score (TBS) is a novel analytical tool that provides a measurement of the bone microarchitecture. Decreased TBS predicts increased fracture risk independently of BMD. To date, no studies have investigated TBS in MS patients. OBJECTIVES: To assess bone quality in MS patients by TBS and to evaluate potential risk factors that may affect BMD and TBS in patients with MS. METHODS: Two hundred sixty MS patients were included. TBS was calculated using TBS iNsight software (MediMaps® ). Multivariable regression analyses were performed with information on smoking, alcohol, glucocorticoid (GC) treatment, sun exposure, physical activity, vitamin D and BMI. RESULTS: Trabecular bone score was not significantly different from an age-matched reference population. Low TBS was associated with high age (P = .014) and smoking (P = .03). Smoking and physical inactivity were associated with low BMD in spine (P = .034, P = .032). GC treatment was not associated with TBS. CONCLUSION: We could not find altered TBS values among MS patients, suggesting that BMD alone, and not the bone microarchitecture, is affected in MS. However, larger studies are needed to verify these findings and to establish the role of TBS in MS. As in the background population, physical activity and non-smoking habits are associated with better bone health in MS.

Early safety and efficacy of fingolimod treatment in Denmark.

BACKGROUND: Initiation of fingolimod treatment is associated with a transient decrease of heart rate, and atrioventricular (AV) conduction block may occur. OBJECTIVE: To evaluate the therapeutic effect and safety of fingolimod treatment in MS patients in Denmark with focus on cardiac and pulmonary side effects at treatment onset. MATERIALS & METHODS: We analysed data from the first 496 fingolimod-treated Danish patients, observed for at least 3 months. In a subset of 204 patients, we monitored cardiac and pulmonary adverse effects following treatment initiation. RESULTS: The overall annualized relapse rate (ARR) was 0.37 (95% CI 0.31-0.44); 0.22 (95% CI 0.03-0.81) in de novo-treated patients, 0.29 (95% CI; 0.23-0.37) in patients switching from IFN-beta or GA and 0.46 (9 5% CI 0.34-0.60) after natalizumab. In the subset of 204 patients, 8 (3.9%) required prolonged cardiac monitoring due to bradycardia and/or second-degree AV block type I. All patients recovered spontaneously. Two patients discontinued fingolimod. Eleven (5.4%) patients reported respiratory complaints and two of these patients discontinued treatment. CONCLUSIONS: Fingolimod appears to be safe and effective in MS patients in a clinical setting. Mild cardiac adverse effects occurred at a similar rate as in clinical trials.

Soluble serum VCAM-1, whole blood mRNA expression and treatment response in natalizumab-treated multiple sclerosis.

BACKGROUND: Natalizumab reduces disease activity in multiple sclerosis (MS). Natalizumab binds to the very late antigen-4 and inhibits vascular cell adhesion molecule-1 (VCAM-1)-mediated transmigration of immune cells across the blood-brain-barrier. This is associated with decreased serum concentrations of soluble (s)VCAM-1 and an altered composition of immune cell-subsets in the blood. OBJECTIVE: We aimed to examine if sVCAM-1 serum concentrations and whole blood mRNA expression levels of immune activation biomarkers is associated with disease activity in natalizumab-treated MS-patients. METHODS: sVCAM-1 serum concentrations and whole blood mRNA expression were measured in blood samples from untreated RRMS-patients and from two independent groups of natalizumab-treated patients. RESULTS: sVCAM-1 serum concentrations and whole blood expression of HLX1 and IL1B mRNA were lower, whereas expression of EBI3 mRNA was higher in natalizumab-treated MS-patients. Five genes were differentially expressed in clinically unstable natalizumab-treated MS-patients in the discovery but not in the validation group. CONCLUSION: Decreased serum concentrations of sVCAM-1 and altered whole blood mRNA expression levels of a panel of immunomarkers, associated with natalizumab-treatment, are not sensitive markers of MS disease activity. However, decreased expression of pro-inflammatory HLX1 and IL1B and increased expression of immunoregulatory EBI3 may indicate a less pathogenic immune activation status in natalizumab-treated MS.

Shift work at young age is associated with increased risk of multiple sclerosis in a Danish population.

BACKGROUND: Epidemiological studies suggest an important role for environmental factors in developing multiple sclerosis (MS). Furthermore several studies have indicated that the effect of environmental factors may be especially pronounced in adolescents. Recently only one study investigated and found that shift work at young age is associated with an increased risk of developing MS. In this study we focused on the effect of shift work in the vulnerable period between 15-19 years. OBJECTIVE: The aim of this study was to investigate the association between shift work at young age and the risk of developing MS. METHODS: We performed a large case-control study including 1723 patients diagnosed with MS and 4067 controls. MS patients were recruited from the Danish Multiple Sclerosis Biobank and controls from The Danish Blood Donor Study. Information on working patterns and lifestyle factors was obtained using a comprehensive lifestyle-environmental factor questionnaire with participants enrolled between 2009 and 2014. Logistic regression models were used to investigate the association between shift work at age 15-19 years and the subsequent risk of MS and were controlled for effects due to established MS risk factors. RESULTS: We found a statistically significant association when total numbers of night shifts were compared with non-shift workers. For every additional 100 night shifts the odds ratio (OR) for MS was 1.20 (95% confidence interval (CI), 1.08-1.34, p=0.001). Increasing intensity of shift work also increased MS risk. For every additional night per month the OR was 1.04 (95% CI, 1.01-1.06, p=0.002). Duration of shift work in years was not associated with risk of MS. CONCLUSION: This study supports a statistically significant association between shift work at age 15-19 years and MS risk.

Minocycline added to subcutaneous interferon ß-1a in multiple sclerosis: randomized RECYCLINE study.

BACKGROUND AND PURPOSE: Combining different therapies may improve disease control in patients with relapsing-remitting multiple sclerosis (RRMS). This study assessed the efficacy and safety of minocycline added to subcutaneous (sc) interferon (IFN) ß-1a therapy. METHODS: This was a double-blind, randomized, placebo-controlled multicentre study. Within 3 months (±1 month) of starting sc IFN ß-1a 44 µg three times weekly, patients with RRMS were randomized to minocycline 100 mg twice daily or placebo, added to sc IFN ß-1a, for 96 weeks. The primary efficacy endpoint was the time to first qualifying relapse. Secondary efficacy endpoints were the annualized relapse rate for qualifying relapses, the number of new/enlarging T2-weighted lesions and change in brain volume [magnetic resonance imaging (MRI) was performed only in a few selected centres]. In addition, a number of tertiary efficacy endpoints were assessed. RESULTS: One hundred and forty-nine patients received minocycline and 155 received placebo; MRI data were available for 23 and 27 patients, respectively. The time to first qualifying relapse did not differ significantly for minocycline versus placebo (hazard ratio 0.85; 95% confidence interval 0.53, 1.35; log-rank = 0.50; P = 0.48). There were no statistically significant differences between the two groups on other efficacy endpoints, although some numerical trends in favour of minocycline were observed. No unexpected adverse events were reported, but more patients discontinued because of adverse events with minocycline versus placebo. CONCLUSION: Minocycline showed no statistically significant beneficial effect when added to sc IFN ß-1a therapy.

Cerebrospinal fluid chitinase-3-like 2 and chitotriosidase are potential prognostic biomarkers in early multiple sclerosis.

BACKGROUND AND PURPOSE: The role of chitinases and chitinase-like proteins in multiple sclerosis (MS) is currently unknown; however, cerebrospinal fluid (CSF) levels of chitinase 3-like 1 (CHI3L1) predict prognosis in early MS. Whether this applies to other chitinases and chitinase-like proteins is yet to be established. Our objective was to investigate the potential of chitinase 3-like 2 (CHI3L2) and chitotriosidase as prognostic biomarkers in optic neuritis (ON) as the first demyelinating episode and to evaluate the ability of CHI3L2 to predict long-term MS risk and disability. METHODS: In a prospective cohort of 73 patients with ON as a first demyelinating episode and 26 age-matched healthy controls levels of CHI3L2 and chitotriosidase in CSF were explored by enzyme-linked immunosorbent assay. Associations with magnetic resonance imaging white matter lesions, CSF oligoclonal bands, immunoglobulin G index and leukocyte count were investigated. Long-term MS risk and disability (Expanded Disability Status Scale, Multiple Sclerosis Functional Composite components) were examined in a retrospective cohort of 78 patients with ON as the first demyelinating episode (mean follow-up 14 years). The predictive ability of CHI3L2 was compared with CHI3L1. RESULTS: Cerebrospinal fluid levels of CHI3L2 and chitotriosidase were significantly elevated in patients with ON and were associated with MS risk measures. CHI3L2 levels predicted MS development after ON (hazard ratio 1.95, P = 0.00039, Cox regression) and cognitive impairment by the Paced Auditory Serial Addition Test (P = 0.0357, linear regression) at follow-up. In a multivariate analysis of MS risk, CHI3L2 performed better than CHI3L1. CONCLUSIONS: CHI3L2 and chitotriosidase are promising biomarkers in patients with a first demyelinating episode. Our findings thus support a role for these proteins as biomarkers in early MS.

Identification of Suitable Reference Genes for Peripheral Blood Mononuclear Cell Subset Studies in Multiple Sclerosis.

Quantitative real-time PCR (qPCR) involves the need of a proper standard for normalizing the gene expression data. Different studies have shown the validity of reference genes to vary greatly depending on tissue, cell subsets and experimental context. This study aimed at the identification of suitable reference genes for qPCR studies using different peripheral blood cell subsets (whole blood (WB) cells, peripheral blood mononuclear cells (PBMCs) and PBMC subsets (CD4(+) T cells, CD8(+) T cells, NK cells, monocytes, B cells and dendritic cells) from healthy controls (HC), patients with relapsing-remitting multiple sclerosis (RRMS) and interferon-ß-treated patients with RRMS (RRMS-IFN-ß). Eight candidate reference genes (CASC3, EEF1A1, GAPDH, HPRT1, RPLP0, UBC, UBE2D2 and YWHAZ) were analysed using normfinder and genorm algorithms to identify the most stably expressed genes. We found reference gene expression varied most across cell subsets, and less variation between the donor groups. UBE2D2 was the most stably expressed gene across both HC and RRMS patients and across cell subsets, while UBC was the most stably expressed gene between HC, RRMS and RRMS-IFN-ß patients. UBE2D2 and HPRT1 was the most stable combination for analyses of cell subsets between HC and RRMS patients, while the combination of UBC and YWHAZ was superior for analysis of cell subsets between HC, RRMS and RRMS-IFN-ß groups. GAPDH was generally unsuitable for blood cell subset studies in multiple sclerosis. In conclusion, we found that blood cell subsets result in marked variation in reference gene expression, and we identified suitable reference genes for studies involving PBMC subsets, RRMS patients and interferon-ß treatment.

Cerebrospinal fluid neurofilament light chain levels predict visual outcome after optic neuritis.

BACKGROUND: Optic neuritis is a good model for multiple sclerosis relapse, but currently no tests can accurately predict visual outcome. OBJECTIVE: The purpose of this study was to examine whether cerebrospinal fluid (CSF) biomarkers of tissue damage and remodelling (neurofilament light chain (NF-L), myelin basic protein, osteopontin and chitinase-3-like-1) predict visual outcome after optic neuritis. METHODS: We included 47 patients with optic neuritis as a first demyelinating episode. Patients underwent visual tests, optical coherence tomography (OCT), magnetic resonance imaging (MRI) and lumbar puncture. Biomarkers were measured in CSF by enzyme-linked immunosorbent assay (ELISA). Patients were followed up six months after onset and this included visual tests and OCT. Outcome measures were inter-ocular differences in low contrast visual acuity (LCVA), retinal nerve fibre layer (RNFL) and ganglion cell layer+inner plexiform layer (GC-IPL) thicknesses. RESULTS: CSF NF-L levels at onset predicted inter-ocular differences in follow-up LCVA (ß=13.8, p=0.0008), RNFL (ß=5.6, p=0.0004) and GC-IPL (ß=4.0, p=0.0008). The acute-phase GC-IPL thickness also predicted follow-up LCVA (ß=12.9, p=0.0021 for NF-L, ß=-1.1, p=0.0150 for GC-IPL). Complete/incomplete remission was determined based on LCVA from 30 healthy controls. NF-L had a positive predictive value of 91% and an area under the curve (AUC) of 0.79 for incomplete remission. CONCLUSION: CSF NF-L is a promising biomarker of visual outcome after optic neuritis. This could aid neuroprotective/regenerative medical advancements.

Cerebrospinal fluid levels of chitinase 3-like 1 and neurofilament light chain predict multiple sclerosis development and disability after optic neuritis.

BACKGROUND: Cerebrospinal fluid (CSF) biomarkers have been suggested to predict multiple sclerosis (MS) after clinically isolated syndromes, but studies investigating long-term prognosis are needed. OBJECTIVE: To assess the predictive ability of CSF biomarkers with regard to MS development and long-term disability after optic neuritis (ON). METHODS: Eighty-six patients with ON as a first demyelinating event were included retrospectively. Magnetic resonance imaging (MRI), CSF leukocytes, immunoglobulin G index and oligoclonal bands were registered. CSF levels of chitinase-3-like-1, osteopontin, neurofilament light-chain, myelin basic protein, CCL2, CXCL10, CXCL13 and matrix metalloproteinase-9 were measured by enzyme-linked immunosorbent assay. Patients were followed up after 13.6 (range 9.6-19.4) years and 81.4% were examined, including Expanded Disability Status Scale and MS functional composite evaluation. 18.6% were interviewed by phone. Cox regression, multiple regression and Spearman correlation analyses were used. RESULTS: Forty-six (53.5%) developed clinically definite MS (CDMS) during follow-up. In a multivariate model MRI (p=0.0001), chitinase 3-like 1 (p=0.0033) and age (p=0.0194) combined predicted CDMS best. Neurofilament light-chain predicted long-term disability by the multiple sclerosis severity scale (p=0.0111) and nine-hole-peg-test (p=0.0202). Chitinase-3-like-1 predicted long-term cognitive impairment by the paced auditory serial addition test (p=0.0150). CONCLUSION: Neurofilament light-chain and chitinase-3-like-1 were significant predictors of long-term physical and cognitive disability. Furthermore, chitinase-3-like-1 predicted CDMS development. Thus, these molecules hold promise as clinically valuable biomarkers after ON as a first demyelinating event.