Beta-2 microglobulin and neopterin as markers of disease activity in multiple sclerosis

Evaluation of Cell-Specific Epigenetic Age Acceleration in People With Multiple Sclerosis

BACKGROUND AND OBJECTIVES

In multiple sclerosis (MS), accelerated aging of the immune system (immunosenescence) may be associated with disease onset or drive progression. DNA methylation (DNAm) is an epigenetic factor that varies among lymphocyte subtypes, and cell-specific DNAm is associated with MS. DNAm varies across the life span and can be used to accurately estimate biological age acceleration, which has been linked to a range of morbidities. The objective of this study was to test for cell-specific epigenetic age acceleration (EAA) in people with MS.

METHODS

This was a case-control study of EAA using existing DNAm data from several independent previously published studies. Data were included if .idat files from Illumina 450K or EPIC arrays were available for both a case with MS and an age-matched and sex-matched control, from the same study. Multifactor statistical modeling was performed to assess the primary outcome of EAA. We explored the relationship of EAA and MS, including interaction terms to identify immune cell-specific effects. Cell-sorted DNA methylation data from 3 independent datasets were used to validate findings.

RESULTS

We used whole blood DNA methylation data from 583 cases with MS and 643 non-MS controls to calculate EAA using the GrimAge algorithm. The MS group exhibited an increased EAA compared with controls (approximately 9 mths, 95% CI 3.6-14.4), p = 0.001). Statistical deconvolution showed that EAA is associated with MS in a B cell-dependent manner (β int = 1.7, 95% CI 0.3-2.8), p = 0.002), irrespective of B-cell proportions. Validation analysis using 3 independent datasets enriched for B cells showed an EAA increase of 5.1 years in cases with MS compared with that in controls (95% CI 2.8-7.4, p = 5.5 × 10-5). By comparison, there was no EAA difference in MS in a T cell-enriched dataset. We found that EAA was attributed to the DNAm surrogates for Beta-2-microglobulin (difference = 47,546, 95% CI 10,067-85,026; p = 7.2 × 10-5), and smoking pack-years (difference = 8.1, 95% CI 1.9-14.2, p = 0.002).

DISCUSSION

This study provides compelling evidence that B cells exhibit marked EAA in MS and supports the hypothesis that premature B-cell immune senescence plays a role in MS. Future MS studies should focus on age-related molecular mechanisms in B cells.

Considerations for Use of Pharmacodynamic Biomarkers to Support Biosimilar Development - (III) A Randomized Trial with Interferon Beta-1a Products

The US Food and Drug Administration (FDA) has taken steps to bring efficiency to the development of biosimilars, including establishing guidance for the use of pharmacokinetic and pharmacodynamic (PD) similarity study data without a comparative clinical study with efficacy end point(s). To better understand the potential role for PD biomarkers in biosimilar development and inform best practices for biomarker selection and analysis, we conducted a randomized, double-blinded, placebo-controlled, single-dose, parallel-arm clinical study in healthy participants. Eighty-four healthy participants (n = 12 per dose arm) received either placebo or one of three doses of either interferon β-1a (7.5-30 μg) or pegylated interferon β-1a (31.25-125 μg) to evaluate the maximum change from baseline and the baseline-adjusted area under the effect curve for the biomarkers neopterin in serum and myxovirus resistance protein 1 in blood. Both PD biomarkers increased following product administration with clear separation from baseline (neopterin: 3.4-fold and 3.9-fold increase for interferon β-1a and pegylated interferon β-1a, respectively; myxovirus resistance protein 1: 19.0-fold and 47.2-fold increase for interferon β-1a and pegylated interferon β-1a, respectively). The dose-response curves support that therapeutic doses were adequately sensitive to detect differences in both PD biomarkers for consideration in a PD similarity study design. Because baseline levels of both biomarkers are low compared with on-treatment values, there was little difference in using PD measures adjusted to baseline compared with the results without baseline adjustment. This study illustrates potential methodologies for evaluating PD biomarkers and an approach to address information gaps when limited information is publicly available for one or more PD biomarkers.

Evaluating the Utility of Proteomics for the Identification of Circulating Pharmacodynamic Biomarkers of IFNβ-1a Biologics

Proteomics has the potential to identify pharmacodynamic (PD) biomarkers for similarity assessment of proposed biosimilars without relying on clinical efficacy end points. In this study, with 36 healthy participants randomized to therapeutic doses of interferon-beta 1a products (IFNβ-1a) or pegylated-IFNβ-1a (pegIFNβ-1a) approved to treat multiple sclerosis or placebo, we evaluated the utility of a proteomic assay that profiles > 7,000 plasma proteins. IFNβ-1a and pegIFNβ-1a resulted in 248 and 528 differentially expressed protein analytes, respectively, between treatment and placebo groups over the time course. Thirty-one proteins were prioritized based on a maximal fold change ≥ 2 from baseline, baseline adjusted area under the effect curve (AUEC) and overlap between the 2 products. Of these, the majority had a significant AUEC compared with placebo in response to either product; 8 proteins showed > 4-fold maximal change from baseline. We identified previously reported candidates, beta-2microglobulin and interferon-induced GTP-binding protein (Mx1) with ~ 50% coefficient of variation (CV) for AUEC, and many new candidates (including I-TAC, C1QC, and IP-10) with CVs ranging from 26%-129%. Upstream regulator analysis of differentially expressed proteins predicted activation of IFNβ1 signaling as well as other cytokine, enzyme, and transcription signaling networks by both products. Although independent replication is required to confirm present results, our study demonstrates the utility of proteomics for the identification of individual and composite candidate PD biomarkers that may be leveraged to support clinical pharmacology studies for biosimilar approvals, especially when biologics have complex mechanisms of action or do not have previously characterized PD biomarkers.

Quantitative proteomic analysis of cerebrospinal fluid of women newly diagnosed with multiple sclerosis

PURPOSE

The lack of reliable diagnostic and/or prognostic biomarkers for multiple sclerosis (MS) is the major obstacle to timely and accurate patient diagnosis in MS patients. To identify new proteins associated with MS we performed a detailed proteomic analysis of cerebrospinal fluid (CSF) of patients newly diagnosed with relapsing-remitting MS (RRMS) and healthy controls.

MATERIAL

Reflecting significantly higher prevalence of MS in women we included only women patients and controls in the study. To eliminate a potential effect of therapy on the CSF composition, only the therapy-naïve patients were included.

METHODS

Pooled CSF samples were processed in a technical duplicate, and labeled with stable-isotope coded TMT tags. To maximize the proteome coverage, peptide fractionation using 2D-LC preceded mass analysis using Orbitrap Fusion Tribrid Mass Spectrometer. Differential concentration of selected identified proteins between patients and controls was verified using specific antibodies.

RESULTS

Of the identified 900 CSF proteins, we found 69 proteins to be differentially abundant between patients and controls. In addition to several proteins identified as differentially abundant in MS patients previously, we observed several linked to MS for the first time, namely eosinophil-derived neurotoxin and Nogo receptor.

CONCLUSIONS

Our data confirm differential abundance of several previously proposed protein markers, and provide indirect support for involvement of copper-iron disbalance in MS. Most importantly, we identified two new differentially abundant CSF proteins that seem to be directly connected with myelin loss and axonal damage via TLR2 signaling and Nogo-receptor pathway in women newly diagnosed with RRMS.

The diagnostic role and dynamic changes in cerebrospinal fluid neopterin during treatment of patients with primary central nervous system lymphoma

This study aimed at evaluating the diagnostic and prognostic role of neopterin (Npt) concentration in the cerebrospinal fluid (CSF) of patients with primary central nervous system lymphoma (PCNSL). Ninety‐nine patients were enrolled in this retrospective study; these included patients with PCNSL (n = 21), other brain tumors (n = 44), and inflammatory diseases (n = 34). CSF Npt concentration was measured using ELISA. Receiver operating characteristic (ROC) curve analysis was performed to assess the discriminative ability of CSF Npt concentration for the diagnosis of PCNSL. CSF Npt concentration in patients with PCNSL was significantly higher than that in patients with other brain tumors and inflammatory diseases (P < .001). On ROC curve analysis, the optimal cutoff CSF Npt level of 10.77 ng/mL for the diagnosis of PCNSL and the diagnostic yield of MRI were increased when used in conjunction with CSF Npt concentration. The CSF Npt concentrations in PCNSL patients with multiple lesions were significantly higher than those in patients with a single lesion. Changes in CSF Npt concentration were consistent with post‐treatment changes in tumor sizes. The CSF Npt concentration may be a good biomarker for the diagnosis, for monitoring of disease course, and for prognostic evaluation of patients with PCNSL.

Biomarker Development in Chronic Inflammatory Diseases

Chronic inflammatory diseases, such as inflammatory bowel disease—namely, Crohn’s disease and ulcerative colitis—psoriasis, multiple sclerosis, rheumatoid arthritis, and many others affect millions of people worldwide, causing a high burden of disease, socioeconomic impact, and healthcare cost. These diseases have common features including autoimmune pathogenesis and frequent co morbidity.

The treatment of these chronic inflammatory diseases usually requires long-term immunosuppressive therapies with undesirable side effects. The future of chronic inflammatory disease prevention, detection, and treatment will be greatly influenced by the use of more effective biomarkers with enhanced performance. Given the practical issues of collecting tissue samples in inflammatory diseases, biomarkers derived from body fluids have great potential for optimized patient management through the circumvention of the abovementioned limitations.

In this chapter, peripheral blood, urine, and cerebrospinal fluid biomarkers used in chronic inflammatory conditions are reviewed. In detail, this chapter reviews biomarkers to fore used or emerging to be used in patients with chronic inflammatory conditions. Those include inflammatory bowel diseases, chronic inflammatory conditions of the liver, biliary tract, pancreas, psoriasis, atopic disease, inflammatory skin diseases, rheumatic diseases, demyelination, and also the chronic inflammatory component of various other diseases in general medicine—including diabetes, cardiovascular disease, renal disease, and chronic obstructive pulmonary disease.

Development of personalized medicine is closely linked to biomarkers, which may serve as the basis for diagnosis, drug discovery, and monitoring of diseases.

Evidence for a Role of Nerve Injury in Painful Intervertebral Disc Degeneration: A Cross-Sectional Proteomic Analysis of Human Cerebrospinal Fluid

Intervertebral disc degeneration (DD) is a cause of low back pain (LBP) in some individuals. However, although >30% of adults have DD, LBP only develops in a subset of individuals. To gain insight into the mechanisms underlying nonpainful versus painful DD, human cerebrospinal fluid (CSF) was examined using differential expression shotgun proteomic techniques comparing healthy control participants, subjects with nonpainful DD, and patients with painful DD scheduled for spinal fusion surgery. Eighty-eight proteins were detected, 27 of which were differentially expressed. Proteins associated with DD tended to be related to inflammation (eg, cystatin C) regardless of pain status. In contrast, most differentially expressed proteins in DD-associated chronic LBP patients were linked to nerve injury (eg, hemopexin). Cystatin C and hemopexin were selected for further examination using enzyme-linked immunosorbent assay in a larger cohort. While cystatin C correlated with DD severity but not pain or disability, hemopexin correlated with pain intensity, physical disability, and DD severity. This study shows that CSF can be used to study mechanisms underlying painful DD in humans, and suggests that while painful DD is associated with nerve injury, inflammation itself is not sufficient to develop LBP.

PERSPECTIVE

CSF was examined for differential protein expression in healthy control participants, pain-free adults with asymptomatic intervertebral DD, and LBP patients with painful intervertebral DD. While DD was related to inflammation regardless of pain status, painful degeneration was associated with markers linked to nerve injury.

The innovative development in interferon beta treatments of relapsing-remitting multiple sclerosis

The introduction of interferon beta therapies more than 20 years ago marked a milestone in the treatment of relapsing-remitting multiple sclerosis (RRMS) with a significant impact on the approach to modern multiple sclerosis (MS) care. Key learnings and perspectives from the early days of disease modifying therapies in MS have improved the knowledge base of MS, need for treatment, and patient care. The continuous development of interferons over the past two decades outlines a journey with increased understanding of the pharmacodynamics and pharmacokinetic mechanisms of interferons, leading to innovative formulations with an improved benefit/risk profile.

Heritability of plasma neopterin levels in the Old Order Amish

BACKGROUND

We examined the heritability of neopterin, a biomarker for cell-mediated immunity and oxidative stress, and potentially for psychiatric disorders, in the Old Order Amish.

METHODS

Plasma neopterin levels were determined in 2015 Old Order Amish adults. Quantitative genetic procedures were used to estimate heritability of neopterin.

RESULTS

Heritability of log-neopterin was estimated at 0.07 after adjusting for age, gender, and household (p=0.03). The shared household effect was 0.06 (p<0.02).

CONCLUSIONS

We found a low heritability of neopterin and small household effect, suggesting that non-household environmental factors are more important determinants of variance of neopterin levels in the Amish.

An update on the evidence base for peginterferon β1a in the treatment of relapsing-remitting multiple sclerosis

Peginterferon β1a is a modified form of interferon β1a with a polyethylene glycol (PEG) group attached to the α-amino group of the N terminus of the interferon molecule. This modification alters the pharmacokinetic and pharmacodynamic properties of interferon β1a, enabling reduced frequency of dosing and may also result in reduced immunogenicity of the interferon β1a molecule. The efficacy of peginterferon β1a 125 µg administered subcutaneously every 2 or 4 weeks was demonstrated at the end of the placebo-controlled period in the phase III ADVANCE study; both dosing regimens met their primary endpoint of reducing annualized relapse rate (ARR) compared with placebo. Peginterferon β1a administered every 2 weeks resulted in a more robust treatment effect on ARR, sustained disability progression and magnetic resonance imaging endpoints (new or enlarging T2 lesions and gadolinium-enhanced lesions) than peginterferon β1a every 4 weeks. Further reductions in the ARR with additional positive impact on magnetic resonance imaging outcomes were noted in year 2 of the ADVANCE study with the every 2-week dosing regimen. An adverse-effect profile similar to other interferon β formulations coupled with the advantage of a significant reduction in the number of injections, could lead to improved long-term adherence to peginterferon β1a. We review the evidence base for the role of peginterferon β1a in the treatment of relapsing-remitting multiple sclerosis.

CSF neopterin level as a diagnostic marker in primary central nervous system lymphoma

BACKGROUND

The diagnosis of primary central nervous system lymphoma (PCNSL) can be challenging. PCNSL lesions are frequently located deep within the brain, and performing a cerebral biopsy is not always feasible. The aim of this study was to investigate the diagnostic value of CSF neopterin, a marker of neuroinflammation, in immunocompetent patients with suspected PCNSL.

METHODS

We retrospectively reviewed the characteristics of 124 patients with brain tumor (n = 82) or an inflammatory CNS disorder (n = 42) in whom CSF neopterin levels were assessed. Twenty-eight patients had PCNSL, 54 patients had another type of brain tumor (glioma n = 36, metastasis n = 13, other n = 5), and 13 patients had a pseudotumoral inflammatory brain lesion.

RESULTS

CSF neopterin levels were significantly higher in the patients with PCNSL than in those with other brain tumors (41.8 vs 5.1 nmol/L, P < .001), those with pseudotumoral inflammatory brain lesions (41.8 vs 4.3 nmol/L, P < .001), and those with nontumefactive inflammatory CNS disorders (41.8 vs 3.8 nmol/L, P < .001). In the 95 patients with space-occupying brain lesions, at a cutoff of 10 nmol/L, the sensitivity of this approach was 96% and the specificity was 93% for the diagnosis of PCNSL. The positive and negative predictive values were 84% and 98%, respectively.

CONCLUSION

Assessing CSF neopterin levels in patients with a suspected brain tumor might be helpful for the positive and differential diagnosis of PCNSL. A prospective study is warranted to confirm these results.

Proteomics urine analysis of pregnant women suffering from multiple sclerosis

Multiple sclerosis (MScl) frequently is remitted during the third trimester of pregnancy but exacerbated in the first postpartum period. In this context, we investigated protein identification, its abundance, and its change in urine related to these two periods. Using mass spectrometry (LTQ Orbitrap), we identified 1699 tryptic peptides (related to 402 proteins) in urine from 31 MScl and 8 control at these two periods. Pregnancy-related peptides were significantly elevated (p < 0.01) in MScl patients compared with controls (Analysis 1: 531 peptides in MScl and 36 peptides in controls higher abundant in the third trimester compared to postpartum). When comparing the longitudinal differences (Analysis 2), we identified 43 (related to 35 proteins) MScl disease-associated peptides (p < 0.01) with increased or decreased difference ratio in MScl compared with controls. The most discriminating peptides identified were trefoil factor 3 and lysosomal-associated membrane protein 2. Both proteins have a role in the innate immune system. Three proteins with a significant decreased ratio were plasma glutamate carboxypeptidase, Ig mu chain C region, and osteoclast associated immune like receptor. Our results indicate that the protein expression pattern in urine of MScl patients contains information about remote CNS and brain disease processes.

Adverse events during the titration phase of interferon-beta in remitting-relapsing multiple sclerosis are not predicted by body mass index nor by pharmacodynamic biomarkers

BACKGROUND

This study aimed to correlate body mass index or biomarkers with the frequency of common adverse events (AEs) with subcutaneous IFN β-1a during treatment titration in patients with relapsing-remitting multiple sclerosis previously naïve to IFN β.

METHODS

Eighty-four patients (66.3% females) were followed up during 8 weeks, 25.3% were overweight and 14.5% were obese.

RESULTS

Biomarkers steadily increased during all study period by 45.3% for β2-microglobulin, 262.8% for olygoadenylate synthetase-1, and 92.8% for neopterin. Overall AE reporting did not vary with the dose or treatment duration.

CONCLUSIONS

BMI was not predictive of increased risk for AEs. Biomarkers did not discriminate on the frequency of any AE either.

Urine: An under-studied source of biomarkers in multiple sclerosis?

There remains a need for sensitive and reliable biomarkers that can be used longitudinally in multiple sclerosis. Whilst both CSF and MRI have been extensively studied, they remain invasive and expensive methods of investigation. On the contrary, urine provides a valuable fluid which is readily available for serial sampling. Some work has been done on urinary biomarkers in multiple sclerosis; however, urinary biomarkers have not been extensively studied and validated for use in routine clinical practice, and urine remains understudied and underutilised. In this review the use of neopterin, urinary free light chains, nitric oxide metabolites and urinary myelin basic protein-like protein as potential biomarkers that have been identified in urine are discussed, and avenues for future study are raised.

Bri2-23 is a potential cerebrospinal fluid biomarker in multiple sclerosis

To identify potential multiple sclerosis (MS)-specific biomarkers, we used a proteomic approach to screen cerebrospinal fluid (CSF) from 40 MS patients and 13 controls. We identified seven proteins (Beta-2-microglobulin, Bri2-23, Fetuin-A, Kallikrein-6, Plasminogen, Ribonuclease-1, and Transferrin) that had significantly altered levels in MS compared to controls. Clinical subgroup analysis revealed that decreased CSF levels of Bri2-23, a peptide cleaved from Bri2, were significantly associated with patients having cerebellar dysfunction and cognition impairment. Furthermore, expression levels of Bri2 were specifically decreased in the cerebellum compared to other areas of same brain in MS but not in controls, suggesting that decreased cerebellar Bri2 expression may play a role in cerebellar dysfunction. The association with cognition impairment is also of interest because Bri2 is linked to the amyloid processing pathway in the brain. CSF levels of Bri2-23 may serve as a biomarker of these functions in MS and merits further investigation.

Autoantibodies to the proteasome in monosymptomatic optic neuritis may predict progression to multiple sclerosis

OBJECTIVE

Proteasome autoantibodies (PAB) have been found in multiple sclerosis (MS) patient sera and cerebrospinal fluid (CSF). Presence of PAB could thus be a possible diagnostic marker for MS. We investigated whether PAB serum status in acute monosymptomatic optic neuritis (ON) and MS differed significantly from that of healthy controls, and whether or not PAB status is predictive of later MS development in patients with ON.

MATERIAL AND METHODS

Sera from ON patients, MS patients and healthy donors were analysed retrospectively using ELISA. Subsequently, a small group of PAB-positive samples were subjected to SDS-PAGE, immunoblotting and 2-D PAGE.

RESULTS

We found that 20 % (6/30) ON patients, 47 % (22/47) MS patients and 9 % (7/81) controls tested PAB positive using ELISA analysis. High PAB levels were found in 2 (4 %) MS patients, 1 (3 %) ON patient and 2 (3 %) controls. PAB positivity in ELISA was confirmed by immunoblotting. Separation of proteasome subunits by 2D PAGE followed by immunoblotting revealed no particular PAB subunit preference.

CONCLUSIONS

A retrospective search in available patient files revealed that 6 of 6 (100.0 %) PAB-positive ON patients developed MS over time. Eight of 24 (33 %) PAB-negative ON patients developed MS over time and 47 % (14/30) of all ON patients developed MS. A series of patient CSF was analysed by ELISA to assess the possible correlation between PAB status of concurrent serum and CSF samples, but no correlation was found. However, the results from the six PAB-positive ON patients could potentially be of prognostic value.

Biological response genes after single dose administration of interferon beta-1b to healthy male volunteers

Treatment with interferon beta-1b (IFNB-1b) is clinically effective in multiple sclerosis patients. However, the mechanism of action is only partially understood, and validated biological response markers are lacking. We assessed IFNB-1b-induced transcriptional changes by microarray technology. Healthy male volunteers received 250 mug IFNB-1b or placebo in a double-blind, randomized controlled trial (n=5 per group). Most transcripts demonstrated peak levels after 6-12 h and returned to baseline after 48 h. We identified 227 differentially regulated genes including novel and previously described markers. This panel may become a valuable tool for development of new IFNB-1b formulations and assessment of clinical drug effects.

Expression of biomarkers of interferon type I in patients suffering from chronic diseases

Interferons (IFNs) are used widely in the treatment of viral infections, tumours and neurological disorders. The aim of this study was to evaluate the endogenous expressions of various IFN-induced compounds [specifically: neopterin (NPT), beta2microglobulin (beta2mg) and 2-5 oligoadenylate synthetase (2-5 OAS)] in patients with various chronic diseases requiring treatment with IFN type I. The results showed that patients with such chronic diseases as hepatitis C virus-associated type II mixed cryoglobulinaemia (MC), chronic hepatitis C (CHC) and relapsing-remitting multiple sclerosis (RRMS) are characterized by different activations of the IFN system. Furthermore, the interindividual variability in baseline levels of IFN-induced biomarkers was higher in patients with chronic diseases than in healthy individuals. When levels of the above biomarkers were measured 24 h after the first injection of IFN in patients with CHC or RRMS, significant increases in expression levels of IFN-induced compounds were recorded but, again, there is a broad range of variability in the degree of increase. Further, a significant inverse correlation between baseline levels of NPT, beta2mg and 2-5 OAS activity and their relative increases after IFN administration was found in patients with CHC or RRMS. Together, the results are consistent with the observation that there is considerable interindividual heterogeneity in the clinical response to IFNs, which suggests that host factors other than disease markers must be taken into account in order to manage and optimize the IFN therapy.

Monitoring of cadmium toxicity in a Thai population with high-level environmental exposure

This study evaluated the utility of single and combined measurements of cadmium toxicity markers for surveillance purposes, using a sample of 224 individuals, 30-87 years of age, who were residents of cadmium polluted area in Mae Sot District, Tak Province, Thailand. Urinary cadmium levels excreted by them ranged between 1 and 58 microg/g creatinine with geometric mean of 8.2 microg/g creatinine which was 16-fold greater than the average for the general Thai population of 0.5 microg/g creatinine. The urinary markers evaluated were total protein, albumin, N-acetyl-beta-D-glucosaminidase (NAG), lysozyme, beta2-microglobulin (beta2-MG) and alpha1-microglobulin (alpha1-MG). Among these markers, only NAG showed a positive correlation with urinary cadmium in both male and female subjects with and without disease (r=0.43-0.71). Further, the prevalence rates for urinary NAG above 8 units/g creatinine (NAG-uria) increased with exposure levels in a dose dependent manner (p=0.05) among subjects with disease. In contrast, however, increased prevalence of beta2-MG above 0.4 mg/g creatinine (beta2-MG-uria) was associated with cadmium above 5 microg/g creatinine only in those without disease (POR=10.6 and 7.8 for 6-10 and >10 microg/g creatinine). Prevalence rates for abnormal excretion of all other markers, except albumin, were markedly increased among those having beta2-MG-uria with and without disease (chi2-test, p<or=0.001-0.02). Thus, urinary beta2-MG and NAG should be used together with urinary cadmium in the monitoring of renal toxicity in a population exposed to high-level cadmium coupled with high prevalence of chronic diseases.