Cerebrospinal fluid levels of brain specific proteins in optic neuritis

Circulating Level of Myelin Basic Protein Predicts Postherpetic Neuralgia: A Prospective Study

OBJECTIVES

Patients with herpes zoster (HZ) would benefit from accurate prediction of whether they are likely to develop postherpetic neuralgia (PHN). We investigated whether a circulating biomarker of neuronal damage could be a predictor of PHN in this nonmatched prospective, nested, case-control study.

MATERIALS AND METHODS

We included patients with HZ who were within 90 days after rash onset. Volunteers without a history of HZ were recruited as controls. We evaluated epidemiologic factors and circulating neuronal damage biomarkers, including cell-free DNA, myelin basic protein (MBP), and soluble protein-100B (S100B). We conducted logistic regression analyses to develop a prediction model of PHN.

RESULTS

We found that cell-free DNA and MBP levels were higher in patients with HZ (n=71) than in controls (n=37). However, only MBP level was higher in patients who developed PHN (n=25), in comparison with those who did not (n=46). MBP level and 3 clinical factors, age, acute pain severity, and response to treatment drugs were identified as independent predictors of PHN. Receiver operating characteristic (ROC) curve analysis showed that the prediction made using a combination of MBP level and clinical factors had an area under ROC curve of 0.853 (95% confidence interval: 0.764 to 0.943), which was better than prediction using clinical factors alone (area under ROC curve: 0.823, 95% confidence interval: 0.728 to 0.917).

DISCUSSION

Our results indicate that circulating MBP level in patients with HZ is a predictor for PHN. The combination of clinical predictors and MBP level enhanced the prediction performance.

Science is 1% inspiration and 99% biomarkers

Neurodegeneration plays a key role in multiple sclerosis (MS) contributing to long-term disability in patients. The prognosis is, however, unpredictable coloured by complex disease mechanisms which can only be clearly appreciated using biomarkers specific to pathobiology of the underlying process. Here, we describe six promising neurodegenerative biomarkers in MS (neurofilament proteins, neurofilament antibodies, tau, N-acetylaspartate, chitinase and chitinase-like proteins and osteopontin), critically evaluating the evidence using a modified Bradford Hill criteria.

Axonal damage markers in the cerebrospinal fluid of patients with clinically isolated syndrome improve predicting conversion to definite multiple sclerosis

Clinically isolated syndrome (CIS) represents the earliest phase of multiple sclerosis (MS). This study tested whether biomarkers for axonal degeneration can improve upon sensitivity and specificity of magnetic resonance imaging (MRI) parameters in predicting conversion from CIS to MS. Patients with CIS ( n=52), relapsing-remitting MS (RRMS, n=38) and age-matched controls ( n=25) were included. Cerebrospinal fluid (CSF) levels of tau and neurofilaments (NfHSMI35) were measured using ELISA. The MRI T2-lesion load and the Expanded Disability Status Scale (EDSS) were recorded. CSF tau and NfHSMI35 were elevated in CIS compared to controls (p<0.05). RRMS patients with acute relapse had higher NfHSMI35 levels than stable patients. Tau and NfHSMI35 levels correlated with EDSS in CIS and RRMS. In RRMS, the number of T2-lesions correlated with tau levels ( R=0.53, P=0.01). The sensitivity predicting the conversion from CIS to MS was higher for the combination of CSF markers (either tau or NfHSMI35 elevated) than for MRI (40 versus 34%), but could be further increased to 60% if CSF and MRI criteria were combined. Similarly, the combination of tau and NfHSMI35 showed higher specificity (94%) than MRI (82%). Tau and NfHSMI35 are valuable biomarkers for axonal damage in the CIS patients. Predicting conversion from CIS to MS can be improved if CSF markers are combined with MRI.

Developing Biomarkers for MS

Existing clinical outcomes of disease activity, including relapse rates, are inherently insensitive to the underlying pathological process in MS. Moreover, it is extremely difficult to measure clinical disability in patients, which is often a retrospective assessment, and definitely not within the time frame of a clinical trial. Biomarkers , conversely are more specific for a pathologic process and if used correctly can prove invaluable in the diagnosis, stratification and monitoring of disease activity, including any subclinical activity which is not visible to the naked eye. In this chapter, we discuss the development of neurofilaments as surrogate outcomes of disability in MS. The validation and qualification are vital steps in biomarker development and to gaining acceptance in scientific community, and the pitfalls leading up to this are also discussed.

Cerebrospinal fluid analysis

The cerebrospinal fluid (CSF) is a bodily fluid, which is both easily accessible and the most proximate to the pathological alterations of multiple sclerosis (MS). Consequently, the analysis of this fluid provides an important window into the pathological underpinnings of this disease. For example, for years, it has been known that the CSF of MS patients contains oligoclonal gamma immunoglobulins (IgG), which are synthesized within the central nervous system and presumably relate to the immune dysfunction, which is characteristically found in MS. This insight has lead to the introduction of highly-effective anti-B-cell therapies into the field of MS therapeutics. Moreover, the presence of an oligoclonal IgG response in the CSF, although not specific for MS, is a very sensitive finding and, as a result, its presence can be quite helpful for establishing an MS diagnosis in the right clinical context. In addition, this finding has predictive value. Thus, patients without a definite diagnosis who have CSF IgG bands are significantly more likely to develop definite MS compared to those patients without such a banding pattern. Other biological molecules can also be found in the CSF including neurofiliment, myelin basic protein (MBP), glial fibrillary acidic protein (GFAP), tau, neuronal cell adhesion molecule (NCAM), and the growth associated protein (GAP-43). However, the value of measuring these (and other) CSF constituents for both diagnostic and prognostic purposes and for following response to therapy is still to be determined.

Cerebrospinal fluid in multiple sclerosis

Background:

Technological advances have made it possible to examine the human cerebrospinal fluid (CSF) in a manner that was previously impossible. CSF provides a window into the changes that occur in the central nervous system (CNS) in health and disease. Through analysis of the CSF, we discern indirectly the state of health of the CNS, and correctly or incorrectly, draw conclusions regarding mechanisms of CNS injury and repair.

Objective, Materials and Methods:

To review the current state of knowledge of changes in the CSF in multiple sclerosis.

Discussion:

Establishing CSF markers that permit evaluation of the various biological processes in multiple sclerosis remains a challenge. Of all the biological processes, inflammatory markers are probably the best identified. Detection of oligoclonal immunoglobulin bands in the CSF is now established as the single most useful laboratory marker in the CSF to aid in the diagnosis of multiple sclerosis. Markers of demyelination, remyelination, neuro-axonal loss, neural repair and regeneration, and astrogliosis are only now being recognized. A good surrogate for any of these pathophysiological processes has not been defined to date.

Conclusion:

The goal of future research is not only to define surrogate markers in the CSF for each of the above functions, but also to extend it to other more readily accessible body fluids like blood and urine. A synopsis of the current literature in most of these areas of CSF evaluation pertaining to multiple sclerosis is presented in this article.

Cerebrospinal fluid and blood biomarkers of neuroaxonal damage in multiple sclerosis

Following emerging evidence that neurodegenerative processes in multiple sclerosis (MS) are present from its early stages, an intensive scientific interest has been directed to biomarkers of neuro-axonal damage in body fluids of MS patients. Recent research has introduced new candidate biomarkers but also elucidated pathogenetic and clinical relevance of the well-known ones. This paper reviews the existing data on blood and cerebrospinal fluid biomarkers of neuroaxonal damage in MS and highlights their relation to clinical parameters, as well as their potential predictive value to estimate future disease course, disability, and treatment response. Strategies for future research in this field are suggested.

Total tau and S100b proteins in different types of multiple sclerosis and during immunosuppressive treatment with mitoxantrone

PURPOSE

Brain-specific proteins are biochemical markers of neurodegeneration. The aim of this study was to estimate the role of biomarkers in neuronal and glial damage as a potent marker of efficiency of immunosuppressive treatment.

MATERIAL AND METHODS

The levels of total Tau protein (tTau) and S100b protein were measured using the ELISA method in serum and cerebrospinal fluid (CSF) of 30 patients with RRMS, 24 patients with SPMS and 30 healthy subjects. Additionally, serum levels of tTau and S100b were assayed every 6 months during the 24-month mitoxantrone therapy.

RESULTS

In CSF and serum of patients with MS, both tTau and S100b were increased compared to control group; however, no significant difference was found between respective MS types. In serum of mitoxantrone-treated patients, both proteins showed to decrease after 24 months, yet the difference was statistically significant only for S100b.

CONCLUSIONS

CSF levels of tTau and S100b are elevated in patients with MS and can reflect an axonal and glial pathology. Measurement of serum concentrations of S100b may be useful for monitoring immunosuppressive therapy and may support clinical assessment. In contrast, tTau concentration did not prove to be a useful marker of mitoxantrone therapy.

Iron and neurodegeneration in multiple sclerosis

Increased iron deposition might be implicated in multiple sclerosis (MS). Recent development of MRI enabled to determine brain iron levels in a quantitative manner, which has put more interest on studying the role of iron in MS. Evidence for abnormal iron homeostasis in MS comes also from analyses of iron and iron-related proteins in CSF and blood and postmortem MS brain sections. However, it is not yet clear if iron accumulation is implicated in MS pathology or merely reflects an epiphenomenon. Further interest has been generated by the idea of chronic cerebrospinal venous insufficiency that might be associated with brain iron accumulation due to a reduction in venous outflow, but its existence and etiologic role in MS are currently controversially debated. In future studies, combined approaches applying quantitative MRI together with CSF and serum analyses of iron and iron-related proteins in a clinical followup setting might help to elucidate the implication of iron accumulation in MS.

Biomarker research in multiple sclerosis: addressing axonal damage and heterogeneity

Multiple sclerosis is the major neurological disease among young adults. Biomarkers predicting disease prognosis in multiple sclerosis are needed. Axonal damage is related to disease progression and occurs early in the multiple sclerosis disease course. Therefore, biomarkers for axonal damage are potential candidate predictors of disease progression. Furthermore, biomarkers for early axonal damage could help in developing and evaluating early treatment. The state of the art and new developments of biomarkers for axonal damage in multiple sclerosis is discussed in this review. Lastly, a new European network is introduced that aims at optimizing cerebrospinal fluid biomarker research in multiple sclerosis. Such networks enhance the opportunities to obtain sufficient samples for in-depth studies on biomarkers in precious material, such as cerebrospinal fluid.

Cerebrospinal fluid myelin basic protein as a prognostic biomarker in dogs with thoracolumbar intervertebral disk herniation

BACKGROUND

Release of myelin basic protein (MBP) into the cerebrospinal fluid (CSF) is associated with active demyelination and correlates with outcome in various neurological diseases.

HYPOTHESIS/OBJECTIVES

To describe associations among CSF MBP concentration, initial neurological dysfunction, and long-term ambulatory outcome in dogs with acute thoracolumbar intervertebral disk herniation (IVDH).

ANIMALS

Fifty seven [corrected] dogs with acute thoracolumbar IVDH and 16 clinically normal dogs.

METHODS

Prospective case series clinical study. Signalment, initial neurological dysfunction as determined by a modified Frankel score (MFS), and ambulatory outcome at >3-month follow-up were recorded. Cisternal CSF MBP concentration was determined by an ELISA. Associations were estimated between CSF MBP concentration and various clinical parameters.

RESULTS

Dogs with thoracolumbar IVDH that did not ambulate at follow-up had a higher CSF MBP concentration (median, 3.56 ng/mL; range, 0.59-51.2 ng/mL) compared with control dogs (median, 2.22 ng/mL; range, 0-3.82 ng/mL) (P=.032). A CSF MBP concentration of >or=3 ng/mL had a sensitivity of 78% and specificity of 76% to predict an unsuccessful outcome based on receiver-operating characteristics curve analysis (area under the curve=0.688, P=.079). Affected dogs with a CSF MBP concentration>or=3 ng/mL had 0.09 times the odds of ambulation at follow-up compared with affected dogs with CSF MBP concentration<3 ng/mL when adjusted for initial MFS (95% confidence interval 0.01-0.66, P=.018).

CONCLUSIONS AND CLINICAL IMPORTANCE

These results would suggest that CSF MBP concentration may be useful as an independent prognostic indicator in dogs with thoracolumbar IVDH.

Disease biomarkers in multiple sclerosis: potential for use in therapeutic decision making

Multiple sclerosis (MS) is an autoimmune disorder of the brain and spinal cord that predominantly affects white matter. MS has a variable clinical presentation and has no 'diagnostic' laboratory test; this often results in delays to definite diagnosis. In confronting the disease, early diagnosis and appropriate, timely therapeutic intervention are critical factors in ensuring favorable long-term outcomes. The availability of reliable biomarkers could radically alter our management of MS at critical phases of the disease spectrum. Identification of markers that could predict the development of MS in high-risk populations would allow for intervention strategies that may prevent evolution to definite disease. Work with anti-myelin antibodies and the ongoing analysis of microarray gene expression have thus far not yielded biomarkers that predict future disease development. Similarly, extensive studies with serum and cerebrospinal fluid (CSF) have not yielded a disease-specific and sensitive diagnostic biomarker for MS. Establishment of disease diagnosis always leads to questions about long-term prognosis because in an individual patient the natural history of the disease is clinically unpredictable. Biomarkers that correlate with myelin loss, spinal cord disease, grey matter and subcortical demyelination need to be developed in order to accurately predict the disease course. The bulk of effort in biomarker development in MS has been concentrated in the area of monitoring disease activity. At present, a disease 'activation' panel of CSF biomarkers would include the following: interleukin-6 or its soluble receptor, nitric oxide and nitric oxide synthase, osteopontin, and fetuin-A. Although disease activity in MS is predominantly inflammatory, disease progression is likely to be the result of neurodegeneration. Therefore, the roles of proteins indicative of neuronal, axonal, and glial loss such as neurofilaments, tau, 14-3-3 proteins, and N-acetylaspartate are all under investigation, as are proteins affecting remyelination and regeneration, such as Nogo-A. With the increasing awareness of cognition dysfunction in MS, molecules such as apolipoprotein and proteins in the amyloid precursor protein pathway implicated in dementia are also being examined. Serum biomarkers that help monitor therapeutic efficacy such as the titer of antibody to beta-interferon, a first-line medication in MS, are established in clinical practice. Ongoing work with biomarkers that reflect drug bioavailability and factors that distinguish between medication responders and nonresponders are also under investigation. The discovery of new biomarkers relies on applying advances in proteomics along with microarray gene and antigen analysis and will hopefully result in the establishment of specific biomarkers for MS.

Quantitative matrix-assisted laser desorption ionization-fourier transform ion cyclotron resonance (MALDI-FT-ICR) peptide profiling and identification of multiple-sclerosis-related proteins

We introduce a matrix-assisted laser desorption ionization-Fourier transform ion cyclotron resonance (MALDI-FT-ICR) method for quantitative peptide profiling, using peak height as a measure for abundance. Relative standard deviations in peak height of peptides spiked over 3 orders of magnitude in concentration were below 10% and allowed for accurate comparisons between multiple sclerosis and controls. Application on a set of 163 cerebrospinal fluid (CSF) samples showed significantly differential abundant peptides, which were subsequently identified into proteins (e.g., chromogranin A, clusterin, and complement C3).

Cerebrospinal fluid biomarkers in multiple sclerosis

In patients with multiple sclerosis (MS) intensive efforts are directed at identifying biomarkers in bodily fluids related to underlying disease mechanisms, disease activity and progression, and therapeutic response. Besides MR imaging parameters cerebrospinal fluid (CSF) biomarkers provide important and specific information since changes in the CSF composition may reflect disease mechanisms inherent to MS. The different cellular and protein-analytical methods of the CSF and the recommended standard of the diagnostic CSF profile in MS are described. A brief update on possible CSF biomarkers that might reflect key pathological processes of MS such as inflammation, demyelination, neuroaxonal loss, gliosis and regeneration is provided.

Cerebrospinal fluid biomarkers of neurodegeneration in chronic neurological diseases

Chronic neurological diseases (CND) like amyotrophic lateral sclerosis (ALS), dementia or multiple sclerosis (MS) share a chronic progressive course of disease that frequently leads to the common pathological pathway of neurodegeneration, including neuroaxonal damage, apoptosis and gliosis. There is an ongoing search for biomarkers that could support early diagnosis of CND and help to identify responders to interventions in therapeutic treatment trials. Cerebrospinal fluid (CSF) is a promising source of biomarkers in CND, since the CSF compartment is in close anatomical contact with the brain interstitial fluid, where biochemical changes related to CND are reflected. We review recent advances in CSF biomarkers research in CND and thereby focus on markers associated with neurodegeneration.

Cerebrospinal fluid brain specific proteins in relation to nitric oxide metabolites during relapse of multiple sclerosis

This study investigated the cerebrospinal fluid (CSF) levels of ferritin, S100B as biomarkers for glial activation and NfH(SM135)--a biomarker of axonal damage--in relation to nitric oxide (NO) metabolites: nitrate and nitrite (NOx) during acute multiple sclerosis (MS) relapse. Thirty-four relapsing-remitting MS (RR-MS) patients during acute relapse and 12 controls were enrolled. Patients were assessed on Expanded Disability Status Scale (EDSS) and underwent lumbar puncture within two weeks following relapse. Twenty patients were available for further follow-up and were assessed on EDSS 6-8 weeks since the relapse onset. The CSF NOx (P<0.0001), NfH(SM135) (P=0.01) and S100B (P=0.009) but not ferritin (P>0.05) were significantly raised in MS group. There was a significant correlation between CSF ferritin and S100B in RR-MS group (P=0.004). CSF NOx did not correlate with S100B and ferritin in study groups. RR-MS patients with detectable NfH(SM135) levels had higher NOx compared with subjects having undetectable NfH(SM135) (P=0.03). In the follow-up study, raised baseline levels of NOx (P=0.016) or NfH(SM135) (P=0.04) inversely correlated with the clinical recovery grade expressed as relative EDSS change between baseline and follow-up. In conclusion, NO metabolites were increased and because of their correlation with a biomarker of axonal degeneration (neurofilaments) and a measure for clinical disability (EDSS), relapse-related nitrosative stress is likely to be relevant to the development of sustained disability in an individual patient.

Cerebrospinal fluid analysis in multiple sclerosis

Although the diagnosis of multiple sclerosis (MS) may be clinically suspect and the magnetic resonance imaging findings compatible, cerebrospinal fluid (CSF) analysis remains mandatory in order to support the diagnosis. This is especially important since our understanding of the defining disease pathogenesis remains incomplete. However, there is no specifically diagnostic CSF test. And until recently, laboratory techniques for CSF analysis had not been rigorously standardized. Unconcentrated CSF without fixative should be used for the determinations of cell count and differential, protein and glucose, lactate, myelin basic protein, and the CSF/serum albumin ratio which is an indicator of blood-CSF barrier disruption. Additionally, CSF immunoglobulin-gamma (IgG) determinations are of major importance and are now included in the MS diagnostic criteria. Testing for oligoclonal IgG bands utilizing isoelectric focusing with IgG immunoblotting, the IgG synthesis rate, and the IgG index should be included. CSF analysis for kappa light chains and IGM may be diagnostically helpful. The search for biomarkers including those possibly present in the CSF which could predict and assess the course as well as response to treatment in a particular MS patient has not yet been successful. CSF immunoglobulin and T-cell/B-cell patterns, soluble HLA class I and II antigens, nitrous oxide metabolites, neurofilament and microtubule components and antibodies, tau protein, 14-3-3-protein, neuronal cell and intercellular adhesion molecules, and chemokines are actively being investigated as MS biomarkers.

Acute axonal damage predicts clinical outcome in patients with multiple sclerosis

The objectives of this study were (1) to determine how cerebrospinal fluid (CSF) neurofilament heavy chain (NfH(SM134) and NfH(SM135)) levels relate to clinical outcome in optic neuritis (ON) and multiple sclerosis (MS) relapse patients treated with high dose oral methylprednisolone; and (2) to correlate neurofilament and myelin basic protein (MBP) concentrations, particularly as the latter was previously associated with clinical disability. Fifty subjects participated in two double-blind, randomized, placebo-controlled clinical trials. Eight/18 patients in the ON trial and 15/32 subjects in the MS attack trial were treated with oral methylprednisolone. In the MS attack trial group, CSF NfH(SM134) and NfH(SM135) measured at week 3 and deltaCSF NfH(SMI34) levels from baseline to week 3 were predictive of clinical outcome at week 8 and 52. In the ON group, no such association was seen. When both groups were combined, baseline CSF NfH(SHM134) and NfH(SM135) correlated positively with baseline enhancing lesion volume (ELV) (r(s) =0.50, P <0.01 and rS =0.53, P <0.01, respectively). Levels of NfH(SM135) at baseline and week 3 also strongly correlated with the MBP concentration. This study supports the view that acute inflammation in ON and MS results in axonal pathology and that the latter has a role in determining functional impairment.

Axonal damage accumulates in the progressive phase of multiple sclerosis: three year follow up study

BACKGROUND

Neurofilament phosphoforms (Nf) are principal components of the axoskeleton released during axonal injury. Cerebrospinal fluid (CSF) levels of Nf phosphoforms might be useful surrogate markers for disability in multiple sclerosis (MS), aid in distinguishing clinical subtypes, and provide valuable prognostic information.

METHOD

Thirty four patients with MS were included in a three year follow up study along with 318 controls with other non-inflammatory neurological diseases. CSF levels of two Nf heavy chain (NfH) phosphoforms (NfH(SMI35), NfH(SMI34)) were quantified at baseline and three year follow up using new ELISA techniques. Levels of NfH phosphoforms, the degree of phosphorylation (NfH(SMI34):NfH(SMI35) ratio), and changes in NfH levels between baseline and follow up (Delta NfH) were related to the clinical phenotype (RR or SP/PP), to three clinical scales (Kurtzke's EDSS, ambulation index (AI), and nine hole peg test (9HPT)), and to progression of disability.

RESULTS

A significantly higher proportion (59%) of patients with SP/PPMS experienced an increase in NfH(SMI35) levels between baseline and follow up compared with those with RRMS (14%, p<0.05). CSF NfH(SMI34) levels at baseline were higher in patients with SP/PP (11 pg/ml) compared with RR (7 pg/ml, p<0.05) and NfH(SMI35) levels were higher at follow up in SP/PP (129 pg/ml) compared with levels below assay sensitivity in RR (p<0.05). NfH(SMI35) correlated with the EDSS (r(s) = 0.54, p<0.01), the AI (r(s) = 0.42, p<0.05), and the 9HPT (r(s) = 0.59, p<0.01) at follow up.

CONCLUSION

The increase in NfH during the progressive phase of the disease together with the correlation of NfH(SMI35) with all clinical scales at follow up suggests that cumulative axonal loss is responsible for sustained disability and that high NfH(SMI35) levels are a poor prognostic sign.