BACKGROUND: Neurofilaments are the major cytoskeletal components of neurons, and cell injury leads to their release into the surrounding area. The aim of this study was to compare the cerebrospinal fluid (CSF) and serum (S) concentrations of neurofilament light chains (NFLs) and phosphorylated neurofilament heavy chains (pNFHs). METHODS: Neurofilament concentrations were measured in CSF and S samples from 172 patients using three enzyme-linked immunosorbent assays. Excel, Stata version 13, MedCal version 17.9.7., and NCSS 2007 software were used for the statistical analysis. RESULTS: There was a statistically significant correlation between the concentrations of CSF NFL and CSF pNFH (rs = 0.748; n = 89; P < 0.001), but Passing-Bablok regression showed systematic deviation between the values obtained using the two assays. This indicates that the assays were not interchangeable. CSF pNFH and S pNFH concentrations showed low correlation. The kappa statistic showed moderate conformity between CSF pNFH and CSF NFL concentrations (κ = 0.556). CONCLUSIONS: The CSF NFL and CSF pNFH assays gave clinically consistent results that reflected the degree of axonal damage, independent of any particular neurological diagnosis. The S pNFH assays had a lower predictive value due to the low correlation coefficient and the kappa index of the CSF pNFH method.

• Keywords
• axonal damage, cerebrospinal fluid, enzyme-linked immunosorbent assay, neurofilament, neurological disease,
• MeSH
• Analysis of Variance MeSH
• Intermediate Filaments metabolism   MeSH
• Middle Aged MeSH
• Humans MeSH
• Nervous System Diseases blood   diagnosis   metabolism   MeSH
• Neurofilament Proteins blood   cerebrospinal fluid   metabolism   MeSH
• Regression Analysis MeSH
• Check Tag
• Middle Aged MeSH
• Humans MeSH
• Male MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Comparative Study MeSH
• Names of Substances
• neurofilament protein H MeSH Browser
• neurofilament protein L MeSH Browser
• Neurofilament Proteins MeSH

Antibodies have different avidities that can be evaluated using modified enzyme-linked immunosorbent assay (ELISA) techniques. We determined levels and avidities of antibodies to light (NFL) and medium (NFM) subunits of neurofilaments and tau protein in serum and cerebrospinal fluid (CSF) from 26 patients and anti-tau antibody levels and their avidities in 20 multiple sclerosis (MS) patients and 20 age- and sex-matched controls. Each sample was analyzed using both standard ELISA and also using a similar ELISA protocol with the addition of urea. The avidities of anti-neurocytoskeletal antibodies were higher in the CSF than those in serum (anti-NFL, p < 0.0001; anti-tau, p < 0.01; anti-NFM, n.s.). There was no relationship between avidities in serum and CSF for individual anti-neurocytoskeletal antibodies. We did not observe the relationship among the avidities of various anti-neurocytoskeletal antibodies. The avidities of anti-tau antibodies in the CSF were significantly higher in the MS patients than those in the controls (p < 0.0001). The study demonstrates the differences in avidities of CSF or serum neurocytoskeletal antibodies measured as the urea resistance by ELISA method. Avidity determination of anti-neurocytoskeletal antibodies could contribute to the evaluation of the immunological status of patients.

• MeSH
• Antibody Affinity MeSH
• Adult MeSH
• Immunoglobulin G blood   cerebrospinal fluid   immunology   MeSH
• Middle Aged MeSH
• Humans MeSH
• Neurofilament Proteins immunology   MeSH
• tau Proteins immunology   MeSH
• Antibodies, Anti-Idiotypic blood   cerebrospinal fluid   immunology   MeSH
• Multiple Sclerosis blood   cerebrospinal fluid   immunology   MeSH
• Aged MeSH
• Check Tag
• Adult MeSH
• Middle Aged MeSH
• Humans MeSH
• Male MeSH
• Aged MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Comparative Study MeSH
• Names of Substances
• Immunoglobulin G MeSH
• neurofilament protein L MeSH Browser
• neurofilament protein M MeSH Browser
• Neurofilament Proteins MeSH
• tau Proteins MeSH
• Antibodies, Anti-Idiotypic MeSH

BACKGROUND: Antibodies against tau protein indicate an interaction between the immune system and the neurocytoskeleton and therefore may reflect axonal injury in multiple sclerosis (MS). METHODOLOGY/PRINCIPAL FINDINGS: The levels and avidities of anti-tau IgG antibodies were measured using ELISA in paired cerebrospinal fluid (CSF) and serum samples obtained from 49 MS patients and 47 controls. Anti-tau antibodies were significantly elevated intrathecally (p<0.0001) in the MS group. The CSF anti-tau antibody levels were lower in MS patients receiving therapy than those without treatment (p<0.05). The avidities of anti-tau antibodies were higher in the CSF than in the serum (MS group p<0.0001; controls p<0.005). Anti-tau avidities in the CSF were elevated in MS patients in comparison with controls (p<0.05), but not in serum. CONCLUSIONS: MS patients have higher levels of intrathecal anti-tau antibodies. Anti-tau antibodies have different avidities in different compartments with the highest values in the CSF of MS patients.

• MeSH
• Antibody Affinity immunology   MeSH
• Adult MeSH
• Middle Aged MeSH
• Humans MeSH
• Spinal Cord immunology   pathology   MeSH
• tau Proteins immunology   MeSH
• Antibodies, Anti-Idiotypic blood   cerebrospinal fluid   MeSH
• Multiple Sclerosis blood   cerebrospinal fluid   immunology   therapy   MeSH
• Case-Control Studies MeSH
• Check Tag
• Adult MeSH
• Middle Aged MeSH
• Humans MeSH
• Male MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• tau Proteins MeSH
• Antibodies, Anti-Idiotypic MeSH