Antibodies In Multiple Sclerosis Patients Research Articles

Anti‐JC virus (JCV) antibody prevalence in the JCV Epidemiology in MS (JEMS) trial

Progressive multifocal leukoencephalopathy (PML) is caused by reactivation of JC virus (JCV) infection due to combined host and viral factors. Anti-JCV antibodies provide a means to assess JCV exposure and stratify PML risk. The reported seroprevalence of anti-JCV antibodies varies from 39% to 91% depending on assay methodology and population studied. A two-step anti-JCV antibody assay (STRATIFY JCV™; Focus Diagnostics, Cypress, CA, USA) detected anti-JCV antibodies in approximately 55% of multiple sclerosis (MS) patients. This study describes the prevalence of anti-JCV antibodies in a large, multinational MS population. This cross-sectional epidemiology study was designed to enroll a minimum of 2000 patients with an MS diagnosis of any type, irrespective of treatment, from Europe, Canada and Australia. Anti-JCV antibody prevalence was determined by STRATIFY JCV; the effects of demographic and disease characteristics were evaluated. A total of 7724 patients from 10 countries participated in the study. Overall anti-JCV antibody prevalence was 57.1% (95% confidence interval 56.0%-58.2%). Seroprevalence was significantly associated with increasing age, gender and country of current residence (P<0.0001). No significant differences in anti-JCV antibody prevalence were associated with MS disease characteristics, including duration and type of MS and number and duration of MS therapies. Overall seroprevalence of anti-JCV antibodies in MS patients from Europe, Canada and Australia was consistent with previous studies using the STRATIFY JCV assay. Anti-JCV prevalence differed significantly by age, gender and country, but no geographical pattern was evident. Disease and treatment type were not associated with differences in anti-JCV antibody status.

Immunoglobulin G1 and immunoglobulin G4 antibodies in multiple sclerosis patients treated with IFNβ interact with the endogenous cytokine and activate complement

A subset of patients with relapsing-remitting multiple sclerosis (RRMS) on therapy with interferon beta (IFNβ) develop neutralising anti-drug antibodies (ADA) resulting in reduced, or loss of, therapeutic efficacy. The aims were to characterise the relative contributions of anti-IFNβ antibody isotypes to drug neutralising activity, ability of these antibodies to cross-react with endogenous IFNβ, to form immune complexes and activate complement. IFNβ-specific ADA were measured in plasma from RRMS patients treated with IFNβ1a (Rebif®). Neutralisation of endogenous and therapeutic IFNβ by ADA was determined by IFNβ bioassay. IFNβ-ADA profile was predominantly comprised of IgG1 and IgG4 antibody isotypes. The contribution of IgG4-ADA towards neutralising activity was found to be minimal. Neutralising IFNβ-ADA blocks endogenous IFNβ activity. ADA interaction with therapeutic IFNβ results in immune complex formation and complement activation. In summary, IgG1 and IgG4 IFNβ-ADA have the ability to neutralise therapeutic and endogenous protein and to activate complement.

Systematic Review and Meta-Analysis of the Sero-Epidemiological Association between Epstein Barr Virus and Multiple Sclerosis

BackgroundA role for Epstein Barr virus (EBV) in multiple sclerosis (MS) has been postulated. Previous systematic reviews found higher prevalences of anti-EBV antibodies in MS patients compared to controls, but many studies have since been published, and there is a need to apply more rigorous systematic review methods.Methodology/Principal FindingsWe examined the link between EBV and MS by conducting a systematic review and meta-analysis of case-control and cohort studies that examined the prevalence of anti-EBV antibodies in the serum of cases and controls. We searched Medline and Embase databases from 1960 to 2012, with no language restriction. The Mantel-Haenszel odds ratios (OR) for anti-EBV antibodies sero-positivity were calculated, and meta-analysis conducted. Quality assessment was performed using a modified version of the Newcastle Ottawa scale. Thirty-nine studies were included. Quality assessment found most studies reported acceptable selection and comparability of cases and controls. However the majority had poor reporting of ascertainment of exposure. Most studies found a higher sero-prevalence of anti-EBNA IgG and anti-VCA IgG in cases compared to controls. The results for anti-EA IgG were mixed with only half the studies finding a higher sero-prevalence in cases. The meta-analysis showed a significant OR for sero-positivity to anti-EBNA IgG and anti-VCA IgG in MS cases (4.5 [95% confidence interval (CI) 3.3 to 6.6, p<0.00001] and 4.5 [95% CI 2.8 to 7.2, p<0.00001] respectively). However, funnel plot examination suggested publication bias for the reporting of the anti-EBNA IgG. No significant difference in the OR for sero-positivity to anti-EA IgG was found (1.4 [95% CI 0.9 to 2.1, p = 0.09]).Conclusion/SignificanceThese findings support previous systematic reviews, however publication bias cannot be excluded. The methodological conduct of studies could be improved, particularly with regard to reporting and conduct of laboratory analyses.

Neutralizing antibodies in multiple sclerosis patients on weekly intramuscular Avonex and biosimilar interferon beta-1a (CinnoVex): Comparing results of measurements in two different laboratories

The appearance of neutralizing antibodies (NAbs) has significant clinical and regulatory consequences for interferons in patients with multiple sclerosis (MS). In a double blind, randomized clinical trial, 84 patients with relapsing remitting MS were enrolled in a 24month study period. Patients were randomly assigned into two groups receiving 30mcg weekly intramuscular injections of either Avonex® (Biogen Idec, USA; 42 patients) or CinnoVex® (CinnaGen Co, Iran; 42 patients). NAb titer was drawn for all patients every 6months and assayed using cytopathic effect assay (CPE) method in Tehran, Iran. To validate the measure done in the Iranian lab, 45 sera with adequate volume and proper storing condition were selected and sent to be rechecked using luciferase reporter gene assay (LA) method for verification in 2 phases in Vancouver, Canada. The cut-off point of 20 TRU was considered for positivity. The two labs found the same three samples to be positive (2 samples from patients received Avonex and 1 received CinnoVex) and 42 to be negative. They had the following values using the Kawade formula as recommended by international standards; 2238, 89 and 302 (TRu/ml) using CPE assay versus 2464, 290 and 169 (TRu/ml) using LA method. As similar results were obtained from CinnoVex or Avonex in our study, we suggest that both medications will have a similar immunogenetic profile.

Characterization of anti-natalizumab antibodies in multiple sclerosis patients

Background: A small proportion of multiple sclerosis (MS) patients treated with natalizumab develop anti-drug antibodies. Objective: The objective of this paper is to characterize the anti-natalizumab antibody response and to investigate differences between persistently and transiently antibody-positive patients. Methods: Screening for anti-natalizumab antibodies was performed using a standardized bridging ELISA. Antibody-positive samples were further analyzed for IgM and IgG1–4 antibodies using ELISA and ImmunoCAP®. Results: Anti-natalizumab antibodies developed in 57 of 1379 (4.1%) treated patients after a median treatment duration of three months. Of the positive patients, 20 (35%) patients reverted to negative, 19 (33%) patients were confirmed persistently positive and 18 (32%) patients were unconfirmed positive. Significantly higher anti-natalizumab antibody levels were detected in persistently compared to transiently positive patients. A cutoff value predicting persistence of antibodies could be determined with a sensitivity of 0.84 and a specificity of 0.80. IgM and IgG4 antibody levels were significantly higher in persistently compared to transiently positive patients, and IgG1, IgG2 and IgG4 increased significantly over time. Conclusions: The level of total anti-natalizumab antibodies in a first positive sample can be used to predict patients at risk for persisting antibody positivity. However, neither IgM nor IgG1–4 antibodies could be used to discriminate between transiently and persistently positive patients.

Clinical relevance of serum natalizumab concentration and anti-natalizumab antibodies in multiple sclerosis

Background: Antibodies against natalizumab have been found in 4.5–14.1% of natalizumab-treated multiple sclerosis (MS) patients. If antibodies persist, they are associated with an adverse effect on treatment response. However, it has proved to be difficult to standardize anti-drug antibody measurements. Objectives: The purpose of this study was to evaluate the clinical and radiological impact of serum natalizumab concentrations and their relation with anti-natalizumab antibodies in MS patients. Methods: In this prospective observational cohort study of 73 consecutive patients treated with natalizumab, we measured serum natalizumab levels and antibody titers before the start of natalizumab treatment, at weeks 12 and 24 and annually after natalizumab initiation. Antibodies against natalizumab were measured by radioimmunoassay and serum natalizumab concentrations using a newly developed enzyme linked immunosorbent assay (ELISA). Magnetic resonance imaging (MRI) scan and clinical evaluation were performed before the start of natalizumab treatment and subsequently every year. Results: Antibodies were detected in 58% of the natalizumab-treated patients. All patients developed their antibodies before week 24. The large majority of these patients reverted to neutralizing antibody (NAb) negative status during follow-up. The presence of antibodies was inversely correlated with serum natalizumab concentration (p<0.001). Only high antibody titers are associated with very low or undetectable serum natalizumab concentration. Both high antibody titers and low serum natalizumab concentrations are associated with relapses and gadolinium-enhancing lesions on MRI. Conclusions: Our data show that both low natalizumab serum concentration and high antibody titers are associated with a lack of efficacy of natalizumab. Measuring serum natalizumab, using a highly specific assay, might lead to more enhanced precision using natalizumab in individual patients.

The role of Acinetobacter in the pathogenesis of multiple sclerosis examined by using Popper sequences

Multiple sclerosis (MS) is an autoimmune neurological disorder. The role of ‘Acinetobacter’ has been examined using the method of Karl Popper and involves nine “Popper sequences”. (1) The frequency of MS increases with latitudes in the Northern Hemisphere, and the reverse is found in the Southern Hemisphere. (2) Sinusitis is found frequently at colder latitudes. (3) Sinusitis occurs frequently in patients with MS. (4) Specific sequences of bovine myelin when injected into experimental animals will produce a neurological disorder resembling MS which is called “experimental allergic encephalomyelitis”. (5) Computer analysis of myelin shows molecular mimicry with sequences found in Acinetobacter. (6) Antibodies to Acinetobacter bacteria are found in MS patients. (7) Acinetobacter bacteria are located on human skin and in the nasal sinuses. (8) IgA antibodies are preferentially elevated in the sera of MS patients, thereby suggesting the trigger microbe is acting across a mucosal surface probably located in the nasal sinuses. (9) Only Acinetobacter bacteria and no other microbes evoke statistically significant titres of antibodies in MS patients. These nine Popper sequences suggest that MS is most probably caused by infections with Acinetobacter bacteria in the nasal sinuses, and this could have therapeutic implications.

Kinetics and incidence of anti-natalizumab antibodies in multiple sclerosis patients on treatment for 18 months

Natalizumab is a monoclonal antibody shown to be highly effective in the treatment of relapsing–remitting multiple sclerosis (RRMS). Patients treated with natalizumab can develop antibodies directed against this agent that may affect the efficacy and safety of the drug. In this observational study, the kinetics of the appearance and the incidence of anti-natalizumab antibodies were followed prospectively for 18 months in a cohort of 64 consecutive patients treated with natalizumab for relapsing MS. Blood samples were drawn immediately before starting natalizumab therapy and each month afterwards. The presence of antibodies against natalizumab was assessed by enzyme-linked immunosorbent assay (ELISA) in all patients. Anti-natalizumab antibodies were detected in nine (14.1%) natalizumab-treated patients, three (4.68%) of whom were transiently positive while six (9.37%) were persistently positive (these patients discontinued natalizumab). All positive titres were observed during the first 4 months of treatment. One patient with a hypersensitivity reaction also had persistent antibodies. We conclude that antibodies against natalizumab develop early, within the first 6 months of therapy with natalizumab. Although no antibodies were detected after 4 months of therapy in this particular study, this does not rule out their development later on in exceptional cases.

Are Corticosteroids Efficacious for Preventing or Treating Neutralizing Antibodies in Multiple Sclerosis Patients Treated With Beta-Interferons?

Persistent, high-titer neutralizing antibodies (NAbs) reduce or eliminate the biologic activity of interferon-beta (IFNB) therapies for multiple sclerosis (MS) and are associated with reduction in efficacy. Most patients who develop NAbs have preceding detectable binding antibodies. There is no consensus on prevention or management of NAb-positive patients but switching to noninterferon therapy and use of immunosuppressive strategies, especially corticosteroids, has been proposed. To evaluate the evidence supporting the efficacy of corticosteroid therapy for (a) reducing the incidence of NAbs; and (b) improving markers of interferon bioavailability, reducing NAbs titers, and improving clinical outcomes in NAb-positive patients with MS receiving IFNB therapy. The objective was addressed through the development of a structured critically appraised topic. This included a case scenario, structured question, search strategy, critical appraisal, results, evidence summary, commentary, and bottom line conclusions. Participants included consultant and resident neurologists, a medical librarian, clinical epidemiologists, and content experts in the fields of neuroimmunology and multiple sclerosis. We selected 4 papers for detailed review, all of which used pulsed methylprednisolone therapy, either alone or in combination with another immunosuppressive therapy. A randomized open-label trial showed that monthly intravenous methylprednisolone initiated at INFB therapy onset was associated with a lower risk of an ever-positive NAb result but was insufficiently sensitive to detect an effect on more clinically meaningful high-titer NAbs. A randomized controlled trial for patients with active disease despite IFNB therapy showed that baseline NAb titers were reduced by subsequent intravenous methylprednisolone treatment, but the incidence of NAbs was too small to assess clinical relevance. Small open-label observational studies suggest that pulse methylprednisolone, alone or in combination with azathioprine, does not restore the bioavailability of IFNB. Pulse methylprednisolone therapy may reduce the risk of developing NAbs (but possibly not high-titer NAbs of clinical importance) when coadministered with newly initiated IFNB therapy. However, current evidence suggests that methylprednisolone therapy does not restore IFNB biologic response in established NAB-positive MS patients.

Gluten Sensitivity in Multiple Sclerosis

Patients with neurological disease of unknown etiology sometimes present with antigliadin and antitissue transglutaminase antibodies. The association between these antibodies and multiple sclerosis has been previously suggested. The purpose of this study was to determine the prevalence of these antibodies in multiple sclerosis patients. We determined the level of serum immunoglobulin A and immunoglobulin G antigliadin and antitissue transglutaminase antibodies in 98 patients with multiple sclerosis. We found a highly significant increase in titers of immunoglobulin G antibodies against gliadin and tissue transglutaminase in the multiple sclerosis patients. Seven patients had a positive IgG AGA, whereas only 2 controls presented positive titers (P = 0.03). Four patients had positive IgG anti-tTG while all the controls tested negative (P = 0.02). However, immunoglobulin A antibodies against gliadin and tissue transglutaminase were not statistically higher in the multiple sclerosis group in comparison to the control group. Our findings support the associations between antibodies against gliadin and tissue transglutaminase to multiple sclerosis. The specific role of these antibodies in the pathogenesis of multiple sclerosis remains uncertain and requires additional research. A gluten free diet should be considered in specific cases of patients who present with gluten antibodies.

Neutralizing antibodies in multiple sclerosis patients treated with 375 μg interferon-β-1b

Background: Neutralizing antibodies (NAbs) to IFN-β may have a detrimental effect on treatment response, but increasing IFN-β dose could reduce their occurrence. The OPTimization of Interferon for MS (OPTIMS) study was a multicenter trial investigating clinical and MRI outcomes with the approved IFN-β-1b dose (250 μg) and a higher dose (375 μg), s.c. every other day. Objective: To analyze the occurrence of NAbs and their effect on clinical and MRI response over a long-term (4-year) follow-up using cross-sectional and longitudinal statistical analysis. Methods: Relapses or disease progression was assessed open-label and MRI scans were performed serially during the first year of the study. Neutralizing antibodies were measured using the MxA protein production neutralization assay. Results: A total of 145 patients with relapsing-remitting multiple sclerosis from 14 centers participated in the study. Neutralizing antibody frequency was negatively associated with MRI treatment response, but no detrimental effect of NAbs on the clinical response was observed. Results obtained using cross-sectional or longitudinal statistical approaches were similar. Over the 4-year period, NAb-positive patients treated with 375 μg had a significantly greater probability of NAb disappearance (hazard ratio: 3.41; 95% confidence interval: 1.78 – 6.43; p < 0.01). Conclusion: Use of an IFN-β-1b dose higher than the currently approved 250-μg dose is associated with an increased probability of NAb disappearance. The OPTIMS study was registered at ClinicalTrials.gov: NCT00473213.

Level of bacterial IgG and IgM antibodies in multiple sclerosis patients

Level of bacterial IgG and IgM antibodies in multiple sclerosis patients

Multiple sclerosis and gluten sensitivity

Objective To compare the frequency of gluten sensitivity in patients with multiple sclerosis (MS) and healthy controls. Patients and Methods The patients were 161 clinically definite MS patients who referred to neurology outpatient clinic of Nemazee Hospital, Shiraz, south of Iran from March 2004 to October 2005. IgG and IgA antigliadin antibodies were measured by enzyme immuno assay (EIA) method. The test of IgA antitranstissue glutaminase (tTG) and duodenal biopsy were carried out in patients with either IgA or IgG AGA positive sera. Antigliadin antibodies were also measured for 166 age and sex matched control group. Results Neither IgG nor IgA antigliadin antibodies showed significant differences between MS patients and controls. Anti-tTG antibody and histopathologic studies were negative in all patients with positive IgG or IgA antigliadin antibodies results. Mean values of IgG and IgA antigliadin antibodies in MS patients with different sex, age, course, and functional systems involvement were not significantly different. Conclusion Gluten sensitivity is not associated with MS in Iran.

Clinical and MRI correlates of autoreactive antibodies in multiple sclerosis patients

Background: Autoreactive antibodies (ARAB) occur more frequently in patients with multiple sclerosis (MS) than in general population and the presence of these antibodies often causes uncertainty regarding the disease course, response to therapy and the diagnosis of MS. Methods: Retrospective analyses of the ARAB, clinical and MRI data of a consecutive patient cohort of MS and clinically isolated syndrome (CIS) patients were conducted. The patients were evaluated for an extensive panel that included various subtypes of antiphospholipid antibody (APLA) including anti-phosphatidylethanolamine (APE), anti-phosphatidylserine (APS), anti-beta-2-glycoprotein-1 (ABGP), anti-cardiolipin (ACA), and several other ARAB such as antinuclear antibody (ANA), anti-neutrophilic cytoplasmic antibodies (ANCA), anti-thyroid peroxidase antibodies (ATA), anti-SS-A, and anti-SS-B antibodies. Quantitative MRI analysis was performed in a subgroup of MS patients measuring T2-lesion volume (LV), T1 black hole LV and brain parenchymal fraction (BPF). Results: A total of 137 patients (mean age 44.7, 84% female) with either MS ( n = 111; age: mean 46.5 ± S.D. 10.3 years; disease duration: mean 13.0 ± S.D. 10.4 years; EDSS: mean 3.2 ± S.D. 1.9) or CIS ( n = 26; age: mean 37.7 ± S.D. 7.8 years; disease duration: mean 1.3 ± S.D. 1.1 years; EDSS: mean 1.0 ± S.D. 0.7) were enrolled. Among MS patients, 82 were RRMS, 26 SPMS, and 3 had PPMS. Seventy-seven (69%) of MS patients showed presence of one or more ARAB. The proportion of MS patients with APLA was 55% (61 patients); IgM subtype was most frequent. Co-occurrence of ACA and APE was more frequent in SPMS as compared to RRMS (15.4% vs. 1.2%, p = 0.012). The proportion of CIS patients with ARAB was 75% with IgM subtype being the most frequent. However, the ARAB in majority of CIS patients (9 out of 14, 64%) were transient on repeated testing. In a subgroup of 62 MS patients, quantitative MRI analysis showed significantly higher T2-LV in patients with positive APLA (15.1 ml for APLA positive vs. 6.75 ml for APLA negative) after correcting for the disease duration ( p = 0.048). The patients with ATA also had significantly higher T2-LV after correction for disease duration (19.0 ml vs.8.5, p = 0.044). Conclusions: ARAB were present in more than two thirds of MS and CIS patients although most of APLA in CIS were transient. The presence of APLA in MS patients was associated with higher T2-LV.

Enolase autoantibodies and retinal function in multiple sclerosis patients

Electroretinographic (ERG) abnormalities have been reported in multiple sclerosis (MS), as well as the presence of circulating antiretinal antibodies. We and others have reported cases of impaired vision and diminished ERGs in MS patients with alpha-enolase autoantibodies. Anti-enolase antibodies have been implicated in autoimmune retinopathy. We performed this study to further explore the relationship between antiretinal antibodies and ERG changes in patients with MS. Patients with clinically definite MS and normal visual acuity were recruited for this study, along with healthy controls. All patients and controls had ERG testing done according to ISCEV standards. Patient and control sera were analyzed for the presence of antiretinal antibodies using Western blot and ELISA techniques, and HLA class II typing was performed using polymerase chain reaction. We found a statistically significant difference between MS patients and controls in the rod-cone b-wave implicit time (p < 0.005). We found autoantibodies against alpha-enolase in 38% of MS patients and 11% of controls (p < 0.02). There was no statistically significant difference between ERG parameters of MS patients with alpha-enolase autoantibodies compared to those without alpha-enolase antibodies. Furthermore, the presence of alpha-enolase did not associate with a particular HLA haplotype. Factors affecting the retina other than alpha-enolase antibodies may account for the delayed rod-cone b-wave implicit times observed in MS patients in this study. Anti-enolase antibodies are likely an epiphenomenon of autoimmune disease, and are not causing retinopathy in MS patients with normal visual acuity. However, the possibility of rare cases of patients with pathogenic alpha-enolase autoantibodies can not be excluded. The pathogenic contribution of these antibodies in MS patients with visual impairment deserves further investigation.

Detection of anti-heat shock protein 90 β (Hsp90β) antibodies in cerebrospinal fluid

Antibodies against heat shock protein 90β (Hsp90β) recognize the antigen on the cell surface of the oligodendrocyte precursor cells and cause a decrease of oligodendrocyte population in cell cultures. These antibodies have been found in patients with multiple sclerosis (MS). This report describes an original and sensitive method to detect anti-Hsp90β antibodies in cerebrospinal fluid (CSF) using a western blot procedure. We have developed the method for autoantibody detection using Hsp90β from cell membrane fraction instead of commercial Hsp90β as antigen. The presence of anti-Hsp90β antibodies in CSF of MS patients may play a pathogenic role in MS, and a large-scale study is needed to establish a possible diagnostic value of these antibodies in MS patients.

The Role of Immune Complexes Consisting of Myelin Basic Protein (MBP), Anti‐MBP Antibodies and Complement in Promoting CD4+ T‐cell Responses to MBP in Health and Multiple Sclerosis

Multiple sclerosis (MS) is an autoimmune condition characterized by degeneration of nerve fibre myelin sheets. A candidate autoantigen, myelin basic protein (MBP), has especially attracted attention. The presence of anti‐MBP antibodies is a predictor of definite MS, but their role in the pathogenesis remains obscure. T cells have long been known to play a pivotal role in the pathogenesis of MS. Recently, an important role for B cells as autoantigen‐presenting cells has been demonstrated in other autoimmune diseases, including rheumatoid arthritis and diabetes. The uptake of MBP by B cells and the presentation of MBP‐derive peptides to T helper (Th) cells by B cells may be promoted by the formation of complement (C) activating immune complexes (ICs) between MBP and natural autoantibodies in healthy individuals and disease‐associated anti‐MBP antibodies in MS patients, respectively. We have investigated the formation of MBP‐containing IC, the binding of MBP to B cells, the MBP‐elicited induction of Th‐cell and B‐cell proliferation and the cytokine production in peripheral blood mononuclear cells (PBMCs) from healthy donors grown in the presence of intact or C‐inactivated serum from healthy donors or patients with MS. While MBP did not induce measurable proliferation of B cells nor CD4+ T cells, we observed the production of TNF‐α, IFN‐γ and IL‐10 by PBMC in response to incubation with MBP in the presence of sera from healthy controls as well as sera from MS patients. By contrast, no production of IL‐2, IL‐4 and IL‐5 was detected. We are currently investigating the capability of MS sera to promote the formation of MBP‐containing IC and thereby enhance the cytokine responses, by virtue of elevated anti‐MBP contents.

Antibodies reactive to heat shock protein 90 induce oligodendrocyte precursor cell death in culture. Implications for demyelination in multiple sclerosis.

Oligodendrocyte precursor cells (OPCs) are extremely efficient at remyelination. These cells persist in the adult human central nervous system and can proliferate. However, the failure to remyelinate is a pathological characteristic of the human demyelinating disease multiple sclerosis (MS), which suggests that these cells are ineffective in this disorder. This paper reports that IgG antibodies in the cerebrospinal fluid (CSF) of MS patients specifically recognize an antigen on OPCs in culture. Control patients were found not to possess these antibodies. The antigen was immunoprecipitated in cell extracts from cultures with purified IgG from MS CSF. Peptide mass fingerprinting identified it as the beta type of heat shock protein 90 (Hsp90). Two-dimensional electrophoresis and immunoblot showed that this antigen in fact corresponds to two specific isoforms of Hsp90beta. Several control assays using monoclonal and polyclonal anti-Hsp90 antibodies confirmed the specific expression of Hsp90 on OPCs. Labeling OPCs in vivo with MS CSF and anti-Hsp90 antibodies and subsequent immunofluorescence confocal microscopy located the antigen on the cell surface. The binding of CSF antibodies from MS patients to the OPC surface led to complement activation and significant extinction of the OPC population. These results suggest that OPCs may be a target of anti-Hsp90 antibodies in MS patients and that this could prevent remyelination.

Treatment with glatiramer acetate induces specific IgG4 antibodies in multiple sclerosis patients

We analysed the humoral immune response to glatiramer acetate (GA, Copaxone) in 20 multiple sclerosis patients treated with GA, 20 patients not treated with GA and 20 normal control subjects. Using an ELISA for detection of total GA-reactive immunoglobulins (all isotypes), all treated patients but also 3/20 untreated and 8/20 healthy subjects scored positive at 1:20 plasma dilutions. At higher dilutions, 5/20 treated patients and two healthy donors had relatively high levels of anti-GA antibodies. Isotype and IgG subclass analysis revealed that the two antibody-positive normal subjects had IgM and small titers of IgG1 or IgG2 antibodies. In contrast, 18 of 20 GA-treated patients, had low but significant titers of GA-reactive IgG4 antibodies. This finding is consistent with the previously described GA-mediated induction of T-helper 2 (TH2)-like regulatory T cells.

Thyroid function and anti-thyroid antibodies in MS patients screened for interferon treatment. A multicenter study

Interferon beta (IFNB) treatment for multiple sclerosis (MS) has been associated with thyroid disorders (TD), in particular in patients with subclinical TD or anti-thyroid (AT) autoantibodies (autoAb) before starting treatment. TD and AT autoAb frequency was reported increased in MS. To determine whether MS patients have subclinical thyroid function abnormalities or anti-thyroid autoimmunity predisposing to develop TD, we performed a prospective multicenter screening of thyroid function and autoimmunity in 152 relapsing–remitting (RR) MS patients selected to receive IFNB treatment and in 437 healthy normothyroidal controls. Thyroid-related hormones and anti-thyroid microsomal antigen (anti-TMA) autoAb were tested with sensitive immunoradiometric or chromatographic assays. Cases were stratified for different progressively decreasing or increasing cutoff values of thyroid-stimulating hormone (TSH) (0.3, 0.2, 0.1, 3 and 5 mIU/l), and odds ratios (OR) with 95% confidence intervals (CI) calculated using logistic regression adjusted for gender, age, and anti-TMA autoAb positivity. The frequency of cases below or above the TSH cutoff values was not significantly different in MS patients and controls, and the risk to have an abnormal TSH level was not significantly increased in MS patients (OR ranging 0.37–0.84; CI, 0.05–3.01), even if anti-TMA autoAb positive (OR ranging 0.35–0.85; CI, 0.04–3.00). Frequencies of subclinical hypothyroidism and of anti-TMA autoAb positivity were, however, trending higher in MS men (ranging 5–7%) than in controls (3%). MS patients do not have an increased risk of subtle thyroid function abnormalities, subclinical TD, or anti-TMA autoAb positivity that may predispose to develop thyroid dysfunction during IFNB treatment. The positive trend for subclinical hypothyroidism and anti-TMA autoAb positivity, however, advises a longitudinal study of thyroid function and autoimmunity during IFNB treatment to see whether patients with baseline subclinical thyroid dysfunction develop clinically significant alteration during treatment.