Serological proteome analysis reveals new specific biases in the IgM and IgG autoantibody repertoires in autoimmune polyendocrine syndrome type 1

OBJECTIVE

Autoimmune polyendocrine syndrome type 1 (APS 1) is caused by mutations in the AIRE gene that induce intrathymic T-cell tolerance breakdown, which results in tissue-specific autoimmune diseases.

DESIGN

To evaluate the effect of a well-defined T-cell repertoire impairment on humoral self-reactive fingerprints, comparative serum self-IgG and self-IgM reactivities were analyzed using both one- and two-dimensional western blotting approaches against a broad spectrum of peripheral tissue antigens.

METHODS

Autoantibody patterns of APS 1 patients were compared with those of subjects affected by other autoimmune endocrinopathies (OAE) and healthy controls.

RESULTS

Using a Chi-square test, significant changes in the Ab repertoire were found when intergroup patterns were compared. A singular distortion of both serum self-IgG and self-IgM repertoires was noted in APS 1 patients. The molecular characterization of these antigenic targets was conducted using a proteomic approach. In this context, autoantibodies recognized more significantly either tissue-specific antigens, such as pancreatic amylase, pancreatic triacylglycerol lipase and pancreatic regenerating protein 1α, or widely distributed antigens, such as peroxiredoxin-2, heat shock cognate 71-kDa protein and aldose reductase. As expected, a well-defined self-reactive T-cell repertoire impairment, as described in APS 1 patients, affected the tissue-specific self-IgG repertoire. Interestingly, discriminant IgM reactivities targeting both tissue-specific and more widely expressed antigens were also specifically observed in APS 1 patients. Using recombinant targets, we observed that post translational modifications of these specific antigens impacted upon their recognition.

CONCLUSIONS

The data suggest that T-cell-dependent but also T-cell-independent mechanisms are involved in the dynamic evolution of autoimmunity in APS 1.

High-affinity σ1 protein agonist reduces clinical and pathological signs of experimental autoimmune encephalomyelitis

BACKGROUND AND PURPOSE

Selective agonists of the sigma-1 receptor (σ1 protein) are generally reported to protect against neuronal damage and modulate oligodendrocyte differentiation. Human and rodent lymphocytes possess saturable, high-affinity binding sites for compounds binding to the σ1 protein and potential immunomodulatory properties have been described for σ1 protein ligands. Experimental autoimmune encephalomyelitis (EAE) is recognized as a valuable model of the inflammatory aspects of multiple sclerosis (MS). Here, we have assessed the role of a σ1 protein agonist, containing the tetrahydroisoquinoline-hydantoin structure, in EAE.

EXPERIMENTAL APPROACH

EAE was induced in SJL/J female mice by active immunization with myelin proteolipid protein (PLP)139-151 peptide. The σ1 protein agonist was injected i.p. at the time of immunization (day 0). Disease severity was assessed clinically and by histopathological evaluation of the CNS. Phenotyping of B-cell subsets and regulatory T-cells were performed by flow cytometry in spleen and cervical lymph nodes.

KEY RESULTS

Prophylactic treatment of EAE mice with the σ1 protein agonist prevented mononuclear cell accumulation and demyelination in brain and spinal cord and increased T2 B-cells and regulatory T-cells, resulting in an overall reduction in the clinical progression of EAE.

CONCLUSIONS AND IMPLICATIONS

This σ1 protein agonist, containing the tetrahydroisoquinoline-hydantoin structure, decreased the magnitude of inflammation in EAE. This effect was associated with increased proportions of B-cell subsets and regulatory T-cells with potential immunoregulatory functions. Targeting of the σ1 protein might thus provide new therapeutic opportunities in MS.

Consensus brain-derived protein, extraction protocol for the study of human and murine brain proteome using both 2D-DIGE and mini 2DE immunoblotting

Two-dimensional gel electrophoresis (2DE) is a powerful tool to uncover proteome modifications potentially related to different physiological or pathological conditions. Basically, this technique is based on the separation of proteins according to their isoelectric point in a first step, and secondly according to their molecular weights by SDS polyacrylamide gel electrophoresis (SDS-PAGE). In this report an optimized sample preparation protocol for little amount of human post-mortem and mouse brain tissue is described. This method enables to perform both two-dimensional fluorescence difference gel electrophoresis (2D-DIGE) and mini 2DE immunoblotting. The combination of these approaches allows one to not only find new proteins and/or protein modifications in their expression thanks to its compatibility with mass spectrometry detection, but also a new insight into markers validation. Thus, mini-2DE coupled to western blotting permits to identify and validate post-translational modifications, proteins catabolism and provides a qualitative comparison among different conditions and/or treatments. Herein, we provide a method to study components of protein aggregates found in AD and Lewy body dementia such as the amyloid-beta peptide and the alpha-synuclein. Our method can thus be adapted for the analysis of the proteome and insoluble proteins extract from human brain tissue and mice models too. In parallel, it may provide useful information for the study of molecular and cellular pathways involved in neurodegenerative diseases as well as potential novel biomarkers and therapeutic targets.

The Spectrum of FIP1L1-PDGFRA-Associated Chronic Eosinophilic Leukemia: New Insights Based on a Survey of 44 Cases

Imatinib is the treatment of choice for FIP1L1/PDGFRA (F/P)-associated chronic eosinophilic leukemia (F/P CEL), but its optimal dosing, duration, and possibility of discontinuation are still a matter of debate. A retrospective multicenter study was conducted with 44 F/P CEL patients identified in the French Eosinophil Network and treated with imatinib. The most frequently involved systems were skin (57%), spleen (52%), and lung (45%), and eosinophilic heart disease was observed in 15 patients (34%). Complete hematologic response (CHR) was obtained in all patients, and complete molecular response (CMR) in 95% of patients (average initial imatinib dose, 165 mg/d). For 29 patients the imatinib dose was tapered with a maintenance dose of 58 mg/d (±34 mg/d), allowing sustained CHR and CMR. None of the patients developed resistance during a median follow-up of 52.3 months (range, 1.4-97.4 mo). Imatinib was stopped in 11 patients; 6 of the patients subsequently relapsed, but 5 remained in persistent CHR or CMR (range, 9-88 mo). These results confirm that an initial low-dose regimen of imatinib (100 mg/d) followed by a lower maintenance dose can be efficient for obtaining long-term CHR and CMR. Our data also suggest that imatinib can be stopped in some patients without molecular relapse.

[Singular, systemic, self-reactive IgG patterns related to age: relationship with cerebral malaria susceptibility in exposed subjects residing in an endemic area in Abidjan, Côte-d'Ivoire]

The impact of autoimmunity on malaria-infection evolution reported by various works has led us to compare reactive patterns of self-dependent systemic IgG from 54 patients aged less than 15 years old to those from 46 subjects older than 15 years. These subjects were divided into 34 Plasmodium falciparum asymptomatic carriers (ACs), 30 cases of uncomplicated malaria (UM), and 36 patients suffering from cerebral malaria (CM) living in the same endemic area. The reactivity of the plasma antibodies against human brain tissue extract was assessed by western blotting. Comparative analysis of reactive bands (linear discriminant analysis, LDA) revealed the existence of patterns that distinguish, among the more susceptible subjects aged less than 15 years old, the different clinical forms. In contrast, in less susceptible subjects aged more than 15 years old, the patterns are homogenous and do not allow the separation of these clinical forms. This self-reactive repertoire might be witnessed as an imprint of the clinical tolerance acquired during the years of living in endemic areas. The singularity of this profile under the age of 15 years might have a prognostic value.

Changes Related to Age in Natural and Acquired Systemic Self-IgG Responses in Malaria

Background. Absence of acquired protective immunity in endemic areas children leads to higher susceptibility to severe malaria. To investigate the involvement of regulatory process related to self-reactivity, we evaluated potent changes in auto-antibody reactivity profiles in children and older subjects living in malaria-endemic zones comparatively to none-exposed healthy controls. Methods. Analysis of IgG self-reactive footprints was performed using Western blotting against healthy brain antigens. Plasmas of 102 malaria exposed individuals (MEIs) from endemic zone, with or without cerebral malaria (CM) were compared to plasmas from non-endemic controls (NECs). Using linear discriminant and principal component analysis, immune footprints were compared by counting the number, the presence or absence of reactive bands. We identified the most discriminant bands with respect to age and clinical status. Results. A higher number of bands were recognized by IgG auto-antibodies in MEI than in NEC. Characteristic changes in systemic self-IgG-reactive repertoire were found with antigenic bands that discriminate Plasmodium falciparum infections with or without CM according to age. 8 antigenic bands distributed in MEI compared with NEC were identified while 6 other antigenic bands were distributed within MEI according to the age and clinical status. Such distortion might be due to evolutionary processes leading to pathogenic/protective events.

Susceptibility to experimental autoimmune encephalomyelitis is associated with altered B-cell subsets distribution and decreased serum BAFF levels

B cells possess the ability to regulate either pathogenic or protective events in several autoimmune diseases such as multiple sclerosis (MS) and its experimental model, experimental autoimmune encephalomyelitis (EAE). Given the extensive use of B-cell-targeting treatments, it appears crucial to more precisely define the dual role of B cells in the progression of the disease. In the present study, we explored the impact of EAE induction on the distribution of potential regulatory B-cell subsets (CD5(+) B1a, marginal zone and transitional 2 B cells) over critical time points in the relapsing-remitting EAE model, SJL/J (H2s). The same approach was carried out in B10.S mice that are resistant to EAE induction, (H2s). The comparative data obtained from these experiments showed that the homeostasis of the regulatory B-cell subsets is altered during the EAE preclinical and acute phases. These observations were associated with a distortion of the BAFF response. All these data suggest the existence of a close relationship between B-cell homeostasis, BAFF response and the susceptibility to develop EAE.

Autoimmune polyendocrine syndrome type 1 in north-western France: AIRE gene mutation specificities and severe forms needing immunosuppressive therapies

BACKGROUND

Autoimmune polyendocrine syndrome type 1 (APS1) has been poorly evaluated in France. We focused on the north-western part of the country to describe clinical phenotypes, especially severe forms of the disease, and AIRE gene mutations.

METHODS

Clinical and immunological data were collected, and pathological mutations were identified by DNA sequencing.

RESULTS

Nineteen patients were identified with APS1. Clinical manifestations varied greatly, showing 1-10 components. Mucocutaneous candidiasis, adrenal failure, hypoparathyroidism, alopecia and other severe infections were the most frequent components. Four patients had severe forms, needing immunosuppressive therapy: 2 for hepatitis; 1 for severe malabsorption, and 1 for a T cell large granular lymphocytic leukemia. These therapies were very effective but caused general discomfort. One patient died of septicemia. Four different AIRE gene mutations were identified, and a 13-bp deletion in exon 8 (c.967-979del13) was the most prevalent. There was at least one allele correlating with this mutation and alopecia occurrence (p = 0.003). No novel mutation was detected.

CONCLUSION

APS1 appears to be rare in north-western France. We identified 4 cases with a severe form needing immunosuppressive therapy. The AIRE gene mutations are more like those found in north-western Europe than those found in Finland.

Serum IgG repertoire in clinically isolated syndrome predicts multiple sclerosis

Objective

We previously showed that serum IgG repertoires distinguished multiple sclerosis (MS) patients from healthy subjects and from patients with other inflammatory neurological diseases (OIND). We questioned whether the serum IgG repertoire of patients presenting a clinically isolated syndrome (CIS) could predict MS.

Methods

The global IgG immune responses against brain antigens in sera from 50 CIS patients were evaluated by immunoblotting. The IgG reactivities were compared with those from MS sera ( n = 82), healthy sera ( n = 27), and sera from OIND ( n = 42). A linear discriminant analysis (LDA) defined a score for each individual.

Results

About 78% of scores obtained from CIS patients were located in the “MS area.” During the follow-up (3.5 ± 1.3 years), 28 patients fulfilled the McDonald criteria for MS, 15 patients remained CIS, and 7 patients developed OIND. Among the patients with an LDA score in the “MS area,” 61.5% converted to MS.

Discussion

Our results suggest that a pathological distortion of the self-reactive IgG repertoire occurs early so that immunomodulating treatment should be started as early as possible; they also highlight the early involvement of B cells in the physiopathological process in MS.

[Acute alcoholic intoxication at the hospital: a clinical stake. A prospective study of one year in a general hospital]

INTRODUCTION

Acute alcoholic intoxications (AAI) are frequent in hospitals. This entails some difficulties to caregivers and their clinical approach is little developed in France. This study aimed at estimating perception of alcohol consumption of hospitalized people with positive alcohol blood test at admission. Alcohol measurements were nonsystematic and ordered by a physician. Then this study assessed the role of a clinical interview the day after an AAI.

METHODS

Each person admitted with a positive alcohol blood test was systematically met by a professional in addictology, referring to a procedure in process for 10 years in this hospital. A prospective collection of the data was performed during 2006.

RESULTS

Nine hundred and seventy-three episodes were identified corresponding to 758 persons (78% of men and 22% of women). The average alcohol blood level was 2.06+/-1.18g/L. Eighty-five percent of those patients were admitted and 52% were interviewed. Damage due to alcohol was identified for 69% and a misuse of alcohol for 92% (19% abuse, 73% dependence according to the DSM IV), without significant correlation to alcohol blood level.

CONCLUSION

Blood alcohol level assay at the hospital admission, when the test has been medically recommended, targets a misusing alcohol group of people. These patients need addictologic care, after a first toxicological stage. This study confirms that in such a case a discussion offer is possible and agreed by diseased people. This offer is a first step towards people who could not express explicitly their need for help and constitute an opportunity to care.

Changes in self-reactive IgG antibody repertoire after treatment of experimental autoimmune encephalomyelitis with anti-allergic drugs

We reduced EAE severity by using two anti-allergic drugs. A control group of mice received i.p. injections of PBS as vehicle while a further two groups were treated either with pyrilamine, a histamine receptor 1 antagonist or with CV6209, a platelet activating factor receptor antagonist. Our results showed that the blockade of the responses to both histamine and PAF leads together to a decline in clinical signs of EAE and significant changes in the serum IgG recognition of some healthy brain antigenic targets. We characterized two discriminant antigens: internexin neuronal intermediate filament protein, and malate dehydrogenase 1, which were able to clearly distinguish untreated mice from treated mice. Their role as potent targets in pathogenic and/or neuroprotective processes is discussed.

Characterization of discriminant human brain antigenic targets in neuropsychiatric systemic lupus erythematosus using an immunoproteomic approach

OBJECTIVE

To characterize discriminant human brain antigenic targets in patients with neuropsychiatric systemic lupus erythematosus (NPSLE), using a standardized immunoproteomic approach.

METHODS

Self-IgG reactivity against normal and injured human brain tissues was studied by Western blotting of sera from 169 subjects, 16 patients with NPSLE, 12 patients with SLE without neuropsychiatric manifestations (non-NPSLE), 32 patients with Sjögren's syndrome with or without central nervous involvement, 82 patients with multiple sclerosis, and 27 healthy subjects. A proteomic approach was then applied to characterize discriminant antigens identified after comparisons of all patterns.

RESULTS

The serum self-IgG reactivity patterns against human brain tissue differed significantly between patients with NPSLE and the control groups. Four normal brain antigenic bands were specifically or preferentially recognized by sera from NPSLE patients (p240, p90, p77, and p24). Protein band p240 was characterized as microtubule-associated protein 2B (MAP-2B), p77 as Hsp70-71, and p24 as triosephosphate isomerase. Protein band p90 was not characterized. In contrast, 1 other protein band (p56, characterized as septin 7) was never recognized by sera from NPSLE patients but was recognized by a majority of sera from non-NPSLE patients.

CONCLUSION

Our findings show that the immunoproteomic approach is a reliable method for assessing serum self-IgG reactivities against human brain tissue in NPSLE. Our characterization of some of the identified discriminant antigens, such as MAP-2B, triosephosphate isomerase, and septin 7, suggests that the stability of neuronal microtubules might be involved in the pathophysiology of NPSLE.

Diversified serum IgG response involving non-myelin CNS proteins during experimental autoimmune encephalomyelitis

We sequentially analyzed the serum IgG response against normal mouse brain during experimental autoimmune encephalomyelitis in SJL/J mice injected with CFA, Bordetella pertussis toxin (BPT) and proteolipid protein 139-151 peptide, compared with mice that received CFA and BPT or were uninjected. Dynamic changes were observed from day 0 to day 28 in the 3 groups. Six highly discriminant antigenic bands (kappa=0.974) were identified. Three non-myelin proteins were characterized (mitochondrial aconitase hydratase 2, phosphoglycerate mutase 1, brain specific pyruvate deshydrogenase). The IgG response against two of them was less frequent in EAE whereas it was associated with multiple sclerosis in our previous work.

New insights into cell responses involved in experimental autoimmune encephalomyelitis and multiple sclerosis

Animal models of autoimmune diseases such as experimental autoimmune encephalomyelitis (EAE) are inflammatory demyelinating diseases which comprise a heterogeneous group of disorders that affect the peripheral and central nervous systems. EAE presents close similarities with multiple sclerosis (MS), a chronic inflammatory disease affecting central nervous system (CNS) white matter. Many studies have shown EAE to be a particularly useful animal model for the understanding of both the mechanisms of immune-mediated CNS pathology and the progressive clinical course of multiple sclerosis. Previous data has underlined the importance of CD4+ T cell involvement in mediating the autoimmune processes associated with the destruction of myelin and the role of the T helper 1 (Th1) pattern of cytokine secretion. However, EAE studies have also demonstrated that other cells involved in innate and/or adaptive immune responses may also play a critical role in the early and progressive events of the immune reaction leading to inflammation and CNS damage. In this review, we present such new data and discuss their potent implication for future new therapeutical approaches.

New antigenic candidates in multiple sclerosis: Identification by serological proteome analysis

Myelin antigen targets that are clearly associated with pathogenic events in multiple sclerosis (M.S.) patients remain to be defined. We recently demonstrated that the analysis of global IgG antibody response against human brain antigens using one-dimensional (1-D) immunoblotting, allowed us to discriminate M.S. patients from controls (both healthy subjects and patients with Sjögren's syndrome). Additionally, this approach also differentiated the three clinical forms of M.S. Indeed, 42 brain antigenic bands (26 from healthy brain and 16 from the M.S. brain) showed the discriminant IgG immune responses. The aim of our study was to characterize the 26 discriminant antigenic bands detected in healthy brain. Protein identification was successively performed by 1-D and two-dimensional (2-D) immunoblottings using sera from 18 M.S. patients, followed by mass spectrometry (MS) analysis and a database search. One hundred and two antigenic spots were then detected on 2-D immunoblots, with M.S. sera against healthy brains. Sixty-four spots were successfully matched with 2-D Coomassie brillant blue stained gels, which were further selected for MS analysis and annotated leading to the identification of 14 of the 26 discriminant antigens. Thus, serological proteome analysis may provide a useful tool for the identification of potentially new M.S.-associated antigens, whose relevance to physiopathological events remains to be defined.

Evaluation of anti-citrullinated filaggrin antibodies as hallmarks for the diagnosis of rheumatic diseases

BACKGROUND

Anti-filaggrin antibodies (AFA) are among the most specific antibodies for rheumatoid arthritis, so procedures for their detection should be included in early biological diagnoses. AFA can be detected by indirect immunofluorescence (anti-keratin antibodies, AKA) or by new enzyme immunoassays (EIA). Their comparative performance needs to be established.

OBJECTIVE

To compare these technical procedures to optimise the serological diagnosis of rheumatoid arthritis.

METHODS

Results obtained using AKA and EIA were compared in 271 sera from 140 patients with rheumatoid arthritis at various stages, 98 patients with other autoimmune diseases, and 33 healthy subjects. EIA were successively undertaken with citrullinated linear filaggrin peptide (home made EIA) or cyclic citrullinated peptide (CCP2, commercial kits). Rheumatoid factor (RF) was assessed by EIA in all patients.

RESULTS

Anti-CCP2 kits showed the best sensitivity and specificity (65% and 96%, respectively). Among the 140 patients with rheumatoid arthritis, those with very recent disease (less than six months' duration, n = 21) were studied as a separate group. In this group, the sensitivity of anti-CCP2 kits decreased to approximately 50%. Nevertheless this assay remained the most accurate when compared with AKA or home made EIA using linear filaggrin peptides. The combination of anti-CCP2 and RF only slightly increased the sensitivity of the diagnosis of very early rheumatoid arthritis.

CONCLUSIONS

Kits using citrullinated cyclic peptides (CCP2) were more suitable than either AKA or EIA using linear filaggrin peptides for the diagnosis of early rheumatoid disease.

Autoantibodies against alpha-fodrin in Sjögren's syndrome with neurological manifestations

OBJECTIVE

To investigate the diagnostic value of autoantibodies against alpha-fodrin in patients with Sjögren's syndrome (SS) with neurological manifestations compared to SS patients without neurological manifestations, a control group, and patients with other neurological autoimmune diseases including systemic lupus erythematosus (SLE) with neurological manifestations and multiple sclerosis (MS).

METHODS

We evaluated alpha-fodrin autoantibodies in 31 patients with SS with neurological manifestations, 53 SS patients without neurological symptoms, 38 patients with SLE, 60 with MS, and 160 controls.

RESULTS

Twenty of the 31 SS patients with neurological manifestations (64.5%) had an increased concentration of IgA and/or IgG anti-alpha-fodrin. This was not statistically different from that of SS patients without neurological symptoms (73.6%), but was higher than the number with SSA/SSB antibodies, which were found in 15 (48%) of our SS patients without neurological manifestations. When the results of the 2 tests were combined, 28 of the 31 (90.3%) patients had positive autoantibodies (alpha-fodrin and/or SSA/SSB). Alpha-fodrin antibodies were increased in 8 (13.3%) of the 60 patients with MS, in 6 (15.7%) of 38 patients with SLE, and in 10 (6.3%) of 160 controls.

CONCLUSION

Our results confirm that alpha-fodrin antibodies are an additional diagnostic tool for SS. This test is of particular interest for patients with SS with neurological manifestations, in whom anti SSA/SSB antibodies are less frequently found.

Distortion of the Self-Reactive IgG Antibody Repertoire in Multiple Sclerosis as a New Diagnostic Tool

To date, none of the myelin-associated Ag targets definitively discriminates between the immune response observed in multiple sclerosis (MS) patients and healthy subjects. However, it has been shown recently that analysis of global immune Ab profiles such as natural autoantibody reactivities can help to distinguish between normal individuals and patients suffering from various immune diseases. The aim of our study was to compare the global IgG immune response against brain self-Ags in sera from 82 MS patients and 27 healthy subjects. The analysis of the immune profiles was performed by Western blotting, and data were subjected to linear discriminant analysis. Particular patterns of IgG reactivity were found in healthy subjects, Sjögren patients, and MS patients. Moreover, this approach separated the three clinical forms of MS with a high concordance rate with the clinical data (kappa value, 77.8%). Our study suggests, for the first time, that serum IgG Ab repertoires are able to distinguish MS patients. In addition, our data suggest that patterns of IgG reactivity could model the pathological processes underlying the various forms of MS. Further characterization of such discriminant Ags could provide useful information regarding their potent role in pathogenesis or regulatory processes in MS.

Interferon beta in multiple sclerosis: relationship between sustained serum IgG levels and clinical outcome

We investigated the effects of interferon beta-1a (IFN beta-1a) on specific response towards two immunodominant MBP peptides and on global production of IgG. We evaluated 54 sera from multiple sclerosis (MS) patients at baseline and 1 year after treatment. We did not observe any modification of immune response to the MBP peptides but we noted a significant decrease in mean IgG concentrations in patients with progression of the disease but not in stable patients. These results suggest that IFN beta1a restores or maintains a beneficial immune response.

IgG reactivity against citrullinated myelin basic protein in multiple sclerosis

An increased level of citrullinated myelin basic protein (MBP-C8) has been reported in the brains of multiple sclerosis (MS) patients. However, the involvement of the immune response to post-translational modified MBP in the pathophysiology of MS remains speculative. The aim of this study was to compare the levels of immunoglobulin G antibodies to several MBP epitopes, before and after citrullination, in the cerebrospinal fluid (CSF) and sera of MS patients using enzyme-linked immunosorbent assay (ELISA). We analyzed antibody reactivity against various MBP-peptides in the CSF and sera of 60 MS patients, and 30 patients with other neurological diseases (OND) as controls. The peptides tested were: MBP(75-98) (peptide 1), native (peptide 2) and citrullinated (peptide 3) MBP(108-126) (ARG(122)-->Cit(122)), and native (peptide 4) and citrullinated (peptide 5) MBP(151-170) (ARG(159, 170)-->Cit(159, 170)). All selected peptides could support an immune reactivity in CSF and sera of MS and OND patients. A higher reactivity against peptide 4 was found in the CSF of MS patients compared with OND patients (P<0.0001), but not against citrullinated peptides (peptides 3 and 5). However, we observed that the citrullination state of peptide 2 modified the patterns of immune reactivity more markedly in MS patients (P<0.0001) than in OND patients (P<0.02). Although some MBP epitopes could be a potential target in MS, our data did not demonstrate any difference of antibody response to MBP peptides in their citrullinated forms.

Molecular analysis of endogenous retrovirus HRES-1: identification of frameshift mutations in region encoding putative 28-kDa autoantigen

A possible involvement of HTLV-1-related endogenous sequence 1 (HRES-1) in autoimmune diseases has been recently reported. In primate cells, PCRs and RT-PCRs using specific primers reveal the presence and the transcription of gag-related sequences. However antisera generated against selected HRES-1 peptides failed to detect a 28-kDa protein deduced from the translated gag ORF and described previously. Such discordant results led us to perform DNA cloning and sequencing of LTR- and gag-related nucleotidic fragments. Repeated sequence analyses on distinct samples revealed frameshift mutations in the gag and LTR ORFs. Our sequence analyses detected a stop codon in the gag-related ORF, which is inconsistent with the expression of a 28-kDa protein. Instead of the two ORFs previously found, our gag-related region contained three ORFs. One of them demonstrated higher nucleotidic and peptidic homologies with the p19 gag of HTLV-I. However, the molecular analyses of our new sequence did not show evidence of potent translation capacities.

Long-term assessment of a sanitary education and lumbar rehabilitation program for health care workers with chronic low back pain at the University Hospital of Lille

A back school was established in 1992 at the University Hospital of Lille (France) for employees with low back pain. We report its medical and socioeconomic benefits with a mean time to follow-up of 4 years. Our retrospective study included 108 health care workers and provides objective data (absenteeism, use of health care) and subjective information (progression of pain and disorder, social and professional impact) before training and a mean of 4 years after training. We found that 92% of the participants were satisfied with the training and that back pain had regressed or resolved for 55% of them. Both the frequency and duration of pain had decreased significantly. Seventy percent continue to apply the advice they received in their everyday life. Dealing with the problems specific to professional activities contributed to reduce the strain experienced on the job by the health care workers and improved their satisfaction at work. Global absenteeism was reduced by 57.8%, whereas it was reduced by 33% for back pain alone 4 years after implementing this program. Our study provides evidence of the positive impact of this type of training on the way back pain is perceived and on everyday life. The assessment of the cost/efficiency ratio completes the list of durable benefits reported here.

Tau and apo E in CSF: potential aid for discriminating Alzheimer's disease from other dementias

To evaluate the usefulness of tau proteins as biological markers in the diagnosis of dementia of the Alzheimer type (DAT), we analyzed the concentration of tau proteins in 253 cerebrospinal fluid (CSF) samples from patients with or without neurological disorders. Our study showed a significant increase of the mean CSF tau concentration in DAT patients compared with that from non-DAT patients. Interestingly, a significative decrease of CSF tau in patients with frontotemporal dementia was found. We also observed a positive correlation between the CSF-tau concentration and the number of apoepsilon4 alleles. The CSF apolipoprotein E concentration was evaluated and revealed no variation between the groups, although we observed a significant correlation between CSF tau and apolipoprotein E in DAT patients.

Different distribution of phosphorylated tau protein isoforms in Alzheimer's and Pick's diseases

Tau proteins aggregate into different neuronal inclusions in several neurodegenerative disorders. In Alzheimer's disease (AD), hyperphosphorylated Tau from paired helical filaments (PHF) of neurofibrillary tangles, named PHF-Tau, have an electrophoretic profile with four main bands (Tau 55, 64, 69, 74 kDa). In Pick's disease, phosphorylated Tau from Pick bodies are made of two major components (Tau 55, 64 kDa) and a minor 69 kDa. Here we show, using specific antibodies against translated exon 2, 3 or 10 of Tau isoforms, that the set of Tau isoforms engaged in the most insoluble part of PHF in AD is made of Tau isoforms with exon 10 while they are lacking in phosphorylated Tau from Pick's disease. Our results suggest that specific sets of Tau isoforms distinguish between typical neuronal inclusions.

Two-dimensional characterization of paired helical filament-tau from Alzheimer's disease: demonstration of an additional 74-kDa component and age-related biochemical modifications

PHF-tau proteins are the major components of the paired helical filament (PHF) from Alzheimer's disease (AD) neurofibrillary lesions. They differ both qualitatively and quantitatively in their degree of phosphorylation when compared with native tau proteins. However, little is known about the extent and heterogeneity of phosphorylated sites or the isoform composition and the isoelectric variants of PHF-tau. Therefore, we have characterized PHF-tau proteins from cortical brain tissue homogenates of 13 AD patients using two-dimensional gel electrophoresis. Whatever the topographical origin of brain tissue homogenates, PHF-tau proteins shared the same two-dimensional gel electrophoresis profile made of a tau triplet of 55, 64, and 69 kDa. A 74-kDa hyperphosphorylated tau component was detected particularly in the youngest and most severely affected AD patients. This additional component of hyperphosphorylated tau was shown to correspond to the longest brain tau isoform. Furthermore, the isoelectric points of PHF-tau from older AD patients were significantly more basic, indicating a lower degree of phosphorylation. These results show that the severity of neurofibrillary degeneration of AD is modulated by age.

Relevance of the quantification of apolipoprotein E in the cerebrospinal fluid in Alzheimer's disease

Apolipoprotein E (Apo E), one of the major structural and functional apolipoproteins, has recently been implicated in the pathogenesis of Alzheimer's disease (AD). Several studies revealed that Apo E4 isoform is associated with the pathogenic process in AD. A significant reduction of cerebrospinal fluid (CSF) Apo E level in AD patients has been reported in two studies. To further investigate the physiopathological significance of such a variation of Apo E concentration in the CSF, we performed a quantification of Apo E by an enzyme linked immunosorbent assay (ELISA). There were no significant differences in CSF Apo E level between AD cases and control subjects or patients suffering from other neurological diseases. Gender, age and Apo E phenotype explained none of CSF Apo E concentration variability.