Increased prevalence of and gene transcription by Chlamydia pneumoniae in cerebrospinal fluid of patients with relapsing-remitting multiple sclerosis

Chlamydia pneumonia infection and risk of multiple sclerosis: A meta-analysis

BACKGROUND

The role of infectious agents, including Chlamydia pneumoniae (Cpn), in the development of multiple sclerosis (MS), is still a matter of major contention.

OBJECTIVE

This meta-analysis study aimed to assess the actual involvement of Cpn in MS development.

METHODS

We undertook a search of international scientific databases to identify eligible studies. We used a random-effects meta-analysis model (REM) to generate the pooled odds ratio (OR) and 95% confidence intervals (CIs). Heterogeneity was calculated using the I2 statistic. Sensitivity and subgroup analyses were applied to assess the effects of study characteristics and socio-demographic variables on the pooled OR.

RESULTS

We identified 37 studies comprising 51 datasets that satisfied the inclusion criteria. Considering diagnostic methods for Cpn, 26 and 25 datasets used PCR- and serological-based methods, respectively. In PCR-based datasets, REM showed a significant positive association between Cpn infection and the development of MS (OR, 5.29; 95% CI, 3.12-8.97), while a non-significant positive association was achieved in serological-based datasets (OR, 1.34; 95% CI, 0.88-2.03). In subgroup analyses on PCR-based datasets, results were significant for both CSF (OR, 5.70) and serum (OR, 4.84) samples; both healthy (OR, 16.11) and hospital-based (OR, 2.88) controls; and both moderate (OR, 5.14) and high (OR, 5.48) quality studies. In serological-based datasets, only those that used CSF samples yielded significant results (OR, 3.41).

CONCLUSIONS

Our findings verify the significant positive relationship between Cpn infection and MS. We advocate prospective cohort studies with lifelong follow-ups and also experimental studies to better understand the role of Cpn in MS development.

A prolonged antibiotic protocol to treat persistent Chlamydophila pneumoniae infection improves the extracranial venous circulation in multiple sclerosis

Objective Chronic cerebrospinal venous insufficiency (CCSVI) is a condition associated with multiple sclerosis (MS). One mechanism that has been proposed is that the venous obstructions found in MS are due to a chronic persistent venulitis caused by the intra-cellular bacterial parasite, Chlamydophila pneumoniae (Cpn). The objective of the current study is to determine the effect of a combined antibiotic protocol (CAP) on the venous flow in MS patients as measured by a quantitative duplex ultrasound examination (QDUS). Method A non-randomised before-after cohort study was conducted to investigate differences in blood flow volumes pre and 6-months post antibiotic treatment for Cpn infection. Flow volume data were measured by QDUS across affected and unaffected sides from multiple veins segments, including internal jugular vein (IJV) segments J2 and J3, and vertebral vein (VV), as well as global arterial blood flow (GABF). Results 91 patients were included in the study. 64 (70%) were found to have positive Cpn serology. There was a statistically significant post-treatment difference seen for the affected side of Cpn infected patients (mean difference = 56 mL/min, p = 0.02). There was a non-significant increase seen for the affected side of uninfected patients (mean difference = 23 mL/min, p = 0.2). The difference in these effects (34 mL/min) was not statistically significant ( p = 0.3). The mean flow rate decreased in the unaffected side for both infected (-27 mL/min, p = 0.5) and uninfected patients (-69 mL/min, p = 0.01). There was a statistically significant post-treatment increase in GABF for the infected patients (mean difference = 90 mL/min, p = 0.02) and a difference of 76 mL/min for non-infected patients ( p = 0.01). Conclusion A CAP appears to improve the extra-cranial circulation in patients diagnosed with MS. This effect is statistically significant in patients with positive Cpn serology, although patients with negative Cpn serology also show some benefit, betraying a lack of specificity of this effect.

Chlamydia pneumoniae infection and the risk of multiple sclerosis: a meta-analysis

We conducted a meta-analysis of studies comparing the presence of Chlamydia pneumoniae (Cpn) between multiple sclerosis (MS) patients and other neurological diseases patients or healthy controls. We identified 26 studies with 1332 MS patients and 1464 controls. Using random-effects methods, MS patients were found more likely to have detectable levels of Cpn DNA (OR = 3.216; 95% CI: 1.204, 8.585) in their cerebrospinal fluid, and intrathecally synthesized immunoglobulins (OR = 3.842; 95% CI: 1.317, 11.212), compared to other patients with neurological diseases. There is no evidence for increased levels of serum immunoglobulins (OR = 1.068; 95% CI: 0.745, 1.530), even though this result is confounded by the presence of studies using normal subjects as controls. Similarly, there is no evidence for association of immunoglobulins against Cpn in the cerebrospinal fluid (OR = 3.815; 95% CI: 0.715, 20.369). Up to 59.7% of the between-studies variability could be explained by the inappropriate matching of cases and controls for gender. In random-effects meta-regressions, adjusting for the confounding effect of gender differences results in stronger and statistically significant associations of MS with detectable levels of Cpn DNA, intrathecally synthesized immunoglobulins and immunoglobulins in the cerebrospinal fluid. Even though the presence of Cpn is clearly more likely in MS patients, these findings are insufficient to establish an etiologic relation.

Bioinformatics evaluation of the possibility of heat shock proteins as autoantigens in multiple sclerosis based on molecular mimicry hypothesis

Molecular mimicry is the explanatory link between the heat shock proteins (HSPs) of infectious agents and triggering multiple sclerosis. Considering that there are many similarities between self- and bacterial-HSPs, the goal was to investigate a panel of 60- and 70kDa HSPs from a variety of bacteria in order to predict the role of each microorganism in triggering or progression of the disease under the molecular mimicry hypothesis. By clarifying the peptides meeting criteria for cross-reactivity and elucidating the role of each microorganism in MS pathogenesis, it would be easier to suggest more effective treatment and preventive strategies for this disease.

Beyond phylotyping: understanding the impact of gut microbiota on host biology

BACKGROUND

Microbial constituents of the gut microbiome interact with each other and the host to alter the luminal environment and impact development, motility, and homeostasis of the gut. Powerful methods are becoming available to investigate connections between the gut microbiome and human health. While high-throughput sequencing of 16S rRNA genes can be used to identify and enumerate microbes in the gut, advances in several techniques (e.g., metagenomics, metatranscriptomics, metabolomics, and metaproteomics) are providing a clearer view as to the specific activities of the microbiota in the context of functional host-microbe interactions. Testing emergent hypotheses regarding microbial effects on host biology, which arise from analyses of 'Big Data' generated from massive parallel high-throughput sequencing technology and spectroscopic techniques, to guide translational research is an important goal for the future. Insights regarding the fundamental operating principles of the gut microbiota should lay the foundation for rational manipulation of the microbiota to promote human health.

PURPOSE

In this review, we provide an overview of current research on the gut microbiome emphasizing current state-of-the-art technologies, approaches, and directions for improvement of our understanding of the impact of the gut microbiota with specific focus on gastrointestinal motility disorders.

Multiple sclerosis: a chronic infective cerebrospinal venulitis?

The aetiology proposed for the development of chronic cerebrospinal venous insufficiency (CCSVI) associated with multiple sclerosis (MS) has been the presence of congenital truncular venous malformations. However, this hypothesis is not consistent with the epidemiology or geographical incidence of MS and is not consistent with many of the ultrasonographic or radiographical findings of the venous disturbances found in MS patients. However, the probability of a venous aetiology of MS remains strong based on evidence accumulated from the time the disorder was first described. The method used in this review was to search PubMed for all past medical publications related to vascular, venous, haematological, epidemiological, biochemical, and genetic investigations and treatments of MS. Epidemiological and geographical findings of prevalence of MS indicate the involvement of an infective agent. This review of the venous pathology associated with MS describes a hypothesis that the pathogenesis of the venous disease could be initiated by a respiratory infective agent such as Chlamydophila pneumonia, which causes a specific chronic persistent venulitis affecting the cerebrospinal venous system. Secondary spread of the agent would initially be via the lymphatic system to specifically involve the azygos, internal jugular and vertebral veins. The hypothesis proposes mechanisms by which an infective venous vasculitis could result in the specific neural damage, metabolic, immunological and vascular effects observed in MS. The hypothesis described is consistent with many of the known facts of MS pathogenesis and therefore provides a framework for further research into a venous aetiology for the disease. If MS does result from a chronic infective venulitis rather than a syndrome involving congenital truncular venous malformations, then additional therapies to the currently used angioplasties will be required to optimize results.

Chlamydia pneumoniae-specific intrathecal oligoclonal antibody response is predominantly detected in a subset of multiple sclerosis patients with progressive forms

The purpose of this study was to verify the actual involvement of Chlamydia pneumoniae in multiple sclerosis (MS) by the evaluation of its specific intrathecal humoral immune response in MS. We measured by enzyme-linked immunosorbent assay (ELISA) technique cerebrospinal fluid (CSF) and serum levels of anti-C. pneumoniae immunoglobulin G (IgG) in 27 relapsing-remitting (RR), 9 secondary progressive (SP), and 5 primary progressive (PP) MS patients, grouped according to clinical and magnetic resonance imaging (MRI) evidence of disease activity. Twenty-one patients with other inflammatory neurological disorders (OIND) and 21 with noninflammatory neurological disorders (NIND) were used as controls. Quantitative intrathecal synthesis of anti-C. pneumoniae IgG was determined by antibody-specific index (ASI), whereas the presence of C. pneumoniae-specific CSF oligoclonal IgG bands was assessed by antigen-specific immunoblotting. ASI values indicative of C. pneumoniae-specific intrathecal IgG synthesis were present in a small proportion of MS (29.3%), OIND (33.3%), and NIND (4.8%) patients and were significantly more frequent (P < .05) in total MS and in OIND than in NIND and in SP (P < .01) and PP MS (P < .05) than in RR MS. C. pneumoniae-specific CSF-restricted OCB were detected only in three SP, one PP, and one RR MS patients. These findings suggest that an intrathecal production of anti-C. pneumoniae IgG is part of humoral polyreactivity driven by MS chronic brain inflammation. However, an intrathecal release of C. pneumoniae-specific oligoclonal IgG can occur in a subset of patients with MS progressive forms in whom a C. pneumoniae-persistent brain infection may play a pathogenetic role.

Chlamydophila pneumoniae Infection and Its Role in Neurological Disorders

Chlamydophila pneumoniae is an intracellular pathogen responsible for a number of different acute and chronic infections. The recent deepening of knowledge on the biology and the use of increasingly more sensitive and specific molecular techniques has allowed demonstration of C. pneumoniae in a large number of persons suffering from different diseases including cardiovascular (atherosclerosis and stroke) and central nervous system (CNS) disorders. Despite this, many important issues remain unanswered with regard to the role that C. pneumoniae may play in initiating atheroma or in the progression of the disease. A growing body of evidence concerns the involvement of this pathogen in chronic neurological disorders and particularly in Alzheimer's disease (AD) and Multiple Sclerosis (MS). Monocytes may traffic C. pneumoniae across the blood-brain-barrier, shed the organism in the CNS and induce neuroinflammation. The demonstration of C. pneumoniae by histopathological, molecular and culture techniques in the late-onset AD dementia has suggested a relationship between CNS infection with C. pneumoniae and the AD neuropathogenesis. In particular subsets of MS patients, C. pneumoniae could induce a chronic persistent brain infection acting as a cofactor in the development of the disease. The role of Chlamydia in the pathogenesis of mental or neurobehavioral disorders including schizophrenia and autism is uncertain and fragmentary and will require further confirmation.

Qualitative and quantitative detection of Chlamydophila pneumoniae DNA in cerebrospinal fluid from multiple sclerosis patients and controls

A standardized molecular test for the detection of Chlamydophila pneumoniae DNA in cerebrospinal fluid (CSF) would assist the further assessment of the association of C. pneumoniae with multiple sclerosis (MS). We developed and validated a qualitative colorimetric microtiter plate-based PCR assay (PCR-EIA) and a real-time quantitative PCR assay (TaqMan) for detection of C. pneumoniae DNA in CSF specimens from MS patients and controls. Compared to a touchdown nested-PCR assay, the sensitivity, specificity, and concordance of the PCR-EIA assay were 88.5%, 93.2%, and 90.5%, respectively, on a total of 137 CSF specimens. PCR-EIA presented a significantly higher sensitivity in MS patients (p = 0.008) and a higher specificity in other neurological diseases (p = 0.018). Test reproducibility of the PCR-EIA assay was statistically related to the volumes of extract DNA included in the test (p = 0.033); a high volume, which was equivalent to 100 µl of CSF per reaction, yielded a concordance of 96.8% between two medical technologists running the test at different times. The TaqMan quantitative PCR assay detected 26 of 63 (41.3%) of positive CSF specimens that tested positive by both PCR-EIA and nested-PCR qualitative assays. None of the CSF specimens that were negative by the two qualitative PCR methods were detected by the TaqMan quantitative PCR. The PCR-EIA assay detected a minimum of 25 copies/ml C. pneumoniae DNA in plasmid-spiked CSF, which was at least 10 times more sensitive than TaqMan. These data indicated that the PCR-EIA assay possessed a sensitivity that was equal to the nested-PCR procedures for the detection of C. pneumoniae DNA in CSF. The TaqMan system may not be sensitive enough for diagnostic purposes due to the low C. pneumoniae copies existing in the majority of CSF specimens from MS patients.

Chlamydophila pneumoniae DNA and mRNA transcript levels in peripheral blood mononuclear cells and cerebrospinal fluid of patients with multiple sclerosis

Chlamydophila pneumoniae DNA and mRNA transcripts were investigated by PCR and RT-PCR in fresh CSF and PBMC specimens co-cultured in Hep-2 cell lines and collected from 14 patients with definite RR MS and 19 patients with other inflammatory (OIND) and non-inflammatory (NIND) neurological controls. A positivity for C. pneumoniae DNA and mRNA was detected in CSF and PBMCs of 9 RR MS patients (64.2%) with evidence of disease activity, whereas only 3 controls were positive for Chlamydial DNA. These preliminary findings suggest that C. pneumoniae may occur in a persistent and metabolically active state at both peripheral and intrathecal levels in MS, but not in OIND and NIND.

Chlamydia pneumoniae-specific serum immune complexes in patients with multiple sclerosis

The significance of Chlamydia pneumoniae infection in patients with multiple sclerosis (MS) is unclear. We determined the frequency of serum C. pneumoniae-specific immune complexes in patients with MS, neurological (OND) and healthy controls in a blinded, cross-sectional study. C. pneumoniae immune complexes were detected in 24% (38/156) of MS patients, 16% (11/69) of OND and 15% (77/499) of healthy controls. The odds ratio for all MS patients was 3.95 (95% CI: 2.15 to 7.24; P < 0.0001) accounting for the covariates: sex, age, socio-economic status and area of residence. The odds ratio for recently diagnosed MS patients was 4.33 (95% CI: 1.76 to 10.64; P = 0.001). Systemic C. pneumoniae infection is more frequent in MS patients than the healthy population and occurs early in the course of the disease. Multiple Sclerosis 2007; 14: 292—299. http://msj.sagepub.com

Hypothesized role of galactocerebroside and NKT cells in the etiology of multiple sclerosis

According to the molecular mimicry theory, multiple sclerosis (MS) develops when the immune system mistakenly attacks a component of the myelin sheath that is structurally similar to a foreign epitope. The glycolipid galactocerebroside (GalC) is a major component of myelin. As lipids comprise between 70% and 85% of myelin, glycolipids should be investigated as candidate autoantigens in MS. GalC displays broad structural similarities to the Borrelia burgdorferi glycolipid antigen BbGL-2 and to the Sphingomonas antigen GalAGSL. In principle, therefore, these bacteria may induce an autoimmune attack on the myelin sheath. GalC is also structurally similar to natural killer T (NKT) cell ligand alpha-galactosylceramide (alpha-GalCer). Further studies must be performed to clarify the role of GalC in the activation of NKT cells and the development of MS.

Multiple sclerosis: an infectious syndrome involving Chlamydophila pneumoniae

The concept of autoimmune myelinopathy as the primary pathology in multiple sclerosis (MS) is problematic. Vasculitis is seen in the MS brain, both within lesions and in adjacent normal-appearing white matter. The first observation in acute relapse is the sudden, orderly death of oligodendrocytes; inflammatory removal of unsupported myelin seems to be a secondary process. An alternative explanation for these findings is that oligodendrocyte infection might trigger an inflammatory response. Many pathogens, including Chlamydophila (Chlamydia) pneumoniae, have been associated with MS. MS might be an infectious syndrome in which C. pneumoniae has a role in a subset of patients. Mechanisms by which such a cryptic infection could engender relapsing-remitting and, ultimately, progressive disease patterns are discussed.

Antibiotic use and risk of multiple sclerosis

Some reports suggest that bacteria, including Chlamydophila pneumoniae, could be involved in the etiology of multiple sclerosis. If that is true, persons who used antibiotics active against these bacteria, compared with nonusers, might be at lower risk of multiple sclerosis. Using a 1993-2000 case-control study nested in the United Kingdom-based General Practice Research Database cohort, the authors identified 163 multiple sclerosis cases who were followed up for at least 3 years before their first symptoms (the index date). Up to 10 controls matched to the cases by age, sex, general practice, and time in the cohort were selected. Exposure to antibiotics was assessed through computerized medical records. Overall antibiotic use or use of antibiotics against C. pneumoniae was not associated with multiple sclerosis risk. However, use of penicillins in the 3 years before the index date decreased the risk of developing a first attack of multiple sclerosis (odds ratio=0.5, 95% confidence interval: 0.3, 0.9 for those who used penicillins for >or=15 days compared with no use). In conclusion, use of antibiotics active against C. pneumoniae was not associated with a decreased risk of short-term multiple sclerosis. The observed lower risk of multiple sclerosis for penicillin users needs to be confirmed in other populations.