Evidence that patients with rheumatoid arthritis have asymptomatic 'non-significant' Proteus mirabilis bacteriuria more frequently than healthy controls

Secrets and lies of host-microbial interactions: MHC restriction and trans-regulation of T cell trafficking conceal the role of microbial agents on the edge between health and multifactorial/complex diseases

Here we critically discuss data supporting the view that microbial agents (pathogens, pathobionts or commensals alike) play a relevant role in the pathogenesis of multifactorial diseases, but their role is concealed by the rules presiding over T cell antigen recognition and trafficking. These rules make it difficult to associate univocally infectious agents to diseases' pathogenesis using the paradigm developed for canonical infectious diseases. (Cross-)recognition of a variable repertoire of epitopes leads to the possibility that distinct infectious agents can determine the same disease(s). There can be the need for sequential infection/colonization by two or more microorganisms to develop a given disease. Altered spreading of infectious agents can determine an unwanted activation of T cells towards a pro-inflammatory and trafficking phenotype, due to differences in the local microenvironment. Finally, trans-regulation of T cell trafficking allows infectious agents unrelated to the specificity of T cell to modify their homing to target organs, thereby driving flares of disease. The relevant role of microbial agents in largely prevalent diseases provides a conceptual basis for the evaluation of more specific therapeutic approaches, targeted to prevent (vaccine) or cure (antibiotics and/or Biologic Response Modifiers) multifactorial diseases.

Antibody Cross-Reactivity in Auto-Immune Diseases

Autoimmunity is defined by the presence of antibodies and/or T cells directed against self-components. Although of unknown etiology, autoimmunity commonly is associated with environmental factors such as infections, which have been reported to increase the risk of developing autoimmune diseases. Occasionally, similarities between infectious non-self and self-tissue antigens may contribute to immunological cross-reactivity in autoimmune diseases. These reactions may be interpreted as molecular mimicry, which describes cross-reactivity between foreign pathogens and self-antigens that have been reported to cause tissue damage and to contribute to the development of autoimmunity. By focusing on the nature of antibodies, cross-reactivity in general, and antibody-antigen interactions, this review aims to characterize the nature of potential cross-reactive immune reactions between infectious non-self and self-tissue antigens which may be associated with autoimmunity but may not actually be the cause of disease onset.

Evaluation of Asymptomatic Bacteriuria and Urinary Tract Infection in Patients With Primary Sjögren's Syndrome

Objectives

This study aims to determine the frequency and risk factors of bacteriuria and urinary tract infection (UTI) in patients with primary Sjögren's syndrome (SS) and their differences from healthy individuals and rheumatoid arthritis (RA) patients.

Patients and methods

The study included 107 female primary SS patients (mean age 50.7±11.6 years; range, 23 to 76 years), 53 healthy female control subjects (mean age 46.8±15.5 years; range 21 to 80 years), and 40 females with RA (mean age 51.7±14.2 years; range, 25 to 79 years). Participants were questioned for UTI risk factors and symptoms. Middle stream urine samples were taken and cultured. All participants were examined with urinary symptom questioning survey of American Urological Association (AUA-7).

Results

The urine cultures were positive in 18 primary SS patients (16.8%), eight RA patients (20%), and two healthy controls (3.7%). Escherichia coli, enterococci, Klebsiella, streptococci, and candida were detected in SS patients' cultures. Extended-spectrum beta-lactamase was positive in three cultures. Asymptomatic bacteriuria was not detected in any SS patient. The highest AUA-7 score was determined in SS group (p=0.031). Nineteen SS patients had vaginal dryness symptom and their AUA-7 scores were higher than the rest of the SS group. The risk of UTI development was not different between those who had or did not have vaginal dryness.

Conclusion

Urinary tract infections are seen more often in SS patients rather than normal population, which may be caused by SS' urinary system effects. It is difficult to distinguish between asymptomatic bacteriuria and infection because of the underlying urinary symptoms. Clinicians must be careful in patients receiving immunosuppressive therapy due to the high frequency of UTIs.

Impact of Mediterranean Diet on Disease Activity and Gut Microbiota Composition of Rheumatoid Arthritis Patients

Rheumatoid arthritis (RA) is an autoimmune disorder in which gut and oral microbiota play a crucial role. Diet is a modifiable factor that can influence both microbiota composition and arthritis outcome; previous studies have suggested associations between dietary habits and RA, with contrasting results. We investigate the protective effect of the Mediterranean diet (MD) on disease activity and the gut microbiota profile in RA patients. Sixty consecutive RA patients were enrolled upon filling a validated 14-item questionnaire for the assessment of adherence to the Mediterranean diet (Prevention with Mediterranean Diet-PREDIMED). Then, 16S analysis was employed to explore the gut microbiota within the two cohorts of patients. Patients with high adherence to MD (20) had a significantly lower C-reactive protein (p < 0.037) and disease activity (p < 0.034) than the 40 patients with low/moderate adherence to MD. An inverse association between MD and disease activity was confirmed by multivariate analysis after adjustments for all the different demographic, clinical and serologic variables. A healthier gut microbiota composition was observed in the high adherence group, with a significant decrease in Lactobacillaceae and an almost complete absence of Prevotella copri with respect to the low/moderate adherence group. In conclusion, our findings support the protective role of MD on disease activity and microbiota composition in RA patients, and suggest the feasibility of shifting the habitual diet to modulate the gut microbiota and promote the benefits associated with MD.

Detection of Shigella spp. nucleic acids in the synovial tissue of Tunisian rheumatoid arthritis patients and other forms of arthritis by quantitative real-time polymerase chain reaction

Enterobacterial components in the joints of patients are believed to contribute to a perpetuating inflammation leading to a reactive arthritis (ReA), a condition in which microbial agents cannot be recovered from the joint. At present, it is unclear whether nucleic acids from Shigella spp. are playing a pathogenic role in causing not only ReA but also other forms of arthritis. Quantitative real-time polymerase chain reaction assay (qPCR) is the method of choice for the identification of bacteria within the synovium. The aim of our study was to detect the presence of Shigella spp. nucleic acids in the synovial tissue (ST) of Tunisian arthritis patients. We investigated 57 ST samples from rheumatoid arthritis (RA) n = 38, undifferentiated oligoarthritis (UOA) n = 12, and spondyloarthritis (SpA) n = 7 patients; 5 ST samples from healthy individuals were used as controls. Shigella spp. DNA and mRNA transcripts encoding the virulence gene A (VirA) were examined using an optimized qPCR with newly designed primers and probes. Using qPCR, Shigella spp. DNA was found in 37/57 (65%) ST samples (24/38, i.e., 63.2% of RA, 8/12, i.e., 67% of UOA, and 5/7, i.e., 71.4% of SpA patients). Paired DNA and mRNA were extracted from 39 ST samples, whose VirA cDNA was found in 29/39 (74.4%) patients. qPCR did not yield any nucleic acids in the five healthy control ST samples. The qPCR assay was sensitive and showed a good intra- and inter-run reproducibility. These preliminary findings generated by an optimized, highly sensitive PCR assay underline a potential role of past gastrointestinal infections. In Tunisian patients, a bacterial etiology involving Shigella spp. in the manifestation of arthritic disorders including RA might be more common than expected.

Infectious Agents and Inflammation: The Role of Microbiota in Autoimmune Arthritis

In higher vertebrates, mucosal sites at the border between the internal and external environments, directly interact with bacteria, viruses, and fungi. Through co-evolution, hosts developed mechanisms of tolerance or ignorance toward some infectious agents, because hosts established "gain of function" interactions with symbiotic bacteria. Indeed, some bacteria assist hosts in different functions, among which are digestion of complex carbohydrates, and absorption and supply of vitamins. There is no doubt that microbiota modulate innate and acquired immune responses starting at birth. However, variations in quality and quantity of bacterial species interfere with the equilibrium between inflammation and tolerance. In fact, correlations between gut bacteria composition and the severity of inflammation were first described for inflammatory bowel diseases and later extended to other pathologies. The genetic background, environmental factors (e.g., stress or smoking), and diet can induce strong changes in the resident bacteria which can expose the intestinal epithelium to a variety of different metabolites, many of which have unknown functions and consequences. In addition, alterations in gut permeability may allow pathogens entry, thereby triggering infection and/or chronic inflammation. In this context, a local event occurring at a mucosal site may be the triggering cause of an autoimmune reaction that eventually involves distant sites or organs. Recently, several studies attributed a pathogenic role to altered oral microbiota in rheumatoid arthritis (RA) and to gut dysbiosis in spondyloarthritis (SpA). There is also growing evidence that different drugs, such as antibiotics and immunosuppressants, can influence and be influenced by the diversity and composition of microbiota in RA and SpA patients. Hence, in complex disorders such RA and SpA, not only the genetic background, gender, and immunologic context of the individual are relevant, but also the history of infections and the structure of the microbial community at mucosal sites should be considered. Here the role of the microbiota and infections in the initiation and progression of chronic arthritis is discussed, as well as how these factors can influence a patient's response to synthetic and biologic immunosuppressive therapy.

Role of human microbiome and selected bacterial infections in the pathogenesis of rheumatoid arthritis

Microorganisms inhabiting human body form a complex ecosystem. The mutual influence of the microbiome and the immune system of the host constitute the basis for numerous diseases, e.g. pseudomembranous colitis, inflammatory bowel disease, type 1 diabetes, atopic diseases, obesity, reactive arthritis. New molecular diagnostic methods and multi-center studies may help in understanding of the role of microbiota in health and disease. Rheumatoid arthritis has a multi-faceted etiology, and its causes are not entirely understood. There are indications for the influence of microbiomes of oral cavity, intestines, lungs and urinary tract on the development of rheumatoid arthritis. Interactions between microorganisms and human immune system play role in the pathogenesis of the disease.

Antimicrobial natural product research: A review from a South African perspective for the years 2009-2016

ETHNOPHARMACOLOGICAL RELEVANCE

This review provides information on the antimicrobial research which has taken place on South African natural products for the last eight years (2009-2016). This important field is the backbone of all studies involving the use of medicinal plants against infectious diseases and hence can form the mainstay for future studies.

MATERIALS AND METHODS

All publications within the years 2009-2016 were considered. Exclusion criteria were studies not involving South African medicinal natural products and those publications where full articles could not be accessed. An overview of the most common experimental methods used and new advances in terms of antimicrobial investigations are provided. Disease categories selected for further investigation were skin and wounds, respiratory, gastrointestinal, sexually transmitted and ophthalmic infections amongst others. Alternate natural products and combinations studies were also included.

RESULTS

The minimum inhibitory concentration (MIC) was the most commonly used experimental method to determine antimicrobial activity. Staphylococcus aureus was the most commonly tested skin pathogen and Klebsiella pneumoniae was the most common pathogen implicated in respiratory disorders. Only 20% of gastrointestinal studies included commonly implicated pathogens such as Shigella flexneri and Campylobacter species.

CONCLUSION

Multidisciplinary studies have emerged as a strong support for antimicrobial investigations and show the importance of including toxicity when studying antimicrobial efficacy. Alternate approaches (for example biofilms and quorum sensing) at examining antimicrobial effects are encouraged. Studies on resistant strains require more insight and future recommendations should look at consistent dosing and investigations on compound interactions amongst others.

Seasonality and autoimmune diseases: The contribution of the four seasons to the mosaic of autoimmunity

Autoimmune diseases (ADs) are a heterogeneous groups of diseases that occur as a results of loss of tolerance to self antigens. While the etiopathogeneis remain obscure, different environmental factors were suggested to have a role in the development of autoimmunity, including infections, low vitamin D levels, UV radiation, and melatonin. Interestingly, such factors possess seasonal variation patterns that could influence disease development, severity and progression. Vitamin D levels which reach a nadir during late winter and early spring is correlated with increased disease activity, clinical severity as well as relapse rates in several disease entities including multiple sclerosis (MS), non-cutaneous flares of systemic lupus erythematosus (SLE), psoriasis, and rheumatoid arthritis (RA). Additionally, immunomodulatory actions of melatonin secretion ameliorate the severity of several ADs including MS and SLE. Melatonin levels are lowest during spring, a finding that correlates with the highest exacerbation rates of MS. Further, melatonin is postulated to be involved in the etiopathogenesis of inflammatory bowel diseases (IBD) through it influence on adhesion molecule and therefore transcription factor expression. Moreover, infections can mount to ADs through pro-inflammatory cytokine release and human antigen mimicry. Seasonal patterns of infectious diseases are correlated with the onset and exacerbation of ADs. During the winter, increased incidence of Epstein-Barr virus (EBV) infectious are associated with MS and SLE flares/onset respectively. In addition, higher Rotavirus infections during the winter precedes type 1 diabetes mellitus onset (T1DM). Moreover, Escherichia coli (E. coli) infection prior to primary biliary cirrhosis (PBC) and T1DM disease onset subsequent to Coxachievirus infections are seen to occur during late summer, a finding that correlate with infectious agents' pattern of seasonality. In this review, the effects of seasonality on the onset, relapses and activity of various ADs were discussed. Consideration of seasonal variation patterns of ADs can possibly provide clues to diseases pathogenesis and lead to development of new approaches in treatment and preventative care.

Complement activation by Proteus mirabilis negatively charged lipopolysaccharides

Proteus mirabilis strains are human pathogens responsible for urinary tract infections and bacteremias and may be involved in rheumatoid arthritis. Lipopolysaccharide (LPS, bacterial endotoxin), the major component of the cell wall, is one of the virulence factors of Proteus. In the presented studies, we have investigated complement activation by LPSs isolated from P. mirabilis O10, O23, O30, and O43 strains, which differ in the number of negative COO— groups on their polysaccharide components. Four P. mirabilis strains studied were sensitive to complement-mediated killing, despite complement binding by their LPSs. The optimal complement binding by LPSs was detected in serum with functional assays for both the classical and alternative pathways.

Complement activation in 80% serum by the smooth, uronic acid, and hexosamine containing P. mirabilis LPSs was not critically determined by the structure of their O-chain polysaccharides. One of four LPSs used as a model, P. mirabilis O10 LPS, fragmented C3 in an LPS dose- and time-dependent manner. It was detected by crossed-immunoelectrophoresis and capture ELISA with anti-C3c antibodies. The lower complement activation by O23 LPS correlates with its reduced C3 fragmentation, compared with three other Proteus LPSs studied. Rabbit anti-O antibodies enhanced the complement binding and factor C3 fragmentation by O10, O23, O30, and O43 P. mirabilis LPSs.

The potential of selected Australian medicinal plants with anti-Proteus activity for the treatment and prevention of rheumatoid arthritis

Background:

A wide variety of herbal medicines are used in indigenous Australian traditional medicinal systems to treat rheumatoid arthritis (RA) and inflammation. The current study was undertaken to test the ability of a panel of Australian plants with a history of the ethnobotanical usage in the treatment of inflammation for the ability to block the microbial trigger of RA.

Materials and Methods:

One hundred and six extracts from 40 plant species were investigated for the ability to inhibit the growth of the bacterial trigger of RA (Proteusmirabilis). The extracts were tested for toxicity in the Artemia nauplii bioassay. The most potent inhibitor of P.mirabilis growth was further analyzed by reversed-phase high performance liquid chromatography (RP-HPLC) coupled to high accuracy time-of-flight (TOF) mass spectroscopy.

Results:

Sixty-five of the 106 extracts tested (61.3%) inhibited the growth of P. The Aleurites moluccanus, Datura leichardtii, Eucalyptus major, Leptospermum bracteata, L. juniperium, Macadamia integriflora nut, Melaleuca alternifolia, Melaleuca quinquenervia, Petalostigma pubescens, P. triloculorae, P. augustifolium, Scaevola spinescens, Syzygiumaustrale, and Tasmannia lanceolata extracts were determined to be the most effective inhibitors of P. mirabilis growth, with minimum inhibitory concentration (MIC) values generally significantly below 1000 μg/ml. T. lanceolata fruit extracts were the most effective P. mirabilis growth inhibitors, with a MIC values of 11 and 126 μg/ml for the methanolic and aqueous extracts, respectively. Subsequent analysis of the T. lanceolata fruit extracts by RP-HPLC coupled to high-resolution TOF mass spectroscopy failed to detect resveratrol in either T. lanceolata fruit extract. However, the resveratrol glycoside piceid and 2 combretastatin stilbenes (A-1 and A-4) were detected in both T. lanceolata fruit extracts. With the exception of the Eucalyptus and Syzygium extracts, all extracts exhibiting Proteus inhibitory activity were also shown to be nontoxic, or of low toxicity in the Artemia nauplii bioassay.

Conclusions:

The low toxicity of these extracts and their inhibitory bioactivity against Proteus spp. indicate their potential in blocking the onset of rheumatoid arthritis.

Efficacy of some colloidal silver preparations and silver salts against Proteus bacteria, one possible cause of rheumatoid arthritis

There has been increased interest in the role of anti-Proteus antibodies in the aetiology of rheumatoid arthritis (RA) and whether chemotherapeutic agents active against Proteus species might reduce the risk and/or exacerbations of RA. We examined the in vitro antibacterial effects of ten different silver preparations which were either ionic silver [Ag(I)] solutions or nanoparticulate silver (NPS) (Ag(0)) suspensions against ATCC and two wild (clinical) strains of Proteus. The data establish the low minimum inhibitory concentration and minimum bactericidal concentration of all the silver formulations tested against these four Proteus strains. In a pilot study, a potent NPS preparation ex vivo showed long-lasting anti-Proteus activity in a normal human volunteer.

Rheumatoid arthritis is caused by a Proteus urinary tract infection

Genetic, molecular and biological studies indicate that rheumatoid arthritis (RA), a severe arthritic disorder affecting approximately 1% of the population in developed countries, is caused by an upper urinary tract infection by the microbe, Proteus mirabilis. Elevated levels of specific antibodies against Proteus bacteria have been reported from 16 different countries. The pathogenetic mechanism involves six stages triggered by cross-reactive autoantibodies evoked by Proteus infection. The causative amino acid sequences of Proteus namely, ESRRAL and IRRET, contain arginine doublets which can be acted upon by peptidyl arginine deiminase thereby explaining the early appearance of anti-citrullinated protein antibodies in patients with RA. Consequently, RA patients should be treated early with anti-Proteus antibiotics as well as biological agents to avoid irreversible joint damages.

Anti-Proteus activity of some South African medicinal plants: their potential for the prevention of rheumatoid arthritis

A wide variety of herbal remedies are used in traditional African medicine to treat rheumatoid arthritis (RA) and inflammation. Thirty-four extracts from 13 South African plant species with a history of ethnobotanical usage in the treatment of inflammation were investigated for their ability to control two microbial triggers for RA (Proteus mirabilis and Proteus vulgaris). Twenty-nine of the extracts (85.3 %) inhibited the growth of P. mirabilis and 23 of them tested (67.7 %) inhibited the growth of P. vulgaris. Methanol and water extracts of Carpobrotus edulis, Lippia javanica, Pelargonium viridflorum, Ptaeroxylon obliquum, Syzygium cordatum leaf and bark, Terminalia pruinoides, Terminalia sericea, Warburgia salutaris bark and an aqueous extract of W. salutaris leaf were effective Proteus inhibitors, with MIC values <2,000 μg/ml. The most potent extracts were examined by Reverse phase high performance liquid chromatography and UV-Vis spectroscopy for the presence of resveratrol. Only extracts from T. pruinoides and T. sericea contained resveratrol, indicating that it was not responsible for the anti-Proteus properties reported here. All extracts with Proteus inhibitory activity were also either non-toxic, or of low toxicity in the Artemia nauplii bioassay. The low toxicity of these extracts and their inhibitory bioactivity against Proteus spp. indicate their potential for blocking the onset of rheumatoid arthritis.

Microbial Infection and Rheumatoid Arthritis

Rheumatoid arthritis (RA) is a complex autoimmune disease affecting 1–2% of general worldwide population. The etiopathogenesis of RA involves the interplay of multiple genetic risk factors and environmental triggers. Microbial infections are believed to play an important role in the initiation and perpetuation of RA. Recent clinical studies have shown the association of microbial infections with RA. Accumulated studies using animal models have also found that microbial infections can induce and/or exaggerate the symptoms of experimental arthritis. In this review, we have identified the most common microbial infections associated with RA in the literature and summarized the current evidence supporting their pathogenic role in RA. We also discussed the potential mechanisms whereby infection may promote the development of RA, such as generation of neo-autoantigens, induction of loss of tolerance by molecular mimicry, and bystander activation of the immune system.

The presence of anti-LPS antibodies and human serum activity against Proteus mirabilis S/R forms in correlation with TLR4 (Thr399Ile) gene polymorphism in rheumatoid arthritis

OBJECTIVES

Proteus mirabilis strains are human pathogens responsible for urinary tract infections, which may also be involved in rheumatoid arthritis (RA).

DESIGN AND METHODS

We determined whether the binding site of anti-LPS antibodies on the O-polysaccharide part of P. mirabilis LPS correlates with the level of TLR4 (Thr399Ile) gene polymorphism in the sera of RA patients. We investigated the deposition of C3d and C5b complement components on the P. mirabilis LPS. The ELISA method used in this study was optimized with LAL test and laser interferometry.

RESULTS

Depending on LPS P. mirabilis used in these studies, the amount of antibodies in RA patients sera varied. We did not observe a correlation between anti-LPS antibodies binding and the level of TLR4 (Thr399Ile) gene polymorphism. We found that the lower complement components deposition by O49 in contrast to O9 LPS correlates with its reduced sensitivities to human complement-mediated killing.

CONCLUSION

The immunological response against P. mirabilis LPS might play a role in rheumatoid arthritis.

Autoimmunity in Rheumatic Diseases Is Induced by Microbial Infections via Crossreactivity or Molecular Mimicry

A general consensus supports fundamental roles for both genetic and environmental, mainly microbial, factors in the development of autoimmune diseases. One form of autoimmune rheumatic diseases is confined to a group of nonpyogenic conditions which are usually preceded by or associated with either explicit or occult infections. A previous history of clinical pharyngitis, gastroenteritis/urethritis, or tick-borne skin manifestation can be obtained from patients with rheumatic fever, reactive arthritis, or Lyme disease, respectively, whilst, other rheumatic diseases like rheumatoid arthritis (RA), ankylosing spondylitis (AS), and Crohn's disease (CD) are usually lacking such an association with a noticeable microbial infection. A great amount of data supports the notion that RA is most likely caused by Proteus asymptomatic urinary tract infections, whilst AS and CD are caused by subclinical bowel infections with Klebsiella microbes. Molecular mimicry is the main pathogenetic mechanism that can explain these forms of microbe-disease associations, where the causative microbes can initiate the disease with consequent productions of antibacterial and crossreactive autoantibodies which have a great impact in the propagation and the development of these diseases.

The role of human xanthine oxidoreductase (HXOR), anti-HXOR antibodies, and microorganisms in synovial fluid of patients with joint inflammation

This work is to investigate the levels of human xanthine oxidoreductase (HXOR), its antibodies, and microorganisms in synovial fluid of patients with untreated rheumatoid joint diseases. Synovial fluids were collected from sixty-four patients with rheumatoid joint diseases. Sixty-four age-matched individuals were included as control. Xanthine oxidoreductase (XOR) proteins level and anti-XOR antibodies were determined in the blood and synovial fluid, using human XOR as antigen, by enzyme-linked immunosorbent (ELISA) assay. Synovial fluids were cultured for bacteria and fungi. The titers of XOR protein in the synovial fluid of patients with rheumatoid arthritis were 90.43 ± 23.37 μg/ml (mean ± SD, n = 29) and up to 62.42 ± 8.74 μg/ml (mean ± SD, n = 35) in other joint inflammation. Anti-HXOR antibodies titers in patients were 167.72 ± 23.64 μg/ml, n = 64, which was significantly higher in rheumatoid arthritis patients. The results indicated that anti-HXOR antibodies in synovial fluids have a protective role as high concentrations against XOR were detected in inflammatory arthritis. These antibodies play a role in eliminating XOR from synovial fluids. However, immune complex formation could activate complement and participate in propagating the inflammatory cycle. Synovial aspirate ordinary microbial cultures were negative for any bacteria or fungi, but that does not exclude organisms of special culture requirements.

Rheumatoid arthritis is linked to Proteus--the evidence

Rheumatoid arthritis (RA) is a chronic inflammatory arthritic and potentially disabling condition, mainly affecting women of middle age and having characteristic clinical features. Various microbial agents were implicated in the causation of RA. Extensive literature based on the results of various genetic, microbiological, molecular, and immunological studies carried out by independent research groups supports the role of Proteus mirabilis bacteria in the etiopathogenesis of RA. New diagnostic markers and criteria and the use of a novel therapeutic protocol in the form of antibiotic and dietary measures are suggested to be used together with current treatments in the management of RA. Prospective longitudinal studies with the use of antimicrobial measures in patients with RA are required to establish the therapeutic benefit of this microbe-disease association.

The incidence of Proteus mirabilis infection increases in patients on treatment but does not trigger disease activity

The aim of this study is to determine whether treatment increases the levels of anti-Proteus antibodies (APA) in patients with rheumatoid arthritis (RA). The blood samples of 32 patients suffering from RA who were recruited in our previous study and continued to participate in our follow-up study were collected after 1 year. Their first and follow-up samples were analysed for the presence of IgG isotype and total immunoglobulins (IgG+IgA+IgM) against Proteus mirabalis (PM) using enzyme-linked immunosorbent assay with two kinds of antigen preparations: whole bacteria and sodium dodecyl sulphate (SDS) lysed bacterial extract. All patients were treated with methotrexate and hydroxychloroquine with adequate dose of non-steroidal anti-inflammatory drug. After 1 year, 11 patients were in clinical remission [erythrocyte sedimentation rate (ESR) less than 30 mm/h and C-reactive protein (CRP) less than or equal to 10 mg/l], while the rest of the 21 were in the state of active disease. Correlation and Student's t test were used for statistical analysis. APA titres were significantly elevated in patients after 1 year of therapy. However, the rise was not different between patients who were in clinical remission and those in the state of active disease. APA titre increases in the treatment of RA, and the probable mechanisms are discussed.

Rheumatoid arthritis is an autoimmune disease triggered by Proteus urinary tract infection

Rheumatoid arthritis (RA) is a chronic and disabling polyarthritic disease, which affects mainly women in middle and old age. Extensive evidence based on the results of various microbial, immunological and molecular studies from different parts of the world, shows that a strong link exists between Proteus mirabilis microbes and RA. We propose that sub-clinical Proteus urinary tract infections are the main triggering factors and that the presence of molecular mimicry and cross-reactivity between these bacteria and RA-targeted tissue antigens assists in the perpetuation of the disease process through production of cytopathic auto-antibodies. Patients with RA especially during the early stages of the disease could benefit from Proteus anti-bacterial measures involving the use of antibiotics, vegetarian diets and high intake of water and fruit juices such as cranberry juice in addition to the currently employed treatments.

Rheumatoid Factors: Good or Bad for You?

BACKGROUND

Rheumatoid factors (RFs) are autoantibodies associated with rheumatoid arthritis. They can be detected in normal individuals, although transiently. This dichotomy has led to questions about the origins and types of RFs. Recently it has been shown that B cells that produce RFs only do so when activated by two signals, one from engagement of the B-cell receptor and the other from recognition of a pathogen-associated molecular pattern through a Toll-like receptor (TLR). These autoantibodies thus link the innate and acquired immune responses.

OBJECTIVE

Through a review of the literature, an examination of the current knowledge of RF induction is presented. The focus is on a discussion of a beneficial or detrimental role for RFs in normal individuals and in those with chronic disease.

RESULTS

What makes RF 'good' in some cases and 'bad' in others may reflect the type of RF produced. Low-affinity polyreactive IgM RFs are probably beneficial as they aid in the clearance of immune complexes that are more efficiently cleared, and the RF B cell can act as an antigen-presenting cell and stimulate host defense. However, large amounts of high-affinity RFs found in patients with chronic disease may be harmful by participation in a vicious cycle of autoantibody production by stimulation of self lymphocytes, and/or deposition in blood vessels thus causing vasculitis.

CONCLUSIONS

Whether RFs are beneficial or detrimental depends on the context in which they are expressed, the type and amount of RF produced, whether the response is perpetuated by TLR ligation and whether other cells are stimulated either directly or indirectly by RF-positive B cells.

Elevated levels of IgM and IgA antibodies to Proteus mirabilis and IgM antibodies to Escherichia coli are associated with early rheumatoid factor (RF)-positive rheumatoid arthritis

OBJECTIVE

Antibodies to Proteus mirabilis were previously detected in patients with established rheumatoid arthritis (RA). We examined the prevalence of antibodies to P. mirabilis and their associations with RA in early synovitis patients.

METHODS

Two hundred and forty-six patients with inflammatory arthritis for less than 1 yr were prospectively evaluated for 1 yr. Of these patients, 30% had rheumatoid factor (RF)-positive RA, 16% RF-negative RA, 17% a spondyloarthropathy and 37% undifferentiated arthritis. Serum antibodies to P. mirabilis, Escherichia coli and other potentially arthritogenic organisms (Chlamydia, Salmonella, Shigella, Campylobacter, Yersinia and parvovirus B19) and for antibodies specific for immunoglobulin (Ig) G damaged with advanced glycation end-products (anti-IgG-AGE) were measured.

RESULTS

IgM and IgA anti-Proteus antibodies were significantly higher in patients with RF-positive RA compared with all other patient groups (P < 0.0005 and P < 0.005). Anti-P. mirabilis IgG, and IgG, IgA, and IgM antibodies to other potentially arthritogenic pathogens did not differ in the patient groups. IgM antibodies to E. coli were elevated in RF-positive RA patients. Anti-P. mirabilis IgM and IgA results were not explained by false-positive reactions, because after absorption of RF there was no decrease in antibodies to Proteus in 10 of 12 patients. Proteus and E. coli antibodies were highest in patients positive for both RF and anti-IgG-AGE antibodies (P<0.001). Patients with erosions tended to have higher IgA anti-Proteus titres, but no association with the shared HLA epitope or treatment was detected.

CONCLUSION

Anti-P. mirabilis IgM and IgA and anti-E. coli IgM antibody elevations are associated with early seropositive RA and the presence of anti-IgG-AGE antibodies. The role that P. mirabilis or E. coli plays in early RF-positive RA requires further investigation.

Structure and serological characterization of the O-antigen of Proteus mirabilis O18 with a phosphocholine-containing oligosaccharide phosphate repeating unit

A phosphorylated, choline-containing polysaccharide was obtained by O-deacylation of the lipopolysaccharide (LPS) of Proteus mirabilis O18 by treatment with aqueous 12% ammonia, whereas hydrolysis with dilute acetic acid resulted in depolymerisation of the polysaccharide chain by the glycosyl phosphate linkage. Treatment of the O-deacylated LPS with aqueous 48% hydrofluoric acid cleaved the glycosyl phosphate group but, unexpectedly, did not affect the choline phosphate group. The polysaccharide and the derived oligosaccharides were studied by NMR spectroscopy, including 2D 1H,1H COSY, TOCSY, ROESY, 1H,13C HMQC and HMQC-TOSCY experiments, along with chemical methods, and the following structure of the pentasaccharide phosphate repeating unit was established: [carbohydrate structure in text] Where ChoP=Phosphocoline Immunochemical studies of the LPS, O-deacylated LPS and partially dephosphorylated pentasaccharide using rabbit polyclonal anti-P. mirabilis O18 serum showed the importance of the glycosyl phosphate group in manifesting the serological specificity of the O18-antigen.

Structural and serological studies of the O-antigen of Proteus mirabilis O-9

The following structure of the O-polysaccharide (O-antigen) of the lipopolysaccharide of Proteus mirabilis O-9 was determined by NMR spectroscopy, including 2D 1H,(1)H COSY, TOCSY, ROESY, and 1H,(13)C HMQC experiments, along with chemical methods: [chemical structure: see text] where the degree of O-acetylation is approximately 70%. Immunochemical studies using rabbit polyclonal anti-Proteus mirabilis O-9 serum showed the importance of the O-acetyl groups in manifesting the serological specificity of the O-9 antigen. Anti-P. mirabilis O-9 cross-reacted with the lipopolysaccharides (LPS) of P. vulgaris O-25 and Proteus penneri 14, which could be accounted for by a structural similarity of their O-polysaccharides.

Rheumatoid arthritis: proposal for the use of anti-microbial therapy in early cases

Rheumatoid arthritis (RA) is a chronic disease, affecting women more than men, especially in those possessing the "shared epitope" (EQK/RRAA) amino acid sequences present in HLA-DR1/4 molecules. Proteus mirabilis carries sequences showing molecular mimicry to the "shared epitope" and to type XI collagen of hyaline cartilage. Elevated levels of antibodies to P. mirabilis have been reported from 14 different countries involving 1375 RA patients and the microbe has been isolated from urine cultures of such patients. Our working hypothesis is that the disease develops as a result of repeated episodes of Proteus upper urinary tract infections. Prospective studies involving the trial of anti-Proteus measures in RA patients should be evaluated in the management of this disease. Antibiotics, high fluid intake, and fruit extracts, such as cranberry juice, have all been found to be effective in the treatment of urinary tract infections. Such measures could be used as possible additional adjuncts to the standard therapy with NSAIDs and DMARDs.

Infectious agents in chronic rheumatic diseases

The possible role of infectious microorganisms in the disease process of both arthritis and autoimmunity continue to attract both basic and clinical researchers. However, proving a causal role for these suspects is a very difficult and complicated task. This article provides an update on various mechanisms in which microbes may play roles as inciting or perpetuating factors in the pathogenesis of connective tissue disease. It also focuses on current theories that specific microorganisms may play a role in rheumatoid arthritis and ankylosing spondylitis.

Genetic diversity in Proteus mirabilis isolates found in the urinary tract of rheumatoid arthritis patients

OBJECTIVE

Elevated levels of anti-Proteus antibodies but not antibodies to E. coli have been reported in patients with rheumatoid arthritis (RA). The suggestion has been made that P. mirabilis may have a role in the aetiopathogenesis of rheumatoid arthritis. The aim of this study was to determine whether there are differences at the genetic level inisolates of P. mirabilis obtained from controls and RA patients.

METHODS

A blind study was performed whereby P. mirabilis isolates obtained from urinary cultures of RA patients and controls were analysed using RAPD PCR. Isolates were then grouped on the basis of their DNA band profile after agarose gel electrophoresis, thereby allowing the composition of the Proteus population in the urinary tract to be analysed at the genetic level.

RESULTS

Fourteen different DNA band profiles were obtained from the 93 isolates tested: 70% of these isolates fell into only five of the 14 groups and approximately 25% of all isolates fell into one group. No differences were observed in the frequency of isolates from either control or RA subjects.

CONCLUSIONS

There is genetic diversity in P. mirabilis populations found in the urinary tract, but there are no differences in the frequency of these bacteria between RA patients and controls.

Molecular mimicry between HLA-DR alleles associated with rheumatoid arthritis and Proteus mirabilis as the Aetiological basis for autoimmunity

Molecular mimicry is one of the pathological mechanisms proposed to explain the association between microorganisms and autoimmune diseases. This review deals with the association between bacteria and rheumatic diseases with a special emphasis on rheumatoid arthritis where upper urinary tract infection by Proteus mirabilis is the possible cause of this severe, arthritic condition. Prospective trials involving anti-Proteus therapy should be carried out.