Aetiological role of bacteria associated with reactive arthritis in pauciarticular juvenile chronic arthritis

Evidence of cellular immune response to outer membrane protein of Salmonella typhimurium in patients with enthesitis-related arthritis subtype of juvenile idiopathic arthritis

OBJECTIVE

enthesitis-related arthritis subtype of juvenile idiopathic arthritis (JIA-ERA) clinically resembles reactive arthritis (ReA). In patients with ReA the immune response is targeted at the outer membrane protein (OMP) of Salmonella typhimurium. We studied the immune response in JIA-ERA to S. typhimurium OMP.

METHODS

synovial fluid mononuclear cells (SFMC) and peripheral blood mononuclear cells (PBMC) were isolated from blood and SF of patients with JIA-ERA. Lymphocyte transformation test was done with S. typhimurium OMP and crude bacterial lysates of Yersinia enterocolitica, Shigella flexneri, and S. typhimurium. IgG and IgA ELISA were performed in serum and SF using S. typhimurium OMP as antigen and compared with sera from healthy controls.

RESULTS

in PBMC samples (n = 25) an antigen-specific proliferative response was seen in 13 patients and a cross-reactive response in 6. Among these 19 patients, 12 showed response to OMP. In SFMC (n = 15) antigen-specific responses were seen in 3 patients and cross-reactive responses in 9. Among these 12 patients, 11 showed response to OMP. The IgG and IgA anti-OMP antibody concentrations in serum and SF were similar in patients and controls.

CONCLUSION

in JIA-ERA, OMP is the major antigenic target recognized by both SFMC and PBMC. Response to OMP is independent of specific bacterial response, suggesting that OMP is the immunodominant antigen. In these patients, absence of significant humoral response suggests response to OMP is mainly T cell mediated.

Seroprevalence of parvovirus B19 IgG in children affected by juvenile idiopathic arthritis

Parvovirus (PV) B19 is the causative agent of the childhood disease erythema infectiosum. An association of PV B19 with chronic arthropathies, sometimes resembling rheumatoid arthritis or juvenile idiopathic arthritis (JIA), has repeatedly been described. Other studies, however, have failed to identify any such relationship. In order to study further whether there is a link between PV B19 and JIA, we determined the prevalence of PV B19 specific IgG antibodies in serum samples from children with rheumatoid diseases and compared it with the prevalence in unaffected children We reasoned that if there is an association between PV B19 and JIA, then the prevalence of PV B19 IgG in the children with JIA should be higher than in the control group. PV B19 IgG status was tested in 406 children with JIA and related diseases, and in 146 children constituting a control group. The percentage of PV B19 IgG positive children was not significantly elevated in the disease subgroups compared with age-matched control groups. In conclusion, our findings do not support the hypothesis that human parvovirus B19 is involved in the pathogenesis of JIA.

Low molecular weight proteins of outer membrane of Salmonella typhimurium are immunogenic in Salmonella induced reactive arthritis revealed by proteomics

In patients with reactive arthritis (ReA)/undifferentiated spondyloarthropathy (uSpA), synovial fluid mononuclear cells (SFMC) show proliferation to bacterial antigens that trigger ReA, i.e. Chlamydia, Yersinia, Campylobactor, Shigella and Salmonella species. We have shown previously that SFMC proliferate significantly to outer membrane proteins of S typhimurium in Salmonella induced ReA. In the present study we characterized the immunoreactive fractions of outer membrane protein (Omp) of S typhimurium in Salmonella induced ReA. Omp of Salmonella was isolated and fractionated by continuous elution sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) using Prep-Cell into eight Omp fractions based on molecular weight. Twenty-three patients with ReA were screened for the bacterial trigger using the SFMC proliferative response to crude lysates of Y enterocolitica, S flexneri, C jejuni and S typhimurium using thymidine uptake assay. SFMC from patients with salmonella induced ReA were tested against eight fractions. Seven of 23 patients with ReA had S typhimurium-induced ReA. Of these seven patients, five patients SFMC had a significant stimulation index (SI) against < 22, 22-26, 25-35 and 28-40 kDa fractions of Omp. These fractions were analysed by SDS-PAGE and matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) mass spectrometry, which revealed 10 proteins. These proteins were 37 kDa OmpA, 33 kDa TsX, 28 kDa putative Omp, 28 kDa Vac J, 39 kDa OmpD, 18 kDa OmpX, 23 kDa OmpW, 43 kDa OmpS1 and 19 kDa peptidoglycan-associated lipoprotein. In conclusion, for the first time we have identified some low molecular weight proteins in the Omps of Salmonella which are T cells immunoreactive in patients with salmonella induced ReA/uSpA.

Is there a relationship between juvenile idiopathic arthritis and periodontitis?

AIM

The aim was to compare the prevalence of periodontal conditions in patients with juvenile idiopathic arthritis (JIA) (n=78, age 14.4 years) with those revealed in a healthy control group (n=75, age 15.5 years).

MATERIAL AND METHODS

In both groups, the approximal plaque index (API), the modified sulcular bleeding index (SBI), and the clinical attachment loss (CAL) were determined. Laboratory parameters for JIA activity included the capsule-reactive protein (CRP) and the immunoglobulins A, G, M.

RESULTS

JIA patients had a significantly higher API (64.6%versus 49.9%, p=0.004) and slightly higher mean percentages of sites with CAL>3.5 mm (0.58%versus 0.22%, p=0.041). There was no significant difference in the prevalence of patients and controls who had sites with CAL >3.5 mm (25.6%versus 17.3%, p=0.212). The mean CAL was slightly greater (0.2 mm; p=0.030) in patients with CRP> or =5.0 mg/l compared with patients with CRP<5.0 mg/l. Patients who took non-steroidal anti-inflammatory drugs (NSAIDs) had a significantly decreased SBI (26.2%versus 51.1%, p=0.019).

CONCLUSION

After adjustment for microbial plaque, JIA is not a risk factor for periodontitis.

Is the enthesitis-related arthritis subtype of juvenile idiopathic arthritis a form of chronic reactive arthritis?

OBJECTIVE

Enteric organisms are known to trigger reactive arthritis. The enthesitis-related arthritis (ERA) form of juvenile idiopathic arthritis (JIA) clinically resembles reactive arthritis. Therefore, we looked for a role of enteric bacteria in ERA.

METHODS

Synovial fluid (SF) was obtained from 26 patients with ERA and 10 patients with rheumatoid arthritis (RA). Blood specimens were also obtained from patients with ERA and from 10 normal individuals. Lymphocyte proliferation assays were done on whole blood and SF mononuclear cells using as antigens crude lysates of the enteric bacteria Salmonella typhimurium, Yersinia enterocolitica, Shigella flexneri and Campylobacter jejuni. Crude lysate of Escherichia coli was used as a control antigen. HLA-B27 typing was done using the polymerase chain reaction. Homing of gut-specific T cells (CD103+) to the synovial compartment was studied using tri-colour flow cytometry. The antigen-specific cytokine profile was determined by flow cytometry.

RESULTS

Antigen-specific lymphoproliferative responses were observed in 14 of 26 patients. Among these patients, 12 showed a response in SF (four each to S. typhimurium and C. jejuni, and in two each to S. flexneri and Y. enterocolitica), and two patients in blood (S. typhimurium in both). None of the healthy controls showed a response in the blood. Lymphoproliferative responses in SF were more frequent in patients with JIA (12/26) than in controls with RA (1/10, P < 0.05). Patients with an antigen-specific response had a higher ratio of SF/blood CD103+ T cells compared with those with no antigen-specific response (P < 0.01). Antigen-specific as well as mitogen-stimulated cytokine production showed a Th1 bias.

CONCLUSION

Enteric bacteria may have a role in exacerbation of disease in patients with ERA. The immune response in patients with ERA is Th1-dominant.

An association between the acute phase response and patterns of antigen induced T cell proliferation in juvenile idiopathic arthritis

The aim of this research was to determine whether all memory T cells have the same propensity to migrate to the joint in patients with juvenile idiopathic arthritis. Paired synovial fluid and peripheral blood mononuclear cell proliferative responses to a panel of antigens were measured and the results correlated with a detailed set of laboratory and clinical data from 39 patients with juvenile idiopathic arthritis. Two distinct patterns of proliferative response were found in the majority of patients: a diverse pattern, in which synovial fluid responses were greater than peripheral blood responses for all antigens tested; and a restricted pattern, in which peripheral blood responses to some antigens were more vigorous than those in the synovial fluid compartment. The diverse pattern was generally found in patients with a high acute phase response, whereas patients without elevated acute phase proteins were more likely to demonstrate a restricted pattern. We propose that an association between the synovial fluid T cell repertoire and the acute phase response suggests that proinflammatory cytokines may influence recruitment of memory T cells to an inflammatory site, independent of their antigen specificity. Additionally, increased responses to enteric bacteria and the presence of alphaEbeta7 T cells in synovial fluid may reflect accumulation of gut associated T cells in the synovial compartment, even in the absence of an elevated acute phase response. This is the first report of an association between the acute phase response and the T cell population recruited to an inflammatory site.

The juvenile-onset spondyloarthritides

The juvenile-onset spondyloarthritides comprise a group of HLA-B27-associated disorders, which are mainly characterized by enthesitis and arthritis affecting the lower extremities, and in a variable proportion of cases, the sacroiliac and spinal joints. Additional features include a variety of extra-articular manifestations, and in some cases, bacterial infections as triggers. Except for the prevalence of some clinical features at onset and severity throughout the course of the disease, juvenile-onset SpA resemble their adult counterpart in most clinical aspects, strength of HLA-B27 association, and the role of arthritogenic bacteria in their pathogenesis. Not surprisingly, several aspects, from nomenclature to classification, and diagnostic criteria reflect to some extent those developed in the adult onset populations.

The elevated ratio of interferon gamma-/interleukin-4-positive T cells found in synovial fluid and synovial membrane of rheumatoid arthritis patients can be changed by interleukin-4 but not by interleukin-10 or transforming growth factor beta

OBJECTIVES

To quantify the T-helper type (Th) 1 cytokine interferon gamma (IFN-gamma)-positive and the Th2 cytokine interleukin (IL)-4-positive cells in synovial fluid (SF) and synovial membrane (SM) at the single-cell level in rheumatoid arthritis (RA) in comparison to reactive arthritis (ReA), and to manipulate the cytokine pattern of RA patients in vitro.

METHODS

Eighteen patients with RA and 17 with ReA were studied. For intracellular staining of cytokines, SF mononuclear cells (MNC) from seven patients with RA, in comparison to eight patients with ReA, were triple stained with anti-IFN-gamma, IL-4 and anti-CD4 or anti-CD8 monoclonal antibodies (mAb) and analysed by flow cytometry. Furthermore, in 13 patients with RA, immunohistology of SM was performed and compared with seven ReA patients. In addition, in six of the RA patients, synovial T cells were grown over 3 weeks in the presence of various cytokines and intracellular cytokine staining analysed by flow cytometry weekly.

RESULTS

In SF, the mean percentage of IFN-gamma+/CD4+ T cells in RA was almost 4-fold higher than the number of IL-4+/CD4+ T cells (11.3+/-5 vs 3.02+/-1.04; P=0.0012), while the ratio of IFN-gamma/IL-4+ CD4+ T cells was only 1.59 in ReA (P=0.047 for the ratio difference). A similar result was obtained for SM: the ratio of IFN-gamma/IL-4+ cells in RA was 4.3 (P<0.0001 for the IFN-gamma/IL-4 difference), but only 1.2 for ReA (P=0.02 for the ratio difference). Of the CD3+ cells in SM, 2.8% were positive for IFN-gamma and 0.4% for IL-4 in three RA patients. A decrease in the number of IFN-gamma-positive SF T cells and an increase in the number of IL-4-positive SF T cells could be achieved in vitro through IL-4, but not by IL-10 or transforming growth factor beta.

CONCLUSIONS

The Th1 pattern in the joint of RA patients demonstrated at the single-cell level may be important for the pathogenesis of RA and may provide a target for future immunotherapy. Our data suggest a therapeutic role for IL-4.

Features of spondyloarthritis around the world

This article elucidates the prevalence and pathogenic roles of the MHC and microbial infections and clinical features and treatment of SpA across different populations from the arctic and subarctic regions to Central America, Asia, and Africa. Preliminary evidence suggests significant genetic and environmental influences on the onset and presentation of SpA, particularly AS, in these populations, which are different than those reported in white Caucasians; however, community surveys and longitudinal and case control studies are difficult to undertake in many of the developing countries. Thus, most of the currently available data have been devised from short-term and retrospective studies and should be treated with caution. Differences in referral and follow-up practices and the availability of rheumatology expertise and relevant resources may explain some of the differences observed in the populations discussed in this article. Furthermore, widely accepted criteria for the classification of SpA may not be applicable to non-Caucasians and need to be evaluated in these subjects. With gradual improvement in the economic status in many of the developing countries in Asia and Africa, it is hoped that with improvement in medical services, more physicians and specialty clinics in rheumatology, and changing referral patterns, better documentation of the various aspects of different SpA can be achieved. Future research should focus on the evaluation of specific risk or protective factors in population groups to better delineate the relative importance of genetic and environmental effects in the pathogenesis of SpA.

Juvenile-onset spondyloarthropathies

This article discusses the clinical spectrum and characteristics of juvenile-onset spondyloarthropathies and includes a review of the demographic, clinical, radiographic (and other imaging techniques), and laboratory data of conditions, syndromes, and diseases making up this group. The pathogenic role of several factors in the context of adult-onset patients, but also in regards to studies already performed in juvenile-onset patients, is discussed.

Pathogenesis of spondylarthropathies. Persistent bacterial antigen, autoimmunity, or both?

We have discussed partially mutually exclusive, partially overlapping models for the pathogenesis of the spondylarthropathies. Not all possibilities have been presented here; others are discussed elsewhere (77, 78). Furthermore, we have not addressed the issue of B27-negative spondylarthropathy. However, in our opinion, the key to understanding the pathogenesis of the spondylarthropathies lies in the interaction between the class I MHC molecule HLA-B27 and the T cell response. Although a T cell response driven by persisting bacterial antigen is still an attractive hypothesis, it does not explain all the known aspects of spondylarthropathy pathogenesis. The possibility of autoimmunity triggered by bacterial infection needs also to be considered, especially the new idea of HLA-B27-derived peptides presented by class II MHC molecules. The predominant involvement of joints is not easily explained in the case of autoimmunity. Cross-reactivity to joint-specific structures such as type II collagen (79) and/or bacteria inside the joint at the beginning of the immune response, with induction of local autoimmunity, might be involved. Most of the issues raised here could be tested by experiment, and we can expect to learn soon whether any of these models will explain the pathogenesis, or if we have to look further. The PCR technique will facilitate the search for bacteria not only in peripheral joints, but also now in sacroiliac biopsy samples from patients with AS and other spondylarthropathies. A prospective study on ReA in an endemic area should teach us more about predisposing factors (for example for Shigella-induced enteritis, which occurs in many parts of the world outside Europe and the US) (80).(ABSTRACT TRUNCATED AT 250 WORDS)

Immunopathogenesis of juvenile rheumatoid arthritis: role of T cells and MHC

Juvenile rheumatoid arthritis (JRA) is defined as chronic arthritis of unknown etiology appearing in patients less than 16 years of age. The disease is heterogeneous and is classified as pauciarticular, polyarticular, or systemic-onset disease. A few lines of evidence suggest that T cells are involved in the pathogenesis of the disease. T cells infiltrating the synovial membrane bear markers of activation and produce cytokines. The association of particular subtypes of JRA with certain HLA class II alleles provides strong evidence in favor of T cell involvement through an HLA-peptide-T cell receptor complex. Limited data from a few patients with JRA on T cell receptor transcripts from synovial membrane or synovial fluid cells point towards oligoclonality. This further supports the concept that T cells infiltrating the synovial membrane or extravasating into synovial fluid in patients with JRA reflect antigen-driven T cell proliferation.

Pediatric rheumatic diseases

The rheumatic diseases of childhood are a relatively common and extraordinarily diverse group of illnesses; nevertheless, they are at least distantly related by similarities of immunodysregulation. These pathophysiologic relationships are reflected in affected children in similarities of historical, physical, and laboratory data as well as therapeutic intervention.

Chlamydia pneumoniae--a new causative agent of reactive arthritis and undifferentiated oligoarthritis

OBJECTIVE

To examine whether reactive arthritis (ReA) known to occur after a urogenital infection with Chlamydia trachomatis can also follow an infection with Chlamydia pneumoniae, a recently described species of Chlamydiae that is a common cause of respiratory tract infections.

METHODS

Specific antibodies (microimmunofluorescence test) and lymphocyte proliferation to C trachomatis and C pneumoniae in paired samples of peripheral blood and synovial fluid were investigated in 70 patients with either reactive arthritis (ReA) or undifferentiated oligoarthritis (UOA).

RESULTS

Five patients with acute ReA after an infection with C pneumoniae are reported. Three had a symptomatic preceding upper respiratory tract infection and two had no such symptoms. In all patients a C pneumoniae-specific lymphocyte proliferation in synovial fluid and a high specific antibody titre suggesting an acute infection was found.

CONCLUSION

C pneumoniae needs to be considered a new important cause of reactive arthritis.

Silicone-reactive disorder: a new autoimmune disease caused by immunostimulation and superantigens

Over 100 cases of disorders closely resembling classic autoimmune diseases have been reported among patients who were injected or implanted with a diverse group of chemicals including paraffins, vegetable oils or silicone. Most cases have occurred in silicone breast implant recipients, especially those who received their prostheses 2-10 years prior to onset of symptoms. A high proportion of patients exhibit classic signs and symptoms of Sjogren's syndrome or scleroderma. Affected patients typically experience some combination of fatigue, myalgia, joint pain, sicca syndrome (dry eyes and mouth), synovitis, rash, alopecia, muscular weakness or lymphadenopathy, and autoantibody formation. Less commonly, patients may have the CREST syndrome (calcinosis, Raynaud's phenomena, esophageal hypomotility, sclerodactyly and telangiectasias), hypertension, pulmonary fibrosis, or central nervous system pathology.

Are antibiotics of any use in reactive arthritis?

In the pathogenesis of reactive arthritis, infection through the mucosal route and genetic susceptibility (HLA-B27) are the most important contributing factors. With regard to non-specific urethritis, most probably caused by Chlamydia trachomatis infection, the use of early antimicrobial therapy has been shown to be effective in preventing arthritic recurrences. When the arthritis has been initiated, short-term conventional antimicrobial therapy seems unable to modify the course of the ongoing disease. In patients with acute reactive arthritis, a prolonged (3-month) treatment with tetracycline shortens the duration of arthritis when triggered by Chlamydia trachomatis, while such treatment has not proved effective in enteroarthritis. In patients with chronic reactive enteroarthritis, a prolonged course of quinolones, such as ciprofloxacin, might be of benefit. Sulfasalazine, which has an effect in the acute exacerbations of ankylosing spondylitis, is probably also effective in chronic reactive arthritis. An antimicrobial effect can be one of the mechanisms by which sulfasalazine exerts its therapeutic effect. Follow-up studies are necessary to assess the influence of antibiotic therapy on the late prognosis of patients with reactive arthritis.