Post-Salmonella reactive arthritis: late clinical sequelae in a point source cohort

Enteric Infection-Associated Reactive Arthritis: A Systematic Review and Meta-Analysis

Background. The objective of this systematic review and meta-analysis was to estimate the proportions of individuals infected with Campylobacter, Escherichia, Salmonella, Shigella, or Yersinia who develop reactive arthritis. Methods. A systematic review was conducted, encompassing English-language articles published before January 2024, sourced from the Embase, PubMed, Scopus, and Web of Science databases. This review included observational studies that reported the occurrence of reactive arthritis (ReA) among patients with Campylobacter, Escherichia, Salmonella, Shigella, or Yersinia infections. Data extraction was carried out independently by two reviewers. Subsequently, a random-effects meta-analysis was performed, with heterogeneity assessed using the I2 value. Additionally, meta-regression was employed to investigate the potential influence of study-level variables on the observed heterogeneity. Results. A total of 87 studies were identified; 23 reported on ReA development after Campylobacter infection, 7 reported on ReA after Escherichia infection, 30 reported ReA onset after salmonellosis, 14 reported ReA after shigellosis, and 13 reported ReA after Yersinia infection. The proportion of Campylobacter patients who developed ReA was 0.03 (95% CI [0.01, 0.06], I2 = 97.62%); the proportion of Escherichia patients who developed ReA was 0.01 (95% CI [0.00, 0.06], I2 = 92.78%); the proportion of Salmonella patients was 0.04 (95% CI [0.02, 0.08], I2 = 97.67%); the proportion of Shigella patients was 0.01 (95% CI [0.01, 0.03], I2 = 90.64%); and the proportion of Yersinia patients who developed ReA was 0.05 (95% CI [0.02, 0.13], I2 = 96%). Conclusion. A significant proportion of Salmonella, Shigella, and Yersinia cases resulted in ReA. Nonetheless, it is important to interpret the findings cautiously due to the substantial heterogeneity observed between studies.

MRI and Sonography of the Knee in Acute Reactive Arthritis: An Observational Cohort Study

INTRODUCTION

Reactive arthritis (ReA) is a unique subgroup of spondyloarthritis with acute presentation and tendency to develop chronicity. Magnetic resonance imaging (MRI) has enabled identification of sensitive markers of response to therapy.

METHODS

A longitudinal pilot study of acute ReA with knee joint involvement satisfying the Braun's criteria was undertaken. Magnetic resonance imaging of the knee was assessed at baseline, and agreement with ultrasonography was assessed. Clinical details were recorded using a detailed and structured case record form. Patients were followed up, and MRI predictors of transition to chronic arthritis were looked for.

RESULTS

In 25 patients with ReA, synovial thickening was the most common feature. Enthesitis was observed on MRI in 20%. Urethritis-related and HLA-B27-positive ReA had higher synovial thickening scores (p = 0.007). Agreement was poor between MRI and ultrasonography (synovial hypertrophy: k = 0.04). On follow-up, 34% (n = 7/21 for >12 months) continued to have active disease. None of the clinical or radiological features were predictive of chronicity.

CONCLUSIONS

Posturethritis and B27-positive ReA was more severe than postenteritis ReA and RA on MRI. One third develop chronic disease on follow-up. Magnetic resonance imaging is superior to sonography, although baseline imaging is not predictive of chronicity. The results of this pilot exploratory study argue for larger studies on MRI in ReA.

Molecular determinants of peaceful coexistence versus invasiveness of non-Typhoidal Salmonella: Implications in long-term side-effects

The genus Salmonella represents a wide range of strains including Typhoidal and Non-Typhoidal Salmonella (NTS) isolates that exhibit illnesses of varied pathophysiologies. The more frequent NTS ensues a self-limiting enterocolitis with rare occasions of bacteremia or systemic infections. These self-limiting Salmonella strains are capable of subverting and dampening the host immune system to achieve a more prolonged survival inside the host system thus leading to chronic manifestations. Notably, emergence of new invasive NTS isolates known as invasive Non-Typhoidal Salmonella (iNTS) have worsened the disease burden significantly in some parts of the world. NTS strains adapt to attain persister phenotype intracellularly and cause relapsing infections. These chronic infections, in susceptible hosts, are also capable of causing diseases like IBS, IBD, reactive arthritis, gallbladder cancer and colorectal cancer. The present understanding of molecular mechanism of how these chronic infections are manifested is quite limited. The current work is an effort to review the prevailing knowledge emanating from a large volume of research focusing on various forms of NTS infections including those that cause localized, systemic and persistent disease. The review will further dwell into the understanding of how this pathogen contributes to the associated long term sequelae.

Cost of Salmonella Infections in Australia, 2015

Gastroenteritis caused from infections with Salmonella enterica (salmonellosis) causes significant morbidity in Australia. In addition to acute gastroenteritis, approximately 8.8% of people develop irritable bowel syndrome (IBS) and 8.5% of people develop reactive arthritis (ReA). We estimated the economic cost of salmonellosis and associated sequel illnesses in Australia in a typical year circa 2015. We estimated incidence, hospitalizations, other health care usage, absenteeism, and premature mortality for four age groups using a variety of complementary data sets. We calculated direct costs (health care) and indirect costs (lost productivity and premature mortality) by using Monte Carlo simulation to estimate 90% credible intervals (CrI) around our point estimates. We estimated that 90,833 cases, 4,312 hospitalizations, and 19 deaths occurred from salmonellosis in Australia circa 2015 at a direct cost of AUD 23.8 million (90% CrI, 19.3 to 28.9 million) and a total cost of AUD 124.4 million (90% CrI, 107.4 to 143.1 million). When IBS and ReA were included, the estimated direct cost was 35.7 million (90% CrI, 29.9 to 42.7 million) and the total cost was AUD 146.8 million (90% CrI, 127.8 to 167.9 million). Foodborne infections were responsible for AUD 88.9 million (90% CrI, 63.9 to 112.4 million) from acute salmonellosis and AUD 104.8 million (90% CrI, 75.5 to 132.3 million) when IBS and ReA were included. Targeted interventions to prevent illness could considerably reduce costs and societal impact from Salmonella infections and sequel illnesses in Australia.

Increased interleukin (IL)-20 and IL-24 target osteoblasts and synovial monocytes in spondyloarthritis

The pathogenesis of spondyloarthritis (SpA) involves activation of the innate immune system, inflammation and new bone formation. The two cytokines interleukin (IL)-20 and IL-24 have been shown to link innate immune activation and tissue homeostasis. We hypothesized that these two cytokines are secreted as part of activation of the innate immune system and affect bone homeostasis in SpA. IL-20 and IL-24 were measured in plasma from axial SpA patients (n = 83). Peripheral SpA patients (n = 16) were included for in-vitro cell culture studies. The plasma IL-20 and IL-24 levels were increased in SpA patients compared with healthy controls (HCs) by 57 and 83%, respectively (both P < 0·0001). The Toll-like receptor 4-induced secretion of the two cytokines was greater in SpA peripheral blood mononuclear cells (PBMCs) compared with HC PBMCs. IL-20 and IL-24 increased the production of monocyte chemoattractant protein-1 by activated SpA synovial fluid monocytes, decreased the production of Dickkopf-1 by SpA fibroblast-like synovial cells and induced mineralization in human osteoblasts. Taken together, our findings indicate disease-aggravating functions of IL-20 and IL-24 in SpA.

Association between Giardia and arthritis or joint pain in a large health insurance cohort: could it be reactive arthritis?

This study aimed to assess the association between giardiasis and subsequent development of arthritis or joint pain using a retrospective cohort of individuals from a large administrative claims database in the United States. Using 2006-2010 data from MarketScan Commercial Claims and Encounters, we conducted a retrospective cohort study in people with an ICD-9-CM code for giardiasis (n = 3301) and persons without giardiasis (n = 14 612) individually matched on age, sex, and enrolment length. We used conditional logistic regression to model the association between giardiasis and arthritis or joint pain documented in the 6 months following initial giardiasis diagnosis or index date for matched controls. After adjusting for healthcare utilization rate, giardiasis was associated with a 51% increase in claims for arthritis or joint pain (odds ratio 1·51, 95% confidence interval 1·26-1·80). In age- and sex-stratified adjusted analyses, the association remained significant across all subgroups (age 0-19 years, age 20-64 years, males, and females). Findings from this study lend epidemiological support for the association between giardiasis and subsequent development of arthritis. Reactive arthritis might occur more frequently than has been reported in the literature. Further research is necessary to determine the mechanisms by which giardiasis could lead to arthritis.

Salmonella as an Inducer of Autoimmunity

A clear etiological link has been established between infection with several gram-negative enteric pathogens, including Salmonella spp., and the incidence of reactive arthritis (ReA), an autoimmune disease that largely affects the joints. ReA is sometimes referred to as Reiter's syndrome, particularly when accompanied by uveitis and urethritis. This review reviews the evidence etiologically linking Salmonella infection with autoimmune disease and addresses the roles that bacterial and host elements play in controlling disease outcome. ReA is an autoimmune disease that largely consists of painful joint inflammation but also can include inflammation of the eye, gastrointestinal tract, and skin. ReA is a member of a broad spectrum of chronic inflammatory disorders termed the seronegative spondyloarthropathies (SNSpAs) that includes ankylosing spondylitis (AS), psoriatic arthritis, and enteropathic arthritis. Salmonella species, as well as other enteric pathogens associated with postgastroenteritis ReA, are facultative intracellular gram-negative bacteria. Many studies have analyzed the association of the HLA class I molecule, HLA-B27, with SNSpAs. Whereas B27 has been shown to be present in 90 to 95% of cases of AS, the association of the B27 haplotype with other SNSpAs is more tenuous. The clear association between ReA and infection with Salmonella or other gram-negative enteric pathogens has led to the suggestion that the adaptive immune response to infection has an autoimmune component. In addition to various Salmonella species, other gram-negative enteric pathogens have been linked to the development of ReA. Given their close relationship to Salmonella, this review considers the involvement of Shigella species in ReA.

Spontaneous, drug-induced, and drug-free remission in peripheral and axial spondyloarthritis

In spondyloarthritis (SpA), spontaneous remission is best described in reactive arthritis, a form of peripheral SpA. Prior SpA observational studies suggested that a significant percentage of patients reached spontaneous remission; however, these patients were followed up under older, broader European Spondyloarthropathy Study Group (ESSG) criteria or were not defined by specific criteria. In general, they were mixed populations of peripheral and axial disease, and the subsets were not differentiated when assessing end points such as remission. There are limited data on the natural history of axial SpA, in part because of the evolution of the criteria with the more recently developed Assessment of SpondyloArthritis International Society (ASAS) criteria, including the designation of non-radiographic axial SpA and peripheral SpA. Clinical trials have been conducted with various remission end points including withdrawal of therapy to determine remission maintenance. The following review addresses the potential for remission in axial and peripheral SpA based on the data from both observational studies and clinical trials.

Systematic review and meta-analysis of the proportion of non-typhoidal Salmonella cases that develop chronic sequelae

The objective of this systematic review and meta-analysis was to estimate the proportion of cases of non-typhoidal salmonellosis (NTS) that develop chronic sequelae, and to investigate factors associated with heterogeneity. Articles published in English prior to July 2011 were identified by searching PubMed, Agricola, CabDirect, and Food Safety and Technology Abstracts. Observational studies reporting the number of NTS cases that developed reactive arthritis (ReA), Reiter's syndrome (RS), haemolytic uraemic syndrome (HUS), irritable bowel syndrome (IBS), inflammatory bowel disease (IBD) or Guillain–Barré syndrome (GBS), Miller–Fisher syndrome (MFS) were included. Meta-analysis was performed using random effects and heterogeneity was assessed using the I² value. Meta-regression was used to explore the influence of study-level variables on heterogeneity. A total of 32 studies were identified; 25 reported on ReA, five reported on RS, seven reported on IBS, two reported on IBD, two reported on GBS, one reported on MFS, and two reported on HUS. There was insufficient data in the literature to calculate a pooled estimate for RS, HUS, IBD, GBS, or MFS. The pooled estimate of the proportion of cases of NTS that developed ReA and IBS had substantive heterogeneity, limiting the applicability of a single estimate. Thus, these estimates should be interpreted with caution and reasons for the high heterogeneity should be further explored.

Non-typhoid salmonella septic arthritis in dual living liver transplant recipient: a case report

Non-typhoid salmonellosis is an infectious disease caused by Salmonella species other than Salmonella typhi. Although the usual clinical course of non-typhoid salmonellosis is a benign self-limiting gastroenteritis, these bacteria are especially problematic in immunocompromised individuals, including patients with malignancies, human immunodeficiency virus, or diabetes, and those receiving corticosteroids or other immunotherapy agents. In addition to enteric symptoms, Salmonella species give rise to extra-intestinal complications, including self-limiting arthritis, which appears 1 to 3 weeks after the onset of infection and lasts from a few weeks to several months. In some patients, however, this arthritis spears to be chronic in nature. We describe herein a living-donor liver transplant recipient who experienced non-typhoid Salmonella-triggered arthritis in the left hip. The patient recovered uneventfully after 6-month-long antibiotics treatment. Clinicians involved in transplantation should be aware of the possibility that transplant recipients, like other immunocompromised individuals, are at risk of salmonellosis and therefore require careful clinical and microbiological evaluation, with the goals of prevention and early recognition of infection.

Post-infectious sequelae of travelers' diarrhea

BACKGROUND

Travelers' diarrhea (TD) has generally been considered a self-limited disorder which resolves more quickly with expeditious and appropriate antibiotic therapy given bacteria are the most frequently identified cause. However, epidemiological, clinical, and basic science evidence identifying a number of chronic health conditions related to these infections has recently emerged which challenges this current paradigm. These include serious and potentially disabling enteric and extra-intestinal long-term complications. Among these are rheumatologic, neurologic, gastrointestinal, renal, and endocrine disorders. This review aims to examine and summarize the current literature pertaining to three of these post-infectious disorders: reactive arthritis, Guillain-Barré syndrome, and post-infectious irritable bowel syndrome and the relationship of these conditions to diarrhea associated with travel as well as to diarrhea associated with gastroenteritis which may not be specifically travel related but relevant by shared microbial pathogens. It is hoped this review will allow clinicians who see travelers to be aware of these post-infectious sequelae thus adding to our body of knowledge in travel medicine.

METHODS

Data for this article were identified by searches of PubMed and MEDLINE, and references from relevant articles using search terms "travelers' diarrhea" "reactive arthritis" "Guillain-Barré syndrome" "Post-Infectious Irritable Bowel Syndrome." Abstracts were included when related to previously published work.

RESULTS AND CONCLUSIONS

A review of the published literature reveals that potential consequences of travelers' diarrhea may extend beyond the acute illness and these post-infectious complications may be more common than currently recognized. In addition since TD is such a common occurrence it would be helpful to be able to identify those who might be at greater risk of post-infectious sequelae in order to target more aggressive prophylactic or therapeutic approaches to such individuals. It is hoped this review will allow clinicians who see travelers to be aware of these post-infectious sequelae thus adding to our body of knowledge in travel medicine.

Pathogen-specific Risk of Reactive Arthritis from Bacterial Causes of Foodborne Illness

Objective.

Reactive arthritis (ReA) is a sequelae of common bacterial infections of acute gastroenteritis. We assessed incidence of ReA following Campylobacter, Salmonella, Shigella, or Yersinia infection utilizing a US Department of Defense medical database.

Methods.

Subjects with acute gastroenteritis attributed to these pathogens were matched with ≥ 4 unexposed subjects. Medical history was analyzed for 6 months postinfection to assess for incident ReA.

Results.

A total of 1753 cases of gastroenteritis were identified. ReA incidence ranged from 0 to 4 per 100,000 person-years.

Conclusion.

These data are consistent with prior studies and highlight the need for continued primary prevention efforts.

Reactive arthritis

Reactive arthritis (ReA) can be defined as the development of sterile inflammatory arthritis as a sequel to remote infection, often in the gastrointestinal or urogenital tract. Although no generally agreed-upon diagnostic criteria exist, the diagnosis is mainly clinical, and based on acute oligoarticular arthritis of larger joints developing within 2-4 weeks of the preceding infection. According to population-based studies, the annual incidence of ReA is 0.6-27/100,000. In addition to the typical clinical picture, the diagnosis of ReA relies on the diagnosis of the triggering infection. Human leucocyte antigen (HLA)-B27 should not be used as a diagnostic tool for a diagnosis of acute ReA. In the case of established ReA, prolonged treatment of Chlamydia-induced ReA may be of benefit, not only in the case of acute ReA but also in those with chronic ReA or spondylarthropathy with evidence of persisting chlamydia antigens in the body. In other forms of ReA, there is no confirmed evidence in favour of antibiotic therapy to shorten the duration of acute arthritis. The outcome and prognosis of ReA are best known for enteric ReA, whereas studies dealing with the long-term outcome of ReA attributable to Chlamydia trachomatis are lacking.

The Genetic Basis of Spondyloarthritis: SPARTAN/IGAS 2009

A joint meeting was held in July 2009 in Houston, Texas, of members of the Spondyloarthritis Research and Therapy Network (SPARTAN), founded in 2003 to promote research, education, and treatment of ankylosing spondylitis (AS) and related forms of spondyloarthritis (SpA), and members of International Genetics of AS (IGAS), founded in 2003 to encourage and coordinate studies internationally in the genetics of AS. The general topic was the genetic basis of SpA, with presentations on the future of human genetic studies; microbes, SpA, and innate immunity; susceptibility of AS to the major histocompatibility complex (MHC) and non-MHC; and individual discussions of the genetics of psoriasis and psoriatic arthritis, uveitis, inflammatory bowel disease, and enteropathic arthritis. Summaries of those discussions are presented.

Reactive Arthritis and Other Musculoskeletal Sequelae Following an Outbreak of Salmonella hadar in Castellon, Spain

Objective.

In 2005 a large outbreak of Salmonella hadar occurred in Spain following the consumption of commercial precooked roast chicken. We estimated the incidence and risk factors for reactive arthritis (ReA) and other musculoskeletal sequelae in the patients of this outbreak in 2 health departments of Castellon province.

Methods.

A prospective cohort study of the patients and their families was carried out. Clinical infection with Salmonella was considered as the exposure factor. The cohort was studied for ReA symptoms using a telephone questionnaire. Telephone interviews or medical examinations of subjects with musculoskeletal symptoms were conducted by a rheumatologist. Robust Poisson regression models were used in the analysis.

Results.

From the cohort of 262 people, 248 (94.7%) participated in the telephone survey, 155 with clinical salmonellosis (infected), 78 noninfected, and 15 with some symptoms but not clinical salmonellosis. One hundred one infected patients (65%) reported musculoskeletal symptoms, compared to 19 noninfected (24%) (adjusted relative risk = 2.60, 95% CI 1.73–3.90). Of the infected group, 16 ReA (incidence 10%, 95% CI 6.0–16.2), 7 enthesopathies, and 2 arthralgias were detected, and zero in the noninfected group. The risk factors for ReA were age, weight loss, and duration of diarrhea. Antibiotic treatment for the infection protected against symptoms of peripheral or axial arthritis (adjusted relative risk = 0.73, 95% CI 0.55–0.98).

Conclusion.

The incidence of ReA and musculoskeletal symptoms after the infection was high. The use of antibiotics for S. hadar infection offered some protection against musculoskeletal symptoms.

Frequency of HLA-B27 and its alleles in patients with Reiter syndrome: comparison with the frequency in other spondyloarthropathies and a healthy control population

This retrospective study analyzed the HLA-B 27 alleles in a group of 20 consecutive patients with the diagnosis of Reiter syndrome (RS) followed in a tertiary referral university hospital in Brazil, during the period 1990-2006, and compared the data with that observed in other patients with spondyloarthropathies followed at the same institution. Eight cases were associated to gastrointestinal infection, eight cases to previous urethritis, and four cases presented no established preceding infection. HLA-B 27 alleles were typed by polymerase chain reaction-amplified DNA hybridized with sequence-specific oligonucleotide probes (HLA-B 2,701 to HLA-B 2,721). They were compared to a group of 108 patients with ankylosing spondylitis (AS), 40 with undifferentiated spondyloarthropathy (uSpA) and 111 healthy controls. Among the 20 patients, 17 were HLA-B 27 positive (85%). Two HLA-B 27 alleles were observed: HLA-B 2,705 (65%) and HLA-B 2,702 (35%). In the other spondyloarthropathies, the observed alleles were HLA-B 2,705 (90% in AS and 92.5% in uSpA), HLA-B 2,702 (8% in AS and 5% in uSpA), HLA-B 2,704 (1% in AS and 2.5% in uSpA) and HLA-B 2,713 (1% in AS). Among the 111 healthy controls, 80% presented HLA-B 2,705, followed by HLA-B 2,702 in 10%, HLA-B 2,703 in 6%, HLA-B 2,707 in 3% and HLA-B 2,713 in 1%. Concluding, in the HLA-B 27 positive patients with RS in this study there was predominance of HLA-B 2,705 allele, in a lower frequency than that observed in patients with other spondyloarthropathies and healthy controls.

Mechanisms of disease: infection and spondyloarthritis

There is compelling evidence that some infections can initiate a chronic nonseptic arthritis. This has proved to be an important area of investigation into gene-environment interactions, particularly since HLA-B27 confers increased susceptibility to reactive arthritis. This research has investigated the microbiology of these events, and the strategies used by pathogens to induce chronic joint inflammation. Insights into the HLA-orchestrated immune response in this context have also shed light on the impact of HLA-B27 on immunity, which might provide insights into the mechanism of other HLA-B27-associated diseases. Despite the genetic link to reactive arthritis, there is no proven relationship between ankylosing spondylitis and an inciting infection. In general, most trials have found antibiotics to be ineffective in modifying the course of spondyloarthritis.

Reactive arthritis or post-infectious arthritis?

The term 'reactive arthritis' was first used in 1969 to describe the development of sterile inflammatory arthritis as a sequel to remote infection, often in the gastrointestinal or urogenital tract. The demonstration of antigenic material (e.g. Salmonella and Yersinia lipopolysaccharide), DNA and RNA, and, in occasional cases, evidence of metabolically active Chlamydia spp. in the joints has blurred the boundary between reactive and post-infectious forms of arthritis. No validated and generally agreed diagnostic criteria exist, but the diagnosis of reactive arthritis is mainly clinical based on acute oligoarticular arthritis of larger joints that develops within 2-4 weeks of the preceding infection. In about 25% of patients, the infection can be asymptomatic. Diagnosis of the triggering infection is very helpful for the diagnosis of reactive arthritis. This is mainly achieved by isolating the triggering infection (stools, urogenital tract) by cultures (stool cultures for enteric microbes) or ligase reaction (Chlamydia trachomatis). However, after the onset of arthritis, this is less likely to be possible. Therefore, the diagnosis must rely on various serological tests to demonstrate evidence of previous infection, but, these serological tests are unfortunately not standardized. Treatment with antibiotics to cure Chlamydia infection is important, but the use of either short or prolonged courses of antibiotics in established arthritis has not been found to be effective for the cure of arthritis. The long-term outcome of reactive arthritis is usually good; however, about 25-50% of patients, depending on the triggering infections and possible new infections, subsequently develop acute arthritis. About 25% of patients proceed to chronic spondyloarthritis of varying activity.

Reactive arthritis

ReA consists of sterile axial or peripheral articular inflammation,enthesitis, and extra-articular manifestations. Most patients are HLA-B27 positive, although determining the B27 status of an individual patient is irrelevant. Exposure to specific bacterial antigens is usually the inciting factor. Diagnosis usually can be made by clinical examination and history. The current standard therapy is NSAIDs and physiotherapy, but molecular biologic treatment may ultimately become the mainstay in recalcitrant and severe ReA.

Emergence ofSalmonellaBlockley, possible association with long-term reactive arthritis, and antimicrobial resistance

We previously reported the case of a patient who became ill with Salmonella serotype Blockley after eating a chicken meal and who was still suffering symptoms of salmonella-reactive arthritis 10 years after the initial infection. The immunological consequences of infection were of concern and prompted a literature review because of the possibility that Salmonella Blockley may be more likely to cause long-term illness in certain patients than more common serovars. The review revealed the additional cause for concern of plasmid-borne extended spectrum beta-lactamases and the high frequency of integron-associated multidrug resistance in some isolates. The serovar was described in 1955 in the USA and Europe. It has become common in South East Asia and recently has been reported more often in Europe. A review of reactive arthritis outbreaks shows that information on the incidence and duration of the condition caused by serovars other than Salmonella serotype Enteritidis and Salmonella serotype Typhimurium is very limited. Rheumatologists can assist microbiologists and epidemiologists by reporting relevant cases of long-term reactive arthritis.

Reiter's syndrome (reactive arthritis) and travelers' diarrhea

Reiter's syndrome [also called reactive arthritis (ReA)] is the triad of arthritis, urethritis, and conjunctivitis. Two cases of Reiter's syndrome triggered by travelers' diarrhea are presented. Health care providers should suspect ReA in travelers with joint symptoms and antecedent diarrheal disease.

Early cytokine profiles in the joint define pathogen clearance and severity of arthritis inChlamydia-induced arthritis in rats

OBJECTIVE

Although Chlamydia trachomatis-induced arthritis is among the most common rheumatic diseases having an identified infectious trigger, the pathogenesis of this arthritis is not well defined. We sought to investigate the host-microbe interactions that contribute to the severity of arthritis initiated by chlamydial infection.

METHODS

We established an experimental rat model of C. trachomatis-induced arthritis that recapitulates many pathologic features of the clinical disease. The severity of the arthritis was defined using an established histopathologic scoring system. Host clearance of the pathogen and local cytokine production were examined by enzyme-linked immunosorbent assays.

RESULTS

Lewis rats were susceptible to C. trachomatis-induced arthritis, whereas BN rats were relatively resistant to this disease. Significant differences in the histopathologic severity of arthritis were originally observed on day 21, and this prompted an examination of the acute phase of the arthritis. As early as day 5 after the onset of the arthritis, pathologic changes in Lewis rats were more severe than those in BN rats. An evaluation of the role of complement using cobra venom factor treatment excluded complement as being the key to differential sensitivity, because decomplementation did not eliminate the differences in arthritis severity between Lewis and BN rats. Host clearance, in contrast, was significantly different between the rat strains, with BN rats showing more prompt and effective clearance of the pathogen from both synovial tissues and spleen compared with Lewis rats. Local cytokine profiles demonstrated that host resistance was characterized by enhanced synovial expression of tumor necrosis factor alpha, interferon-gamma (IFNgamma), and interleukin-4.

CONCLUSION

These studies demonstrated that cytokines thought to be proinflammatory in nature can play an important role in host defense in infection-triggered arthritis and serve to highlight the dynamic cytokine relationships that constitute effective host-pathogen interactions.

Etiology of reactive arthritis inPan paniscus, P. troglodytes troglodytes, andP. troglodytes schweinfurthii

The character of arthritis has not received the same attention in Pan paniscus as it has in P. troglodytes. Reactive arthritis (a form of spondyloarthropathy) in the latter has been considered to be either a sexually transmitted or an infectious-agent diarrhea-related disorder. The unique sexual promiscuity of P. paniscus enables us to distinguish between those hypotheses. The macerated skeletons of 139 adult P. paniscus, P. troglodytes troglodytes, and P. troglodytes schweinfurthii were macroscopically analyzed for osseous and articular pathologies. The sex of the animal was recorded at the time of acquisition. Twenty-one percent of the P. paniscus, 28% of the P. t. troglodytes, and 27% of the P. t. schweinfurthii specimens had peripheral and central joint erosive disease characteristic of spondyloarthropathy. Subchondral pauciarticular distribution and reactive new bone clearly distinguish this disease from rheumatoid arthritis, osteoarthritis, and direct bone/joint infection. The fact that P. paniscus and P. t. troglodytes were similar in terms of disease frequency makes the notion of sexual transmission unlikely. While the frequencies of spondyloarthropathy were indistinguishable among all species/subspecies studied, the patterns of joint involvement were disparate. The Pan paniscus and P. t. troglodytes home ranges are geographically separate. We assessed possible habitat factors (e.g., exposure to specific infectious agents of diarrhea) by comparing P. paniscus and P. t. troglodytes with P. t. schweinfurthii. The latter shared similar patterns and habitats (separated by the Congo River) with P. paniscus. The explanation offered for habitat-specific patterns is differential bacterial exposure-most likely Shigella or Yersinia in P. paniscus and P. t. schweinfurthii.

Comparison of arthritis characteristics in lowlandGorilla gorilla and mountainGorilla beringei

Gorilla gorilla and the less-studied G. beringei occupy very different, geographically separate habitats. We studied the occurrence of various forms of arthritis to examine possible nature/nurture causality. The macerated skeletons of 38 G. beringei and 99 G. gorilla individuals were examined macroscopically for the presence of articular and osseous pathologies. Contrasting with only isolated osteoarthritis and infectious arthritis was the frequent occurrence of a form of erosive arthritis associated with joint fusion. Twenty-one percent of the G. beringei and 20% of G. gorilla specimens were afflicted, which are statistically indistinguishable frequencies. While both had prominent axial disease, they differed in patterns of peripheral arthritis. Whereas G. beringei showed a pauciarticular pattern, the pattern in G. gorilla was more often polyarticular. Susceptibility to spondyloarthropathy was apparently genetically imprinted before Gorilla separated into G. gorilla and G. beringei. However, the different patterns of peripheral joint involvement suggest a causality resulting from lifestyle (e.g., the presence/absence or extent of knuckle walking) or a habitat-related infectious agent.

Synovial fibroblasts infected with Salmonella enterica serovar Typhimurium mediate osteoclast differentiation and activation

The mechanisms whereby arthritogenic organisms may induce cartilage and bone erosions in infection-triggered arthritis remain unknown. In this study, we asked whether an arthritogenic organism could contribute to osteoclast differentiation and activation through regulation of the receptor activator of NF-kappaB ligand (RANKL) in synovial fibroblasts. Rat synovial fibroblasts were infected in vitro with Salmonella enterica serovar Typhimurium and monitored over time. The expression of RANKL in resting and infected synovial fibroblasts was quantified by reverse transcription-PCR and Western blotting. Osteoclast progenitors, isolated from femurs of 8-week-old rats and cultured in the presence of macrophage colony-stimulating factor, were cocultured with either infected or noninfected synovial fibroblasts for 2 to 4 days. Differentiation and maturation of osteoclasts were determined by morphology and tartrate-resistant acid phosphatase (TRAP) staining and by a bone resorption bioassay. RANKL expression was undetectable in resting synovial fibroblasts but was dose-dependently upregulated in cells after Salmonella infection. Osteoprotegerin was constitutively expressed by synovial fibroblasts and was not upregulated by infection. Further, we observed the formation of multinucleated TRAP-positive cells and formation of bone resorption pits in cocultures of bone marrow-derived osteoclast precursors with synovial fibroblasts infected with Salmonella but not with heat-killed Salmonella or noninfected cells. Arthritogenic bacteria may alter bone structure via synovial fibroblast intermediaries, since infected synovial fibroblasts (i) upregulate RANKL expression and (ii) enhance osteoclast precursor maturation into multinucleated, TRAP-positive, bone-resorbing, osteoclast-like cells. These data provide a link between infection and osteoclastogenesis. A better understanding of infection-mediated osteoclast differentiation and activation may provide new therapeutic strategies for inflammatory joint disease.

[Reiter's syndrome after Salmonella infection]

Two patients with Reiter's syndrome, after Salmonella infection were treated on the Infections disease ward at Clinical hospital center in Kragujevac. In the first patient, ten days after the onset of Salmonella infection, signs of edema and pain in the right ankle occurred, accompanied by expressed conjunctivitis. Within next two months consecutive metatarsophalanges changes joint of the right foot have appeared. In the second patient, two weeks after the onset of Salmonella infection, edema of the left hand joints and a week later edema of the right hand and right ankle joints appeared. In both patients inflammatory syndrome was expressed (high erythrocyte sedimentation rates, fibrinogen, C-reactive protein) along with negative rheumatoid factors and positive antigen HLA-B27. Outcome of the disease in both cases was favourable upon receiving nonsteroid antirheumatic therapy. Signs of arthritis disappeared after three months. No signs of recurrent arthritis have been seen during the next four years in the first and next two years in the second patient.

Microbial factors in spondyloarthropathies: insights from population studies

Infections and genetics play a role in the development of reactive arthritis. The clinical manifestations and severity of the features depend on the triggering infections and the epidemiologic setting. Reports from hospital-based series show the lowest frequency of reactive arthritis, but often, patients have severe arthritis associated with a high frequency of HLA-B27. At the population level, reactive arthritis occur in 7 to 15% of the infected subjects. The disease is usually mild, affects small joints, can be polyarticular, often rapidly disappears, and has a low association with HLA-B27. There also seems to be a change in the spectrum of triggering infections. Reports of Yersinia arthritis are less common, whereas arthritis in association with Campylobacter or Salmonella infections seems to be increasing. The role of early antimicrobial chemotherapy for the prevention of reactive arthritis needs to be studied.

Reactive arthritis: newer developments

Reactive arthritis (ReA) is characterized by an aseptic inflammatory articular involvement occurring in a genetically predisposed individual secondary to an infectious process localized outside the joint. ReA usually refers to an acute or insidious oligoarthritis process after enteric (enteroarthritis) or urogenital (uroarthritis) infection. Conventional antirheumatic therapeutic modalities based on nonsteroid anti-inflammatory drugs, sulfasalazine, and steroids are effective in the majority of patients. In more refractory cases, the use of second-line agents including methotrexate and more recently biological agents such as etanercept and infliximab has been found highly effective. The role of antibiotics remains not well established, although they appear to be effective in acute ReA of urogenital origin.

Rapid diagnosis of acute Salmonella gastrointestinal infection

Serologic tests for the detection of Salmonella serotype Enteritidis in children may become supplementary to stool culture examination. A total of 190 children were examined with a new 1-step, 2-minute test (TUBEX) that detects anti-Salmonella immunoglobulin M antibodies, which was found to be 92.6% sensitive and 94.8% specific (P<.0001).

Invasion of Salmonella into human intestinal epithelial cells is modulated by HLA-B27

OBJECTIVE

To investigate the influence of the major histocompatibility complex (MHC) class I molecule HLA-B27 on (i) the invasion of Salmonella and Yersinia into human intestinal epithelial cells, (ii) the survival of intracellular Salmonella in these cells, and (iii) the production of certain inflammatory cytokines by the cells after Salmonella infection.

METHODS

The human intestinal epithelial cell line Henle-407 was transfected with HLA-B27 DNA. These cells and HLA-B27-negative control cells were infected with Salmonella or Yersinia, and viable intracellular bacteria were determined as colony-forming units. Cytokine production was assayed with ELISA.

RESULTS

Salmonella invaded HLA-B27-positive Henle cells in higher numbers than HLA-B27-negative control cells. However, HLA-B27 did not affect the invasion of Yersinia or the survival of the intracellular bacteria in these intestinal epithelial cells. Salmonella infection induced production of interleukin-8 (IL-8), IL-6 and monocyte chemotactic protein 1 (MCP-1) by Henle cells that was not affected by HLA-B27 in a specific way.

CONCLUSIONS

These findings suggest that HLA-B27 enhances the invasion of Salmonella into intestinal epithelial cells. The interaction between bacteria and intestinal epithelial cells plays an important role during the early phases of ReA. HLA-B27-linked modulation of Salmonella invasion may lead to an increased load of Salmonella in intestinal tissue and thus increased susceptibility to reactive arthritis.

Campylobacter jejuni infection during pregnancy: long-term consequences of associated bacteremia, Guillain-Barré syndrome, and reactive arthritist

Campylobacter jejuni infections are the main cause of foodborne gastroenteritis in the United States and other developed countries. Generally, C. jejuni infections are self-limiting and treatment is not necessary; however, infections caused by this organism can lead to potentially dangerous long-term consequences for some individuals. Bacteremia, Guillain-Barré syndrome (GBS; an acute flaccid paralytic disease), and reactive arthritis (ReA) are the most serious of the long-term consequences of C. jejuni infections. During pregnancy, foodborne infections may be hazardous to both the woman and the fetus. C. jejuni-induced bacteremia during pregnancy may lead to intrauterine infection of the fetus, abortion, stillbirth, or early neonatal death. Infection of a newborn by the mother during the birth process or shortly after birth may lead to neonatal enteritis, bacteremia, and/or meningitis. C. jejuni enteritis is the inducing antecedent infection in approximately 30% of cases of GBS. Thus, pregnant women infected with C. jejuni may contract GBS. GBS during pregnancy does not affect fetal or infant development and does not increase spontaneous abortion or fetal death; however, it may induce spontaneous delivery during the third trimester in severe cases. Reactive arthritis occurs in approximately 2% of C. jejuni enteritis cases and leads to the impaired movement of various joints. Pregnant women with C. jejuni-induced reactive arthritis can be expected to deliver a normal infant. A pregnant patient with GBS or ReA may be unable to care for a newborn infant because of the physical impairment induced by these diseases. Since C. jejuni infections put both fetuses and pregnant women at risk, pregnant women must take special care in food handling and preparation to prevent such infections.

From farm to table to brain: foodborne pathogen infection and the potential role of the neuro-immune-endocrine system in neurotoxic sequelae

The American diet is among the safest in the world; however, diseases transmitted by foodborne pathogens (FBPs) still pose a public health hazard. FBPs are the second most frequent cause of all infectious illnesses in the United States. Numerous anecdotal and clinical reports have demonstrated that central nervous system inflammation, infection, and adverse neurological effects occur as complications of foodborne gastroenteritis. Only a few well-controlled clinical or experimental studies, however, have investigated the neuropathogenesis. The full nature and extent of neurological involvement in foodborne illness is therefore unclear. To our knowledge, this review and commentary is the first effort to comprehensively discuss the issue of FBP induced neurotoxicity. We suggest that much of this information supports the role of a theoretical model, the neuro-immune-endocrine system, in organizing and helping to explain the complex pathogenesis of FBP neurotoxicity.

Randomised, blinded, placebo controlled trial of doxycycline for chronic seronegative arthritis

OBJECTIVE

To determine whether long term doxycycline improves symptoms in patients with chronic seronegative or reactive arthritis.

METHODS

A randomised, triple blind, controlled clinical trial of three months' treatment with doxycycline or placebo of patients with chronic reactive or seronegative arthritis was conducted. The primary study end points were three month pain and functional status measured by a self administered Arthritis Impact Measurement Scales version 2 (AIMS2) quality of life questionnaire. Secondary end points were pain and functional status at 6-12 months, three month rheumatologist assessed joint count, pain, and arthritis activity, and treatment efficacy in those with previous exposure to chlamydia.

RESULTS

Of 60 patients randomly allocated to receive doxycycline or placebo, results from 37 were evaluable at three months. Groups were well balanced for major prognostic variables. Doxycycline had no detectable effect at three months on pain change scores (mean difference 1.5, 95% CI -1.2 to 4.2, p=0.25) or composite functional change scores (mean difference 0.8, 95% CI -5.6 to 7.1, p=0.81). Furthermore, there were no differences in secondary study end points, and no apparent treatment effect in patients with previous chlamydia infection.

CONCLUSION

Three months' treatment with doxycycline did not improve pain or functional status in patients with chronic reactive or seronegative arthritis.

Reactive arthritis and Reiter's syndrome following an outbreak of gastroenteritis caused by Salmonella enteritidis

Reactive arthritis and Reiter's syndrome have been reported following gastroenteritis. Prevalence studies for these conditions are uncommon, and the prevalence of Reiter's syndrome after Salmonella enteritidis infection has not been previously reported. After a large outbreak of S. enteritidis gastroenteritis, a survey of persons exposed to the implicated food source was conducted, and those with reactive arthritis were evaluated for possible risk factors. Among 481 persons responding to the questionnaire, 217 cases of S. enteritidis gastroenteritis were identified (31 confirmed and 186 clinical cases; attack rate, 45%). Twenty-nine percent of the cases had symptoms of reactive arthritis, 3% had symptoms of Reiter's syndrome, and 10% had reactive arthritis with oral ulcers. Markers for severe illness (diarrhea > or =7 days, emergency room visit or hospitalization, and antibiotic treatment) were statistically significant but colinear factors associated with reactive arthritis. Increased awareness of postdysenteric reactive arthritis and Reiter's syndrome is recommended.

Frequency of triggering bacteria in patients with reactive arthritis and undifferentiated oligoarthritis and the relative importance of the tests used for diagnosis

OBJECTIVE

Reactive arthritis (ReA) triggered by Chlamydia trachomatis or enteric bacteria such as yersinia, salmonella, Campylobacter jejuni, or shigella is an important differential diagnosis in patients presenting with the clinical picture of an undifferentiated oligoarthritis (UOA). This study was undertaken to evaluate the best diagnostic approach.

PATIENTS AND METHODS

52 patients with ReA, defined by arthritis and a symptomatic preceding infection of the gut or the urogenital tract, and 74 patients with possible ReA, defined by oligoarthritis without a preceding symptomatic infection and after exclusion of other diagnoses (UOA), were studied. The following diagnostic tests were applied for the identification of the triggering bacterium: for yersinia induced ReA-stool culture, enzyme immunoassay (EIA), and Widal's agglutination test for detection of antibodies to yersinia; for salmonella or campylobacter induced ReA-stool culture, EIA for the detection of antibodies to salmonella and Campylobacter jejuni; for infections with shigella-stool culture; for infections with Chlamydia trachomatis-culture of the urogenital tract, microimmunofluorescence and immunoperoxidase assay for the detection of antibodies to Chlamydia trachomatis.

RESULTS

A causative pathogen was identified in 29/52 (56%) of all patients with ReA. In 17 (52%) of the patients with enteric ReA one of the enteric bacteria was identified: salmonella in 11/33 (33%) and yersinia in 6/33 (18%). Chlamydia trachomatis was the causative pathogen in 12/19 (63%) of the patients with urogenic ReA. In patients with the clinical picture of UOA a specific triggering bacterium was also identified in 35/74 (47%) patients: yersinia in 14/74 (19%), salmonella in 9/74 (12%), and Chlamydia trachomatis in 12/74 (16%).

CONCLUSIONS

Chlamydia trachomatis, yersinia, and salmonella can be identified as the causative pathogen in about 50% of patients with probable or possible ReA if the appropriate tests are used.

Chlamydia and associated arthritis

An inflammatory arthritis is known to follow urogenital infection with the intracellular bacterium Chlamydia trachomatis in some individuals, and recent research results have elucidated important aspects of the characteristics of this Chlamydia-associated joint disease. Although the several extra-articular features of Chlamydia-induced arthritis have been defined clinically, their detailed causes remain largely unexplained. Current data indicate that the clinical characteristics of joint disease associated with C. trachomatis infection and those associated with postenteric arthritis are not easily distinguishable, although the response of each to antibiotic therapy does differ. The biologic characteristics of Chlamydia and enteric organisms in the joint show profound differences, and these are probably responsible for the variable responses to drug treatment. Molecular analyses of synovial C. trachomatis have demonstrated that long-term infection of the joint occurs primarily in synovial tissue and that the organism exhibits highly unusual biologic properties in its synovial context. These unusual molecular, biochemical, and other characteristics provide explanations for the frequent culture negativity of joint materials for C. trachomatis and for several other aspects of the arthritogenic process. Much remains to be learned concerning the behavior of this organism in the joint and concerning its interaction with its synovial host cells.

Modification of disease outcome in Salmonella-infected patients by HLA-B27

OBJECTIVE

To study whether HLA-B27 modifies the outcome of Salmonella infection in vivo.

METHODS

The frequency of HLA-B27 was determined in 198 Salmonella-infected patients and 100 healthy controls by immunofluorescence and polymerase chain reaction. The excretion of Salmonella was monitored at monthly intervals. The symptoms of acute infection and possible joint involvement were evaluated using questionnaires.

RESULTS

Thirty-eight of 198 Salmonella-infected patients (19.2%) and 13 of 100 healthy controls (13.0%) were HLA-B27 positive. The excretion of Salmonella did not differ significantly between HLA-B27-positive and -negative patients, or for patients with versus those without joint symptoms. As many as 35 patients (17.7%) reported Salmonella-triggered joint symptoms. Three of 14 patients (21.4%) with arthralgia, 5 of 13 patients (38.5%) with probable reactive arthritis (ReA), and 6 of 8 patients (75%) with confirmed ReA were HLA-B27 positive. The duration and severity of joint symptoms directly correlated with HLA-B27 positivity. Women reported Salmonella-induced pain and swelling of joints more frequently than men (P = 0.07 and P = 0.03, respectively). Patients with Salmonella-triggered joint symptoms reported abdominal pain and headache more frequently than patients without joint symptoms (P = 0.05 and P = 0.004, respectively).

CONCLUSION

HLA-B27 did not (at least, not strongly) confer susceptibility to Salmonella infection. Salmonella excretion correlated neither with HLA-B27 positivity nor with the occurrence of joint symptoms. Joint symptoms were surprisingly common during or after Salmonella infection. HLA-B27-positive patients had a significantly increased risk of developing joint and tendon symptoms. Moreover, HLA-B27 positivity correlated with the development of more severe and prolonged joint symptoms.

HLA-B27 expression and reactive arthritis susceptibility in two patient cohorts infected with Salmonella Typhimurium

BACKGROUND

Reactive arthritis (ReA) is an inflammatory arthritis triggered by certain gastrointestinal and genitourinary infections. Single source outbreaks of triggering infections provide an opportunity to elucidate host susceptibility factors in this disease.

AIM

To determine the role of Major Histocompatibility Complex (MHC) Class I alleles in ReA susceptibility after two large single source outbreaks of Salmonella Typhimurium gastroenteritis.

METHODS

A questionnaire screening for features of ReA and a request for HLA class I typing were sent to all patients affected by two single source outbreaks of S. Typhimurium gastroenteritis. Individuals with arthritis of recent onset were interviewed, examined and diagnostic criteria for ReA applied.

RESULTS

Nineteen cases of reactive arthritis, 11 female, were diagnosed in the 424 respondents with S. Typhimurium gastroenteritis from both outbreaks. Clinical features of the arthritis were similar to those described after other large single source outbreaks of Salmonella infection. HLA-B27 was expressed by only two of the 19 ReA patients and therefore did not predict susceptibility to this form of arthritis. Caucasians were, however, more likely to develop reactive arthritis than Asians.

CONCLUSIONS

In this study, susceptibility to ReA was not increased in HLA-B27 positive individuals or males but was greater in those of Caucasian descent.

Tumor necrosis factor receptor p55 controls the severity of arthritis in experimental Yersinia enterocolitica infection

OBJECTIVE

To dissect the host defense mechanisms in relation to the development of Yersinia-associated arthritis by evaluating the impact of tumor necrosis factor receptor p55 (TNFRp55) deficiency on Yersinia enterocolitica infection.

METHODS

TNFRp55-/- and C57BL/6 mice were inoculated intravenously with arthritogenic strain 8081 of Yenterocolitica serotype 0:8. Mice were observed daily for generating survival curves and monitoring arthritis. In subsequent sets of experiments, mice were sacrificed at day 14 after infection for examination of histopathology of joints, bacterial clearance, macrophage microbicidal activity, nitric oxide (NO) production, oxidative burst generation, and cytokine production.

RESULTS

There was an 80% mortality rate in TNFRp55-/- mice compared with 25% in the controls at 8 weeks after inoculation with 70 colony-forming units of Y. enterocolitica 0:8. Histologic examination of joint tissues revealed that TNFRp55-/- mice developed more severe arthritis, including cartilage degradation and bony destruction, than controls at day 14 after infection. The more extensive joint pathology in TNFRp55-/- mice was correlated with the higher bacterial load in liver, spleen, and lungs, and with the increased levels of interleukin-10. TNFRp55-/- mice displayed impaired intracellular killing of bacteria by macrophages. This was associated with decreased NO production and impaired oxidative burst activity.

CONCLUSION

This study demonstrates that TNF signaling through TNFRp55 controls the severity of Yersinia-induced arthritis and implicates TNF-mediated macrophage microbicidal activity as a central event in this process.