Reactive arthritis or post-infectious arthritis?

YouTube as a source of information on reactive arthritis: a quality analysis

OBJECTIVE

YouTube is often used by patients and healthcare professionals to obtain medical information. Reactive arthritis (ReA) is a type of inflammatory arthritis triggered by infection, usually in the genitourinary or gastrointestinal tract. However, the accuracy and quality of ReA-related information on YouTube are not fully known. This study aimed to assess the reliability and quality of YouTube videos pertaining to ReA.

MATERIALS AND METHODS

A YouTube search was performed on August 1, 2023, using the keywords "reactive arthritis," "Reiter's disease," and "Reiter's syndrome." The number of days since upload; the number of views, likes, and comments; and the duration of videos were recorded. The modified DISCERN tool (mDISCERN) and the global quality scale (GQS) were used to evaluate the reliability and quality of the videos. Two physicians independently classified videos as low, moderate, or high quality and rated them on a five-point GQS (1 = poor quality, 5 = excellent quality). The source of videos was also noted.

RESULTS

Of the 180 videos screened, 68 met the inclusion criteria. The most common topic (61, 89.7%) was "ReA overview." Among the 68 videos analyzed, the main source of uploads was physicians 45 (66.2%), and 66 (97%) were categorized as useful. Around half of the YouTube videos about ReA were of high quality (33, 48.5%) according to the GQS. Upon comparing videos uploaded by rheumatologists, non-rheumatology healthcare professionals, and independent users, significant differences were found in mDISCERN and GQS but not in the number of views, likes, and comments or duration. Upon comparing high-, moderate-, and low-quality videos, significant differences were found in the number of views, likes, and comments; duration; and in mDISCERN and GQS.

CONCLUSION

YouTube is a source of information on ReA of variable quality, with wide viewership and the potential to influence patients' knowledge and behavior. Our results showed that most YouTube videos on ReA were of high quality. Videos presented by physicians had higher quality. YouTube should consider avoiding low-quality videos by using validity scales such as mDISCERN and GQS.

Pre-Rheumatology Referral Consultation and Investigation Pattern in Children with Joint Complaints: Focus on Juvenile Idiopathic Arthritis

The diagnosis of juvenile idiopathic arthritis (JIA) is often entrusted to the pediatric rheumatologist specialist. Timely referral to a specialized center is crucial. This study aims to assess the consultation and investigation patterns of patients with joint complaints before rheumatology referral. This longitudinal cohort study included patients with joint complaints who were referred to the Pediatric Rheumatology Unit. The cohort included 301 patients (58% female), 50 of them (17%) diagnosed with JIA. Compared to patients with orthopedic conditions or functional diseases, JIA patients had seen more specialists (p < 0.01) and received a quicker diagnosis (p < 0.01). Patients with early JIA diagnosis (within 3 months from symptoms onset) were younger (8.46 vs. 11.5 years old; p = 0.04), more frequently female (78% vs. 47%, p = 0.03), and with higher erythrocyte sedimentation rate (ESR) values (37 vs. 9 mm/h; p = 0.02) than those diagnosed later. Patients with a late diagnosis of JIA had a significantly longer median time between the first healthcare visit and the PR referral (25 vs. 101 days; p < 0.01). The main contributor to diagnostic delay in JIA was the time required for PR referral after the first healthcare consult. Younger age, female sex, and higher ESR values were associated with earlier diagnosis of JIA.

Leaky gut, circulating immune complexes, arthralgia, and arthritis in IBD: coincidence or inevitability?

Most host-microbiota interactions occur within the intestinal barrier, which is essential for separating the intestinal epithelium from toxins, microorganisms, and antigens in the gut lumen. Gut inflammation allows pathogenic bacteria to enter the blood stream, forming immune complexes which may deposit on organs. Despite increased circulating immune complexes (CICs) in patients with inflammatory bowel disease (IBD) and discussions among IBD experts regarding their potential pathogenic role in extra-intestinal manifestations, this phenomenon is overlooked because definitive evidence demonstrating CIC-induced extra-intestinal manifestations in IBD animal models is lacking. However, clinical observations of elevated CICs in newly diagnosed, untreated patients with IBD have reignited research into their potential pathogenic implications. Musculoskeletal symptoms are the most prevalent extra-intestinal IBD manifestations. CICs are pivotal in various arthritis forms, including reactive, rheumatoid, and Lyme arthritis and systemic lupus erythematosus. Research indicates that intestinal barrier restoration during the pre-phase of arthritis could inhibit arthritis development. In the absence of animal models supporting extra-intestinal IBD manifestations, this paper aims to comprehensively explore the relationship between CICs and arthritis onset via a multifaceted analysis to offer a fresh perspective for further investigation and provide novel insights into the interplay between CICs and arthritis development in IBD.

Immunologic derangement caused by intestinal dysbiosis and stress is the intrinsic basis of reactive arthritis

Reactive arthritis (ReA) is defined as arthritis resulting from infections in other body parts, such as the gastrointestinal and urogenital tracts. The primary clinical manifestations involve acute-onset and self-limiting asymmetric large joint inflammation in the lower limbs. Although bacterial or chlamydia infections have long been recognized as playing a pivotal role in its pathogenesis, recent studies suggest that antibiotic treatment may perpetuate rather than eradicate chlamydia within the host, indicating an involvement of other mechanisms in Reactive arthritis. Reactive arthritis is currently believed to be associated with infection, genetic marker (HLA-B27), and immunologic derangement. As an autoimmune disease, increasing attention has been given to understanding the role of the immune system in Reactive arthritis. This review focuses on elucidating how the immune system mediates reactive arthritis and explores the roles of intestinal dysbiosis-induced immune disorders and stress-related factors in autoimmune diseases, providing novel insights into understanding reactive arthritis.

The development of inflammatory arthritis following SARS-CoV-2 infection: a systematic review of the literature

BACKGROUND

Given the widespread impact of COVID-19, it is important to explore any atypical presentations and long-term sequelae associated with this viral infection, including the precipitation of inflammatory arthritis.

OBJECTIVE

To identify and summarize clinical reports of acute inflammatory arthritis associated with COVID-19.

METHODS

A systematic review of the PubMed (MEDLINE), Google Scholar, and Cochrane Central databases through January 31, 2022 was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. The inclusion criteria were: human subjects and English language. Data extraction and qualitative synthesis of the demographics, clinical presentations, treatments, and outcomes were performed. Quality assessment was performed using the Joanna-Briggs Institute critical appraisal tools.

RESULTS

A total of 37 articles collectively describing the cases of 54 patients were included. The mean age was 48.2 years (6-78 years). 53.7% of patients were male and 46.3% were female. The onset of articular symptoms varied considerably, and the majority of cases were described as polyarticular (29). The classification of inflammatory arthritis in the included studies was as follows: reactive (19), post-viral (13), new-onset rheumatoid arthritis (RA) (8), crystal-proven arthropathy flare (4), acute viral (2), new-onset psoriatic arthritis (2), flare of preexisting RA (2), and other (4). Arthritis treatment regimens varied but consisted largely of NSAIDs and corticosteroids with most patients experiencing improvement or resolution of their joint symptoms.

CONCLUSION

There is limited low-level evidence suggesting that patients may develop acute arthritis during or after SARS-CoV-2 infection. This review highlights the need for further research to elucidate the relationship between COVID-19 and the development of inflammatory arthritis.

Cutaneous and rheumatological manifestations of reactive arthritis: A case report

Reactive arthritis is a rare form of spondyloarthropathies occurring after genital or enteric infection. It is most often self-limited but can progress to chronic spondylarthritis. We report the case of a 30-year-old man who presented with acute arthritis occurring 2 months after an episode of urethral discharge. Physical examination revealed polyarthritis, dactylitis, sacroiliac joint involvement, and plantar papulosquamous plaques. The human leukocyte antigen B27 was positive. Detection of Chlamydia trachomatis and Gonococcus in the first catch urine specimen was negative. Hepatitis B and C, Chlamydia trachomatis, human immunodeficiency virus, and syphilis serologic test results were negative. Pelvic magnetic resonance imaging revealed left sacroiliitis. The patient was treated with antibiotics, diclofenac, and sulfasalazine. After 6 months of follow-up, a significant clinical improvement was obtained without remission, suggesting an evolution to chronic spondylarthritis. Diagnosis of Reactive arthritis is difficult since microbiologic examinations are commonly negative. This disease should be considered in patients with rheumatologic manifestations occurring after a urogenital or enteric infection, mainly when associated with skin manifestations and human leukocyte antigen B27.

Reactive arthritis after SARS-CoV-2 infection

SARS-CoV-2 has been recognised as a potential trigger of inflammatory arthritis in individuals with inflammatory rheumatic diseases as well as in previously unaffected individuals. However, new-onset arthritis after COVID-19 is a heterogeneous phenomenon that complicates differential diagnosis. For example, acute arthritis with features of viral arthritis has been reported after COVID-19, as has crystal-induced arthritis. Arthritides mimicking reactive arthritis (ReA) have also been described, but these patients often do not fulfil the typical features of ReA: several reports describe cases of patients older than 45 years at the onset of arthritis, and the characteristic genetic feature of ReA, HLA-B27, is rarely found. Because viral infections are much less likely to cause ReA than bacterial infections, and respiratory infections are rarely the cause of ReA, it is currently unknown whether SARS-CoV-2 can cause true ReA. Here, we report the case of a 30-year-old patient who presented with acute pain, swelling and redness in the left metatarsophalangeal (MTP) joint and ankle 7 days after resolution of a SARS-CoV-2 infection. Diagnostics revealed arthritis of the MTP2, synovitis of the upper ankle with significant joint effusion and peritendinitis of the flexor tendons. Based on the clinical manifestations and diagnostic test results, ReA appeared to be the most likely cause. A screening for typical ReA-associated infections was negative. The patient was treated with NSAIDs and intra-articular and systemic glucocorticoids. At a follow-up visit after discontinuation of glucocorticoids, the patient was symptom-free. Overall, we observed a ReA with typical clinical, genetic and patient characteristics after SARS-CoV-2 infection, and we conclude that a direct association with COVID-19 is highly plausible.

[History of reactive arthritis. Historical milestones and future]

The introduction of the term reactive arthritis (ReA) for the joint inflammation observed after infection with Yersinia enterocolitica, in which "a causative pathogen cannot be isolated from the synovial fluid", and the association with the HLA-B27 were the historical milestones for a new classification and assignment to the spondylarthritides (SpA). The division into postinfectious and reactive arthritis proposed in 1976 was put into perspective in the 1990s because of investigations with the newly available molecular biological method of the polymerase chain reaction. Microbial products could be identified from joint samples of patients with ReA. Therefore, it was proposed to abandon the distinction between the two groups of diseases and to prefer the term ReA for both. This created a terminological and nosological issue. On the one hand, there are generally accepted classification and diagnostic criteria for the classical HLA-B27-associated ReA that are assigned to SpA. On the other hand, an increasing number of bacterial pathogens, viruses, amoebas, helminths as well as antiviral and antibacterial vaccinations are described as triggers of arthritis, which have been published under the term ReA. Since the beginning of the SARS-CoV‑2 pandemic, cases of acute post-COVID-19 arthritis have been described, which were also classified as ReA because of comparable clinical features.

Reactive arthritis before and after the onset of the COVID-19 pandemic

Most accepted definitions of reactive arthritis (ReA) consider it a type of spondyloarthritis (SpA) precipitated by a gut or urogenital infection. A wider definition considers any arthritis that occurs after a mucosal surface infection as ReA. There is limited consensus regarding a working definition, status of HLA-B27, or even classification criteria for ReA. This may also contribute to a lack of systemic studies or clinical trials for ReA, thereby reducing further treatment recommendations to expert opinions only. The emergence of post-COVID-19 ReA has brought the focus back on this enigmatic entity. Post-COVID-19 ReA can present at extremes of age, appears to affect both sexes equally and can have different presentations. Some present with small joint arthritis, others with SpA phenotype-either with peripheral or axial involvement, while a few have only tenosynovitis or dactylitis. The emergence of post-vaccination inflammatory arthritis hints at similar pathophysiology involved. There needs to be a global consensus on whether or not to include all such conditions under the umbrella of ReA. Doing so will enable studies on uniform groups on how infections precipitate arthritis and what predicts chronicity. These have implications beyond ReA and might be extrapolated to other inflammatory arthritides.

Key Points

• Classical reactive arthritis (ReA) has a spondyloarthritis phenotype and is preceded by symptomatic gut or urogenital infection

• The demonstration of antigen and nucleic acid sequences of pathogens in synovium has blurred the difference between invasive arthritis and reactive arthritis

• Post-COVID-19 ReA has a transient phenotype and can have different presentations. All reported cases are self-limiting

• The large amount of literature reporting post-COVID-19 ReA calls for introspection if the existing definitions of ReA need to be updated.

Reactive arthritis: a clinical review

Reactive arthritis (ReA) is a form of inflammatory arthritis triggered by a remote antecedent infection, usually in the genitourinary or gastrointestinal tract. It is part of the spondyloarthropathy (SpA) spectrum, an umbrella term for a group of distinct conditions with shared clinical features. Typically, it presents with an asymmetric oligoarthritis of the lower limb joints, and patients may also have sacroiliitis, enthesitis and dactylitis. Other features often seen include anterior uveitis, urethritis and skin manifestations such as pustular lesions on the plantar areas. Although ReA was characterised initially as a sterile arthritis, the detection of metabolically active Chlamydia species in the joint fluid of some affected patients has generated further questions on the pathophysiology of this condition. There are no formal diagnostic criteria, and the diagnosis is mainly clinical. HLA-B27 can support the diagnosis in the correct clinical context, and serves as a prognostic indicator. The majority of patients have a self-limiting course, but some develop chronic SpA and require immunomodulatory therapy.

Enteric Pathogens and Reactive Arthritis: Systematic Review and Meta-Analyses of Pathogen-Associated Reactive Arthritis

The objective of this systematic review and meta-analysis was to estimate the proportion of postinfectious reactive arthritis (ReA) after bacterial enteric infection from one of four selected pathogens. We collected studies from PubMed, Web of Science, and Embase, which assessed the proportion of postinfectious ReA published from January 1, 2000 to April 1, 2018. Papers were screened independently by title, abstract, and full text; papers in English, Spanish, and Portuguese utilizing a case-control (CC) or cohort study design, with a laboratory confirmed or probable acute bacterial enteric infection and subsequent ReA, were included. The proportion of ReA cases was pooled between and across pathogens. Factors that can induce study heterogeneity were explored using univariate meta-regression, including region, sample size, study design, and ReA case ascertainment. Twenty-four articles were included in the final review. The estimated percentage of cases across studies describing Campylobacter-associated ReA (n = 11) was 1.71 (95% confidence interval [CI] 0.49-5.84%); Salmonella (n = 17) was 3.9 (95% CI 1.6-9.1%); Shigella (n = 6) was 1.0 (95% CI 0.2-4.9%); and Yersinia (n = 7) was 3.4 (95% CI 0.8-13.7%). Combining all four pathogens, the estimated percentage of cases that developed ReA was 2.6 (95% CI 1.5-4.7%). Due to high heterogeneity reflected by high I² values, results should be interpreted with caution. However, the pooled proportion developing ReA from studies with sample sizes (N) <1000 were higher compared with N > 1000 (6% vs. 0.3%), retrospective cohort studies were lower (1.1%) compared with CC or prospective cohorts (6.8% and 5.9%, respectively), and those where ReA cases are identified through medical record review were lower (0.3%) than those identified by a specialist (3.9%) or self-report (12%). The estimated percentage of people who developed ReA after infection with Campylobacter, Salmonella, Shigella, or Yersinia is relatively low (2.6). In the United States, this estimate would result in 84,480 new cases of ReA annually.

[Post-Corona-Virus-Disease‑19 arthritis. Manifestation under the clinical picture of a reactive arthritis]

A total of 13 case reports of reactive arthritis reported in the literature in connection with coronavirus disease 2019 (COVID‑19) are reviewed. Men were affected more frequently than women. The arthritis was manifested 4-44 days after the infection or the occurrence of the COVID‑19 symptoms. Acute arthritis was monoarticular or oligoarticular. Only 1 out of 7 patients examined was human-leucocyte-antigen(HLA)-B27 positive. A direct viral infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) could not be detected in the synovial fluid and was not investigated in the synovial membrane. The arthritis was successfully treated with nonsteroidal anti-inflammatory drugs and/or intra-articular or systemic corticosteroids. The pathogenesis of post-COVID‑19 reactive arthritis is unknown.

Reactive Arthritis Update: Spotlight on New and Rare Infectious Agents Implicated as Pathogens

Purpose of Review

This article presents a comprehensive narrative review of reactive arthritis (ReA) with focus on articles published between 2018 and 2020. We discuss the entire spectrum of microbial agents known to be the main causative agents of ReA, those reported to be rare infective agents, and those reported to be new candidates causing the disease. The discussion is set within the context of changing disease terminology, definition, and classification over time. Further, we include reports that present at least a hint of effective antimicrobial therapy for ReA as documented in case reports or in double-blind controlled studies. Additional information is included on microbial products detected in the joint, as well as on the positivity of HLA-B27.

Recent Findings

Recent reports of ReA cover several rare causative microorganism such as Neisseria meningitides, Clostridium difficile, Escherichia coli, Hafnia alvei, Blastocytosis, Giardia lamblia, Cryptosporidium, Cyclospora cayetanensis, Entamoeba histolytica/dispar, Strongyloides stercoralis, β-haemolytic Streptococci, Mycobacterium tuberculosis, Mycoplasma pneumoniae, Mycobacterium bovis bacillus Calmette-Guerin, and Rickettsia rickettsii. The most prominent new infectious agents implicated as causative in ReA are Staphylococcus lugdunensis, placenta- and umbilical cord–derived Wharton’s jelly, Rothia mucilaginosa, and most importantly the SARS-CoV-2 virus.

Summary

In view of the increasingly large spectrum of causative agents, diagnostic consideration for the disease must include the entire panel of post-infectious arthritides termed ReA. Diagnostic procedures cannot be restricted to the well-known HLA-B27-associated group of ReA, but must also cover the large number of rare forms of arthritis following infections and vaccinations, as well as those elicited by the newly identified members of the ReA group summarized herein. Inclusion of these newly identified etiologic agents must necessitate increased research into the pathogenic mechanisms variously involved, which will engender important insights for treatment and management of ReA.

Supplementary Information

The online version contains supplementary material available at 10.1007/s11926-021-01018-6.

Expanding the spectrum of reactive arthritis (ReA): classic ReA and infection-related arthritis including poststreptococcal ReA, Poncet's disease, and iBCG-induced ReA

Reactive arthritis (ReA) is a form of sterile arthritis that occurs secondary to an extra-articular infection in genetically predisposed individuals. The extra-articular infection is typically an infection of the gastrointestinal tract or genitourinary tract. Infection-related arthritis is a sterile arthritis associated with streptococcal tonsillitis, extra-articular tuberculosis, or intravesical instillation of bacillus Calmette–Guérin (iBCG) therapy for bladder cancer. These infection-related arthritis diagnoses are often grouped with ReA based on the pathogenic mechanism. However, the unique characteristics of these entities may be masked by a group classification. Therefore, we reviewed the clinical characteristics of classic ReA, poststreptococcal ReA, Poncet’s disease, and iBCG-induced ReA. Considering the diversity in triggering microbes, infection sites, and frequency of HLA-B27, these are different disorders. However, the clinical symptoms and intracellular parasitism pathogenic mechanism among classic ReA and infection-related arthritis entities are similar. Therefore, poststreptococcal ReA, Poncet’s disease, and iBCG-induced ReA could be included in the expanding spectrum of ReA, especially based on the pathogenic mechanism.

[Postinfectious reactive arthritis after chlamydia infection in competitive sports : Clinical management and current literature review]

BACKGROUND

Reactive arthritis following infection with chlamydia is a rare but important differential diagnosis in atraumatic joint swelling. A delayed diagnosis often leads to prolonged periods of absence from physical activity. This can have serious consequences, especially for the career of competitive athletes.

OBJECTIVES

Recommendation for the clinical management of postinfectious reactive arthritis for rapid diagnosis and targeted treatment in the symptomatic clinical course.

MATERIALS AND METHODS

Review of the literature on the topics "chlamydia", "reactive arthritis", "postinfectious arthritis" and "sexually acquired reactive arthritis", including presentation of two clinical cases of postinfectious reactive arthritis after chlamydia infection from competitive sports.

RESULTS AND CONCLUSION

Reactive arthritis following chlamydia infection in competitive athletes is a rare entity. However, it can be accompanied by far-reaching individual consequences, especially with regard to possible downtime in sports. Long-term consequences such as chronic joint damage in maintained synovitis must also be considered. In order to make a diagnosis, a specific anamnesis and the direct detection of the pathogen in the specimen of synovial fluid by polymerase chain reaction is essential. This allows a reliable diagnosis to be made with immediate initiation of therapy. However, a prolonged course of the disease cannot be excluded even if therapy is started in due time.

Infectious arthritis and the temporomandibular joint. A review

OBJECTIVE

Microorganisms can cause acute infectious arthritis, chronic infectious arthritis, or reactive inflammatory arthritis. The aim of this study is to perform a narrative review of the pathophysiology, etiology, and diagnostic features of infectious arthritis and TMJ infectious arthritis.

METHODS

A search of the literature was performed using Medline, Scielo, Embase, and Google Scholar databases. The terms employed for the search were "Temporomandibular Joint Disorders" and "Infectious Arthritis"; or "Septic Arthritis"; or "Bacterial, Fungal, or Viral Arthritis." Over three hundred articles were screened for eligibility.

RESULTS

The selected articles were utilized to perform a narrative review of the general aspects of infectious arthritis and infectious arthritis affecting the TMJ.

CONCLUSION

Infectious arthritis is a rare, yet very morbid, form of arthritis. Understanding general aspects of joint infections and specific features of TMJ infectious arthritis is imperative for an adequate diagnosis.

The microbiome in spondyloarthritis

A causal link between the wealth of microbes that populate our body surfaces, designated as microbiota, and inflammatory disorders, including ankylosing spondylitis and the related spondyloarthritis (SpA) has been suspected for decades. This specially concerns the gut microbiota that became only recently accessible to thorough description thanks to massive sequencing methods or metagenomics. Here, we review evidences supporting the existence of microbiota imbalance or dysbiosis in the context of SpA. We also discuss currently existing evidences for a causal relationship between such dysbiosis and disease development, as well as putative therapeutic implications.

Chlamydia-induced reactive arthritis diagnosed during gout flares: A case report and cumulative effect of inflammatory cytokines on chronic arthritis

RATIONALE

The pathology of gouty arthritis and reactive arthritis (ReA) partially overlaps, and both diseases are characterized by the production of inflammatory cytokines associated with the activation of monocytes and macrophages. However, the precise cytokine profile of cases with a coexistence of both diseases is unknown, and there are few reports on the course of treatment in patients with both gouty arthritis and ReA.

PATIENT CONCERNS

A 39-year-old man with a recurrent episode of gouty arthritis presented prednisolone-resistant polyarthritis with high level of C-reactive protein (CRP). He had the features of gouty arthritis such as active synovitis of the first manifestation of metatarsophalangeal (MTP) joints and the presence of monosodium urate (MSU) crystals from synovial fluid. But he also had the features of ReA such as the presence of tenosynovitis in the upper limb, the positivity of human leukocyte antigen (HLA)-B27, a history of sexual contact and positive findings of anti-Chlamydia trachomatis-specific IgA and IgG serum antibodies.

DIAGNOSES

He was diagnosed with HLA-B27 associated Chlamydia-induced ReA accompanied by gout flares.

INTERVENTIONS

He was treated with 180 mg/day of loxoprofen, 1 mg/day of colchicine, and 10 mg/day of prednisolone for gout flares. However, his polyarthritis worsened with an increased level of CRP (23.16 mg/dL). Accordingly, we added 500 mg/day of salazosulfapyridine followed by adalimumab (ADA) 40 mg once every 2 weeks.

OUTCOMES

After starting ADA, the patient's symptoms and laboratory findings showed rapid improvement and he achieved clinical remission 1 month after initiation of ADA treatment. As of this writing, the patient's clinical remission has been maintained for >1 year.

LESSONS

This case suggests that with exacerbation of arthritis during gouty arthritis, coexistence with other pathologies such as peripheral spondyloarthritis should be considered, and early intensive treatment including tumor necrosis factor inhibitors may be necessary.

The "Biology-First" Hypothesis: Functional disorders may begin and end with biology-A scoping review

While it is generally accepted that gastrointestinal infections can cause functional disturbances in the upper and lower gastrointestinal tract-known as postinfectious irritable bowel syndrome (PI-IBS) and functional dyspepsia (PI-FD)-it has still not been widely recognized that such an infection can also initiate functional non-intestinal diseases, and that non-intestinal infections can provoke both intestinal and non-intestinal functional disturbances. We conducted a scoping review of the respective literature and-on the basis of these data-hypothesize that medically unexplained functional symptoms and syndromes following an infection may have a biological (genetic, endocrine, microbiological) origin, and that psychological and social factors, which may contribute to the disease "phenotype," are secondary to this biological cause. If this holds true, then the search for psychological and social theories and factors to explain why one patient develops a chronic functional disorder while another does not is-at least for postinfectious states-misleading and detracts from exploring and identifying the true origins of these essentially biological disorders. The biopsychosocial model may, as the term implies, always begin with biology, also for functional (somatoform) disorders.

Gut Microbiota Perturbations in Reactive Arthritis and Postinfectious Spondyloarthritis

OBJECTIVE

Reactive arthritis (ReA) is an inflammatory disorder occurring several weeks after gastrointestinal or genitourinary tract infections. HLA-B27 positivity is considered a risk factor, although it is not necessarily predictive of disease incidence. Among nongenetic factors, the intestinal microbiome may play a role in disease susceptibility. The objective of this study was to characterize the gut microbiota and host gene interactions in ReA and postinfectious spondyloarthritis.

METHODS

Adult subjects with peripheral spondyloarthritis and control subjects with preceding infections who did not develop arthritis were prospectively recruited from a geographic region with a high prevalence of ReA. Clinical variables, HLA status, and 16S ribosomal RNA gene sequencing of intestinal microbiota were analyzed.

RESULTS

Subjects with ReA showed no significant differences from controls in gut bacterial richness or diversity. However, there was a significantly higher abundance of Erwinia and Pseudomonas and an increased prevalence of typical enteropathogens associated with ReA. Subjects with ultrasound evidence of enthesitis were enriched in Campylobacter, while subjects with uveitis and radiographic sacroiliitis were enriched in Erwinia and unclassified Ruminococcaceae, respectively; both were enriched in Dialister. Host genetics, particularly HLA-A24, were associated with differences in gut microbiota diversity irrespective of disease status. We identified several co-occurring taxa that were also predictive of HLA-A24 status.

CONCLUSION

This is the first culture-independent study characterizing the gut microbial community in postinfectious arthritis. Although bacterial factors correlated with disease presence and clinical features of ReA, host genetics also appeared to be a major independent driver of intestinal community composition. Understanding of these gut microbiota-host genetic relationships may further clarify the pathogenesis of postinfectious spondyloarthritides.

Reactive Arthritis

Reactive arthritis is classified as a spondyloarthropathy. Current concepts of disease suggest an infectious trigger, followed by inflammatory arthritis. Several mechanisms have been proposed to explain the interaction of host susceptibility and microorganism. Diagnosis relies on a compatible clinical syndrome and microbiologic confirmation of the pathogen. Antibiotic therapy seems useful in Chlamydia-triggered arthritis. The role of antibiotics in arthritis triggered by enteric pathogens is less clear. The role of tumor necrosis factor alpha inhibitors in therapy is evolving. Many patients have a course limited to a few months, but others experience extraarticular disease and more prolonged courses.

A bicentre retrospective study of features and outcomes of patients with reactive arthritis

OBJECTIVE

Reactive arthritis (ReA) is a sterile arthritis following an extra-articular infection, usually of the gastrointestinal or genitourinary tract. The aim of this study was to assess the incidence and the clinical and therapeutic characteristics of ReA and to compare them with those of a historical cohort. We hypothesised that improved hygiene together with prevention and treatment of sexually transmitted infections may have decreased the incidence of ReA.

METHODS

All patients with ReA diagnosed in the University Hospital Centres of Lyon Sud and Besançon from January 2002 to December 2012 were included in the study retrospectively and were compared with ReA patients diagnosed from January 1986 to December 1996 in the same two hospitals. Medical records were reviewed, clinical features, treatments and outcomes were analysed and diagnoses were compared with international diagnostic criteria.

RESULTS

Twenty-seven patients were included between 2002 and 2012 compared with 31 between 1986 and 1996. The overall incidence of ReA in patients hospitalised in the rheumatology department did not change, although the current evolution is more severe with development of chronic disease in the form of more frequent spondyloarthritis. While the incidence of Chlamydiae trachomatis has decreased, new microbes are now found to be involved.

CONCLUSIONS

ReA still exists and its incidence has been stable over the last 30 years. However, ReA currently more often progress to spondyloarthritis. Our study also highlights the need for diagnostic criteria that accurately detect ReA.

Causality of Chlamydiae in Arthritis and Spondyloarthritis: a Plea for Increased Translational Research

Current molecular genetic understanding of the metabolically active persistent infection state of Chlamydia trachomatis and Chlamydia pneumoniae in the synovium in patients with arthritis and spondyloarthritis favors a causal relationship. Here, we examine how adequately the accepted criteria for that etiologic relationship are fulfilled, emphasizing the situation in which these microorganisms cannot be cultivated by standard or other means. We suggest that this unusual situation of causality by chlamydiae in rheumatic disease requires establishment of a consensus regarding microorganism-specific terminology as well as the development of new diagnostic and classification criteria. Recent studies demonstrate the value of molecular testing for diagnosis of reactive arthritis, undifferentiated spondyloarthritis, and undifferentiated arthritis caused by C. trachomatis and C. pneumoniae in clinical practice. Data regarding combination antibiotic therapy is consistent with the causative role of chlamydiae for these diseases. Observations of multiple intra-articular coinfections require more research to understand the implications and to respond to them.

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.

Coinfection of Chlamydiae and other Bacteria in Reactive Arthritis and Spondyloarthritis: Need for Future Research

Reactive (inflammatory) arthritis has been known for many years to follow genital infection with the intracellular bacterial pathogen Chlamydia trachomatis in some individuals. Recent studies from several groups have demonstrated that a related bacterium, the respiratory pathogen Chlamydia pneumoniae, can elicit a similar arthritis. Studies of these organisms, and of a set of gastrointestinal pathogens also associated with engendering inflammatory arthritis, have been relatively extensive. However, reports focusing on coinfections with these and/or other organisms, and the effects of such coinfections on the host immune and other systems, have been rare. In this article, we review the extant data regarding infections by multiple pathogens in the joint as they relate to engendering arthritis, and we suggest a number of research areas that must be given a high priority if we are to understand, and therefore to treat in an effective manner, such arthritides.

The incidence of sexually acquired reactive arthritis: a systematic literature review

Reactive arthritis (ReA) is an inflammatory spondyloarthritis occurring after infection at a distant site. Chlamydia trachomatis is proposed to be the most common cause of ReA, yet the incidence of sexually acquired ReA (SARA) has not been well established. We therefore carried out a systematic literature review to collate and critically evaluate the published evidence regarding the incidence of SARA. MEDLINE and EMBASE databases were searched using free-text and MeSH terms relating to infection and ReA. The title and abstract of articles returned were screened independently by two reviewers and potentially relevant articles assessed in full. Data was extracted from relevant articles and a risk of bias assessment carried out using a validated tool. Heterogeneity of study methodology and results precluded meta-analysis. The search yielded a total of 11,680 articles, and a further 17 were identified from review articles. After screening, 55 papers were assessed in full, from which 3 met the relevant inclusion criteria for the review. The studies reported an incidence of SARA of 3.0-8.1 % and were found to be of low to moderate quality. More studies are required to address the lack of data regarding the incidence of SARA. Specific and sensitive classification criteria must be developed in order for consistent classification and valid conclusions to be drawn. In clinical practice, it is recommended clinicians discuss the possibility of ReA developing at the time of STI diagnosis and to encourage patients to return if they experience any relevant symptoms.

The role of intracellular organisms in the pathogenesis of inflammatory arthritis

Inflammatory arthritis is a condition which is characterised by recurrent episodes of joint pain and swelling. It encompasses a spectrum of disorders ranging from rheumatoid arthritis to ankylosing spondylitis. In these conditions, for reasons that are poorly understood, the immune system raises an inflammatory response within the joint space. In some cases, autoantigens have been identified (e.g., anticitrullinated peptides in rheumatoid arthritis), but the absence of these, in the seronegative arthritides, for example, raises question as to the underlying pathogenesis. Interest has, therefore, turned to host-pathogen interactions and whether aberrant immune responses to these could explain the development of arthritis. This has been most widely studied in reactive arthritis (ReA), where an infectious episode precedes the development of the joint symptoms. In this review, we present the evidence for the role of host-bacterial interactions in the pathogenesis of joint inflammation with particular emphasis on ReA. We discuss a range of possible mechanisms including molecular mimicry, persistent low grade infections, and abnormal host responses to common bacterial causes of reactive arthritis as well as discussing some of the clinical challenges that we face in making the diagnosis and in treatment of persistent symptoms.

An update on the contribution of the MHC to AS susceptibility

The 40-year-old association of HLA-B27 with ankylosing spondylitis is one of the best examples of disease association with a hereditary marker. Genomewide association and family studies suggest that other important major histocompatibility complex (MHC) influences are operative in ankylosing spondylitis (AS) susceptibility. HLA-B27 positive hepatitis C individuals are immunologically more efficient in combating viral infections such as HIV-1, hepatitis C, and influenza and less efficient in combating against certain bacteria (and perhaps other organisms) capable of surviving intracellularly. A recent representative population survey of the frequency of HLA-B27 in the USA found a lower frequency of HLA-B27 in older US adults, perhaps reflecting this. Other HLA class I and class II alleles have been implicated in AS susceptibility, the most consistent being HLA-B*40/B60 (B*40:01) but also B14, B15, A*0201, DRB1*04:04, and certain DPA1 and DPB1 alleles. Non-HLA MHC alleles have also been implicated, although many such studies have been inconsistent, likely due to power issues related to the low number of HLA-B27-negative AS patients examined. The best evidence is for major histocompatibility complex class I chain-related gene A (MICA) whose recognition by intestinal epithelial T cells expressing different V-delta-1 gamma/delta TCR further implicates the gut in AS pathogenesis. The HLA class I and class II and other non-HLA allelic associations underscore the importance of T cells in AS pathogenesis.

Antibiotics for Treatment of Reactive Arthritis: A Systematic Review and Metaanalysis

Objective.

To examine the efficacy and safety of antibiotic treatments for reactive arthritis (ReA).

Methods.

We did a systematic review and metaanalysis of randomized controlled trials of antibiotics for treatment of ReA. We searched electronic databases and conference proceedings up to November 2011. Included trials reported on remission, joint counts, and pain or patient global scores in any language.

Results.

Twelve trials were eligible for inclusion and 10 provided data for metaanalysis. The pooled relative risk of failure to achieve remission from a random effects model showed no significant benefit of antibiotic treatment on remission (7 trials, 375 participants, RR 0.74, 95% CI 0.49–1.10); however, substantial heterogeneity was observed (I2 = 76.3%, p < 0.0001). The treatment effect did not differ significantly by the type of organism triggering the ReA (chlamydia, 4 trials, RR 0.80, 95% CI 0.63–1.03, vs other microorganisms, 5 trials, RR 0.72, 95% CI 0.29–1.79, metaregression p = 0.477) or use of combination antibiotics (monotherapy, 6 trials, RR 0.70, 95% CI 0.39–1.26, vs combination therapy, 1 trial, RR 0.79, 95% CI 0.63–0.99, metaregression p = 0.466). When unblinded trials were excluded, the treatment effect was attenuated and heterogeneity decreased (RR 0.87, 95% CI 0.70–1.10, I2 = 32.8%, p = 0.19). No significant effects of antibiotic treatment were observed on joint counts, pain, or patient global scores; however, antibiotics were associated with a 97% increase in gastrointestinal adverse events.

Conclusion.

Trials of antibiotic treatment for ReA have produced heterogeneous results that may be related to differences in study design. The efficacy of antibiotics is uncertain.

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.

Chronic Lyme Disease and Co-infections: Differential Diagnosis

In Lyme disease concurrent infections frequently occur. The clinical and pathological impact of co-infections was first recognized in the 1990th, i.e. approximately ten years after the discovery of Lyme disease. Their pathological synergism can exacerbate Lyme disease or induce similar disease manifestations. Co-infecting agents can be transmitted together with Borrelia burgdorferi by tick bite resulting in multiple infections but a fraction of co-infections occur independently of tick bite. Clinically relevant co-infections are caused by Bartonella species, Yersinia enterocolitica, Chlamydophila pneumoniae, Chlamydia trachomatis, and Mycoplasma pneumoniae. In contrast to the USA, human granulocytic anaplasmosis (HGA) and babesiosis are not of major importance in Europe. Infections caused by these pathogens in patients not infected by Borrelia burgdorferi can result in clinical symptoms similar to those occurring in Lyme disease. This applies particularly to infections caused by Bartonella henselae, Yersinia enterocolitica, and Mycoplasma pneumoniae. Chlamydia trachomatis primarily causes polyarthritis. Chlamydophila pneumoniae not only causes arthritis but also affects the nervous system and the heart, which renders the differential diagnosis difficult. The diagnosis is even more complex when co-infections occur in association with Lyme disease. Treatment recommendations are based on individual expert opinions. In antibiotic therapy, the use of third generation cephalosporins should only be considered in cases of Lyme disease. The same applies to carbapenems, which however are used occasionally in infections caused by Yersinia enterocolitica. For the remaining infections predominantly tetracyclines and macrolides are used. Quinolones are for alternative treatment, particularly gemifloxacin. For Bartonella henselae, Chlamydia trachomatis, and Chlamydophila pneumoniae the combination with rifampicin is recommended. Erythromycin is the drug of choice for Campylobacter jejuni.

Signalling profiles of circulating leucocytes in patients recovered from reactive arthritis

OBJECTIVES

Reactive arthritis (ReA) is a sterile joint inflammation triggered by a remote infection and associated with human leucocyte antigen (HLA)-B27. Its pathogenesis is unknown, but abnormal response to microbial structures or endogenous inflammatory mediators may be involved. We studied responses in leucocyte signalling profiles in patients with previous ReA after a full recovery.

METHOD

The study comprised 10 HLA-B27-positive healthy subjects with a history of Yersinia enterocolitica-triggered ReA (B27+ReA+) and 20 healthy reference subjects, of whom 10 carried HLA-B27 (B27+ReA-) and 10 did not (B27-ReA-). Phosphospecific fluorescent monoclonal antibodies and flow cytometry were used to determine activation of nuclear factor kappa B (NF-κB), signal transducers and activators of transcription (STATs) 1, 3, 5, and 6, and two mitogen-activated protein (MAP) kinases, p38 and extracellular signal-regulated kinase (ERK)1/2, in monocytes, lymphocytes, lymphocyte subsets, and neutrophils. B27+ReA+ and B27-ReA- whole-blood samples were incubated with Yersinia with or without infliximab to study the role of tumour necrosis factor (TNF) in lymphocyte subset activation. Samples of the three subject groups were studied using soluble bacterial or endogenous stimuli. Fluorescence levels were determined as relative fluorescence units (RFU) and the proportion of positively fluorescing cells.

RESULTS

The intracellular activation of circulating leucocytes in response to soluble stimuli was consistently comparable in B27+ReA+, B27+ReA-, and B27-ReA- subjects. Infliximab inhibited Yersinia-induced lymphocyte NF-κB phosphorylation similarly in B27+ReA+ and B27-ReA- groups.

CONCLUSIONS

ReA susceptibility is not reflected in leucocyte signalling profiles elicited by phlogistic stimuli. However, the possibility remains that aberrations occur in response to combinations of stimuli, such as those associated with leucocyte adhesion.

Bone strength in children with growing pains: long-term follow-up

OBJECTIVES

To examine the changes in bone strength in a cohort of children with 'growing pains' (GP) after 5 years follow-up and the correlation with pain outcome.

METHODS

Bone strength was measured by quantitative ultrasound. Subjects were 39 children with GP previously studied. Controls were normograms based on the measurement of bone speed of sound in 1085 healthy children. Current GP status was assessed by parental questionnaires. Bone strength was compared with pain outcome.

RESULTS

We examined 30/39 (77%) patients after 5 years. Bone strength was significantly increased when compared to the first study (Z score 0.65±1.77 vs. -0.62±0.90, p<0.001). While overall there was no significant difference in the bone strength between the 16 (53%) patients whose GP resolved and the 14 (47%) who continued to have GP episodes (p=0.71), all 6 (20%) patients with a speed of sound Z-score <-1 continued to have GP (p=0.003).

CONCLUSIONS

Our findings that pain improves in most patients parallel to the increase in bone strength may support the hypothesis of GP representing in some patients a local overuse syndrome.

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.

Association and frequency of HLA-A, B and HLA-DR genes in south Tunisian patients with spondyloarthritis (SpA)

The aim of this study is to investigate the association of HLA-A, B and HLA-DR gene expression and to assess an association of additional HLA antigens besides HLA-B27 in south Tunisian patients with spondyloarthritis (SpA). Eighty-five patients diagnosed with ankylosing spondylitis (AS, n=68) and reactive arthrithis (ReA, n=17) were selected and compared with 100 healthy controls (HC). HLA class I antigens were typed serologically using microlymphocytotoxicity technique. HLA-DRB1* alleles were studied by polymerase chain reaction amplification with sequence-specific primers. The significance of differences between patients and controls was tested by chi-square analysis. We found significantly increased frequencies of HLA-A3 (30.6%; pC=0.04; OR=2.95), HLA-B27 (62.35%; pC=4.10(-17), OR=53.55), and HLA-DRB1*15 (17.2%; pC=0.026; RR=2.58) alleles in SpA patients compared to HC. The most frequent and strongest association was observed for HLA-B27 in AS (pC=6.6 ×10(-16), OR=52.23). When AS and ReA patients were analysed separately, HLA-DRB1*15 and HLA-A3 were increased only in AS (pC=0.01, OR=2.99 and pC=0.03, OR=3.14, respectively). In ReA patients, HLA-DRB1*04 (p=0.033, pC=NS, OR=2.89) was found to be the most common allele. By analysing the HLA-B27-negative subgroup, HLA-A3 and HLA-DRB1*15 expression was found to be dependent on the presence of HLA-B27. HLA-B27 expression was higher in male (45/53; 85%) as compared to female (8/53; 15%) patients (p=0.03). Apart from HLA-B27, HLA-A3 and HLA-DRB1*15 are the MHC class I and II alleles found most frequent in Tunisian patients with AS, whereas HLA-DRB1*04 was found most frequent in ReA patients. HLA-B27 is more frequent in male than in female patients.

Is the role of Chlamydia trachomatis underestimated in patients with suspected reactive arthritis?

Reactive arthritis is usually caused by bacteria of either the enteric or genital tracts. In the genital tract, Chlamydia trachomatis is perhaps the only aetiological agent. In Iran, newer evidence suggests that as C. trachomatis is more commonly found in the general population than was previously believed, its role in reactive arthritis may well be currently overlooked. In this review, as well as emphasizing the potential role of C. trachomatis in reactive arthritis in patients from developing countries, we also make recommendations for further clinical studies to determine its prevalence. Moreover, we also stress the need for standardization of new testing methodologies for C. trachomatis, including the use of new commercial systems in an attempt to determine a truer picture of chlamydial infection in reactive arthritis.