Immune linkages between inflammatory bowel disease and spondyloarthropathies

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.

Development of Inflammatory Bowel Disease in Children With Juvenile Idiopathic Arthritis Treated With Biologics

OBJECTIVE

The aim of our study was to describe the distinct features of inflammatory bowel disease (IBD) in juvenile idiopathic arthritis (JIA) patients and to identify risk factors for its development.

METHODS

Data from the German biologics in pediatric rheumatology registry (Biologika in der Kinderrheumatologie) collected between 2001 and 2021 were analyzed retrospectively.

RESULTS

In 5009 JIA patients, 28 developed confirmed IBD before the age of 18 years: 23 (82.1%) with Crohn disease (CD), 4 (14.3%) with ulcerative colitis (UC), and 1 (3.6%) with IBD-unclassified (IBD-U). The incident rate of IBD during 20 years of observation was 0.56% (0.46% for CD, 0.08% for UC, and 0.02% for IBD-U), of whom 20.3% were HLA-B27 positive, 25% had enthesitis-related arthritis, and 14.3% psoriatic arthritis. Within 90 days before IBD diagnosis, 82.1% (n = 23) received treatment with etanercept (ETA), 39.3% (n = 11) non-steroidal anti-inflammatory drugs, 17.9% (n = 5) systemic corticosteroids, 8 (28.6%) methotrexate (MTX), 14.3% (n = 4) sulfasalazine, 10.7% (n = 3) leflunomide, and 3.6% (n = 1) adalimumab and infliximab, respectively. The incidence of IBD was lower in patients treated with MTX, but higher in patients treated with ETA except if ETA was combined with MTX. Also in patients on leflunomide or sulfasalazine, the IBD incidence was higher.

CONCLUSIONS

In our JIA cohort, an increased IBD incidence is observed compared to the general population, and the ratio of CD to UC is markedly higher hinting at a distinct phenotype of IBD. Pretreatment with MTX seems to be protective. Treatment with ETA does not prevent IBD development and JIA patients treated with leflunomide and sulfasalazine may be at an increased risk for IBD development.

Utility of magnetic resonance imaging in Crohn's associated sacroiliitis: A cross-sectional study

OBJECTIVE

Prevalence of sacroiliitis in Crohn's disease (CD) is variable depending on defining criteria. This study utilized standardized sacroiliac joint (SIJ) magnetic resonance imaging (MRI) to identify sacroiliitis in CD patients and its association with clinical and serological markers.

METHODS

Consecutive adult subjects with CD prospectively enrolled from an inflammatory bowel disease clinic underwent SIJ MRI. Data collected included CD duration, history of joint/back pain, human leukocyte antigen-B27 status, Bath Ankylosing Spondylitis Metrology Index (BASMI), Bath Ankylosing Spondylitis Disease Activity Index, Harvey Bradshaw Index (HBI) for activity of CD, Ankylosing Spondylitis Disease Activity Score, and various serologic markers of inflammation. Three blinded readers reviewed MRIs for active and structural lesions according to the Spondyloarthritis Research Consortium of Canada modules.

RESULTS

Thirty-three CD patients were enrolled: 76% female, 80% White, median age 36.4 years (interquartile range 27.2-49.0), moderate CD activity (mean HBI 8.8 ± SD 4.5). Nineteen subjects (58%) reported any back pain, 13 of whom had inflammatory back pain. Four subjects (12%) showed sacroiliitis using global approach and 6 (18%) met Assessment of SpondyloArthritis international Society MRI criteria of sacroiliitis. Older age (mean 51.2 ± SD 12.5 vs. 37.2 ± 14; P = .04), history of dactylitis (50.0% vs. 3.4%, P = .03) and worse BASMI (4.1 ± 0.7 vs. 2.4 ± 0.8, P ≤ .001) were associated with MRI sacroiliitis; no serologic measure was associated.

CONCLUSION

There were 12%-18% of CD patients who had MRI evidence of sacroiliitis, which was not associated with back pain, CD activity or serologic measures. This data suggests that MRI is a useful modality to identify subclinical sacroiliitis in CD patients.

Etiopathogenesis of sacroiliitis: implications for assessment and management

The sacroiliac joints connect the base of the sacrum to the ilium. When inflamed, they are suspected to cause low back pain. Inflammation of the sacroiliac joints is called sacroiliitis. The severity of the pain varies and depends on the degree of inflammation. Sacroiliitis is a hallmark of seronegative spondyloarthropathies. The presence or absence of chronic sacroiliitis is an important clue in the diagnosis of low back pain. This article aims to provide a concise overview of the anatomy, physiology, and molecular biology of sacroiliitis to aid clinicians in the assessment and management of sacroiliitis. For this narrative review, we evaluated articles in English published before August 2019 in PubMed. Then, we selected articles related to the painful manifestations of the sacroiliac joint. From the retrieved articles, we found that chronic sacroiliitis may be caused by various forms of spondyloarthritis, such as ankylosing spondyloarthritis. Sacroiliitis can also be associated with inflammatory bowel disease, Crohn’s disease, gout, tuberculosis, brucellosis, and osteoarthritis, indicating common underlying etiological factors. The pathophysiology of sacroiliitis is complex and may involve internal, environmental, immunological, and genetic factors. Finally, genetic factors may also play a central role in progression of the disease. Knowing the genetic pre-disposition for sacroiliitis can be useful for diagnosis and for formulating treatment regimens, and may lead to a substantial reduction in disease severity and duration and to improved patient performance.

Propionibacterium acnes, Coagulase-Negative Staphylococcus, and the "Biofilm-like" Intervertebral Disc

STUDY DESIGN

Patients scheduled for spinal surgery were screened prospectively for a microbial presence associated with intervertebral disc specimens. Inclusion was limited to patients requiring surgery for any of five conditions: study patients with cervical spine intervertebral herniation (IVH), lumbar spine IVH, lumbar spine discogenic pain, and control patients with idiopathic scoliosis/Scheurermann's kyphosis or trauma/neuromuscular deformity. Exclusion criteria included ongoing systemic infection, abnormal pre-operative white cell counts, documented or suspected spinal infection, or previous surgery to the involved disc.

OBJECTIVE

The aim of this study was to test for an association between the presence of a bacterial entity in operated discs and a diagnosis of pathologic disc disease.

SUMMARY OF BACKGROUND DATA

An association has been described between microbial colonization and progressive intervertebral disc degeneration in 36 herniation patients undergoing microdiscectomies. A total of 19 patients had positive cultures on long-term incubation, with Propionibacterium acnes present in 84% of discs.

MATERIALS AND METHODS

Discs were harvested during surgery, using strict sterile technique. Each disc was divided, with half the sample sealed in a sterile, commercially prepared anaerobic culture transport container, and half fixed in formalin. Live specimens were cultured for bacteria at a university-affiliated laboratory in a blinded fashion. Fixed pathologic specimens were gram-stained and read by a board-certified pathologist.

RESULTS

A total of 169 intervertebral discs from 87 patients were evaluated (46 males, 41 females). Positive cultures were noted in 76 of 169 discs (45%), with 34 discs positive for P. acnes and 30 discs positive for Staphylococcus. No pathologic evidence was seen of microorganisms, acute or chronic inflammation, or infection. Pooling the IVH and discogenic pain patients and contrasting them with control patients showed a significant association of IVH with positive bacterial cultures (χ = 15.37; P = 0.000088).

CONCLUSION

Endemic bacterial biofilms are significantly associated with IVH and discogenic pain.

LEVEL OF EVIDENCE

N/A.

Enteropathic spondyloarthritis: from diagnosis to treatment

Enteropathic arthritis (EA) is a spondyloarthritis (SpA) which occurs in patients with inflammatory bowel diseases (IBDs) and other gastrointestinal diseases. Diagnosis is generally established on the medical history and physical examination. It was, generally, made according to the European Spondyloarthropathy Study Group (ESSG) criteria. Rheumatic manifestations are the most frequent extraintestinal findings of IBD with a prevalence between 17% and 39%, and IBD is associated, less frequently, with other rheumatic disease such as rheumatoid arthritis, Sjogren syndrome, Takayasu arteritis, and fibromyalgia. Although the pathogenesis of EA has not been plainly clarified, the most popular theory supposes that joint inflammation occurs in genetically predisposed subjects with bacterial gut infections, provided an important evidence for a possible relationship between inflammation of the gut mucosa and arthritis. The management of patients with EA requires an active cooperation between the gastroenterologist and rheumatologist.

Development of Inflammatory Bowel Disease in Patients with Juvenile Idiopathic Arthritis Treated with Etanercept

Objective.

With the increasing use of etanercept for juvenile idiopathic arthritis (JIA) new possible adverse events are reported including new autoimmune diseases. Our purpose was to examine if the incidence of inflammatory bowel disease (IBD) in patients with JIA using etanercept is higher than in the healthy age-matched population. We give the clinical characteristics of the IBD in patients with JIA using etanercept.

Methods.

The national JIA registries for etanercept of The Netherlands, Germany, Finland, Denmark, and Italy were searched for patients with JIA and IBD. The total number of patient-years was used to calculate incidence. The physicians of the identified patients were asked to give clinical details.

Results.

Thirteen cases of IBD in JIA patients were identified in the registries between 1999 and 2008. The IBD incidence in JIA patients while using etanercept was 362 per 100,000 patient-years under etanercept, about 43 times higher than in the general pediatric population. Clinical presentation of IBD in JIA patients using etanercept was similar to that in non-JIA patients. The median time between onset of JIA and onset of IBD was 6 years and 10 months. The time between the start of etanercept and the first appearance of IBD symptoms was between 9 days and 4.5 years.

Conclusion.

The incidence of IBD in JIA patients using etanercept seems to be markedly increased, analyzing data from European registries. This incidence of IBD in the etanercept registries cannot be compared to the incidence of IBD in JIA patients using other treatment without etanercept, because such registries do not exist yet in all European countries. These findings are in keeping with a report of 8 new IBD cases occurring in French children with JIA using etanercept. These findings illustrate the need for large international disease-specific registries focused on outcome and pharmacovigilance.

Synovial biomarkers in the spondylarthropathies

PURPOSE OF THE REVIEW

To explore the concept of a biomarker, or surrogate endpoint, to enhance early diagnosis or predict the response to therapeutic intervention in patients with spondylarthropathy.

RECENT FINDINGS

Immunopathologic studies have suggested that the features of spondylarthropathy are distinctive, supporting a prominent role for innate immune cells, and can be consistently differentiated from rheumatoid arthritis. Successful treatment of spondylarthropathy synovitis resulted in rapid and sustained decrease in infiltration by macrophage populations and neutrophils, and decreased expression of many proinflammatory mediators. Consistent with studies in rheumatoid arthritis, significant correlations between the effects of both methotrexate and infliximab on disease activity and sublining macrophage populations were reported. These observations highlight the possibility that macrophage populations may be a synovial tissue biomarker of therapeutic intervention in spondylarthropathy. Preliminary studies have evaluated advanced genomic and proteomic methodologies in spondylarthropathy.

SUMMARY

Defining the immunopathology of spondylarthropathy has been associated with identifying potential biomarkers of the clinical response to therapeutic intervention. A surrogate marker of arthritis activity in spondylarthropathy could profoundly enhance screening for efficacy and optimization of dose ranges in early-phase randomized clinical trials.

The treatment of the rheumatological manifestations of the inflammatory bowel diseases

The strong link between the bowel and the osteo-articular system is suggested by many clinical and experimental observations. However, the therapeutic approach is still empirical. For symptomatic therapy it is better to favour the use of steroids and avoid non-steroidal anti-inflammatory drugs because they may induce intestinal ulcerations and can activate inflammatory bowel disease. Second line drugs (sulfasalazine, methotrexate, azathioprine, cyclosporine and leflunomide) should be used for selected indications. In some cases (severe spondylitis, severe and persistent enthesopathy) anti-TNF-alpha agents (infliximab) should be considered as first line therapy. In all cases it is mandatory to select the best therapeutic option for each individual patient, considering that the optimal treatment of bowel inflammation may induce "per se" a remission of the musculo-skeletal manifestations.

Immunomodulatory effects of etanercept on peripheral joint synovitis in the spondylarthropathies

OBJECTIVE

Because different tumor necrosis factor alpha (TNFalpha) blockers may have distinct immunomodulatory effects on specific disease manifestations, the present study was carried out to investigate the immunomodulating effects of etanercept on peripheral synovitis in the spondylarthropathies (SpA).

METHODS

Peripheral joint disease was assessed clinically, histologically, and radiologically in a prospective 2-year study of 20 patients with SpA treated with etanercept. Synovial tissue biopsy samples obtained at weeks 0, 12, and 52 were analyzed by histology and immunohistochemistry for the extent of inflammation, changes to tissue architecture, and matrix degradation. Serum levels of myeloid-related protein 8 (MRP-8)/MRP-14, matrix metalloproteinase 3 (MMP-3), and cartilage oligomeric matrix protein (COMP) were determined by enzyme-linked immunosorbent assay.

RESULTS

Etanercept induced a rapid and sustained clinical improvement of peripheral joint disease. Histologic synovitis was down-regulated, with a profound reduction in global cellular infiltration and T lymphocytes, but not B lymphocytes. The most prominent change in markers of inflammation was a reduction in the different macrophage subsets (CD68, CD163, MRP-8, and MRP-14), but this was not paralleled by a decrease in serum MRP-8/MRP-14. Structural changes included normalization of lining layer hyperplasia and a moderate reduction in vascularity. However, no effect on the microarchitecture of lymphoid aggregates was observed. In terms of an effect on matrix degradation, the synovial expression of MMP-3 and MMP-9 was down-modulated in correlation with a rapid and profound decrease in serum MMP-3. At week 52, serum COMP levels were also reduced. No significant radiologic disease progression was observed in these patients over a 2-year period.

CONCLUSION

Use of etanercept effectively down-modulated the immunopathologic processes of SpA synovitis, both in the short term and in the long term.

Chronic intestinal inflammation and seronegative spondyloarthropathy in children

BACKGROUND

Spondyloarthropathy in adults has been shown to be associated with either clinical or subclinical intestinal inflammation, however this association has rarely been described in children.

AIM

To report paediatric patients primarily referred to a paediatric gastroenterology centre for suspected inflammatory bowel disease and found to be affected by a seronegative spondyloarthropathy. Intestinal inflammatory lesions and rheumatological features have been described in them.

SUBJECTS

During a 18-month period, 129 children were referred because of symptoms and signs suggesting an inflammatory bowel disease; 31 of them (range age: 5-17 years) were selected because they also had signs of axial and/or peripheral arthropathy and form the basis of our study.

METHODS

The investigated patients underwent ileo-colonoscopy with biopsy and rheumatological assessment that also included X-ray and magnetic resonance imaging of the sacroiliac joints.

RESULTS

Only seven children had a classical inflammatory bowel disease (four had ulcerative colitis, three had Crohn's disease), 12 had an indeterminate colitis, 12 a lymphoid nodular hyperplasia of the distal ileum as main feature. In the latter two groups, endoscopy and histology revealed an intestinal inflammation of chronic type distinct from the classical pattern found in inflammatory bowel disease. All were HLA B27 negative and fulfilled the European Spondyloarthropathy Study Group criteria for spondyloarthropathy (except five children classified as undifferentiated spondyloarthropathy).

CONCLUSIONS

In a group of children primarily investigated for suspected inflammatory bowel disease and also presenting a seronegative spondyloarthropathy we have described both intestinal and rheumatological features. The majority of them exhibited either an indeterminate colitis or a lymphoid nodular hyperplasia of the distal ileum as main feature. These patients may be a population at risk of developing a full inflammatory bowel disease phenotype.

Tumor necrosis factor α blockade treatment down-modulates the increased systemic and local expression of toll-like receptor 2 and toll-like receptor 4 in spondylarthropathy

OBJECTIVE

Abnormal host defense against pathogens has been implicated in the pathogenesis of spondylarthropathy (SpA), a disease characterized by abundant synovial infiltration with innate immune cells. Given the role of Toll-like receptors (TLRs) in activation of innate inflammation and the occurrence of TLR-dependent infections after tumor necrosis factor alpha (TNFalpha) blockade treatment, the present study was undertaken to analyze TLRs and their modulation by TNFalpha blockade in SpA.

METHODS

Peripheral blood mononuclear cells (PBMCs) were obtained from SpA and rheumatoid arthritis (RA) patients during infliximab therapy, and from healthy controls. TLR-2 and TLR-4 expression and TNFalpha production upon lipopolysaccharide (LPS) stimulation were analyzed by flow cytometry on different monocyte subsets. Synovial biopsy specimens from 23 SpA patients before and after infliximab or etanercept treatment, from 15 RA patients, and from 18 osteoarthritis (OA) patients were analyzed by immunohistochemistry.

RESULTS

Expression of TLR-4, but not TLR-2, was increased on PBMCs from patients with SpA, whereas both TLRs were increased in RA patients. TLR expression was particularly increased on the CD163+ macrophage subset. Infliximab reduced TLR-2 and TLR-4 expression on monocytes of SpA and RA patients, leading to lower levels than in controls and to impaired TNFalpha production upon LPS stimulation. In inflamed synovium, the expression of both TLRs and of CD163 was significantly higher in patients with SpA than in those with RA or OA. Paralleling the systemic effect, TLRs in synovium were down-regulated following treatment with infliximab as well as etanercept, indicating a class effect of TNFalpha blockers.

CONCLUSION

Inflammation in SpA is characterized by increased TLR-2 and TLR-4 expression, which is sharply reduced by TNFalpha blockade. These findings suggest a potential role of innate immunity-mediated inflammation in SpA and provide an additional clue regarding the mechanism of action as well as the potential side effects of TNFalpha blockade.

Endophyte-infected tall fescue diet alters gene expression in heifer luteal tissue as revealed by interspecies microarray analysis

Cattle consuming endophyte-infected tall fescue grass have an associated reduction in circulating progesterone and reduced reproductive rates. In this study, commercially available rat microarrays were used to analyze the gene expression in luteal tissues from heifers fed endophyte-free fescue, endophyte-infected fescue, or endophyte-infected fescue supplemented with the dopamine (DA) antagonist, domperidone. The number of hybridized spots represented approximately 40% of the total 10,000 rat genes/ESTs evaluated. Each luteal sample was analyzed in triplicate, resulting in within treatment correlation coefficients of >/=0.98. Median values of mRNA abundance from luteal tissue taken from the endophyte-infected fed heifers revealed 598 genes and ESTs that were down regulated and 56 genes and ESTs that were upregulated compared with luteal mRNA values from the endophyte-free treatment. There were fewer comparative differences between median values from luteal mRNA from the endophyte-free versus feeding endophyte-infected plus domperidone treated heifers. Only 19 genes and ESTs were upregulated and two were down-regulated.

Inflammatory bowel disease-specific autoantibodies in HLA-B27-associated spondyloarthropathies: increased prevalence of ASCA and pANCA

AIMS

An association between inflammatory bowel disease (IBD) and spondyloarthropathies (SpA) has repeatedly been reported. The aim of the present study was to investigate whether serologic markers of IBD, e.g. antibodies against Saccharomyces cerevisiae (ASCA), antibodies against exocrine pancreas (PAB) and perinuclear antineutrophil cytoplasmic antibodies (pANCA) are present in HLA-B27-associated SpA.

METHODS

87 patients with HLA-B27-positive SpA and 145 controls were tested for ASCA, PAB and pANCA employing ELISA or indirect immunofluorescence, respectively. Antibody-positive patients were interviewed regarding IBD-related symptoms using a standardized questionnaire.

RESULTS/CONCLUSION

When compared to the controls, ASCA IgA but not ASCA IgG levels were significantly increased in patients with SpA, in particular in ankylosing spondylitis (AS) and undifferentiated SpA (uSpA). pANCA were found in increased frequency in patients with SpA whereas PAB were not detected. The existence of autoantibodies was not associated with gastrointestinal symptoms but sustains the presence of a pathophysiological link between bowel inflammation and SpA.

Long-term efficacy and safety of infliximab in the treatment of ankylosing spondylitis: an open, observational, extension study of a three-month, randomized, placebo-controlled trial

OBJECTIVE

Treatment of ankylosing spondylitis (AS) with infliximab, an anti-tumor necrosis factor alpha monoclonal antibody, was shown to be efficacious in patients with active disease during a 3-month treatment period. The purpose of this study was to evaluate the efficacy and safety of infliximab treatment of AS for a 1-year period.

METHODS

This study was an open, observational, extension study of a 3-month, randomized, placebo-controlled trial. All patients who had tolerated infliximab (infliximab/infliximab group) or placebo (placebo/infliximab 12-week crossover group) therapy for 3 months entered the open extension trial (n = 65). Infliximab was administered at a dosage of 5 mg/kg every 6 weeks after the induction phase (weeks 0, 2, and 6). The primary end point was a 50% improvement in the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI).

RESULTS

At week 54, a total of 54 of the 69 patients (78%) continued to take infliximab. The intent-to-treat primary efficacy analysis at week 54 showed that 47% of patients in the infliximab/infliximab group (95% confidence interval 31-63) and 51% of the patients in the placebo/infliximab group (95% confidence interval 36-67) achieved 50% improvement in BASDAI scores. In the analysis of those who completed the study, the mean BASDAI scores improved between weeks 0 and 54 in both treatment groups: from 6.6 to 2.4 in the infliximab/infliximab group and from 6.3 to 2.6 in the placebo/infliximab group. The dosage of nonsteroidal antiinflammatory drugs was reduced in approximately 70% of the patients. There were significant improvements in measures of functioning, metrologic parameters, and quality of life. Between weeks 12 and 54, a total of 4 patients had serious adverse events that were possibly related to infliximab and resulted in their discontinuing the study.

CONCLUSION

Infliximab therapy in AS patients resulted in a rapid and significant improvement in BASDAI scores (>50% improvement) and a durable response for 1 year. The safety profile of infliximab in AS was comparable to that observed in the postmarketing experience for the approved indications.