Tissue-Resident Memory CD8+ T Cells From Skin Differentiate Psoriatic Arthritis From Psoriasis

OBJECTIVE

To compare immune cell phenotype and function in psoriatic arthritis (PsA) versus psoriasis in order to better understand the pathogenesis of PsA.

METHODS

In-depth immunophenotyping of different T cell and dendritic cell subsets was performed in patients with PsA, psoriasis, or axial spondyloarthritis and healthy controls. Subsequently, we analyzed cells from peripheral blood, synovial fluid (SF), and skin biopsy specimens using flow cytometry, along with high-throughput transcriptome analyses and functional assays on the specific cell populations that appeared to differentiate PsA from psoriasis.

RESULTS

Compared to healthy controls, the peripheral blood of patients with PsA was characterized by an increase in regulatory CD4+ T cells and interleukin-17A (IL-17A) and IL-22 coproducing CD8+ T cells. One population specifically differentiated PsA from psoriasis: i.e., CD8+CCR10+ T cells were enriched in PsA. CD8+CCR10+ T cells expressed high levels of DNAX accessory molecule 1 and were effector memory cells that coexpressed skin-homing receptors CCR4 and cutaneous lymphocyte antigen. CD8+CCR10+ T cells were detected under inflammatory and homeostatic conditions in skin, but were not enriched in SF. Gene profiling further revealed that CD8+CCR10+ T cells expressed GATA3, FOXP3, and core transcriptional signature of tissue-resident memory T cells, including CD103. Specific genes, including RORC, IFNAR1, and ERAP1, were up-regulated in PsA compared to psoriasis. CD8+CCR10+ T cells were endowed with a Tc2/22-like cytokine profile, lacked cytotoxic potential, and displayed overall regulatory function.

CONCLUSION

Tissue-resident memory CD8+ T cells derived from the skin are enhanced in the circulation of patients with PsA compared to patients with psoriasis alone. This may indicate that aberrances in cutaneous tissue homeostasis contribute to arthritis development.

JAK1: Number one in the family; number one in inflammation?

Several cytokines involved in inflammatory pathologies signal via the Janus kinase-signal transducer and activator of transcription pathway. Four JAKs are known: JAK1, JAK2, JAK3 and TYK2. The specific activation of JAKs and STATs determines the biological effects of each cytokine. JAK1 is involved in the signalling of 'γc' receptor cytokines (IL-2, IL-4, IL-7, IL-9, IL-15 and IL-21), pro-inflammatory cytokines including IL-6, as well as IFN. The critical position of JAK1 downstream of these cytokines suggests that JAK1-selective inhibitors are comparable to non-selective ones, without the unwanted consequences of JAK2- or JAK3-blockade. JAK inhibition has led to a better understanding of the biology of synovial inflammation and bone homeostasis. Moreover, the efficacy of non-selective JAK inhibitors and novel JAK1-selective drugs in RA supports a role for JAK1 in its pathogenesis. JAK1-selective drugs are also showing promise in axial spondyloarthritis, suggesting that they may target additional regulatory pathways that impact cytokines such as TNF and IL-17A, which do not use JAKs. Additionally, evidence now supports a JAK1 predominance in the signalling of IL-6 and oncostatin M, and indirectly, of TNF in synovial fibroblasts, macrophages and endothelial cells. Notably, bone homeostasis is also dependent on cytokines relying on JAK1 signalling to promote receptor activator of NF-κB ligand expression in osteoblasts and T cells, contributing to osteoclastogenesis. Here, the contribution of JAK1 over other kinases is unclear. While beneficial effects of JAK inhibitors on bone erosion are supported by preclinical and clinical data, effects on new bone formation in axial spondyloarthritis requires additional study.

Points to consider for the treatment of immune-mediated inflammatory diseases with Janus kinase inhibitors: a consensus statement

OBJECTIVES

Janus kinase inhibitors (JAKi) have been approved for use in various immune-mediated inflammatory diseases. With five agents licensed, it was timely to summarise the current understanding of JAKi use based on a systematic literature review (SLR) on efficacy and safety.

METHODS

Existing data were evaluated by a steering committee and subsequently reviewed by a 29 person expert committee leading to the formulation of a consensus statement that may assist the clinicians, patients and other stakeholders once the decision is made to commence a JAKi. The committee included patients, rheumatologists, a gastroenterologist, a haematologist, a dermatologist, an infectious disease specialist and a health professional. The SLR informed the Task Force on controlled and open clinical trials, registry data, phase 4 trials and meta-analyses. In addition, approval of new compounds by, and warnings from regulators that were issued after the end of the SLR search date were taken into consideration.

RESULTS

The Task Force agreed on and developed four general principles and a total of 26 points for consideration which were grouped into six areas addressing indications, treatment dose and comedication, contraindications, pretreatment screening and risks, laboratory and clinical follow-up examinations, and adverse events. Levels of evidence and strengths of recommendations were determined based on the SLR and levels of agreement were voted on for every point, reaching a range between 8.8 and 9.9 on a 10-point scale.

CONCLUSION

The consensus provides an assessment of evidence for efficacy and safety of an important therapeutic class with guidance on issues of practical management.

Points to consider for the treatment of immune-mediated inflammatory diseases with Janus kinase inhibitors: a consensus statement

OBJECTIVES

Janus kinase inhibitors (JAKi) have been approved for use in various immune-mediated inflammatory diseases. With five agents licensed, it was timely to summarise the current understanding of JAKi use based on a systematic literature review (SLR) on efficacy and safety.

METHODS

Existing data were evaluated by a steering committee and subsequently reviewed by a 29 person expert committee leading to the formulation of a consensus statement that may assist the clinicians, patients and other stakeholders once the decision is made to commence a JAKi. The committee included patients, rheumatologists, a gastroenterologist, a haematologist, a dermatologist, an infectious disease specialist and a health professional. The SLR informed the Task Force on controlled and open clinical trials, registry data, phase 4 trials and meta-analyses. In addition, approval of new compounds by, and warnings from regulators that were issued after the end of the SLR search date were taken into consideration.

RESULTS

The Task Force agreed on and developed four general principles and a total of 26 points for consideration which were grouped into six areas addressing indications, treatment dose and comedication, contraindications, pretreatment screening and risks, laboratory and clinical follow-up examinations, and adverse events. Levels of evidence and strengths of recommendations were determined based on the SLR and levels of agreement were voted on for every point, reaching a range between 8.8 and 9.9 on a 10-point scale.

CONCLUSION

The consensus provides an assessment of evidence for efficacy and safety of an important therapeutic class with guidance on issues of practical management.

Tumor necrosis factor inhibitors are associated with reduced complement activation in spondylarthropathies: An observational study

BACKGROUND

The complement system is involved in pathogenesis of cardiovascular disease, and might play a role in accelerated atherogenesis in spondylarthropathies (SpA). Hence, we examined complement activation in SpA, and its relationship to antirheumatic treatment, inflammatory and cardiovascular markers.

METHODS

From PSARA, a prospective observational study, we examined 51 SpA patients (31 psoriatic arthritis (PsA), and 20 ankylosing spondylitis (AS)), starting tumor necrosis factor (TNF) inhibitor alone (n = 25), combined with methotrexate (MTX) (n = 10), or MTX monotherapy (n = 16). Complement activation was determined by the soluble terminal complement complex (sC5b-9), inflammation by erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP), and endothelial function by finger plethysmography (Endopat) at baseline, after 6 weeks and 6 months of treatment.

RESULTS

SpA patients had sC5b-9 levels at (PsA) or above (AS) the upper limit of the estimated reference range. Median sC5b-9 levels decreased significantly from baseline to 6 weeks, with no significant difference between the AS and PsA group. Notably, a significant reduction in sC5b-9 was observed after administration of TNF inhibitor ± MTX, whereas no significant changes were observed in patients treated with MTX alone. Between 6 weeks and 6 months, sC5b-9 remained stable across all subgroups. Reduction in sC5b-9 was independently related to decreased ESR and CRP, and to increased high density cholesterol and total cholesterol. Reduction in sC5b-9 from baseline to 6 weeks was associated with improved EF in age and gender adjusted analyses.

CONCLUSION

TNF-inhibition, but not MTX monotherapy, led to rapid and sustained reduction of complement activation in SpA. Thus, the observed decrease in cardiovascular morbidity in patients treated with TNF-inhibitors might be partly due to its beneficial effect on complement.

TRIAL REGISTRATION

Clinical Trials (NCT00902005), retrospectively registered on the 14th of May 2009.

Rate of serious infections in spondyloarthropathy patients treated with anti-tumour necrosis factor drugs: a survey from the Italian registry GISEA

OBJECTIVES

To determine the incidence of serious infections (SIs) among the spondyloarthropathy (SpA) patients from the "Gruppo Italiano per lo Studio delle Early Arthritis" (GISEA) registry and treated with tumour necrosis factor (TNF) inhibitors (TNFIs), and to identify the factors associated with the development of the infections.

METHODS

This observational study on 3321 GISEA-registered SpA patients collected real-world demographic and clinical data relating to their biological drug treatments. The overall incidence of infections was analysed by type of SpA.

RESULTS

A total of 3321 SpA patients (1731 males, 52.2%; mean age 47±13 years; median disease duration 3 years, interquartile range [IQR] 0-8) were eligible for inclusion in the analysis. Two hundred and fifty-nine patients experienced at least one of 391 microbiologically diagnosed SIs, 32% of which were recorded during the first 12 months of treatment. The overall incidence of SIs was 43.9/1000 patient-years of follow-up (95% confidence interval [CI] 39.6-48.4): 29.9/1000 (95% CI 23.1-38.1) among those treated with adalimumab (ADA); 36.1/1000 (95% CI 30.0-43.1) among those treated with etanercept (ETN); and 61.4/1000 (95% CI 53.3-70.5) among those treated with infliximab (INF). The highest incidence was observed among the patients with psoriatic arthritis (PsA), but the difference was statistically significant only in comparison with the patients with undifferentiated SpA (p=0.002), whose incidence of SIs was also lower than in the patients with ankylosing spondylitis (AS) (p=0.034). Multivariate models showed that the number of comorbidities (hazard ratio [HR] 1.29, 95%CI 1.2-1.4; p<0.001), age at the start of TNFi treatment (HR 0.99, 95%CI 0.97-0.99; p=0.030), steroid use (HR 1.40, 95%CI 1.1-1.8; p=0.012) and male sex (HR 0.72, 95%CI 0.5-0.9; p=0.012) were all statistically significant predictors of infection. The factors independently associated with a lower risk of SIs were the use of ETN (HR 0.52, 95%CI 0.4-0.7; p<0.001) or ADA (HR 0.59, 95%CI 0.4-0.8; p=0.002) rather than INF.

CONCLUSIONS

The incidence of SIs was higher among patients with PsA or AS than among those with undifferentiated SpA, and among patients treated with INF than among those treated with ADA or ETN. Male sex, steroid use and the number of comorbidities were all factors predictive of SIs.

Inflammatory bowel diseases and spondyloarthropathies: From pathogenesis to treatment

Spondyloarthropathies (SpA) include many different forms of inflammatory arthritis and can affect the spine (axial SpA) and/or peripheral joints (peripheral SpA) with Ankylosing spondylitis (AS) being the prototype of the former. Extra-articular manifestations, like uveitis, psoriasis and inflammatory bowel disease (IBD) are frequently observed in the setting of SpA and are, in fact, part of the SpA classification criteria. Bowel involvement seems to be the most common of these manifestations. Clinically evident IBD is observed in 6%-14% of AS patients, which is significantly more frequent compared to the general population. Besides, it seems that silent microscopic gut inflammation, is evident in around 60% in AS patients. Interestingly, occurrence of IBD has been associated with AS disease activity. For peripheral SpA, two different forms have been proposed with diverse characteristics. Of note, SpA (axial or peripheral) is more commonly observed in Crohn's disease than in ulcerative colitis. The common pathogenetic mechanisms that explain the link between IBD and SpA are still ill-defined. The role of dysregulated microbiome along with migration of T lymphocytes and other cells from gut to the joint ("gut-joint" axis) has been recognized, in the context of a genetic background including associations with alleles inside or outside the human leukocyte antigen system. Various therapeutic modalities are available with monoclonal antibodies against tumour necrosis factor, interleukin-23 and interleukin-17, being the most effective. Both gastroenterologists and rheumatologists should be alert to identify the co-existence of these conditions and ideally follow-up these patients in combined clinics.

Sensitivity and Specificity of Autoantibodies Against CD74 in Nonradiographic Axial Spondyloarthritis

OBJECTIVE

Autoantibodies against CD74 (anti-CD74) are associated with ankylosing spondylitis (AS). The present multicenter study, the International Spondyloarthritis Autoantibody (InterSpA) trial, was undertaken to compare the sensitivity and specificity of anti-CD74 and HLA-B27 in identifying patients with nonradiographic axial spondyloarthritis (axSpA).

METHODS

Patients ages 18-45 years with inflammatory back pain of ≤2 years' duration and a clinical suspicion of axSpA were recruited. HLA-B27 genotyping and magnetic resonance imaging of sacroiliac joints were performed in all patients. One hundred forty-nine patients with chronic inflammatory back pain (IBP) not caused by axSpA served as controls, and additional controls included 50 AS patients and 100 blood donors whose specimens were analyzed.

RESULTS

One hundred patients with inflammatory back pain received a diagnosis of nonradiographic axSpA from the investigators and fulfilled the Assessment of SpondyloArthritis international Society (ASAS) criteria. The mean age was 29 years, and the mean symptom duration was 12.5 months. The sensitivity of IgA anti-CD74 and IgG anti-CD74 for identifying the 100 axSpA patients was 47% and 17%, respectively. The specificity of both IgA anti-CD74 and IgG anti-CD74 was 95.3%. The sensitivity of HLA-B27 was 81%. The positive likelihood ratios were 10.0 (IgA anti-CD74), 3.6 (IgG anti-CD74), and 8.1 (HLA-B27). Assuming a 5% pretest probability of axSpA in chronic back pain patients, the posttest probability, after consideration of the respective positive test results, was 33.3% for IgA anti-CD74, 15.3% for IgG anti-CD74, and 28.8% for HLA-B27. A combination of IgA anti-CD74 and HLA-B27 results in a posttest probability of 80.2%.

CONCLUSION

IgA anti-CD74 may be a useful tool for identifying axSpA. The diagnostic value of the test in daily practice requires further confirmation.

Contribution of ancient human remains analysis to the understanding of the variability in HLA-B gene variants in relation to the diagnosis of spondyloarthropathies

Genetic investigations on ancient human remains affected by rheumatological pathologies are a research field of particular interest for identifying the pathogenesis of diseases, especially those having an autoimmune background such as spondyloarthopaties (SpA). Reliable studies concerning this topic require collaboration between multiple disciplines, usually starting from paleopathologic observations up to molecular genetic screening. Here, we focused our investigation in a medieval necropolis in the Basque Country (13th-15th century, N = 163), which presents a high frequency of joint pathologies through two approaches: on the one hand, the analysis of joint manifestations for the differential diagnosis of the SpA and, on the other hand, the determination of the alleles of the HLA-B gene. The morphological analysis allowed determining that 30% of the individuals had rheumatic bone manifestations, with SpA being the most frequent (45%). The genetic analysis of individuals with and without pathologies, based on the study of the HLA-B gene, allowed finding 17 alleles for this gene, with HLA-B40, HLA-B27 and HLA-B35 being the most frequent. Although these alleles have been traditionally described as genetic markers associated to the development of SpA, in this study they were also found in individuals with other rheumatic diseases (osteoarthritis and rheumatoid arthritis) and even in individuals without pathologies. These data confirm the complexity of the relationship of the HLA-B gene variants with SpA, since it is not possible to establish a diagnosis of SpA with these variants alone. However, we suggest that allele HLA-B40, in combination with some specific rheumatic bone manifestations, facilitates the diagnosis of SpA.

Stress proteins in the pathogenesis of spondyloarthritis

Spondyloarthritis is an autoinflammatory rheumatic disease in which arthritis and osteoproliferation lead the patients who suffer from it to chronic disability. This disease is associated with the expression of class I MHC molecule HLA-B27, which tends to be misfolded in the endoplasmic reticulum and, therefore, expressed in aberrant forms. This phenomena lead to endoplasmic reticulum stress, which in time, evokes a whole response to cellular injury. Under these conditions, the molecules involved in restoring cell homeostasis play a key role. Such is the case of the "heat-shock proteins", which usually regulate protein folding, but also have important immunomodulatory functions, as well as some roles in tissue modeling. In this review, we attempt to summarize the involvement of cell stress and heat-shock proteins in the homeostatic disturbances and pathological conditions associated with this disease.

The Role of Autophagy in the Degradation of Misfolded HLA-B27 Heavy Chains

OBJECTIVE

To determine whether autophagy is involved in the degradation of misfolded HLA-B27 in experimental spondyloarthritis.

METHODS

Bone marrow-derived macrophages from HLA-B27/human β2 -microglobulin (hβ2 m)-transgenic rats were incubated in the presence or absence of interferon-γ and proteasome or autophagy inhibitors. Immunoprecipitation, immunoblotting, and immunofluorescence analysis were used to measure HLA-B27 heavy chains and autophagy. Autophagy was induced using rapamycin. Macrophages from HLA-B7/hβ2 m-transgenic and wild-type rats were used as controls.

RESULTS

HLA-B27-expressing macrophages showed phosphatidylethanolamine-conjugated microtubule-associated protein 1 light chain 3B levels similar to those in both control groups, before and after manipulation of autophagy. Blocking autophagic flux with bafilomycin resulted in the accumulation of misfolded HLA-B27 dimers and oligomers as well as monomers, which was comparable with the results of blocking endoplasmic reticulum-associated degradation (ERAD) with the proteasome inhibitor bortezomib. HLA-B7 monomers also accumulated after blocking each degradation pathway. The ubiquitin-to-heavy chain ratio was 2-3-fold lower for HLA-B27 than for HLA-B7. Activation of autophagy with rapamycin rapidly eliminated ~50% of misfolded HLA-B27, while folded HLA-B27 or HLA-B7 monomeric heavy chains were minimally affected.

CONCLUSION

This study is the first to demonstrate that both autophagy and ERAD play roles in the elimination of excess HLA class I heavy chains expressed in transgenic rats. We observed no evidence that HLA-B27 expression modulated the autophagy pathway. Our results suggest that impaired ubiquitination of HLA-B27 may play a role in the accumulation of misfolded disulfide-linked dimers, the elimination of which can be enhanced by activation of autophagy. Manipulation of the autophagy pathway should be further investigated as a potential therapeutic target in spondyloarthritis.

Role of Stem Cells in Pathophysiology and Therapy of Spondyloarthropathies-New Therapeutic Possibilities?

Considerable progress has been made recently in understanding the complex pathogenesis and treatment of spondyloarthropathies (SpA). Currently, along with traditional disease modifying anti-rheumatic drugs (DMARDs), TNF-α, IL-12/23 and IL-17 are available for treatment of such diseases as ankylosing spondylitis (AS) and psoriatic arthritis (PsA). Although they adequately control inflammatory symptoms, they do not affect the abnormal bone formation processes associated with SpA. However, the traditional therapeutic approach does not cover the regenerative treatment of damaged tissues. In this regards, stem cells may offer a promising, safe and effective therapeutic option. The aim of this paper is to present the role of mesenchymal stromal cells (MSC) in pathogenesis of SpA and to highlight the opportunities for using stem cells in regenerative processes and in the treatment of inflammatory changes in articular structures.

Prevalence of thyroid autoantibodies in patients with systematic autoimmune rheumatic diseases. Cross-sectional study

BACKGROUND

Thyroid autoimmunity is more common in patients with rheumatic diseases than in healthy populations. The degree of association seems subject to influence from patients' geographical location. Here, we aimed to ascertain the prevalence of thyroid autoantibodies in a cohort of patients with systemic rheumatic disease and the degree of association between its presence and inflammatory activity.

DESIGN AND SETTING

Cross-sectional observational study in a rheumatology unit.

METHODS

301 patients with systemic lupus erythematosus (SLE), 210 with rheumatoid arthritis (RA), 58 with scleroderma (SSc) and 80 with spondyloarthritis (SpA) were studied regarding thyroid function (TSH and T4), anti-thyroglobulin (TgAb) and anti-thyroperoxidase (TPOab) and compared with 141 healthy controls. Disease activity in patients with rheumatic disease was assessed through appropriate indexes.

RESULTS

There were more antithyroid antibodies in SLE patients with hypothyroidism (P = 0.01; odds ratio, OR 2.7; 95% confidence interval, CI: 1.20-6.26) and in those without hypothyroidism (P = 0.06; OR 2.4; 95% CI: 1.28-4.55) than in controls. SSc patients also showed: P = 0.03 both with antithyroid antibodies and hypothyroidism (OR 3.4; 95% CI: 1.06-10.80) and without hypothyroidism (OR 3.1; 95% CI: 1.11-0.13). RA and SpA patients had the same prevalence as controls (P not significant). Presence of autoantibodies with and without hypothyroidism was not associated with the activity or functional indexes evaluated.

CONCLUSION

SLE and SSc were associated with higher prevalence of thyroid autoantibodies in patients with and without hypothyroidism, unlike SpA and RA. There was no link between thyroid autoantibody presence and disease activity or functional impairment.

Intestinal Metabolites Are Profoundly Altered in the Context of HLA-B27 Expression and Functionally Modulate Disease in a Rat Model of Spondyloarthritis

OBJECTIVE

HLA-B27-associated spondyloarthritides are associated with an altered intestinal microbiota and bowel inflammation. We undertook this study to identify HLA-B27-dependent changes in both host and microbial metabolites in the HLA-B27/β2 -microglobulin (β2 m)-transgenic rat and to determine whether microbiota-derived metabolites could impact disease in this major model of spondyloarthritis.

METHODS

Cecal contents were collected from Fischer 344 33-3 HLA-B27/β2 m-transgenic rats and wild-type controls at 6 weeks (before disease) and 16 weeks (with active bowel inflammation). Metabolomic profiling was performed by high-throughput gas and liquid chromatography-based mass spectrometry. HLA-B27/β2 m-transgenic rats were treated with the microbial metabolites propionate or butyrate in drinking water for 10 weeks, and disease activity was subsequently assessed.

RESULTS

Our screen identified 582 metabolites, of which more than half were significantly altered by HLA-B27 expression at 16 weeks. Both microbial and host metabolites were altered, with multiple pathways affected, including those for amino acid, carbohydrate, xenobiotic, and medium-chain fatty acid metabolism. Differences were even observed at 6 weeks, with up-regulation of histidine, tyrosine, spermidine, N-acetylmuramate, and glycerate in HLA-B27/β2 m-transgenic rats. Administration of the short-chain fatty acid propionate significantly attenuated HLA-B27-associated inflammatory disease, although this was not associated with increased FoxP3+ T cell induction or with altered expression of the immunomodulatory cytokines interleukin-10 (IL-10) or IL-33 or of the tight junction protein zonula occludens 1. HLA-B27 expression was also associated with altered host expression of messenger RNA for the microbial metabolite receptors free fatty acid receptor 2 (FFAR2), FFAR3, and niacin receptor 1.

CONCLUSION

HLA-B27 expression profoundly impacts the intestinal metabolome, with changes evident in rats even at age 6 weeks. Critically, we demonstrate that a microbial metabolite, propionate, attenuates development of HLA-B27-associated inflammatory disease. These and other microbiota-derived bioactive mediators may provide novel treatment modalities in HLA-B27-associated spondyloarthritides.

Interleukin-22 drives the proliferation, migration and osteogenic differentiation of mesenchymal stem cells: a novel cytokine that could contribute to new bone formation in spondyloarthropathies

OBJECTIVES.

The SpAs are genetically and therapeutically linked to IL-23, which in turn regulates IL-22, a cytokine that has been implicated in the regulation of new bone formation in experimental models. We hypothesize that IL-22, a master regulator of stem cells in other niches, might also regulate human mesenchymal stem cell (MSC) osteogenesis.

METHODS.

The effects of IL-22 on in vitro MSC proliferation, migration and osteogenic differentiation were evaluated in the presence or absence of IFN-γ and TNF (to ascertain IL-22 activity in pro-inflammatory environments). Colorimetric XTT assay, trans-well migration assays, quantitative real-time PCR (qRT-PCR) for MSC lineage markers and osteogenesis assays were used.

RESULTS.

Combined treatment of MSC with IL-22, IFN-γ and TNF resulted in increased MSC proliferation ( P = 0.008) and migration ( P = 0.04), an effect that was not seen in cells treated with IL-22 alone and untreated cells. Osteogenic and adipogenic, but not chondrogenic, transcription factors were upregulated by IL-22 alone ( P < 0.05). MSC osteogenesis was enhanced following IL-22 exposure ( P = 0.03, measured by calcium production). The combination of IFN-γ and TNF with or without IL-22 suppressed MSC osteogenesis ( P = 0.03).

CONCLUSION.

This work shows that IL-22 is involved in human MSC proliferation/migration in inflammatory environments, with MSC osteogenesis occurring only in the absence of IFN-γ/TNF. These effects of IL-22 on MSC function is a novel pathway for exploring pathological, post-inflammation osteogenesis in human SpA.

Interleukin-23-Dependent γ/δ T Cells Produce Interleukin-17 and Accumulate in the Enthesis, Aortic Valve, and Ciliary Body in Mice

OBJECTIVE

The spondyloarthritides (SpA) are a group of rheumatic diseases characterized by ossification and inflammation of entheseal tissue, the region where tendon attaches to bone. Interleukin-23 (IL-23) is involved in the pathogenesis of SpA by acting on IL-23 receptor (IL-23R) expressed on enthesis-resident lymphocytes. Upon IL-23 binding, CD3+CD4-CD8- tissue-resident lymphocytes secrete IL-17A and IL-22, leading to inflammation, bone loss, and ossification. Knowledge about enthesis-resident lymphocytes remains fragmentary, and the contribution of entheseal γ/δ T cells in particular is not clear. This study was undertaken to investigate the presence of γ/δ T cells in the enthesis.

METHODS

We used 2-photon microscopy and flow cytometry to analyze entheseal lymphocytes from C57BL/6, Tcrd-H2BeGFP, Rorc-GFP, and IL-23R-eGFP mice. To analyze entheseal γ/δ T cells in IL-23-induced inflammation, Tcrd-H2BeGFP mice were crossed with mice of the susceptible B10.RIII background. Hydrodynamic injection of IL-23 minicircle DNA was performed for overexpression of IL-23 and induction of inflammation. Light-sheet fluorescence microscopy was used to visualize arthritic inflammation.

RESULTS

Activated Vγ6+CD27- γ/δ T cells were abundant in uninflamed entheseal tissue and constituted the large majority of retinoic acid receptor-related orphan nuclear receptor γt (RORγt)+IL-23R+ enthesis-resident lymphocytes. Fetal thymus-dependent γ/δ T cells were the main source of IL-17A at the enthesis. Under inflammatory conditions, γ/δ T cells increased in number at the Achilles tendon enthesis, aortic root, and adjacent to the ciliary body.

CONCLUSION

Entheseal γ/δ T cells are derived from fetal thymus and are maintained as self-renewing tissue-resident cells. As main IL-17A producers within tissues exposed to mechanical stress including enthesis, γ/δ T cells are key players in the pathogenesis of IL-23-induced local inflammation.

Biologic agents in juvenile spondyloarthropathies

The juvenile spondyloarthropathies (JSpA) are a group of related rheumatic diseases characterized by involvement of peripheral large joints, axial joints, and entheses (enthesitis) that begin in the early years of life (prior to 16(th) birthday).The nomenclature and concept of spondyloarthropathies has changed during the last few decades. Although there is not any specific classification of JSpA, diseases under the spondyloarthropathy nomenclature umbrella in the younger patients include: the seronegative enthesitis and arthropathy (SEA) syndrome, juvenile ankylosing spondylitis, reactive arthritis, and inflammatory bowel disease-associated arthritis. Moreover, the ILAR criteria for Juvenile Idiopathic Arthritis includes two categories closely related to spondyloarthritis: Enthesitis-related arthritis and psoriatic arthritis.We review the pathophysiology and the use of biological agents in JSpA. JSpA are idiopathic inflammatory diseases driven by an altered balance in the proinflammatory cytokines. There is ample evidence on the role of tumor necrosis factor (TNF) and interleukin-17 in the physiopathology of these entities. Several non-biologic and biologic agents have been used with conflicting results in the treatment of these complex diseases. The efficacy and safety of anti-TNF agents, such as etanercept, infliximab and adalimumab, have been analysed in controlled and uncontrolled trials, usually showing satisfactory outcomes. Other biologic agents, such as abatacept, tocilizumab and rituximab, have been insufficiently studied and their role in the therapy of SpA is uncertain. Interleukin-17-blocking agents are promising alternatives for the treatment of JSpA patients in the near future. Recommendations for the treatment of patients with JSpA have recently been proposed and are discussed in the present review.

[General concepts and pathogenesis of the spondyloarthropathies]

The spondyloarthritides are a group of interrelated diseases with a close association with the HLA-B27 antigen that share many common articular and extra-articular features. This paper summarizes the different classification criteria that are currently in use. While the exact pathogenesis of these diseases is not yet clearly elucidated, there are a number of hypotheses relating to HLA-B27, modifications of the microbiome and biomechanical stresses. This in turn leads to upregulation of various proinflammatory cytokines such as TNF-alpha, IL-17, IL-22 and IL-23, which results in further inflammation and osteoproliferation.

The quantitative prediction of HLA-B*2705 peptide binding affinities using Support Vector Regression to gain insights into its role for the Spondyloarthropathies

Computational methods are increasingly utilised in many immunoinformatics problems such as the prediction of binding affinity of peptides. The peptides could provide valuable insight into the drug design and development such as vaccines. Moreover, they can be used to diagnose diseases. The presence of human class I MHC allele HLA-B*2705 is one of the strong hypothesis that would lead spondyloarthropathies. In this paper, Support Vector Regression is used in order to predict binding affinity of peptides with the aid of experimentally determined peptide-MHC binding affinities of 222 peptides to HLA-B*2705 to get more insight into this problematic disease. The results yield a high correlation coefficient as much as 0.65 and the SVR-based predictive models can be considered as a useful tool in order to predict the binding affinities for newly discovered peptides.

Relationship of Psoriatic Arthritis to Other Spondyloarthritides

In the early 1970s, Moll and co-workers formulated the unified concept of spondyloarthritides, a group of conditions sharing similar clinical features. Subsequently, criteria for their classification have been proposed by Amor and coworkers, the European Spondylarthropathy Study Group, and the Assessment in SpondyloArthritis international Society. Opinion, however, is divided between those who believe that the different entities of the complex represent the variable expression of the same disease ("lumpers") and those who think that these should be considered separately but under the same umbrella ("splitters"). Several sets of criteria have been proposed for psoriatic arthritis (PsA), the most recent being the ClASsification for Psoriatic Arthritis (CASPAR) criteria. According to some authors, there are persuasive arguments to support the view of PsA as a distinct entity.

Which patients with rheumatoid arthritis, spondyloarthritis, or juvenile idiopathic arthritis receive TNF-α antagonists in France? The CORPUS cohort study

OBJECTIVES

Limited information is available about the characteristics of patients with active inflammatory rheumatic diseases who start TNF-α antagonist therapy. Our objective was to assess TNF-α antagonist prescription patterns in this context in France.

METHODS

Between 2007 and 2009, 102 rheumatologists, internists, and pediatricians in French university hospitals and private practice prospectively recruited biologics-naïve patients with active rheumatoid arthritis (RA) (DAS28>3.2 despite methotrexate therapy), spondyloarthritis (SA) (BASDAI≥4 despite non-steroidal anti-inflammatory drug [NSAID] use), and juvenile idiopathic arthritis (JIA) (unresponsive to methotrexate). Patients were monitored prospectively for 1 year.

RESULTS

Of the 543 RA, 287 SA, and 53 JIA patients included in the study, 382 RA, 171 SA, and 28 JIA patients had complete follow-up data available after 1 year. Among these patients, 110/382 (28.8%) with RA, 81/171 (47.4%) with SA, and 26/28 (92.9%) with JIA received at least one TNF-α antagonist dose during the 1-year follow-up. The main physician-reported reason for not starting TNF-α antagonists in patients with RA or SA was low disease activity (72% for RA and 67% for SA); absence of TNF-α antagonist therapy was due to patient refusal in only 10% and to contraindications in 6% to 7% of cases.

CONCLUSIONS

In France, TNF-α antagonists, which are fully reimbursed by the national health insurance system, were used almost routinely in JIA patients unresponsive to methotrexate and were given to about half the SA patients with BASDAI≥4 despite NSAID use and a third of RA patients with DAS28>3.2 despite methotrexate therapy.

Prevalence of lower extremity peripheral arterial disease in individuals with chronic immune mediated inflammatory disorders

OBJECTIVE

To compare the prevalence of lower extremity peripheral artery disease (PAD) and to assess whether age-associated progression in ankle-brachial index (ABI) differs between individuals with chronic immune-mediated inflammatory diseases (CIID) and the general population.

METHODS

Pooled analysis with data from individuals aged 50 years and older with ABI measurements, obtained from population-based cross-sectional studies conducted in Catalonia (Spain). Information on three CIID diagnoses (i.e., inflammatory bowel disease, systemic connective tissue disorders, and inflammatory polyarthropathies and spondylopathies, considered as one entity for purposes of analysis) was obtained from electronic medical records. To ascertain the statistical association between PAD and CIID, logistic regression models were fitted and adjusted for age, sex, and cardiovascular risk factors. We tested the interaction between age and CIID diagnosis for ABI values.

RESULTS

We included 8799 individuals, 312 (3.6%) with CIID. The age-standardized prevalence of PAD was higher in the CIID group (12% vs. 6% in general population, p = 0.001), and the model adjusted for age, sex, and cardiovascular risk factors also showed higher risk in individuals with CIID [Odds Ratio (95% confidence interval) = 1.65 (1.15-2.38); p = 0.007]. The inflammatory polyarthropathies/spondylopathies diagnosis was significantly associated with PAD in the fully adjusted model [1.80 (1.18-2.75); p = 0.006]. The atherosclerotic process was accelerated in individuals with CIID, compared to the general population (p for interaction<0.001).

CONCLUSION

In individuals with CIID, age-standardized prevalence of PAD was significantly higher than in the general population and the atherosclerotic process was accelerated. However, only inflammatory polyarthropathies/spondylopathies was associated with significant risk of PAD.

Th22 Cells Contribution in Immunopathogenesis of Rheumatic Diseases

Newly identified T helper cell 22 (Th22) is a subset of CD4+T cells with specific properties apart from other known CD4+ T cell subsets with distinguished gene expression and function. Th22 cells are characterized by production of a distinct profile of effector cytokines, including interleukin (IL)-22, IL-13, and tumor necrosis factor-α (TNF-α). The levels of Th22 and related cytokine IL-22 are increased in various autoimmune diseases and positively associated with some rheumatic diseases such as rheumatoid arthritis, systemic lupus erythematosus, behcet's disease, ankylosing spondylitis and psoriatic arthritis. In summary, IL-22 and Th22 cells play a significant and complicated role in inflammatory and autoimmune rheumatic diseases, therefore, targeting IL-22 or Th22 have unique and attractive advantages due to the fact that Th22 subset is recently identified and its associated research is extremely limited. This review discusses the role of Th22 and its cytokine IL-22 in the immunopathogenesis of rheumatic disease.

Role of IL-17 in the pathogenesis of psoriatic arthritis and axial spondyloarthritis

Th17 cells are a discrete subset of T cell subpopulation, which produce IL-17 and certain other pro-inflammatory cytokines. A regulatory role of Th17 cells have been proposed in several autoimmune diseases including psoriasis, psoriatic arthritis (PsA), ankylosing spondylitis (AS), rheumatoid arthritis, inflammatory bowel disease, systemic lupus erythematosus, and multiple sclerosis. Psoriatic disease is an autoimmune disease which mainly involves skin and joints. Until recently, psoriasis and PsA were thought to be Th1 mediated disease, but after the discovery of IL-17 and IL-17 knockout animal studies as well as human experimental data indicate a crucial role of the Th17 cells in the pathogenesis of psoriasis and PsA. Our research group have not only found abundance of CD4(+)IL-17(+) T cells, mainly the memory phenotype (CD4RO(+)CD45RA(-)CD11a(+)) in the synovial fluid, but also have shown the existence of a functional IL-17 receptor in synovial fibroblast of psoriatic arthritis patients. Similarly, both animal and human studies indicate a regulatory role of the Th17 cells in AS; most critical observations are that Th17 cytokines (IL-17 and IL-22) can contribute to bone erosion, osteitis and new bone formation the hall mark skeletal features associated with the pathophysiology of AS. In this review article, we have discussed the contributing role of the IL-23/IL-17 axis in the pathogenesis of PsA and AS.

Seronegative arthritis in Latin America: a current review

In many Latin American countries seronegative arthritis, especially the spondyloarthritides (SpA), is commonly characterized by associated axial and peripheral involvement. In this article, the authors review the ethnic distribution of the population and the different SpA in 10 Latin American countries, and the main characteristics of the Ibero-American Registry of Spondyloarthropathies (RESPONDIA) compared with other international registries. The peripheral component of SpA is more frequent in mixed-race populations, whereas psoriatic arthritis is significantly more frequent in countries with predominantly white populations.

Lack of hepatitis B virus reactivation after anti-tumour necrosis factor treatment in potential occult carriers with chronic inflammatory arthropathies

BACKGROUND

Hepatitis B virus (HBV) reactivation in patients positive for antibody to HB core antigen (anti-HBc), negative for HB surface antigen (HBsAg) and HBV-DNA (potential occult HBV carriers), treated with anti-tumor necrosis factor (TNF)α, is a debated question. The aim of the study was to evaluate the safety of anti-TNFα therapy in anti-HBc positive/HBsAg negative subjects with rheumatoid arthritis (RA) and spondyloarthropathy (SpA).

METHODS

All consecutive HBsAg negative RA and SpA outpatients referring to the Immuno-Rheumatology Institute at the S. Andrea hospital, Sapienza, University of Rome who had to undergo anti-TNFα therapy.

RESULTS

Among the 169 enrolled subjects, 20 (12%) were potential occult HBV carriers (anti-HBc positive, HBsAg and HBV-DNA negative patients with or without anti-HBs). During the follow-up (mean ± SD 45 ± 22 months), aminotransferases and HBV-DNA, tested every two and six months respectively, did not change.

CONCLUSION

This study confirms the substantial safety of anti-TNFα therapy in potential occult HBV carriers RA and SpA patients.

Current issues in pediatric inflammatory bowel disease-associated arthropathies

Joint involvement is the most common extraintestinal manifestation in children with inflammatory bowel disease (IBD) and may involve 16%-33% of patients at diagnosis or during follow-up. It is possible to distinguish asymmetrical, transitory and migrating arthritis (pauciarticular and polyarticular) and spondyloarthropathy (SpA). Clinical manifestations can be variable, and peripheral arthritis often occurs before gastrointestinal symptoms develop. The inflammatory intestinal pattern is variable, ranging from sub-clinical inflammation conditions, classified as indeterminate colitis and nodular lymphoid hyperplasia of the ileum, to Crohn’s disease or ulcerative colitis. Unlike the axial form, there is an association between gut inflammation and evolution of recurrent peripheral articular disease that coincides with a flare-up of intestinal disease. This finding seems to confirm a key role of intestinal inflammation in the pathogenesis of SpA. An association between genetic background and human leukocyte antigen-B27 status is less common in pediatric than n adult populations. Seronegative sacroiliitis and SpA are the most frequent forms of arthropathy in children with IBD. In pediatric patients, a correct therapeutic approach relies on the use of nonsteroidal antiinflammatory drugs, local steroid injections, physiotherapy and anti-tumor necrosis factor therapy (infliximab). Early diagnosis of these manifestations reduces the risk of progression and complications, and as well as increasing the efficacy of the therapy.

Anti-TNF therapy and malignancy in spondyloarthritis in the Leuven spondyloarthritis biologics cohort (BIOSPAR)

OBJECTIVES

To report the incidence of malignancy in a large single-centre cohort in Belgium of patients with spondyloarthritis (SpA) treated with one or more anti-TNF therapies and to compare the results with the incidence of malignancy in the Belgian population.

METHODS

From September 2000 until March 2010, all SpA patients that started treatment with one or more anti-TNF therapies were included in this single-centre prospective longitudinal observational study. The primary outcome of this study was the incidence of malignancy after starting anti-TNF treatment. Incidence rates were compared with the incidence rates of malignancy in Belgium in 2008 for the 45-50 year-old population, as documented by the Belgian Cancer Registry.

RESULTS

231 patients with a mean age of 47.86 y were included for a total of 1020.74 patient years of treatment and 1199.83 patient years follow-up after the start of treatment. In our study population, 6 out of 231 patients (2.6 %) developed a malignancy after the start of anti-TNF treatment. The overall incidence rate of malignancy in our study population is 500.1 per 100000 patient years, indicating a higher incidence compared to the Belgian population. We see a higher incidence rate in females as well in males; standardised incidence ratios are in the same range for both (154.3 for females and 130.6 for males).

CONCLUSIONS

We see a tendency towards a higher incidence of malignancy in SpA patients treated with anti-TNF therapy. However, it is not clear whether this increased risk is disease-related or treatment-related.

Orbital inflammatory disease: unusual presentation of enthesitis in an HLA-B27 spondyloarthropathy

BACKGROUND

Orbital inflammatory disease can complicate many systemic inflammatory disorders, including sarcoidosis, vasculitis, Crohn's disease, systemic lupus erythematosus, rheumatoid arthritis, myasthenia gravis and scleroderma, but has not been reported with spondyloarthropathies.

OBSERVATIONS

The authors describe a 29-year-old woman who developed orbital myositis, in addition to anterior uveitis, sacroiliitis and peripheral arthritis, as a complication of an underlying HLA-B27 related spondyloarthropathy, which responded temporarily to corticosteroid therapy and more completely to adalimumab.

CONCLUSIONS

The patient reported herein presents with orbital inflammation as an extra-articular manifestation of HLA-B27 associated undifferentiated spondyloarthropathy. We propose that enthesitis is the likely mechanism of orbital inflammation in this patient.

Psoriasiform dermatitis in a non-psoriatic patient treated with adalimumab

Anti-TNF drugs may be associated with various adverse reactions including cutaneous ones. We describe the case of a 45-year-old woman affected by undifferentiated spondyloarthritis who presented a localized psoriasiformis dermatitis during treatment with adalimumab, without any medical history of psoriasis.

IL-23 induces spondyloarthropathy by acting on ROR-γt+ CD3+CD4-CD8- entheseal resident T cells

The spondyloarthropathies are a group of rheumatic diseases that are associated with inflammation at anatomically distal sites, particularly the tendon-bone attachments (entheses) and the aortic root. Serum concentrations of interleukin-23 (IL-23) are elevated and polymorphisms in the IL-23 receptor are associated with ankyosing spondylitis, however, it remains unclear whether IL-23 acts locally at the enthesis or distally on circulating cell populations. We show here that IL-23 is essential in enthesitis and acts on previously unidentified IL-23 receptor (IL-23R)(+), RAR-related orphan receptor γt (ROR-γt)(+)CD3(+)CD4(-)CD8(-), stem cell antigen 1 (Sca1)(+) entheseal resident T cells. These cells allow entheses to respond to IL-23 in vitro-in the absence of further cellular recruitment--and to elaborate inflammatory mediators including IL-6, IL-17, IL-22 and chemokine (C-X-C motif) ligand 1 (CXCL1). Notably, the in vivo expression of IL-23 is sufficient to phenocopy the human disease, with the specific and characteristic development of enthesitis and entheseal new bone formation in the initial complete absence of synovitis. As in the human condition, inflammation also develops in vivo at the aortic root and valve, which are structurally similar to entheses. The presence of these entheseal resident cells and their production of IL-22, which activates signal transducer and activator of transcription 3 (STAT3)-dependent osteoblast-mediated bone remodeling, explains why dysregulation of IL-23 results in inflammation at this precise anatomical site.

Th17 and interleukin 23 in the pathogenesis of psoriatic arthritis and spondyloarthritis

Psoriatic arthritis and spondyloarthritis (SpA) are complex immune-mediated diseases affecting peripheral and axial joints. T cells have been considered fundamental in triggering the disease and maintaining the process in the chronic phase. The recent discovery of the CD4+ Th17 lymphocyte subset and the interleukin 23/interleukin 17 axis has further contributed to the definition of unknown pathways, challenging previous models and the role of Th1/Th2 T cells in immune mediated diseases, including SpA.

Low frequency of axial involvement in southern Italian Caucasian children with HLA-B27 positive juvenile onset undifferentiated spondyloarthritis

OBJECTIVES

To establish how many children with HLA B27-positive juvenile undifferentiated spondyloarthritis (JuSpA) living in southern Italy develop axial disease after 5 years of disease.

METHODS

All children with B27-positive enthesitis-related arthritis (ERA) consecutively seen in a 7-year period were entered in a special register and were followed prospectively. Each patient was examined at 6-month intervals, even if asymptomatic. In patients with inflammatory spinal pain and/or buttock pain, MRI of the sacroiliac joints and spine was performed. Five years after inclusion, sacroiliac joint plain radiographs were obtained and read blindly after being mixed with those of control subjects.

RESULTS

Thirteen children, 9 boys and 4 girls, with B27-positive ERA and one girl with B27-positive isolated SpA dactylitis were seen in the study period. Their median age at disease onset and at our first examination were 10 (range 2-16) and 12 years (range 3-16), respectively. During follow-up, only one patient had axial symptoms, i.e. alternate buttock pain. MRI revealed moderate bone oedema at both sacroiliac joints. After five years of disease, no patient showed reduced spinal movement. No sign of sacroiliitis was seen in any patient and control on plain films. A new MRI of the sacroiliac joints of the patient who showed bone oedema in the first years of disease was normal.

CONCLUSIONS

This study confirms that the onset of axial involvement in Italian Caucasian HLA-B27 positive children with ERA is rare in the first five years of disease.

IL-6 inhibition for the treatment of rheumatoid arthritis and other conditions

New data published or presented in the past year has expanded our understanding of the clinical use of interleukin 6 (IL-6) inhibitors and their role in the management of rheumatoid arthritis (RA) and other rheumatic diseases. Data has become available on the use of tocilizumab (TCZ) in comparison to adalimumab, as therapy in RA patients with an inadequate response to TNF inhibitors and on its role as monotherapy. Early data on the efficacy and safety of subcutaneously administered TCZ suggests a potential role for this formulation of the drug. Extension studies of the use of TCZ in systemic juvenile inflammatory arthritis have confirmed the long-term efficacy of the drug in this illness, while studies on the use of TCZ and other IL-6 inhibitors in spondyloarthropathies has been less encouraging. Finally, new agents targeting the IL-6 pathway have entered late stage clinical trials, and the early results are promising.

Human leukocyte antigen B27 in 453 Asian Indian patients with seronegative spondyloarthropathy

BACKGROUND

Spondyloarthropathies are a group of closely related inflammatory arthritis which involve the axial skeleton and are negative for rheumatoid factor.

OBJECTIVE

This case-control study was conducted to examine HLA- B27 positivity in patients with seronegative spondyloarthritis (SSA) as per ESSG criteria and compare the frequency with healthy controls because a lower positivity is reported in Indians.

METHOD

The study included 453 patients and 200 controls. HLA -B27 typing was done by microlymphocytotoxicity and/or by sequence specific primers (SSP) using commercial kits. Patients were categorised as Ankylosing Spondylitis (AS), Undifferentiated Spondyloarthropathy, SSA with inflammatory bowel disease, reactive arthritis, psoriatic arthritis and juvenile spondyloarthropathy.

RESULTS

HLA- B27 antigen was present in 56% of patient and 3.5% controls with highest frequency in juvenile spondyloarthropathy (80%), followed by AS (76%). The P value < 0.001 for all categories of SSA and overall Odds ratio was 34.9.

CONCLUSION

This study showed HLA-B27 frequency slightly lower than reported in Caucasian SSA patients and in our opinion HLA- B27 testing is extremely useful in young patients with suspected SSA.

Immunologic and genetic links between spondylarthropathies and inflammatory bowel diseases

BACKGROUND AND OBJECTIVE

Spondyloarthritis (SpA) is a well recognized extraintestinal manifestation of Inflammatory Bowel Diseases (IBDs), either Crohn's Disease(CD) or Ulcerative Colitis (UC). A much larger percentage of SpA patients have subclinical gut inflammation manifested either by endoscopic findings or by histology. The aim of the present article is to review clinical and experimental evidences regarding the immunological and genetic links between gut and joint inflammation in IBDs and SpA.

EVIDENCE AND INFORMATION SOURCES

A systematic review using PubMed database entering IBD and SpA as key words was performed.

STATE OF THE ART

The association with HLA-B27 is less strong in IBD-associated SpA than in Idiopathic Ankylosing Spondylitis (AS) and there is some evidence for an association between gut inflammation in SpA and CD related CARD15 mutations. A common inflammatory pathogenic pathway has been suggested in gut and joint inflammation in IBD. Treatment of SpA associated with IBD has gained major advances in recent years with the advent of anti-TNF-alpha therapy.

PERSPECTIVES

The adaptive immune response in IBD is thought to be strictly differentiated between Th1 and Th2 in CD and UC respectively. Recent findings, however, suggest that novel effector pathways could drive tissue damage. The most important pathway now emerging is the IL-23/IL-17 axis.

CONCLUSIONS

Present and future advancements of knowledge on mechanisms of inflammation will likely lead to new therapeutic targets.

Verification of Berlin algorithm for diagnosing undifferentiated spondyloarthropathy patients in Chinese population

OBJECTIVE

To evaluate the diagnosing value of the Berlin algorithm, comparing to that of the established ESSG and Amor criteria in Chinese patients with undifferentiated spondyloarthropathy.

METHODS

A total of 92 clinically diagnosed undifferentiated spondyloarthropathy patients with axial involvement were compared to 123 patients with other kinds of rheumatic diseases by using the parameters listed in the Berlin algorithm, ESSG criteria, and Amor criteria.

RESULTS

In the 92 undifferentiated spondyloarthropathy patients with axial involvement, the prevalence rate of HLA-B27 was 71.76% (61/85). Elevated ESR and/or CRP was found in 40.96% (34/83) SpA patients and abnormal MRI manifestation of sacroiliac joint was found in 91% (39/43) SpA patients. The specificity of HLA-B27 was 78% and similar with the Berlin study. The sensitivity/specificity of ESSG, Amor criteria and Berlin algorithm on diagnosing USpA was 72.83%/92.68%, 64.13%/93.50% and 67.39%/95.93%, respectively. The coincidence between the three diagnosing criteria and the rheumatologist's opinion was moderate.

CONCLUSION

Our study showed the new Berlin algorithm has important value of diagnosing undifferentiated spondyloarthropathy in China, which has the similar diagnosing capacity comparing to the traditional criteria ESSG and Amor criteria.

HLA-b27 subtypes in patients with spondylarthropathies, IgE levels against some allergens and their relationship to the disease parameters

In suitable genetic backgrounds, some exogenous and/or endogenous antigens may cause SpA. In this study, we investigated HLA B27 subtypes and its relationship to some allergens and clinical findings in a group of SpA patients. Forty-eight patients (19F, 29M) with SpA (27 with ankylosing spondylitis, 5 with reactive arthritis, 15 undifferentiated and 1 with psoriatic arthritis) were included to the study. HLA-B alleles have been assessed using the LiPA (Line Probe Assay) reverse hybridization principle method. The allergens studied were following: egg white, yolk, wheat flour, hot pepper, tomatoes, olive, onion, chicken, black tea, sheep cheese, penicillin panel (m1, m25, m28, m30), fungus panel (m1, m2, m3, m6), and housemix panel (e1, e2, d1, d2, m2, m3). 59.3% of the patients were positive for HLA-B27. Of these patients, 53.6% had B*2702 allele which was the most common, followed by B*2708 (21.1%) and B*2701 (10.5%). HLA-B27 was positive in 70% of the ankylosing spondylitis patients and 52% had B*2702 subgroup and B35 was the most common subgroup among the patients who were HLA-B27 negative. Allergic reactions against these 13 allergens were more severe in patients HLA-B27 positive. The most frequent allergic reactions were against the onion and housemix panel, followed by red pepper, tomatoes, sheep cheese and olive. HLA-B*2702 and HLA-B*2701 subgroups had more severe allergic reactions that correlated with a disease severity (p < 0.001). These results indicate that B*2702 and B*2708 is more frequent in our region in contrast to B*2705 which is more commonly found all around the world and that our region represents a heterogeneous distribution. IgE levels against some allergen were found higher in patients with SpA (Fig. 2, Tab. 5, Ref. 37).

Alteration of antigen-independent immunologic synapse formation between dendritic cells from HLA-B27-transgenic rats and CD4+ T cells: selective impairment of costimulatory molecule engagement by mature HLA-B27

OBJECTIVE

To investigate the molecular mechanism responsible for the reduced capacity of dendritic cells (DCs) from HLA-B27-transgenic rats to form conjugates with naive T cells.

METHODS

We monitored interactions between DCs derived from HLA-B27-transgenic, HLA-B7-transgenic control, and nontransgenic rats and naive CD4+ T cells. Chemoattraction was studied in Transwell assays, and the formation of an immunologic synapse was examined by videomicroscopy and electron microscopy. Involvement of specific molecules in the defective interaction was examined in antibody-blocking assays.

RESULTS

T cells migrated normally toward B27 DCs, but upon contact, the frequency of T cells undergoing a Ca2+ response was decreased, indicating impaired immunologic synapse formation. The immunologic synapse formed between B27 DCs and T cells appeared to be normal, as assessed by electron microscopy and by the Ca2+ response. Blocking lymphocyte function-associated antigen 1 on T cells or blocking activated leukocyte cell adhesion molecules on DCs inhibited an equivalent proportion of conjugates from forming between B27 or control DCs and T cells, whereas blocking CD86 on DCs and blocking CD28, CD2, or CD4 on T cells inhibited a greater number of conjugates from forming with control DCs, indicating specific involvement of costimulatory molecules in the reduced formation of conjugates with B27 DCs. Mature B27 molecules on the DC surface were responsible for this decreased formation of conjugates.

CONCLUSION

In the HLA-B27-transgenic rat model of spondylarthropathy, mature B27 molecules expressed by DCs impair the formation of an antigen-independent immunologic synapse with naive CD4+ T cells by interfering with the engagement of costimulatory molecules. This phenomenon could potentially affect the production and/or maintenance of regulatory T cells and contribute to the expansion of pathogenic CD4+ T cells.

Inhibition of anti-tuberculosis T-lymphocyte function with tumour necrosis factor antagonists

Reactivation of latent Mycobacterium tuberculosis (Mtb) infection is a major complication of anti-tumour necrosis factor (TNF)-α treatment, but its mechanism is not fully understood. We evaluated the effect of the TNF antagonists infliximab (Ifx), adalimumab (Ada) and etanercept (Eta) on anti-mycobacterial immune responses in two conditions: with ex vivo studies from patients treated with TNF antagonists and with the in vitro addition of TNF antagonists to cells stimulated with mycobacterial antigens. In both cases, we analysed the response of CD4⁺ T lymphocytes to purified protein derivative (PPD) and to culture filtrate protein (CFP)-10, an antigen restricted to Mtb. The tests performed were lymphoproliferation and immediate production of interferon (IFN)-γ. In the 68 patients with inflammatory diseases (rheumatoid arthritis, spondylarthropathy or Crohn's disease), including 31 patients with a previous or latent tuberculosis (TB), 14 weeks of anti-TNF-α treatment had no effect on the proliferation of CD4⁺ T lymphocytes. In contrast, the number of IFN-γ-releasing CD4⁺ T lymphocytes decreased for PPD (p < 0.005) and CFP-10 (p < 0.01) in patients with previous TB and for PPD (p < 0.05) in other patients (all vaccinated with Bacille Calmette-Guérin). Treatments with Ifx and with Eta affected IFN-γ release to a similar extent. In vitro addition of TNF antagonists to CD4⁺ T lymphocytes stimulated with mycobacterial antigens inhibited their proliferation and their expression of membrane-bound TNF (mTNF). These effects occurred late in cultures, suggesting a direct effect of TNF antagonists on activated mTNF⁺ CD4⁺ T lymphocytes, and Ifx and Ada were more efficient than Eta. Therefore, TNF antagonists have a dual action on anti-mycobacterial CD4⁺ T lymphocytes. Administered in vivo, they decrease the frequency of the subpopulation of memory CD4⁺ T lymphocytes rapidly releasing IFN-γ upon challenge with mycobacterial antigens. Added in vitro, they inhibit the activation of CD4⁺ T lymphocytes by mycobacterial antigens. Such a dual effect may explain the increased incidence of TB in patients treated with TNF antagonists as well as possible differences between TNF antagonists for the incidence and the clinical presentation of TB reactivation.

Correlation between Yersinia enterocolitica and type I collagen reactivity in patients with arthropathies

We investigated the association with Yersinia infection in patients with arthropathies in our region. To assess the reactivity to articular antigens, the correlation of anti-Yersinia with anti-type I and type II collagen antibodies was studied. Sera from 124 patients with musculoskeletal symptoms, and 47 synovial fluids (SF) from patients with rheumatoid arthritis (RA), spondyloarthopathies (SpA) or osteoarthritis (OA) were examined. Immunoglobulins against Yersinia enterocolitica, type I and type II collagens were determined by enzyme-linked immunosorbent assay. Immunoglobulin (Ig) A to Yersinia lipopolysaccharide (LPS) was present in 13/124 sera (10%) and 3/47 SF (6%). By Western blot, IgA to Yersinia outer proteins (Yops) was found in 14/124 sera (11%) and 2/47 SF (4%). Yersinia DNA from SF was not amplified by polymerase chain reaction. We found a significant correlation with anti-collagen type I but not type II antibodies. These results suggest different reactivity to articular collagen in patients with Yersinia antibodies.

Left Ventricular Posterior Wall Pseudoaneurysm: A Rare Sequela of Mitral Valve Infective Endocarditis in a Chronic Patient of HLA-B27 Positive Spondyloarthritis

Left ventricular posterior wall pseudoaneurysm after native mitral valve infective endocarditis is a very rare occurrence. We report such a case in a patient with HLA-B27-associated spondyloarthritis and normal coronary arteries. Excision of the aneurysm with left ventricular reconstruction and mitral valve replacement resulted in an excellent outcome.

Treatment of chronic inflammatory diseases with biologic agents: opportunities and risks for the elderly

The treatment armamentarium in rheumatic inflammatory diseases has drastically increased in the last years. Earlier uses of conventional disease-modifying antirheumatic drugs (DMARDs), along with the arrival of newer therapies including the so-called "biologic" agents, have provided better long-term outcomes for patients suffering from these illnesses. Biologic agents have shown efficacy for several diseases and failed in others. Due to a high prevalence of some of these diseases in the elderly population, this age group may also benefit, although treatment will have to be tailored to its special needs. In this mini review, we will discuss the use of these medications in rheumatic diseases with a significant prevalence in the elderly, their proven and potential uses, and the considerations that need to be taken into account when using them in this population.

HLA-B27 and the pathogenesis of spondyloarthropathies

The association of HLA-B27 with ankylosing spondylitis, a chronic inflammatory disease of the axial skeleton, and other spondyloarthropathies, is among the strongest of an MHC antigen and any disease. Yet, the basis for this association remains unknown. In this review the main current hypotheses concerning the pathogenetic role of HLA-B27 will be discussed. They focus on three molecular properties of the molecule: (1) its peptide-presenting specificity, (2) its slow folding and tendency to misfold, and (3) its capacity to form covalent heavy chain homodimers amenable to recognition by leukocyte receptors. On the basis of the peptide specificity spondyloarthropathies would be triggered through T-cell autoimmunity against a self-ligand of HLA-B27 elicited by a cross-reactive foreign antigen. HLA-B27 misfolding would trigger disease through activation of inflammatory pathways following induction of endoplasmic reticulum stress, thus independently of antigen presentation. Recognition of heavy chain homodimers by leukocyte receptors might be involved in disease through immunomodulation of both innate and adaptive responses to arthritogenic pathogens. None of these hypotheses can yet satisfactorily account for the pathogenesis of spondyloarthritides. It is proposed that the pathogenetic role of HLA-B27 will eventually be explained through a global understanding of its biology, in which the various features of this molecule are envisaged as inter-dependent in their contribution to disease.

Concepts and epidemiology of spondyloarthritis

The term 'spondyloarthritides' (SpA) comprises ankylosing spondylitis (AS), reactive arthritis, arthritis/spondylitis with inflammatory bowel disease, and arthritis/spondylitis with psoriasis. The main links between these diseases are an association with HLA-B27 and a similar clinical picture. Patients normally present with chronic low back pain or asymmetrical arthritis, predominantly of the lower limbs, and an overlap of these symptoms often occurs. AS is regarded as the most severe subtype. Recent attention has focused on earlier diagnosis of AS among patients with chronic low back, and this is becoming more important as effective therapies for early treatment have become available. AS is a disease of young people, normally starting in the third decade of life. The incidence and prevalence rates of AS, and of SpA as a whole, are strongly dependent and are directly correlated to the prevalence of HLA-B27 in a given population. Incidence rates of 0.5-8.2/100 000 population and prevalence rates of 0.2-1.2% have been described for AS, and about double these figures have been reported for SpA.

Spondyloarthropathy: disease at the crossroads of immunity

Up until recently, the prevailing paradigm relating to spondyloarthropathy (SpA) pathogenesis was that they were human leukocyte antigen (HLA)-associated, T-cell-driven autoimmune diseases. This view is now being questioned. Careful studies of well-characterised cohorts of patients with SpA, including detailed analysis of involved tissue, together with clinical trials of targeted treatments, in particular anti-tumour necrosis factor (TNF) therapies, have contributed enormously to both interest in and understanding of disease pathogenesis. In this chapter, our current knowledge and understanding of the relative contributions of the components of the innate and adaptive arms of the immune response to SpA pathogenesis is reviewed. It is clear that both arms of the immune response are involved and inter-dependent in SpA. With continued emphasis on discovery research, including detailed analysis of novel therapeutic interventions, significant additional breakthroughs in SpA are likely to be forthcoming.

Consistent patterns of expression of HLA class I free heavy chains in healthy individuals and raised expression in spondyloarthropathy patients point to physiological and pathological roles

OBJECTIVES

Major histocompatibility complex class I (MHC-I) proteins exist at the cell surface in antigen presenting forms and as beta2m-independent free heavy chains (FHCs). FHCs have been implicated in spondyloarthritis, but little is known about their expression in healthy individuals. We studied FHC expression on various human cell types, comparing spondyloarthropathy patients with healthy and rheumatoid arthritis (RA) patient controls.

METHODS

MHC-I expression was analysed by flow cytometry. FHC levels were normalized for overall MHC-I to generate a relative expression level. Relative FHC levels were analysed for peripheral blood and trophoblast samples from healthy volunteers, RA and spondyloarthropathy patients. Macrophages and dendritic cells were cultured in vitro to analyse changes following activation. Peripheral blood leucocytes from patients with ankylosing spondylitis (AS) and RA were treated with inflammatory stimuli and subsequent alterations in their relative FHC levels were analysed.

RESULTS

We found consistent patterns of differential relative FHC expression across lymphocyte subpopulations and particularly high expression on extravillous trophoblast. FHCs were present at higher levels in a reactive arthritis (ReA) population than in healthy controls and RA patients; differences not merely due to the presence of Human Leucocyte Antigen (HLA) B27. Treatment of leucocytes from arthritic patients with bacterial lipopolysaccharide resulted in significant up-regulation of FHC compared with an HLA B27+ control population.

CONCLUSIONS

Our findings define normal levels and tissue expression of FHCs, and support the hypothesis that disregulation of heavy chain expression may play a pathogenic role in spondyloarthropathy.