JAK-STAT Signaling and Beyond in the Pathogenesis of Spondyloarthritis and Their Clinical Significance

PURPOSE OF REVIEW

Janus kinase-signal transducers and activators of transcription cell signaling proteins (JAK-STATs) play a key regulatory role in functioning of several inflammatory cytokines. JAK-STAT signaling proteins are the key regulators of the cytokine/cytokine receptor system involved in the pathogenesis of various autoimmune disease including spondyloarthritis (SpA). This article mainly highlights the JAK-STAT signaling system, its association with the relevant cytokine/cytokine-receptor system, and its regulatory role in pathogenesis of SpA. Also, we have briefly addressed the principle for the use JAKi in SpA and the current status of use of JAK inhibitors (JAKi) in SpA.

RECENT FINDINGS

Recent developments with newer JAK molecules as well as other molecules beyond JAK inhibitors are now an exciting field for the development of novel therapies for autoimmune diseases and various malignant conditions. In this article, we have provided a special emphasis on how various cell signaling systems beyond JAK/STAT pathway are relevant to SpA and have provided a comprehensive review on this upcoming field in respect to the novel TYK2 inhibitors, RORγT inhibitors, mTOR inhibitors, NGF inhibitors, and various STAT kinase inhibitors. SpA are a group of autoimmune diseases with multifactorial etiologies. SpA is linked with genetic predisposition, environmental risk factors, and the immune system-mediated systemic inflammation. Here, we have provided the regulatory role of JAK/STAT pathway and other intracellular signaling system in the pathogenesis of SpA and its therapeutic relevance.

Nuclease activity and protein A release of Staphylococcus aureus clinical isolates determine the virulence in a murine model of acute lung infection

Staphylococcus aureus is a common cause of hospital-acquired pneumonia associated with high mortality. Adequate clinical treatment is impeded by increasing occurrence of antibiotic resistances. Understanding the underlying mechanisms of its virulence during infections is a prerequisite to finding alternative treatments. Here, we demonstrated that an increased nuclease activity of a S. aureus isolate from a person with cystic fibrosis confers a growth advantage in a model of acute lung infection compared to the isogenic strain with low nuclease activity. Comparing these CF-isolates with a common MRSA-USA300 strain with similarly high nuclease activity but significantly elevated levels of Staphylococcal Protein A (SpA) revealed that infection with USA300 resulted in a significantly increased bacterial burden in a model of murine lung infection. Replenishment with the cell wall-bound SpA of S. aureus, which can also be secreted into the environment and binds to tumor necrosis factor receptor -1 (TNFR-1) to the CF-isolates abrogated these differences. In vitro experiments confirmed significant differences in spa-expression between USA300 compared to CF-isolates, thereby influencing TNFR-1 shedding, L-selectin shedding, and production of reactive oxygen species through activation of ADAM17.

Axial spondyloarthritis in patients with recurrent fever attacks: data from the AIDA network registry for undifferentiated autoInflammatory diseases (USAIDs)

Beckground

Despite the recent advances in the field of autoinflammatory diseases, most patients with recurrent fever episodes do not have any defined diagnosis. The present study aims at describing a cohort of patients suffering from apparently unexplained recurrent fever, in whom non-radiographic axial spondylarthritis (SpA) represented the unique diagnosis identified after a complete clinical and radiologic assessment.

Materials and methods

Patients' data were obtained from the international registry on Undifferentiated Systemic AutoInflammatory Diseases (USAIDs) developed by the AutoInflammatory Disease Alliance (AIDA) network.

Results

A total of 54 patients with recurrent fever episodes were also affected by non-radiographic axial SpA according to the international classification criteria. SpA was diagnosed after the start of fever episodes in all cases; the mean age at the diagnosis of axial SpA was 39.9 ± 14.8 years with a diagnostic delay of 9.3 years. The highest body temperature reached during flares was 42°C, with a mean temperature of 38.8 ± 1.1°C. The most frequent manifestations associated to fever were: arthralgia in 33 (61.1%) cases, myalgia in 24 (44.4%) cases, arthritis in 22 (40.7%) cases, headache in 15 (27.8%) cases, diarrhea in 14 (25.9%) cases, abdominal pain in 13 (24.1%) cases, and skin rash in 12 (22.1%) cases. Twenty-four (44.4%) patients have taken daily or on-demand non-steroidal anti-inflammatory drugs (NSAIDs) and 31 (57.4%) patients have been treated with daily or on demand oral glucocorticoids. Colchicine was used in 28 (51.8%) patients, while other conventional disease modifying anti-rheumatic drugs (cDMARDs) were employed in 28 (51.8%) patients. Forty (74.1%) patients underwent anti-tumor necrosis factor (TNF) agents and 11 (20.4%) were treated with interleukin (IL)-1 inhibitors. The response to TNF inhibitors on recurrent fever episodes appeared more effective than that observed with anti-IL-1 agents; colchicine and other cDMARDs were more useful when combined with biotechnological agents.

Conclusion

Signs and symptoms referring to axial SpA should be inquired in patients with apparently unexplained recurrent fever episodes. The specific treatment for axial SpA may lead to a remarkable improvement in the severity and/or frequency of fever episodes in patients with unexplained fevers and concomitant axial SpA.

Exploring the perspective of patients with immune-mediated inflammatory diseases and care providers on the use of immunomodulatory drugs in infections: an interview study

Objectives

Immunomodulatory agents are safe and effective as treatment for various immune-mediated inflammatory diseases (IMIDs), but are associated with a slightly increased infection risk. It is uncertain whether, in the event of an infection, continuation or temporary interruption of immunomodulatory agents leads to better outcomes. Owing to this uncertainty, it is of importance to explore the perspectives of health-care providers (HCPs) and patients on this topic. In this study, we set out to identify and provide an overview of reasons for both treatment strategies.

Methods

Semi-structured interviews were conducted with HCPs involved in the pharmacological treatment of IMIDs and with IMID patients using one or more immunomodulatory agent. Purposive sampling was used to enrich data variation. Interviews were conducted until data saturation was reached and subsequently analysed using qualitative content analysis.

Results

In total, 13 HCPs and 19 IMID patients were interviewed. A wide range of reasons for both treatment strategies were identified, categorized into 10 overarching themes, including IMID characteristics, infection characteristics and the patient-HCP relationship.

Conclusion

In this interview study, we identified various reasons for continuation or temporary interruption of immunomodulatory agents during infections for both IMID patients and HCPs. We found overlapping themes, such as IMID characteristics; however, the content and interpretation of these themes might differ between HCPs and patients. Both HCPs and patients mentioned that the decision for a treatment strategy is often about weighing benefits against risks (e.g. infection severity vs disease flare).

Not so Mutually Exclusive Diseases: A Case of Co-occurrence of Inflammatory Spondyloarthritis and Diffuse Skeletal Hyperostosis in a Young Patient

Diffuse idiopathic skeletal hyperostosis (DISH) and axial spondyloarthritis (axial SpA) are differential diagnoses of lower back pain. While the latter is considered to be an inflammatory disease, DISH is thought to be a metabolic condition. The authors report a case of a 34-year-old man who presented with a one-year history of axial lower back pain associated to migratory polyarthritis, buttock and heel pain. Imaging revealed contiguous calcification of the anterior longitudinal ligament of the cervical segment, meeting major criteria for DISH. However, he also exhibited signs of bilateral sacroiliitis highly suggestive of axial SpA for which he initiated biological therapy.

LEARNING POINTS

Although the most used criteria for diffuse idiopathic skeletal hyperostosis (DISH) were designed to exclude radiographic signs of spondyloarthritis (SpA), both conditions can be present simultaneously.There are only few case reports in the literature that demonstrate the association of the two diseases.Overlap and misperception of SpA and DISH could result in undertreatment of individual patients and have a negative impact on prognosis.

Long-Term Adherence to Etanercept in Treatment Effectiveness of Patients with Spondyloarthritis: 7-Year Data from the Iraq National Registry

INTRODUCTION

The diagnosis and treatment of spondyloarthritis (SpA) is a global challenge, with no cure available. Adherence to treatment with biologic disease-modifying antirheumatic drugs, such as the tumor necrosis factor-α inhibitor etanercept, varies among patients with SpA. Inadequate or poor adherence to treatment may have a negative effect on clinical outcome and quality of life and may lead to greater health-related expense.

METHODS

This observational, retrospective study used real-world patient data from the Iraq National Center of Rheumatology database to retrospectively assess long-term adherence to etanercept, specifically evaluating 1- and 7-year adherence to etanercept among Iraqi patients with SpA.

RESULTS

In total, data from 763 patients were included in the analysis. The majority of patients were men (82.2%). Mean disease duration at baseline was 5.85 years; 84.0% of patients received concomitant steroids, and 14.2% were treated with concomitant methotrexate. Measures of disease activity and functional status (mean ± SD) at baseline based on the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) and the Bath Ankylosing Spondylitis Functional Index (BASFI) were 8.06 ± 0.83 (range 6.0-9.5) and 7.75 ± 1.12 (range 4.1-9.7), respectively. Around 30% of patients initiated etanercept treatment within 1 year of diagnosis. After 1 and 7 years, 91.7% (700/763) and 60.6% (80/132) of patients were adherent to etanercept treatment. Mean (± SD) changes from baseline in BASDAI and BASFI scores for adherent versus non-adherent patients at 1 year were 6.73 (± 1.90) versus 4.20 (± 1.85) (p = 0.0001) and 6.43 (± 2.04) versus 4.18 (± 1.88) (p = 0.0001), respectively.

CONCLUSIONS

These results suggest that Iraqi patients with SpA benefit from long-term adherence to etanercept treatment; however, additional analyses are needed to further assess the reasons for treatment discontinuation, which may include disease remission.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT04507776.

Targeting Toll-like Receptor (TLR) Pathways in Inflammatory Arthritis: Two Better Than One?

Inflammatory arthritis is a cluster of diseases caused by unregulated activity of the immune system. The lost homeostasis is followed by the immune attack of one’s self, what damages healthy cells and tissues and leads to chronic inflammation of various tissues and organs (e.g., joints, lungs, heart, eyes). Different medications to control the excessive immune response are in use, however, drug resistances, flare-reactions and adverse effects to the current therapies are common in the affected patients. Thus, it is essential to broaden the spectrum of alternative treatments and to develop disease-modifying drugs. In the last 20 years, the involvement of the innate immune receptors TLRs in inflammatory arthritis has been widely investigated and targeting either the receptor itself or the proteins in the downstream signalling cascades has emerged as a promising therapeutic strategy. Yet, concerns about the use of pharmacological agents that inhibit TLR activity and may leave the host unprotected against invading pathogens and toxicity issues amid inhibition of downstream kinases crucial in various cellular functions have arisen. This review summarizes the existing knowledge on the role of TLRs in inflammatory arthritis; in addition, the likely druggable related targets and the developed inhibitors, and discusses the pros and cons of their potential clinical use.

Responsiveness of the EuroQoL 5-Dimension (EQ-5D) questionnaire in patients with spondyloarthritis

Background

Spondyloarthritis (SpA) has a significant impact on patients’ quality of life due to functional impairments. Generic health instruments like the EuroQoL 5-dimension (EQ-5D) is important for cost-utility analysis of health care interventions and calculation of quality-adjusted life-years. It has been validated in patients with SpA. However, its responsiveness property is unclear. Hence, the aim of study is to test the responsiveness properties of the EQ-5D health measure for Chinese patients with SpA.

Methods

Prospective and consecutive recruitment of 151 Chinese patients with SpA was conducted with follow-up assessments 6 months later. Demographic data including smoking and drinking habits, education level, income and occupation was collected. Disease-associated data including disease duration, presence of back pain, peripheral arthritis, dactylitis, enthesitis, uveitis, psoriasis, and inflammatory bowel disease was also recorded. Questionnaires regarding disease activity and functional disability (BASDAI, BASFI, BASGI, BASMI, ASDAS), mental health (HADS) and the EQ-5D scores were recorded. Responsiveness was tested against the global rating of change scale (GRC) and changes in disease activity using BASDAI and ASDAS-CRP.

Results

A total of 113 (74.8%) patients completed the follow-up assessments. Most patients (61.6%) had low disease activity level with BASDAI <4 and 39.7% of patients had inactive disease by ASDAS-CRP. EQ-5D scores was well discriminated along with BASDAI and BASFI scores. EQ-5D scores also correlated well with HADS. The GRC was not able to discriminate adequately. No significant ceiling or floor effect was observed.

Conclusions

EQ-5D demonstrates satisfactory responsiveness property for assessment of changes in SpA disease activity.

Level of evidence

II

Diversity of Functionally Distinct Clonal Sets of Human Conventional Memory B Cells That Bind Staphylococcal Protein A

Staphylococcus aureus, a common cause of serious and often fatal infections, is well-armed with secreted factors that disarm host immune defenses. Highly expressed in vivo during infection, Staphylococcal protein A (SpA) is reported to also contribute to nasal colonization that can be a prelude to invasive infection. Co-evolution with the host immune system has provided SpA with an Fc-antibody binding site, and a Fab-binding site responsible for non-immune superantigen interactions via germline-encoded surfaces expressed on many human BCRs. We wondered whether the recurrent exposures to S. aureus commonly experienced by adults, result in the accumulation of memory B-cell responses to other determinants on SpA. We therefore isolated SpA-specific class-switched memory B cells, and characterized their encoding VH : VL antibody genes. In SpA-reactive memory B cells, we confirmed a striking bias in usage for VH genes, which retain the surface that mediates the SpA-superantigen interaction. We postulate these interactions reflect co-evolution of the host immune system and SpA, which during infection results in immune recruitment of an extraordinarily high prevalence of B cells in the repertoire that subverts the augmentation of protective defenses. Herein, we provide the first evidence that human memory responses are supplemented by B-cell clones, and circulating-antibodies, that bind to SpA determinants independent of the non-immune Fc- and Fab-binding sites. In parallel, we demonstrate that healthy individuals, and patients recovering from S. aureus infection, both have circulating antibodies with these conventional binding specificities. These findings rationalize the potential utility of incorporating specially engineered SpA proteins into a protective vaccine.

Protein A of Staphylococcus aureus strain NCTC8325 interacted with heparin

Heparin, known for its anticoagulant activity, is commonly used as the coatings of medical devices. The attaching of Staphylococcus aureus, a prominent human and animal pathogen, to the heparin coatings usually leads to catheter-related bloodstream infections. Hence, the study of the interaction between heparin and S. aureus surface proteins is desired. Here, we found that protein A (SpA) of S. aureus was a heparin-binding protein, contributing to the interaction between S. aureus and heparin. The cell-wall-anchored SpA was one of the most critical S. aureus virulence factors with a lysin-like motif (LysM). When SpA was mutated to remove the LysM motif, the heparin-binding capability of SpA dropped 50%. The in-frame deletion of spa also reduced the heparin-binding capability of S. aureus. There was 1.3-fold more of heparin bound to wild type S. aureus than the Δspa::Em strain. These results would help understand the host-microbe interaction and the infection by S. aureus.

Microbial-derived antigens and metabolites in spondyloarthritis

Spondyloarthritis (SpA) is a group of chronic, immune-mediated, inflammatory diseases affecting the bone, synovium, and enthesis. Microbiome, the community of microorganisms that has co-evolved with human hosts, plays a pivotal role in human health and disease. This invisible "essential organ" supplies the host with a myriad of chemicals and molecules. In turn, microbial metabolites can serve as messengers for microbes to communicate with each other and in the cross-talk with host cells. Gut dysbiosis in SpA is associated with altered microbial metabolites, and an accumulated body of research has contributed to the understanding that changes in intestinal microbiota can modulate disease pathogenesis. We review the novel findings from human and animal studies to provide an overview of the contribution of individual microbial metabolites and antigens to SpA.

Electrochemical label free sensing of human IgG - Protein A interaction

A novel and rapid Electrochemical Immunosensing platform was developed for the direct sensing of antibody human immuno globulin gamma (IgG) interaction with virulence factor of S. aureus, staphylococcal protein A (SpA) in the presence of electroactive redox couple ferri/ferro cyanide (K₃/K₄[Fe(CN)₆]). The receptor SpA was attached to BioPE-DOTAP binary lipid bilayer tethered on alkane thiol molecular cushions. Atomic force microscopy (AFM), High-resolution transmission electron microscope (TEM), Fourier-transform infrared spectroscopy (FT-IR), dynamic light scattering (DLS) techniques were used to study the molecular interactions. The AFM images showed array like formation of BioPE-DOTAP on the monolayer surface. The IgG sensor showed a linear range from 10^-21 M to 10^-16 M.

Novel luminescent affiprobes for molecular detection of Staphylococcus aureus using flow cytometry

AIMS

Diagnosis of Staphylococcus aureus is important in various diseases from hospital-acquired infections to foodborne diseases. This work reports two new luminescent affiprobes for specific detection of S. aureus.

METHODS AND RESULTS

To develop advanced luminescent affiprobes, enhanced green fluorescent protein (EGFP) was flanked by single and double repeats of ZpA963 affibody using molecular biology studies. The recombinant proteins including fluorescent monomeric affibody (fA₁ ) and fluorescent dimeric affibody (fA₂ ) were expressed in the bacterial expression system, purified and used to identify the S. aureus. Fluorescence microscope and flow cytometry results demonstrated that the treated samples with fA₁ and fA₂ had relatively high fluorescent mean intensities in comparison to the untreated S. aureus cells. Moreover, it was revealed that 'fA₂ ' affiprobe had lower dissociation constant value (about 25-fold) and was more effective for detection of S. aureus than the 'fA₁ ' affiprobe. In addition, the binding of the affiprobes for some other pathogenic bacteria i.e. Escherichia coli, Bacillus cereus, Enterococcus faecalis and Staphylococcus saprophyticus was examined. Expectedly, no cross-reaction was observed for binding the constructed affiprobes to these bacteria, eliminating possibilities for false positive results.

CONCLUSIONS

The results show that 'fA₁ ' affiprobe and 'fA₂ ' affiprobe are two new efficient luminescent affiprobes for detecting S. aureus.

SIGNIFICANCE AND IMPACT OF THE STUDY

We developed a new approach for detection of Staphylococcus aureus in a simple one-step process and in low concentrations of probes. In the best of our knowledge, this is the first study to direct detection of bacterial cells by affiprobes and may be used to develop new diagnostic kits.

Appropriateness of laboratory tests in the diagnosis of inflammatory rheumatic diseases among patients newly referred to rheumatologists

INTRODUCTION

Autoantibody tests are commonly ordered when screening for rheumatic diseases. Rheumatoid factor (RF) and antinuclear antibody (ANA) have low positive predictive values in general practice. Overuse of diagnostic tests can result in an increase in unnecessary referrals, patient anxiety, and further costs.

OBJECTIVE

The objective was to evaluate the utilization patterns, appropriateness, and associated costs of tests including ANA, extractable nuclear antibodies (ENA), anti-double stranded DNA (anti-dsDNA), RF, and HLA-B27 in patients referred to rheumatologists.

METHODS

A review was conducted of consecutive referrals (accepted and rejected) using university rheumatologists' practices over one year. Inappropriate investigations, and associated costs were analyzed. Tests were considered appropriate if at least one criterion for a specific disease was provided.

RESULTS

Of 638 referrals the most common reported reasons for referral were: spondyloarthropathies (SpA), rheumatoid arthritis (RA), and lupus (SLE). Prior to referral: 61% had undergone ANA testing at least once, ANA was repeated in one third; 19% had ENA and 21% had anti-dsDNA. 20% had ANA testing with no clinical indication. Half of ENA and anti-dsDNA testing was in the context of a negative ANA. RF was requested in 65% and in close to one third, there was no clinical suspicion of inflammatory arthritis.

CONCLUSION

Despite the recommendations by CRA Choosing Wisely Campaign, at least 50% of laboratory investigations, including RF, ANA, ENA, and anti-dsDNA, are inappropriately ordered. More selective ordering of the above tests would lead to marked cost reduction.

Protein A superantigen: structure, engineering and molecular basis of antibody recognition

Staphylococcus aureus interacts with the human immune system through the production of secreted factors. Key among these is protein A, a B-cell superantigen capable of interacting with both antibody Fc and VH regions. Here, we review structural and molecular features of this important example of naturally occurring bacterial superantigens, as well as engineered variants and their application in biotechnology.

The good side of inflammation: Staphylococcus aureus proteins SpA and Sbi contribute to proper abscess formation and wound healing during skin and soft tissue infections

Staphylococcus aureus is the most prominent cause of skin and soft tissue infections (SSTI) worldwide. Mortality associated with invasive SSTI is a major threat to public health considering the incidence of antibiotic resistant isolates in particular methicillin resistant S. aureus both in the hospital (HA-MRSA) and in the community (CA-MRSA). To overcome the increasing difficulties in the clinical management of SSTI due to MRSA, new prophylactic and therapeutic approaches are urgently needed and a preventive vaccine would be welcome. The rational design of an anti-S. aureus vaccine requires a deep knowledge of the role that the different bacterial virulence factors play according to the type of infection. In the present study, using a set of isogenic deficient mutants and their complemented strains we determined that the staphylococcal surface proteins SpA and Sbi play an important role in the induction of inflammatory cytokines and chemokines in the skin during SSTI. SpA and Sbi initiate signaling cascades that lead to the early recruitment of neutrophils, modulate their lifespan in the skin milieu and contribute to proper abscess formation and bacterial eradication. Moreover, the expression of SpA and Sbi appear critical for skin repair and wound healing. Thus, these results indicate that SpA and Sbi can promote immune responses in the skin that are beneficial for the host and therefore, should not be neutralized with vaccine formulations designed to prevent SSTI.

Humoral and Cellular Patterns of Early Endothelial Progenitor Cells in Relation to the Cardiovascular Risk in Axial Spondylarthritis

Background

Spondylarthritis (SpA) significantly affects sacroiliac, intervertebral and peripheral joints. Patients with SpA suffer from increased cardiovascular risk (CVR). The endothelial progenitor cell (EPC) system critically perpetuates vascular repair. The aim of the study was to evaluate circulating EPCs in axial (ax)SpA with special attention on parameters of disease activity and CVR.

Methods

Disease activity and functional impairment were quantified in 50 axSpA patients by using standardized parameters (Bath ankylosing spondylitis disease activity index (BASDAI), C-reactive protein (CRP), finger-floor distance (FFD) and Ott’ sign). Circulating EPCs and EPC regeneration were analyzed (fluorescence-activated cell sorting (FACS) and colony-forming unit (CFU) assay). Serum vasomodulatory mediators were quantified by enzyme-linked immunosorbent assay (ELISA).

Results

EPC colony numbers were lower in axSpA as compared to controls. Females displayed more colonies than males. In addition, fewer colonies were observed in smokers, in patients with a BASDAI of below 4 and in hypertension. Circulating CD133⁺/KDR⁺ cells did not differ between the groups. Follow-up analysis (33 months later) did not show any differences in gender, colony formation, CD133⁺/KDR⁺ cells or serum levels of vasomodulatory mediators if related to the categories of BASDAI, Ott’ sign or FFD.

Conclusions

EPC colony formation is significantly affected in axSpA with particularly low levels in males. EPC-related parameters do not allow predicting disease activity-related or functional parameters nor are they useful for CVR assessment in SpA.

Psychometric validation of the EuroQoL 5-dimension (EQ-5D) questionnaire in patients with spondyloarthritis

BACKGROUND

Spondyloarthritis (SpA) has a significant impact on patients' quality of life due to functional impairments. Generic health instruments like the EuroQoL 5-dimension (EQ-5D) is important for the cost-utility analysis of health care interventions and calculation of quality-adjusted life years. However, the applicability of the EQ-5D health measure in Chinese patients with SpA is currently unknown. Hence, the aim of the study is to test the psychometric properties and to validate the use of the EQ-5D health measure for utility analyses in Chinese patients with SpA.

METHODS

Prospective and consecutive recruitment of 220 Chinese patients with SpA was conducted. Demographic data including smoking and drinking habits, education level, income, and occupation was collected. Disease-associated data including disease duration, the presence of back pain, peripheral arthritis, dactylitis, enthesitis, uveitis, psoriasis, and inflammatory bowel disease was also recorded. Questionnaires regarding disease activity and functional disability (BASDAI, BASFI, BASGI, BASMI, ASDAS, ODI), mental health (HADS depression and anxiety), and the EQ-5D scores were recorded. SF-36 scores were used to verify the findings. Baseline correlations were performed along with test-retest reliability, validity, and internal consistency tests. Specifically, the relationship between EQ-5D and disease activity and functional scores was studied.

RESULTS

EQ-5D scores achieved acceptable internal consistency and reliability. A ceiling effect was observed for all domains of the EQ-5D except for pain/discomfort. No floor effect was observed. Significant negative correlations were observed between ODI, HADS, BASFI, BASMI, BASDAI, and ASDAS-CRP and with EQ-5D. A higher disease activity was well-differentiated by EQ-5D, as with the disability and mental health scores.

CONCLUSIONS

The EQ-5D demonstrates satisfactory psychometric properties for assessment of SpA patients. It has high utility for demonstrating changes in disease activity and disability.

Juvenile Spondyloarthritis: A Distinct Form of Juvenile Arthritis

Juvenile spondyloarthritis (SpA) is a distinct form of juvenile arthritis characterized by male predominance and adolescent onset. Clinical manifestations include lower extremity and sacroiliac joint arthritis, enthesitis, and subclinical gastrointestinal inflammation. Juvenile SpA is an immune-mediated inflammatory disease long recognized as associated with HLA-B27, which may be related to the microbial environment as suggested by its coexistence with reactive arthritis and psoriasis. Treatment of peripheral arthritis includes nonsteroidal anti-inflammatory drugs, joint injections, and disease-modifying agents, whereas treatment of axial disease may necessitate a tumor necrosis factor inhibitor biologic agent. Fewer than half of children achieve remission off medication 5 years after diagnosis.

New advances in the understanding and treatment of axial spondyloarthritis: from chance to choice

Axial spondyloarthritis (axSpA) is a chronic inflammatory condition that encompasses ankylosing spondylitis (AS) as well as non-radiographic axial disease (nr-axSpA) and can lead to chronic pain, structural damage and disability. The introduction of tumour necrosis factor inhibitor (TNFi) drugs for AS heralded a new era of drug therapeutics for what was previously a largely untreatable disease. This has now been expanded with the licensing of secukinumab, an interleukin 17A (IL-17A) inhibitor for the treatment of AS. Although biologic disease modifying antirheumatic drugs (bDMARDs) are not a first line treatment option in AS or axSpA, they are highly effective following incomplete or no response to physiotherapy and non-steroidal anti-inflammatory drugs (NSAIDs). Current research strategies aim to test whether the desired treatment goal of disease remission may now be achievable with early and stratified use of bDMARDs in both AS and nr-axSpA. This review summarizes the current literature on axSpA including pathophysiology, treatment indications, radiographic progression and the evidence for new developments in the treatment of both AS and nr-axSpA.

Staphylococcal Protein A Is a Key Factor in Neutrophil Extracellular Traps Formation

Staphylococcus aureus are strong inducers of neutrophil extracellular traps (NETs), a defense mechanism of neutrophils against pathogens. Our aim was to explore the role of Protein A in S. aureus-induced NETosis. We determined the Protein A production of four different S. aureus strains and found a direct relationship between the degree of NETosis induction and Protein A production: strains producing higher concentrations of Protein A evoke significantly more NETs. A S. aureus strain in which Protein A as well as a second binding protein for immunoglobulins (Sbi) have been knocked-out (ΔSpA ΔSbi) induced significantly less NETosis than the wild-type strain. NETosis induction by this knockout strain can be rescued by the addition of purified Protein A. Dead S. aureus did not induce NETosis. In conclusion, Protein A is a determinant for NETosis induction by S. aureus.

Comparison of apparent diffusion coefficient in spondylarthritis axial active inflammatory lesions and type 1 Modic changes

OBJECTIVE

The goal of this study was to evaluate whether the values of ADC in spondylarthritis axial active inflammatory lesions are different from ADC values in type 1 Modic changes.

SUBJECTS AND METHODS

95 patients with recent lumbar pain, including 46 patients with diagnosed or suspected spondylarthritis and 49 patients with purely degenerative history, underwent spine MRI. T1w, STIR, and diffusion-weighted images (DWI) were obtained. Two musculoskeletal radiologists interpreted the images. Axial active inflammatory lesions from the SpA group and type 1 Modic changes from the degenerative group were identified on T1w and STIR sequences. ADC values from these lesions and from healthy subchondral bone were compared.

RESULTS

All axial active inflammatory lesions (n=27) and type 1 Modic changes (n=22) identified in T1w and STIR images were visible on DWI. ADC values were significantly higher (p<0.05) for axial active inflammatory lesions (median=0.788×10(-3)mm(2)/s, IQR 25-75 [0.7×10(-3)mm(2)/s; 0.9×10(-3)mm(2)/s]) than for type 1 Modic changes (median=0.585×10(-3)mm(2)/s, IQR 25-75 [0.55×10(-3)mm(2)/s; 0.60×10(-3)mm(2)/s]) and normal subchondral bone (median=0.443×10(-3)mm(2)/s, IQR 25-75 [0.40×10(-3)mm(2)/s; 0.50×10(-3)mm(2)/s]). Intra-class correlation coefficients for intra- and inter-reader ADC values comparison were excellent (0.89 and 0.98 respectively).

CONCLUSION

DWI is a sensitive and fast sequence that offer the possibility of quantifying diffusion coefficients of the lesions, which could help to discriminate between spondylarthritis axial active inflammatory and type 1 Modic changes.

Demyelination and other neurological adverse events after anti-TNF therapy

Tumor necrosis factor (TNF) α inhibitors are an essential therapeutic option for several inflammatory diseases, like rheumatoid arthritis, spondyloarthropathies and inflammatory bowel diseases. As TNFα antagonists have become increasingly utilized, there have been a number of reports of neurological adverse events in patients receiving anti-TNFα therapy. The frequency of central nervous system adverse events after initiation of anti-TNFα therapy is unknown. However, questions have been raised about a possible causal association. Although several hypotheses have been proposed in an attempt to explain the possible relationship between TNFα antagonist and demyelination, none is considered to be adequate. Thus, in this report we deal with the implication of TNFα in multiple sclerosis and we discuss the possible relationship of TNFα antagonist and demyelinating diseases.