Pain sensitisation and joint inflammation in patients with active rheumatoid arthritis

INTRODUCTION

Despite better therapies and strategies, many people with rheumatoid arthritis (RA) have persistent pain, often from abnormal pain processing, now termed nociplastic pain. However, RA patients with fibromyalgia (FM), a central nociplastic pain syndrome, also have power doppler ultrasound (PDUS+) joint inflammation. To understand the complex causes of pain, we performed clinical examination and patient-reported outcome measures (PROMs) plus comprehensive PDUS evaluation not previously combined.

METHODS

In a cross-sectional study of sequential RA patients with at least moderate DAS28 erythrocyte sedimentation rate disease activity, we assessed 66/68 joints for swelling and tenderness, respectively, FM American College of Rheumatology 2010 diagnostic criteria, completed PROMs for function, quality of life and mood, alongside PDUS examination of 44 joints. Statistical analysis included logistic regression modelling and regularised (lasso) logistic regression methods.

RESULTS

From 158 patients, 72 (46%) patients met FM criteria, with significantly worse tender joint counts and PROMs, but no differences in PDUS compared with the non-FM group. Categorising patients by PDUS+ joint presence and/or FM criteria, we identified four distinct groups: 43 (27.2%) patients with -FM-PD, 43 (27.2%) with -FM+PD, 42 (26.6%) with +FM-PD and 30 (19%) with +FM+PD. Both FM+ groups had worse PROMs for fatigue, mood and pain, compared with the FM- groups. We were unable to develop algorithms to identify different groups.

CONCLUSION

The unexpected group -FM-PD group may have peripheral nociplastic pain, not commonly recognised in rheumatology. Only 46% of patients demonstrated PDUS+ inflammation. However clinical examination and PROMs did not reliably differentiate groups, emphasising PDUS remains an important tool.

Type 17-specific immune pathways are active in early spondyloarthritis

OBJECTIVE

Undifferentiated, early inflammatory arthritis (EIA) can differentiate into seropositive or seronegative rheumatoid arthritis (RA), peripheral spondyloarthritis (SpA) or remain as seronegative undifferentiated inflammatory arthritis (UIA). Little is known about immune pathways active in the early stages of SpA and seronegative UIA, in contrast to detailed knowledge of seropositive RA. The aim of this study was to examine if specific immune pathways were active in synovial CD4+ and CD8+ T cells in EIA.

METHODS

Synovial fluid (SF) samples from 30 patients with EIA were analysed for expression of IL-17A, IFNγ and TNFα in CD8+ or CD4+ T cells. Final clinical diagnoses were made at least 12 months after sample collection, by two independent clinicians blind to the study data.

RESULTS

Flow cytometry analysis of all EIA samples indicated considerable variation in synovial IL-17A+CD8+ T cells (Tc17) cell frequencies between patients. The group with a final diagnosis of SpA (psoriatic arthritis or peripheral SpA, n=14) showed a significant enrichment in the percentage of synovial Tc17 cells compared with the group later diagnosed with seronegative UIA (n=10). The small number of patients later diagnosed with seropositive RA (n=6) patients had few Tc17 cells, similar to our previous findings in established disease. In contrast, RA SF contained a significantly higher percentage of CD8+IFNγ+ T cells compared with SpA or seronegative UIA.

CONCLUSION

These results suggest that adaptive T cell cytokine pathways differ not only between RA and SpA but also seronegative UIA early in the disease process, with a particular activation of Tc17 pathways in early SpA.

Human in vitro-induced IL-17A+ CD8+ T-cells exert pro-inflammatory effects on synovial fibroblasts

IL-17A+ CD8+ T-cells, termed Tc17 cells, have been identified at sites of inflammation in several immune-mediated inflammatory diseases. However, the biological function of human IL-17A+ CD8+ T-cells is not well characterized, likely due in part to the relative scarcity of these cells. Here, we expanded IL-17A+ CD8+ T-cells from healthy donor PBMC or bulk CD8+ T-cell populations using an in vitro polarization protocol. We show that T-cell activation in the presence of IL-1β and IL-23 significantly increased the frequencies of IL-17A+ CD8+ T-cells, which was not further enhanced by IL-6, IL-2, or anti-IFNγ mAb addition. In vitro-generated IL-17A+ CD8+ T-cells displayed a distinct type-17 profile compared with IL-17A- CD8+ T-cells, as defined by transcriptional signature (IL17A, IL17F, RORC, RORA, MAF, IL23R, CCR6), high surface expression of CCR6 and CD161, and polyfunctional production of IL-17A, IL-17F, IL-22, IFNγ, TNFα, and GM-CSF. A significant proportion of in vitro-induced IL-17A+ CD8+ T-cells expressed TCRVα7.2 and bound MR1 tetramers indicative of MAIT cells, indicating that our protocol expanded both conventional and unconventional IL-17A+ CD8+ T-cells. Using an IL-17A secretion assay, we sorted the in vitro-generated IL-17A+ CD8+ T-cells for functional analysis. Both conventional and unconventional IL-17A+ CD8+ T-cells were able to induce pro-inflammatory IL-6 and IL-8 production by synovial fibroblasts from patients with psoriatic arthritis, which was reduced upon addition of anti-TNFα and anti-IL-17A neutralizing antibodies. Collectively, these data demonstrate that human in vitro-generated IL-17A+ CD8+ T-cells are biologically functional and that their pro-inflammatory function can be targeted, at least in vitro, using existing immunotherapy.

A Comprehensive Review of Ixekizumab Efficacy in Nail Psoriasis from Clinical Trials for Moderate-to-Severe Psoriasis and Psoriatic Arthritis

Nail psoriasis is a difficult-to-treat manifestation of psoriatic disease affecting up to 80% of patients with psoriatic arthritis (PsA) and 40-60% of patients with plaque psoriasis (PsO). Ixekizumab (IXE), a high-affinity monoclonal antibody that selectively targets interleukin-17A, is approved for the treatment of patients with PsA and patients with moderate-to-severe PsO. This narrative review aims to summarize nail psoriasis data generated from IXE clinical trials in patients with PsA (SPIRIT-P1, SPIRIT-P2, and SPIRIT-H2H) and/or moderate-to-severe PsO (UNCOVER-1, -2, -3, IXORA-R, IXORA-S, and IXORA-PEDS) with an emphasis on head-to-head clinical trial data. Across numerous trials explored, IXE treatment was associated with greater improvement in resolution of nail disease versus comparators at week 24, results which were maintained up to and beyond week 52. Additionally, patients experienced higher rates of resolution of nail disease versus comparators at week 24 and maintained high levels of resolution up to week 52 and beyond. In both PsA and PsO, IXE demonstrated efficacy in treating nail psoriasis, and therefore may be an effective therapy option. Trial Registration: ClinicalTrials.gov identifier UNCOVER-1 (NCT01474512), UNCOVER-2 (NCT01597245), UNCOVER-3 (NCT01646177), IXORA-PEDS (NCT03073200), IXORA-S (NCT02561806), IXORA-R (NCT03573323), SPIRIT-P1 (NCT01695239), SPIRIT-P2 (NCT02349295), SPIRIT-H2H (NCT03151551).

Optimising psoriatic arthritis therapy with immunological methods to increase standard evaluation: the protocol of an open-label multicentre, parallel-group, two-arm randomised controlled study evaluation precision medicine approach in the treatment of psoriatic arthritis

INTRODUCTION

Psoriatic arthritis (PsA) affects around 150 000 people in the UK of whom around 50% require treatment with biologics. The most used biologics for PsA target tumour necrosis factor (TNF) or interleukin-17A (IL-17A). About 50% of patients respond to each, but it is not currently possible to predict response for individual patients, necessitating sequential treatment steps. A recent proof of concept study in PsA suggested that using peripheral immunophenotype to choose therapy could improve time to treatment response.This study will test the hypothesis, within an open-label parallel-group biomarker-stratified multicentre randomised controlled trial, which the baseline proportion of CD4+T cells with an activated type 17 immunophenotype (Th17 levels) predicts response to IL-17A or TNF inhibitors in PsA. Additional analyses will identify if the model can be refined by combining additional clinical and immunophenotypic factors. Statistical modelling will be used to predict the likely effectiveness of these approaches compared with standard care.

METHODS AND ANALYSIS

Patients with PsA eligible to start their first biologic as part of standard care are recruited and baseline blood tests are taken for immunophenotyping. Participants are stratified equally by Th17 levels and randomised 1:1 to receive either TNF (adalimumab) or IL-17A (secukinumab) inhibitors. The primary analysis will establish the interaction between baseline immunophenotype and treatment on the primary outcome (achievement of minimal disease activity criteria at week 24). In secondary analysis, modelling will identify if this prediction model can be optimised further by incorporating clinical phenotypes and additional immunophenotyping techniques.

ETHICS AND DISSEMINATION

Ethical approval for the study was granted by the North West Preston Research Ethics Committee (ref 21/NW/0016). Dissemination will be via conference presentations and peer-reviewed publications, aiming to impact on treatment guidelines.

TRIAL REGISTRATION NUMBER

ISRCTN17228602.

A systematic review and meta-analysis of questionnaires to screen for pain sensitisation and neuropathic like pain in inflammatory arthritis

BACKGROUND

Targeted pain relief is a major unmet medical need for patients with inflammatory arthritis (IA), where approximately 40% of patients experience persistent pain. Self-reported questionnaires which report on pain sensitivity and neuropathic like pain may provide an insight into certain pain types to guide targeted treatment.

OBJECTIVE

In this systematic review and meta-analysis we evaluated self-reported pain sensitivity and neuropathic like pain in subjects with IA, as defined by questionnaires.

METHODS

MEDLINE, Embase, Web of Science, PsycINFO and google scholar were searched for publications and conference abstracts, reporting on pain sensitivity and neuropathic pain using painDETECT, DN4, LANSS, CSI, PSQ and McGill pain questionnaire in adult patients with IA. Risk of bias was assessed using National Institute of Health Quality Assessment Tool. Meta-analysis according to individual questionnaire criteria, was undertaken.

RESULTS

63 studies (38 full text and 25 conference abstracts) were included in the review, reporting on a total of 13,035 patients. On meta-analysis, prevalence of pain sensitivity/neuropathic like pain in IA was 36% (95% CI 31-41%) according to painDETECT, 31% (95% CI 26-37%) according to the DN4, 40% (95% CI 32-49%) according to the LANSS and 42% (95% CI 34-51%) according to the CSI. On meta-regression, prevalence of pain sensitivity/neuropathic pain in RA was significantly lower than SpA (p = 0.01) and PsA (p = 0.002) using the painDETECT questionnaire. Across all questionnaires, pain sensitivity and neuropathic like pain were significantly associated with worse pain severity, disease activity, disability, quality of life and anxiety and depression measures. Studies reporting on whether neuropathic like pain is a predictor of treatment outcome were inconsistent.

CONCLUSION

Pain sensitivity and neuropathic like pain contribute to pain perception in up to 42% of patients with IA. Despite substantial heterogeneity between studies on meta-analysis, this review highlights the large proportion of patients with IA who may experience pain due to underlying mechanisms other than, or in addition to, synovial inflammation.

Psoriatic and rheumatoid arthritis joints differ in the composition of CD8+ tissue-resident memory T cell subsets

CD69+CD103+ tissue-resident memory T (TRM) cells are important drivers of inflammation. To decipher their role in inflammatory arthritis, we apply single-cell, high-dimensional profiling to T cells from the joints of patients with psoriatic arthritis (PsA) or rheumatoid arthritis (RA). We identify three groups of synovial CD8+CD69+CD103+ TRM cells: cytotoxic and regulatory T (Treg)-like TRM cells are present in both PsA and RA, while CD161+CCR6+ type 17-like TRM cells with a pro-inflammatory cytokine profile (IL-17A+TNFα+IFNγ+) are specifically enriched in PsA. In contrast, only one population of CD4+CD69+CD103+ TRM cells is detected and at similarly low frequencies in both diseases. Type 17-like CD8+ TRM cells have a distinct transcriptomic signature and a polyclonal, but distinct, TCR repertoire. Type 17-like cells are also enriched in CD8+CD103- T cells in PsA compared with RA. These findings illustrate differences in the immunopathology of PsA and RA, with a particular enrichment for type 17 CD8+ T cells in the PsA joint.

Clinically relevant patient clusters identified by machine learning from the clinical development programme of secukinumab in psoriatic arthritis

Objectives

Identify distinct clusters of psoriatic arthritis (PsA) patients based on their baseline articular, entheseal and cutaneous disease manifestations and explore their clinical and therapeutic value.

Methods

Pooled baseline data in PsA patients (n=1894) treated with secukinumab across four phase 3 studies (FUTURE 2–5) were analysed to determine phenotypes based on clusters of clinical indicators. Finite mixture models methodology was applied to generate clinical clusters and mean longitudinal responses were compared between secukinumab doses (300 vs 150 mg) across identified clusters and clinical indicators through week 52 using machine learning (ML) techniques.

Results

Seven distinct patient clusters were identified. Cluster 1 (very-high (VH) – SWO/TEN (swollen/tender); n=187) was characterised by VH polyarticular burden for both tenderness and swelling of joints, while cluster 2 (H (high) – TEN; n=251) was marked by high polyarticular burden in tender joints and cluster 3 (H – Feet – Dactylitis; n=175) by high burden in joints of feet and dactylitis. For cluster 4 (L (Low) – Nails – Skin; n=209), cluster 5 (L – skin; n=283), cluster 6 (L – Nails; n=294) and cluster 7 (L; n=495) articular burden was low but nail and skin involvement was variable, with cluster 7 marked by mild disease activity across all domains. Greater improvements in the longitudinal responses for enthesitis in cluster 2, enthesitis and Psoriasis Area and Severity Index (PASI) in cluster 4 and PASI in cluster 6 were shown for secukinumab 300 mg compared with 150 mg.

Conclusions

PsA clusters identified by ML follow variable response trajectories indicating their potential to predict precise impact on patients’ outcomes.

Trial registration numbers

NCT01752634, NCT01989468, NCT02294227, NCT02404350

P19 Frequencies of IL-17+CD8+ T-cells and tissue resident memory T-cells in early inflammatory arthritis

Background

Early inflammatory arthritis (EIA) is classically described as arthritis of ≤ 12 months duration. EIA can be sub-divided into psoriatic arthritis (PsA), other spondyloarthritides (SpA), rheumatoid arthritis (RA) or reactive arthritis (ReA). EIA is often difficult to classify. IL-17+CD8+ T-cells have previously been identified within the joints of patients with PsA. Many of these cells have properties of tissue resident memory (TRM) T-cells, a recently defined subset of CD8+ T cells which remain resident within tissues ready to respond rapidly. We sought to identify the presence and frequency of Tc17 and/ or TRM cells within the joints of patients with EIA to facilitate correct diagnosis and management.

Methods

27 EIA patient samples were collected from patients in the Rheumatology clinic setting. Consent was obtained using established ethics. Samples underwent synovial fluid mononuclear cell (SFMC) isolation and cryopreservation. After thawing, 2 million cells from each sample were stimulated for 3 hours with PMA, Ionomycin and Golgistop. Samples were stained for CD-3, CD-14, CD-4, CD-8 and cytokine expression (IL-17, IFN- γ and TNF-α). A further 2 million cells from 21 of these samples were stained using an extracellular stain for the presence of TRM cells (CD69+CD103+ CD8+ T cells). Samples were all acquired on BD Canto. Analysis was completed using FlowJo and PRISM.

Results

Patients were classified into disease groups based on clinical features and laboratory results, blinded to the SF results. Seronegative RA was subdivided based on disease pattern into RA like or oligo-arthritis like. Patient numbers per group: seropositive RA = 5, seronegative RA (RA-like) =4, seronegative RA (oligo-like) =8, PsA=4, SpA=6. The frequency of Tc17 cells was significantly increased in SF of patients with PsA compared to all other groups (ordinary one-way ANOVA p < 0.0001). Specific comparisons were seropositive RA vs PsA (p = 0.003), seronegative RA vs PsA (RA like p = 0.0002, oligo IA p < 0.0001) and PsA vs SpA (p = 0.0013). The frequency of TRM cells was also significantly increased in PsA compared to all other groups (ordinary one-way ANOVA p = 0.0013), and specific groups: seropositive RA and PsA (p = 0.0031), seronegative RA and PsA (RA like p = 0.0086, oligo IA p = 0.0039) and PsA and SpA P = 0.0009. In contrast, Th17 cells and IFN-γ+ CD8+ T-cells (Tc1 cells) were found in all SF with no significant difference between sub-groups.

Conclusion

This preliminary study of 27 patients with EIA shows that the frequency of Tc17 and CD69+CD103+CD8+ TRMcells are increased in the SF of patients with early PsA compared to other patient groups. Our data also show that TRM cells are present at detectable frequencies in the joints of most patients with EIA. Further work is required to establish if these cells could function as a clinical biomarker to aid diagnosis.

Disclosures

C.D. Hughes None. K.J.A. Steel None. S. Ryan None. S. Lahnunlimi None. B. Menon None. L.S. Taams None. B.W. Kirkham Consultancies; BK has worked as a consultant for Eli Lilly, Gilead, Jannsen and Novartis. Grants/research support; BK has received research support from Eli Lilly and Novartis.

P266 IL-4/13 inhibitor dupilumab associated with new onset peripheral axial spondyloarthritis in patients with atopic dermatitis

Background

Dupilumab is a recombinant human monoclonal antibody that inhibits signalling of interleukin-4 and interleukin-13. It has NICE approval for use in patients with moderate to severe atopic eczema who have failed at least one standard therapy. The main reported side effects in clinical trials were allergic conjunctivitis (1-5%), injection site reactions (8-19%) and herpes viral infections (3-7%).

Methods

Here we report symptoms and signs of a new peripheral axial spondyloarthritis/ psoriatic arthritis type presentation in 8 patients within 16 weeks of commencing dupilumab. This has not been described previously in the clinical trials patient population.

Results

These patients had a long history of atopy with severe eczema and raised baseline IgE levels of > 12000. A positive response to dupilumab was seen in all patients as evidenced by marked improvements in the Eczema Area and Severity Index (EASI). Musculoskeletal symptom onset began between 2 and 16 weeks after commencement of drug. Patients typically complained of inflammatory type pain in the small joints and entheseal sites. 2/8 patients had inflammatory sounding spinal pain. Early morning stiffness was common. All patients had normal acute phase reactants and one patient had a positive rheumatoid factor. 6/8 patients had radiologically evident enthesitis as seen on MRI or ultrasound (power doppler ultrasound signal-PDUS). 3/8 patients had such severe symptoms that they had to discontinue dupilumab. All patients were commenced on non-steroidal anti inflammatories. One patient was commenced on a low dose JAK inhibitor and exhibited improvement in musculoskeletal symptoms.

Conclusion

IL-4 has been shown to suppress delayed type hypersensitivity reactions (DTHRs) in both human and mice studies. It has been demonstrated previously that IL-4 can prevent bone erosion and disease progression in animal models of inflammatory arthritis. Guenova et al (2015) showed that IL-4 can selectively suppress IL-23 transcription and secretion with reduced Th17 function. They suggest that administration of IL-4 may be of therapeutic benefit in Th17 mediated inflammatory conditions. Conversely, dupilumab through the inhibition of IL-4 and IL-13 and possible resultant increased IL-17 and IL-23 levels, has perhaps unmasked a tendency towards development of a peripheral axial SpA phenotype in these patients.

Disclosures

C.D. Hughes None. B. Menon None. Z. Willsmore None. R. Woolf None. C. Smith Grants/research support; CS is a PI/CoPI on a number of commercially supported studie (Abbvie, Janssen, Leo, Sanofi). A. Pink None. B.W. Kirkham Consultancies; BK has worked as a consultant for Eli Lilly, Gilead, Janssen and Novartis. Grants/research support; BK has received research support from Eli Lilly and Novartis.

Polyfunctional, Proinflammatory, Tissue-Resident Memory Phenotype and Function of Synovial Interleukin-17A+CD8+ T Cells in Psoriatic Arthritis

Objective

Genetic associations imply a role for CD8+ T cells and the interleukin‐23 (IL‐23)/IL‐17 axis in psoriatic arthritis (PsA) and other spondyloarthritides (SpA). IL‐17A+CD8+ (Tc17) T cells are enriched in the synovial fluid (SF) of patients with PsA, and IL‐17A blockade is clinically efficacious in PsA/SpA. This study was undertaken to determine the immunophenotype, molecular profile, and function of synovial Tc17 cells in order to elucidate their role in PsA/SpA pathogenesis.

Methods

Peripheral blood (PB) and SF mononuclear cells were isolated from patients with PsA or other types of SpA. Cells were phenotypically, transcriptionally, and functionally analyzed by flow cytometry (n = 6–18), T cell receptor β (TCRβ) sequencing (n = 3), RNA‐Seq (n = 3), quantitative reverse transcriptase–polymerase chain reaction (n = 4), and Luminex or enzyme‐linked immunosorbent assay (n = 4–16).

Results

IL‐17A+CD8+ T cells were predominantly TCRαβ+ and their frequencies were increased in the SF versus the PB of patients with established PsA (P < 0.0001) or other SpA (P = 0.0009). TCRβ sequencing showed that these cells were polyclonal in PsA (median clonality 0.08), while RNA‐Seq and deep immunophenotyping revealed that PsA synovial Tc17 cells had hallmarks of Th17 cells (RORC/IL23R/CCR6/CD161) and Tc1 cells (granzyme A/B). Synovial Tc17 cells showed a strong tissue‐resident memory T (Trm) cell signature and secreted a range of proinflammatory cytokines. We identified CXCR6 as a marker for synovial Tc17 cells, and increased levels of CXCR6 ligand CXCL16 in PsA SF (P = 0.0005), which may contribute to their retention in the joint.

Conclusion

Our results identify synovial Tc17 cells as a polyclonal subset of Trm cells characterized by polyfunctional, proinflammatory mediator production and CXCR6 expression. The molecular signature and functional profiling of these cells may help explain how Tc17 cells can contribute to synovial inflammation and disease persistence in PsA and possibly other types of SpA.

Precision medicine in psoriatic arthritis: how should we select targeted therapies?

Psoriatic arthritis (PsA) is a heterogeneous inflammatory arthritis associated with psoriasis. Patients manifest variable presentations with potential involvement of peripheral joints, spine, tendons, skin, and nails. There has been a rapid expansion in targeted treatment options for patients with PsA, but typically less than half of those who receive therapy achieve optimal treatment targets. Many patients respond to second-line or third-line biological therapies, but little evidence exists to guide the choice of therapeutics for each individual. At present, choice of therapy is driven by active clinical disease domains, clinician familiarity with existing treatments, and cost. Here, we review recent data that highlight the potential for personalised, or precision, medicine in PsA and other forms of inflammatory arthritis, noting that this research is still at a preliminary stage. In the future, a combination of detailed immunophenotyping and sophisticated statistical analyses should help to facilitate a personalised medicine approach in PsA, following examples from other clinical areas, such as oncology. This change in approach to the treatment of PsA has the potential to maximise outcomes for patients and to provide optimal therapies without delay.

The role of IL-17A in axial spondyloarthritis and psoriatic arthritis: recent advances and controversies

Although the pathogenic mechanisms underlying axial spondyloarthritis (axSpA) and psoriatic arthritis (PsA) are not fully elucidated, several lines of evidence suggest that immune responses mediated by interleukin 17A (IL-17A) play a pivotal role in both diseases. This is best highlighted by the significant clinical efficacy shown with inhibitors of IL-17A in treating axSpA and PsA. Nevertheless, a number of knowledge gaps exist regarding the role of IL-17A in the pathophysiology of spondyloarthritis in man, including its cellular origin, its precise role in discrete disease processes such enthesitis, bone erosion, and bone formation, and the reasons for the discrepant responses to IL-17A inhibition observed in certain other spondyloarthritis manifestations. In this review, we focus on the latest data from studies investigating the role of IL-17A in ankylosing spondylitis (AS) and PsA that build on existing and emerging scientific knowledge in the field. Key remaining research questions are also highlighted to guide future research.

Best-practice Indicators in Psoriatic Disease Care

OBJECTIVE

In 2016, members of the Group for Research and Assessment of Psoriasis and Psoriatic Arthritis (GRAPPA), in collaboration with KPMG LLP (UK), conducted a study to measure care in psoriatic arthritis (PsA). A key finding was that centers do not usually have processes in place to measure the effect of improved quality of care. Our objectives were to identify and select best-practice indicators to enable PsA caregivers to assess and monitor the outcomes of specific initiatives aimed at improving care in 4 focus areas: (1) shortening time to diagnosis; (2) improving multidisciplinary collaboration; (3) optimizing disease management; and (4) improving disease monitoring.

METHODS

(1) Structured review of scientific and grey literature to obtain evidence for a long list of 100 potential indicators across the 4 focus areas; (2) survey expert rheumatologists and dermatologists to review the long list and identify the most meaningful and feasible indicators for use in day-to-day practice; (3) consensus discussion to identify a shortlist of indicators based on predefined selection criteria; (4) electronic group discussion to refine definitions of shortlisted indicators and targets; and (5) review of the shortlisted indicators at the annual GRAPPA meeting in July 2018 to ensure the indicators meet the preliminary criteria.

RESULTS

The expert group arrived at a consensus with a shortlist of 8 best-practice indicators across 4 key focus areas aligned with the patient pathway.

CONCLUSION

There were 8 evidence-based best-practice indicators and respective targets that were identified to enable the monitoring of quality of care and target improvements.

Real world long-term impact of intensive treatment on disease activity, disability and health-related quality of life in rheumatoid arthritis

Background

The emphasis on treating rheumatoid arthritis (RA) intensively reduces disease activity but its impact in routine care is uncertain. We evaluated temporal changes in disease activities and outcomes in a 10-year prospective observational cohort study of patients in routine care at one unit.

Methods

The Guy’s and St Thomas’ RA cohort was established in 2005. It involved most RA patients managed in this hospital. Clinical diagnoses of RA were made by rheumatologists. Patients were seen regularly in routine care. Each visit included measurement of disease activity scores for 28 joints (DAS28), health assessment questionnaire scores (HAQ) and EuroQol scores. Patients received intensive treatments targeting DAS28 remission.

Results

In 1693 RA patients mean DAS28 scores fell from 2005 to 15 by 11% from 4.08 (95% CI: 3.91, 4.25) in 2005 to 3.64 (3.34, 3.78); these falls were highly significant (p < 0.001). DAS28 components: swollen joint counts fell by 32% and ESR by 24%; in contrast tender joint counts and patient global assessments showed minimal or no reductions. The reduction in DAS28 scores was predominantly between 2005 and 2010, with no falls from 2011 onwards. Associated with falls in mean DAS28s, patients achieving remission increased (18% in 2005; 27% in 2015) and the number with active disease (DAS28 > 5.1) decreased (25% in 2005; 16% in 2015). In 752 patients seen at least annually for 3 years, persisting remission (68 patients) and intermittent remission (376 patients) were associated with less disability and better health related quality of life. Over time biologic use increased, but they were used infrequently in patients in persistent remission.

Conclusions

Over 10 years an intensive management strategy in a routine practice setting increased combination DMARD and biologic use: disease activity levels declined; this association is in keeping with a causal relationship. Patients who achieved remission, even transiently, had better functional outcomes than patients never achieving remission.

Electronic supplementary material

The online version of this article (10.1186/s41927-019-0054-y) contains supplementary material, which is available to authorized users.

The need for comparative data in spondyloarthritis

Spondyloarthritis comprises a group of inflammatory diseases, characterised by inflammation within axial joints and/or peripheral arthritis, enthesitis and dactylitis. An increasing number of biologic treatments, including biosimilars, are available for the treatment of spondyloarthritis. Although there are a growing number of randomised controlled trials assessing treatments in spondyloarthritis, there is a paucity of data from head-to-head studies. Comparative data are required so that clinicians and payers have the level of evidence required to inform clinical decision-making and health economic assessments. In the absence of head-to-head studies, statistical methods such as network meta-analyses and matching-adjusted indirect comparisons (MAICs) are used for assessing comparative effectiveness.

Network meta-analysis can be used to compare treatments for trials using a common comparator (e.g. placebo); however, for those without a common comparator or where considerable heterogeneity exists between the study populations, a MAIC that controls for differences in study design and baseline patient characteristics may be used. MAICs, unlike network meta-analyses, are of value for longer-term comparisons beyond the placebo-controlled phase of clinical trials, which is important for chronic diseases requiring long-term treatment, like spondyloarthritis. At present, there are a number of limitations that restrict the effectiveness of MAIC, such as the poor availability of individual patient-level data from trials, which results in patient-level data from one trial being compared with published whole-population data from another. Despite these limitations, drug reimbursement agencies are increasingly accepting MAIC as a means of comparative effectiveness and greater methodological guidance is needed.

This report highlights a number of challenges that are specific to conducting comparative studies like MAIC in spondyloarthritis, including disease heterogeneity, the paucity of biomarkers and the duration of studies required for radiographic endpoints in this slow-progressing disease.

Contribution of the IL-17 Pathway to Psoriasis and Psoriatic Arthritis

Investigators have accrued compelling evidence that the IL-17 pathway is central to the pathogenesis of psoriasis and psoriatic arthritis. The evidence comprises genome-wide association studies (GWAS), data from experimental murine models and findings from in vitro studies on patients' cells or tissue biopsies. More recently, the success of drugs blocking the IL-17 pathway in treating both psoriasis (PsO) and psoriatic arthritis (PsA) confirms that IL-17 is a clinically relevant therapeutic target. However, there remain many unanswered questions: is PsA simply an extension of PsO from the skin to the synovial tissue or are there differences in the underlying pathogenesis of these diseases? Which cell type represents the primary source of IL-17 in PsO and PsA? And how are these cells regulated? This review outlines the IL-17 pathway, summarises the evidence supporting its role in PsO and PsA and discusses recent data that may help to address these yet unresolved questions.

The SSB-positive/SSA-negative antibody profile is not associated with key phenotypic features of Sjögren's syndrome

OBJECTIVE

To determine whether the Sjögren's syndrome B (SSB)-positive/Sjögren's syndrome A (SSA)-negative antibody profile is associated with key phenotypic features of SS.

METHODS

Among registrants in the Sjögren's International Collaborative Clinical Alliance (SICCA) with possible or established SS, we compared anti-SSA/anti-SSB reactivity profiles against concurrent phenotypic features. We fitted logistic regression models to explore the association between anti-SSA/anti-SSB reactivity profile and each key SS phenotypic feature, controlling for potential confounders.

RESULTS

Among 3297 participants, 2061 (63%) had negative anti-SSA/anti-SSB, 1162 (35%) had anti-SSA with or without anti-SSB, and 74 (2%) anti-SSB alone. Key SS phenotypic features were more prevalent and had measures indicative of greater disease activity in those participants with anti-SSA, either alone or with anti-SSB, than in those with anti-SSB alone or negative SSA/SSB serology. These between-group differences were highly significant and not explained by confounding by age, race/ethnicity or gender. Participants with anti-SSB alone were comparable to those with negative SSA/SSB serology in their association with these key phenotypic features. Among SICCA participants classified with SS on the basis of the American-European Consensus Group or American College of Rheumatology criteria, only 2% required the anti-SSB-alone test result to meet these criteria.

CONCLUSIONS

The presence of anti-SSB, without anti-SSA antibodies, had no significant association with SS phenotypic features, relative to seronegative participants. The solitary presence of anti-SSB antibodies does not provide any more support than negative serology for the diagnosis of SS. This serological profile should thus be interpreted cautiously in clinical practice and potentially eliminated from future classification criteria.

Interleukin-17+CD8+ T cells are enriched in the joints of patients with psoriatic arthritis and correlate with disease activity and joint damage progression

OBJECTIVE

Psoriatic arthritis (PsA) is associated with HLA class I genes, in contrast to the association with HLA class II in rheumatoid arthritis (RA). Since IL-17+ cells are considered important mediators of synovial inflammation, we sought to determine whether IL-17-producing CD8+ T cells may be found in the joints of patients with PsA and whether these cells might contribute to the disease process.

METHODS

Mononuclear cells from paired samples of synovial fluid (SF) and peripheral blood (PB) from patients with PsA or patients with RA were stimulated ex vivo, and CD4- T cells were examined by flow cytometry for cytokine expression, cytotoxic markers, and frequencies of γ/δ or mucosal-associated invariant T cells. Clinical measures of arthritis activity (C-reactive protein [CRP] level, erythrocyte sedimentation rate [ESR], Disease Activity Score in 28 joints [DAS28]) and power Doppler ultrasound (PDUS) scores for the presence of active synovitis in the aspirated knee were recorded and assessed for correlations with immunologic markers.

RESULTS

Within the CD3+ T cell compartment, both IL-17+CD4- (predominantly CD8+) and IL-17+CD4+ T cells were significantly enhanced in the SF compared to the PB of patients with PsA (P = 0.0003 and P = 0.002, respectively; n = 21), whereas in patients with RA, only IL-17+CD4+ T cells were increased in the SF compared to the PB (P = 0.008; n = 14). The frequency of IL-17+CD4- T cells in PsA SF was positively correlated with the CRP level (r = 0.52, P = 0.01), ESR (r = 0.59, P = 0.004), and DAS28 (r = 0.52, P = 0.01), and was increased in patients with erosive disease (P < 0.05). In addition, the frequency of IL-17+CD4- T cells positively correlated with the PDUS score, a marker for active synovitis (r = 0.49, P = 0.04).

CONCLUSION

These results show, for the first time, that the PsA joint, but not the RA joint, is enriched for IL-17+CD8+ T cells. Moreover, the findings reveal that the levels of this T cell subset are correlated with disease activity measures and the radiographic erosion status after 2 years, suggesting a previously unrecognized contribution of these cells to the pathogenesis of PsA.

Interleukin-17A: a unique pathway in immune-mediated diseases: psoriasis, psoriatic arthritis and rheumatoid arthritis

Experimental evidence points to the importance of the cytokine interleukin-17A (IL-17A) in the pathogenesis of several immunoinflammatory diseases including psoriasis, psoriatic arthritis and rheumatoid arthritis. Although a principal effector of T helper type 17 cells, IL-17A is produced by many other cell types including CD8(+) T cells and γδ T cells, and is found at high levels associated with mast cells and neutrophils at sites of skin and joint disease in humans. IL-17A up-regulates expression of numerous inflammation-related genes in target cells such as keratinocytes and fibroblasts, leading to increased production of chemokines, cytokines, antimicrobial peptides and other mediators that contribute to clinical disease features. Importantly, IL-17A must be considered within the context of the local microenvironment, because it acts synergistically or additively with other pro-inflammatory cytokines, including tumour necrosis factor. Several direct IL-17A inhibitors have shown promising activity in proof of concept and phase 2 clinical studies, thereby providing confirmation of experimental data supporting IL-17A in disease pathogenesis, although levels of response are not predicted by pre-clinical findings. IL-17A inhibitors produced rapid down-regulation of the psoriasis gene signature and high clinical response rates in patients with moderate-to-severe plaque psoriasis, consistent with an important role for IL-17A in psoriasis pathogenesis. Clinical response rates with IL-17A inhibitors in psoriatic arthritis and rheumatoid arthritis, however, were improved to a lesser degree compared with placebo, suggesting that IL-17A is either important in a subset of patients or plays a relatively minor role in inflammatory joint disease. Ongoing phase 3 clinical trials should provide further information on the role of IL-17A in these diseases.

Effects of golimumab, an anti-tumour necrosis factor-α human monoclonal antibody, on lipids and markers of inflammation

OBJECTIVES

To assess the effect of golimumab, with or without methotrexate (MTX), on serum lipids and inflammatory markers of cardiovascular disease (CVD) in patients with rheumatoid arthritis (RA) in two phase 3, randomised, placebo-controlled trials (GO-BEFORE and GO-FORWARD).

METHODS

Patients in GO-BEFORE (n=637, MTX-naïve) and GO-FORWARD (n=444, MTX-inadequate response) were randomised to placebo+MTX, golimumab 100 mg+placebo, golimumab 50 mg+MTX, or golimumab 100 mg+MTX. Subcutaneous injections (placebo and golimumab) were given every 4 weeks. Patients with an insufficient response entered early escape at week 16 (GO-FORWARD) or 28 (GO-BEFORE). All placebo+MTX patients in GO-FORWARD crossed over to golimumab 50 mg+MTX at week 24. Changes from baseline to weeks 14 (GO-FORWARD) or 24 (GO-BEFORE), and 52 in serum lipid levels and inflammatory markers were assessed.

RESULTS

At week 14 in the GO-FORWARD trial, total cholesterol (TC), high-density lipoprotein (HDL) and low-density lipoprotein (LDL) increased in golimumab+MTX patients versus MTX-only patients (16.00 vs 2.00 (p<0.001); 3.00 vs 0.00 (p<0.05); 8.00 vs 4.00 (p<0.001); respectively); favourable changes in LDL subfractions were only observed in golimumab-treated patients. At week 24 in GO-BEFORE, TC and LDL increased, and LDL subfractions improved in the MTX-only and golimumab+MTX groups. Inflammatory markers of CVD risk improved significantly with golimumab+MTX versus placebo+MTX in both studies and were generally maintained through week 52. Atherogenic indices were generally stable.

CONCLUSIONS

While TC and LDL levels increased mildly in RA patients receiving golimumab+MTX, atherogenic indices generally remained stable, favourable changes in LDL subfractions were observed, and inflammatory markers improved.

TNF-α blockade induces IL-10 expression in human CD4+ T cells

IL-17+ CD4+ T (Th17) cells contribute to the pathogenesis of several human inflammatory diseases. Here we demonstrate that TNF inhibitor (TNFi) drugs induce the anti-inflammatory cytokine IL-10 in CD4+ T cells including IL-17+ CD4+ T cells. TNFi-mediated induction of IL-10 in IL-17+ CD4+ T cells is Treg-/Foxp3-independent, requires IL-10 and is overcome by IL-1β. TNFi-exposed IL-17+ CD4+ T cells are molecularly and functionally distinct, with a unique gene signature characterized by expression of IL10 and IKZF3 (encoding Aiolos). We show that Aiolos binds conserved regions in the IL10 locus in IL-17+ CD4+ T cells. Furthermore, IKZF3 and IL10 expression levels correlate in primary CD4+ T cells and Aiolos overexpression is sufficient to drive IL10 in these cells. Our data demonstrate that TNF-α blockade induces IL-10 in CD4+ T cells including Th17 cells and suggest a role for the transcription factor Aiolos in the regulation of IL-10 in CD4+ T cells.

Interaction with activated monocytes enhances cytokine expression and suppressive activity of human CD4+CD45ro+CD25+CD127(low) regulatory T cells

OBJECTIVE

Despite the high frequency of CD4+ T cells with a regulatory phenotype (CD25+CD127(low) FoxP3+) in the joints of patients with rheumatoid arthritis (RA), inflammation persists. One possible explanation is that human Treg cells are converted into proinflammatory interleukin-17 (IL-17)-producing cells by inflammatory mediators and thereby lose their suppressive function. The aim of this study was to investigate whether activated monocytes, which are potent producers of inflammatory cytokines and are abundantly present in the rheumatic joint, induce proinflammatory cytokine expression in human Treg cells and impair their regulatory function.

METHODS

The presence and phenotype of CD4+CD45RO+CD25+CD127(low) T cells (memory Treg cells) and CD14+ monocytes in the peripheral blood (PB) and synovial fluid (SF) of patients with RA were investigated by flow cytometry. Memory Treg cells obtained from healthy control subjects underwent fluorescence-activated cell sorting and then were cocultured with autologous activated monocytes and stimulated with anti-CD3 monoclonal antibodies. Intracellular cytokine expression, phenotype, and function of cells were determined by flow cytometry, enzyme-linked immunosorbent assay, and proliferation assays.

RESULTS

In patients with RA, the frequencies of CD4+CD45RO+CD25+CD127(low) Treg cells and activated CD14+ monocytes were higher in SF compared with PB. In vitro-activated monocytes induced an increase in the percentage of IL-17-positive, interferon-γ (IFNγ)-positive, and tumor necrosis factor α (TNFα)-positive Treg cells as well as IL-10-positive Treg cells. The observed increase in IL-17-positive and IFNγ-positive Treg cells was driven by monocyte-derived IL-1β, IL-6, and TNFα and was mediated by both CD14+CD16- and CD14+CD16+ monocyte subsets. Despite enhanced cytokine expression, cells maintained their CD25+FoxP3+CD39+ Treg cell phenotype and showed an enhanced capacity to suppress T cell proliferation and IL-17 production.

CONCLUSION

Treg cells exposed to a proinflammatory environment show increased cytokine expression as well as enhanced suppressive activity.

Primary Sjögren's syndrome as a systemic disease: a study of participants enrolled in an international Sjögren's syndrome registry

OBJECTIVE

To study the prevalence of extraglandular manifestations in primary Sjögren's syndrome (SS) among participants enrolled in the Sjögren's International Collaborative Clinical Alliance (SICCA) Registry.

METHODS

A total of 1,927 participants in the SICCA registry were studied, including 886 participants who met the 2002 American-European Consensus Group (AECG) criteria for primary SS, 830 "intermediate" cases who had some objective findings of primary SS but did not meet AECG criteria, and 211 control individuals. We studied the prevalence of immunologic and hematologic laboratory abnormalities, specific rheumatologic examination findings, and physician-confirmed thyroid, liver, and kidney disease, as well as lymphoma among SICCA participants.

RESULTS

Laboratory abnormalities, including hematologic abnormalities, hypergammaglobulinemia, and hypocomplementemia, frequently occurred among primary SS cases and were more common among the intermediate cases than among control participants. Cutaneous vasculitis and lymphadenopathy were also more common among primary SS cases. In contrast, the frequency of physician-confirmed diagnoses of thyroid, liver, and kidney disease and lymphoma was low and only primary biliary cirrhosis was associated with primary SS case status. Rheumatologic and neurologic symptoms were common among all SICCA participants, regardless of case status.

CONCLUSION

Data from the international SICCA registry support the systemic nature of primary SS, manifested primarily in terms of specific immunologic and hematologic abnormalities. The occurrence of other systemic disorders among this cohort is relatively uncommon. Previously reported associations may be more specific to select patient subgroups, such as those referred for evaluation of certain neurologic, rheumatologic, or other systemic manifestations.

In vivo activated monocytes from the site of inflammation in humans specifically promote Th17 responses

Th17 cells are a recently defined subset of proinflammatory T cells that contribute to pathogen clearance and tissue inflammation by means of the production of their signature cytokine IL-17A (henceforth termed IL-17). Although the in vitro requirements for human Th17 development are reasonably well established, it is less clear what their in vivo requirements are. Here, we show that the production of IL-17 by human Th17 cells critically depends on both the activation status and the anatomical location of accessory cells. In vivo activated CD14+ monocytes were derived from the inflamed joints of patients with active rheumatoid arthritis (RA). These cells were found to spontaneously and specifically promote Th17, but not Th1 or Th2 responses, compared with resting CD14+ monocytes from the blood. Surprisingly, unlike Th17 stimulation by monocytes that were in vitro activated with lipopolysaccharide, intracellular IL-17 expression was induced by in vivo activated monocytes in a TNF-alpha- and IL-1beta-independent fashion. No role for IL-6 or IL-23 production by either in vitro or in vivo activated monocytes was found. Instead, in vivo activated monocytes promoted Th17 responses in a cell-contact dependent manner. We propose that, in humans, newly recruited memory CD4(+) T cells can be induced to produce IL-17 in nonlymphoid inflamed tissue after cell-cell interactions with activated monocytes. Our data also suggest that different pathways may be utilized for the generation of Th17 responses in situ depending on the site or route of accessory cell activation.

Arthroscopic estimation of the extent of chondropathy

INTRODUCTION

Arthroscopy has been used to evaluate articular cartilage (AC) pathology in osteoarthritis (OA) for outcome measurement and validation of non-invasive imaging. However, many fundamental aspects of arthroscopic assessment remain un-validated.

OBJECTIVES

This study evaluated arthroscopic estimates of extent of chondropathy.

METHODS

Serial arthroscopic assessments were performed in a group of 15 sheep before and after bilateral stifle medial meniscectomy (MMx). Post-mortem assessments were performed in un-MMx sheep and 4 and 16 weeks post-MMx. Arthroscopic assessments of the extent of each grade of chondropathy were compared with a non-arthroscopic hybrid assessment that incorporated biomechanical, thickness and macroscopic assessments.

RESULTS

Arthroscopy evaluated only 36% of AC and missed significant pathological changes, softening and chondro-osteophyte, occurring in peripheral regions. The patterns of change in arthroscopic assessments were similar to those of the non-arthroscopic assessment but there was a very strong tendency to over-estimate the extent of softened AC after MMx. In spite of these limitations arthroscopic assessments were responsive to change. Estimates of the extent of normal and softened AC were most responsive to change over time followed by estimates of superficial and deep fibrillation. Arthroscopy was as an excellent discriminator between normal and OA. Assessments of chondro-osteophyte and exposed bone were not responsive to change.

CONCLUSIONS

Arthroscopic estimates of extent of chondropathy are prone to substantial error. While experience and training may reduce these errors other approaches may more effectively improve performance.

Synovial macrophages as a biomarker of response to therapeutic intervention in rheumatoid arthritis: standardization and consistency across centers

Successive studies from one academic center (Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands) have consistently suggested that synovial tissue expression of sublining macrophages may be a biomarker of clinical response to therapeutic intervention in rheumatoid arthritis (RA) clinical trials. A proof-of-concept, randomized clinical trial was completed at a second academic center (St. Vincent's University Hospital, Dublin, Ireland), and the relationship between the change in disease activity and the change in sublining macrophages in distinct treatment cohorts was determined. The preliminary findings were not conclusive, but appeared to support a role for sublining CD68+ macrophages as a biomarker of clinical response to therapeutic intervention in cohorts of patients with RA.

Synovial membrane cytokine expression is predictive of joint damage progression in rheumatoid arthritis: a two-year prospective study (the DAMAGE study cohort)

OBJECTIVE

The primary aim of this prospective 2-year study was to explain the wide variability in joint damage progression in patients with rheumatoid arthritis (RA) from measures of pathologic changes in the synovial membrane.

METHODS

Patients underwent clinical measurements and joint damage assessments by magnetic resonance imaging (MRI) and radiography at enrollment and at year 2. Synovial membrane was obtained by knee biopsy and assessed histologically by hematoxylin and eosin staining. Interleukin-1beta (IL-1beta), IL-10, IL-16, IL-17, RANKL, tumor necrosis factor alpha (TNFalpha), and interferon-gamma (IFNgamma) messenger RNA (mRNA) expression was determined by quantitative reverse transcription-polymerase chain reaction. The relationship of synovial measurements to joint damage progression was determined by multivariate analysis.

RESULTS

Sixty patients were enrolled. Histologic features had no relationship to damage progression. Multivariate analysis by several different methods consistently demonstrated that synovial membrane mRNA levels of IL-1beta, TNFalpha, IL-17, and IL-10 were predictive of damage progression. IL-17 was synergistic with TNFalpha. TNFalpha and IL-17 effects were most pronounced with shorter disease duration, and IL-1beta effects were most pronounced with longer disease duration. IFNgamma was protective. These factors explained 57% of the MRI joint damage progression over 2 years.

CONCLUSION

We have demonstrated for the first time in a prospective study that synovial membrane cytokine mRNA expression is predictive of joint damage progression in RA. The findings for IL-1beta and TNFalpha are consistent with results of previous clinical research, but the protective role of IFNgamma, the differing effects of disease duration, and IL-17-cytokine interactions had only been demonstrated previously by animal and in vitro research. These findings explain some of the variability of joint damage in RA and identify new targets for therapy.

Arthroscopy -- a potential "gold standard" for the diagnosis of the chondropathy of early osteoarthritis

OBJECTIVES

The aims of this study were to: 1. Evaluate the performance of arthroscopy for the diagnosis of chondropathy and to compare it to that of direct non-arthroscopic assessments; 2. Determine intra-observer reliability of arthroscopic assessments; 3. Evaluate the effects of the arthroscopic video quality and probing upon diagnostic performance.

DESIGN

The ovine medial meniscectomy (MMx) model of early osteoarthritis (OA) was used assuming that pre-MMx articular cartilage (AC) was "normal" and post-MMx AC "chondropathic". Video recordings of arthroscopic assessments of each stifle compartment were evaluated. Scores were given for the quality of the video and the amount of probing. The diagnostic performances of dynamic shear modulus (G), light microscopic assessment and superficial zone collagen birefringence assessments were evaluated and compared to that of arthroscopy. Intra-observer reliability of arthroscopic assessments was also evaluated.

RESULTS

Arthroscopic assessments had high sensitivity (91-100%), specificity (62-88%) and accuracy (75-93%) for the diagnosis of chondropathy 16 weeks after MMx. Arthroscopy compared favourably with the direct non-arthroscopic assessments in the lateral compartment and was found to have extremely high intra-observer reliability (kappa 0.78-1.00). The quality of arthroscopic video recordings and the amount of probing did not significantly influence accuracy or reliability.

CONCLUSIONS

Arthroscopy performs as well as direct non-arthroscopic assessments of AC for diagnosis of early OA. These results suggest that arthroscopy can be used as a "gold standard" for the validation of non-invasive assessments like magnetic resonance imaging and that arthroscopic diagnosis can be based on small amounts of video footage without AC probing.

Biomechanical, histologic and macroscopic assessment of articular cartilage in a sheep model of osteoarthritis

OBJECTIVES

Our primary objective was to explore the full potential of the ovine medial meniscectomy (MMx) model of early osteoarthritis (OA) for studies to validate non-destructive articular cartilage (AC) assessments and therapeutic interventions. Our secondary objective was to re-evaluate the relationships between the different types of AC assessment after MMx in sheep.

METHODS

Macroscopic assessments, dynamic shear modulus (G*), phase lag and AC thickness measurements were performed at a total of 5437 reference points on all six articular surfaces in four normal joints and 16 MMx ovine stifle (knee) joints. Comparisons with histologic assessments of gross structural damage, collagen organisation (birefringence) and proteoglycan content were possible at 702 of these points.

RESULTS

Histologic gross structural damage and proteoglycan loss were seen throughout the joint with greatest severity (fibrillation) in closest proximity to the MMx site. Increases in AC (30-50%) thickness, reductions in G* (30-40%) and collagen birefringence intensity (15-30%) occurred more evenly throughout the joint. Macroscopic softening was evident only when G* declined by 80%. G* correlated with AC thickness (rho=-0.47), collagen organisation rho=0.44), gross structural damage (rho=-0.44) and proteoglycan content (rho=0.42). Multivariate analysis showed that collagen organisation contributed twice as much to dynamic shear modulus (t=6.66 as proteoglycan content (t=3.21). Collagen organisation (rho=0.11) and proteoglycan content (rho=0.09) correlated only weakly to phase lag.

CONCLUSIONS

Macroscopic assessments were insensitive to AC softening suggesting that arthroscopic assessments of AC status might also perform poorly. Collagen integrity was more important for the maintenance of AC stiffness (G*) than proteoglycan content. The development of major AC softening and thickening throughout the joint following MMx suggested involvement of non-mechanical (e.g., protein and biochemical) chemical and cytokine mediated processes in addition to the disturbance in biomechanical loading. The ovine MMx model provides a setting in which the spectrum of AC changes associated with the initiation and progression of OA may be evaluated.

Accuracy and reliability of arthroscopic estimates of cartilage lesion size in a plastic knee simulation model

PURPOSE

The goal of the study was to determine the accuracy and reliability of arthroscopic percent area estimates in a plastic knee simulation model. A second goal was to determine the effect of lesion location within the knee and lesion size on accuracy and reliability.

TYPE OF STUDY

Cross-sectional study of arthroscopic estimates of cartilage lesion size.

METHODS

Three experienced arthroscopists performed 3 sets arthroscopic percent area estimates in 5 different plastic knees. Each knee had lesions drawn on 5 surfaces (patellar, medial and lateral femoral condyle, medial and lateral tibial plateaus). Accuracy and reliability were studied using Bland and Altman limits of agreement (LOA) and intraclass correlation coefficients.

RESULTS

There was a strong tendency to overestimate lesion size by over 100% on the femoral and patellar surfaces. Intraobserver and interobserver reliabilities were generally poor. The range for the 95% LOA (+/- 1.96 standard deviation [SD] of the difference scores) between repeated measurements was almost 6 times the size of the lesion itself. Reliability of estimates was poorest for the largest lesions and worse at femoral, lateral tibial, and patellar sites.

CONCLUSIONS

Assessments of arthroscopic measurements using LOA found that accuracy and reliability were generally poor, although results were better at the medial tibial plateau and for smaller lesions. In spite of these problems, arthroscopy remains a promising measurement tool because it permits physical assessment of cartilage integrity. This study sets the foundations for improvement in techniques of arthroscopic measurement of cartilage lesion size.

Effects of a PEGylated soluble TNF receptor type 1 (PEG sTNF-RI) on cytokine expression in adjuvant arthritis

OBJECTIVE

To investigate the effects of TNF blocking therapy on synovial immune activity in rat adjuvant arthritis (AA) by measuring mRNA expression of key macrophage and T cell cytokines during PEG sTNF-RI treatment (10mg/kg) on days 8, 10 and 12.

METHODS

Paw volume was assessed every 3-4 days. Ankles were removed for quantitative radiology and histology and synovial membrane removed to determine cytokine mRNA expression using semi-quantitative RT-PCR. T cells in joints were quantified by immunohistochemistry.

RESULTS

Paw volume was significantly decreased in rats treated with PEG STNF-RI from days 12 to 17. Histology scores and synovial T cell numbers were reduced on days 13 and 17 and radiology scores significantly reduced on day 13. Expression of synovial TNF, IFN-gamma, IL-17, IL-2 and IL-4 mRNA was unchanged in treated rats and TGF-beta expression was significantly increased at day 13.

CONCLUSIONS

PEG sTNF-RI attenuates AA and disease recurs after treatment ceases, similar to human rheumatoid arthritis. Continued TNF production and/or ongoing T cell activity, may explain the recrudescence of disease once treatment is stopped.

Poor accuracy and interobserver reliability of knee arthroscopy measurements are improved by the use of variable angle elongated probes

OBJECTIVES

(a)To determine the accuracy and reliability of arthroscopic measurements of cartilage lesion diameter in an artificial right knee model; (b) to determine whether the use of a set of variable angle elongated probes improves performance; and (c) to identify other sources of variability.

METHODS

Ovoid "lesions" were drawn on the five cartilage surfaces of four plastic knees models. Two observers assessed these 20 lesions arthroscopically, measuring two diameters in orientations parallel and orthogonal to the probe. Observer 1 (orthopaedic surgeon) and observer 2 (arthroscopic rheumatologist) made two sets of measurements, firstly with the conventional probe and five months later with the variable angle elongated (VAE) probes. The knees were disarticulated to determine true lesion diameter.

RESULTS

Observer 1 had negligible bias and good accuracy regardless of orientation or probe type. Observer 2 demonstrated both bias and poor accuracy using the conventional probe. Both improved using VAE probes. Poor interobserver reliability with conventional probes also improved using VAE probes. Major sources of variability could be traced to the probe type, the characteristics of the operator, and the orientation of the lesion in relation to the probe; the lesion location itself did not cause variability.

CONCLUSIONS

Variation in accuracy and poor interobserver reliability of measurements with conventional methods of cartilage lesion diameter measurement improved when specially designed measurement probes were used. Arthroscopic measurements performed as well as most clinical and radiographic measures. These findings have important implications for the use of arthroscopy as an outcome in multicentre trials where arthroscopists have different levels of experience.

Reduction of joint inflammation and bone erosion in rat adjuvant arthritis by treatment with interleukin-17 receptor IgG1 Fc fusion protein

OBJECTIVE

To investigate the role of interleukin-17 (IL-17) in inflammatory arthritis by blockade with an IL-17 receptor/human IgG1 Fc fusion protein (muIL-17R:Fc) in adjuvant-induced arthritis (AIA) in the rat.

METHODS

AIA was induced in 39 DA rats with the use of Freund's complete adjuvant. Rats received either 7.3 or 20 mg/kg of muIL-17R:Fc or phosphate buffered saline intraperitoneally every other day from the time of arthritis induction for approximately 17 days. Paw volume, arthritis severity, and weight were assessed every 3-4 days. Rats were killed between days 21 and 23 post-induction. Ankles were removed for quantitative radiology and histology and for immunohistochemistry for T cells.

RESULTS

Treatment with muIL-17R:Fc attenuated paw volume in a dose-dependent manner. Both the 7.3 and 20 mg/kg doses of muIL-17R:Fc significantly reduced radiographic scores in the treated rats compared with the controls. The 20 mg/kg dose of muIL-17R:Fc significantly reduced histology scores compared with the controls. T cell numbers were unchanged in the muIL-17R:Fc-treated rats as a function of dose.

CONCLUSION

In vivo blockade of IL-17 by muIL-17R:Fc treatment attenuated AIA and reduced joint damage, suggesting that IL-17 plays an important role in the inflammation and joint destruction of AIA. IL-17 may be a potential therapeutic target for inflammatory diseases in humans, such as rheumatoid arthritis.

The in vivo effects of tumour necrosis factor blockade on the early cell mediated immune events and syndrome expression in rat adjuvant arthritis

Anti-TNF therapy is effective in rheumatoid arthritis (RA); however, its mechanisms of action are incompletely understood. T cell-driven mechanisms are thought to play an important role in RA and the effects of TNF blockade on these mechanisms are unclear. Adjuvant arthritis (AA) is a T cell dependent model of inflammatory arthritis. The aims of this study were to investigate the effects of TNF blockade on in vivo T cell cytokine expression and to clarify the role of TNF in the inguinal lymph nodes (ILN) in early arthritis. AA was induced in male DA rats. Rats received either 3 mg/kg or 10 mg/kg PEG sTNF-RI at days 0, 2 and 4 postinduction or 10 mg/kg anti-TNF antibody on day of arthritis induction. Control rats received either saline or normal sheep serum. Paw volume was assessed every 3-4 days. Rats were sacrificed on days 0, 6, 13 and 21 postinduction. Ankles were removed for quantitative radiology and histology. Synovium and ILN were removed for cell culture and to determine mRNA expression of cytokines using semiquantitative RT-PCR. TNF and IFN-gamma protein production was measured using a bioassay and an ELISA. TNF blockade did not suppress mRNA expression of T cell cytokines in the ILN of rats in the early phase of AA, suggesting ongoing T cell activity. TNF protein production by ILN cells in culture was reduced in PEG sTNF-RI treated rats, although mRNA expression was increased in the ILN prior to culture. Early administration of PEG sTNF-RI did not attenuate AA, in contrast to an anti-TNF antibody, which suppressed disease. A shorter half-life for the PEG sTNF-RI compared with the anti-TNF antibody or the development of anti-PEG sTNF-RI antibodies may account for these results.

The kappa-opioid agonist, asimadoline, alters cytokine gene expression in adjuvant arthritis

OBJECTIVE

We have previously found that the kappa-opioid agonist, asimadoline, attenuates adjuvant arthritis in a dose-dependent, antagonist-reversible manner. To elucidate possible mechanisms, we investigated the effects of asimadoline (5 mg/kg/day i.p.) or vehicle on in vivo cytokine expression and T-cell recruitment in adjuvant arthritis.

METHODS

Arthritis severity was assessed every 3-4 days for 21 days. Rats were killed on days 0, 13 and 21 post-induction and synovial membrane and inguinal lymph nodes were removed for mRNA extraction. Changes in cytokine mRNA expression were measured using reverse transcription-polymerase chain reaction (RT-PCR) and densitometry. T cells in joints were quantified by immunohistochemistry.

RESULTS

Asimadoline significantly decreased arthritis severity at day 13, with a concomitant decrease in synovial membrane expression of cytokines interleukin-17 and transforming growth factor-beta (TGF-beta) mRNA at day 13, and no change in T cell numbers in the joints of arthritic rats. By contrast, in the inguinal lymph nodes, expression of tumour necrosis factor was increased at day 13 and TGF-beta mRNA was increased throughout.

CONCLUSION

An altered balance, therefore, in the pro- and anti-inflammatory effects of TGF-beta by asimadoline might explain its striking anti-arthritic actions.

Prospective evaluation of magnetic resonance imaging and physical examination findings in patients with greater trochanteric pain syndrome

OBJECTIVE

This study examined patients with greater trochanteric pain syndrome (GTPS) to determine the prevalence of gluteus medius pathology by utilizing magnetic resonance imaging (MRI), and to evaluate the presence of Trendelenburg's sign, pain on resisted hip abduction, and pain on resisted hip internal rotation as predictors of a gluteus medius tear in this group of patients.

METHODS

Twenty-four subjects with clinical features consistent with GTPS were recruited. A standard physical assessment was performed at study entry, including assessment of the 3 specific physical signs. Following this initial assessment, MRI of the affected hip was performed. A 1.5T whole body MRI system was utilized, with T1 and T2 fast spin-echo sequences performed in the coronal and axial planes. All MR images were reviewed in random order by a single radiologist. In 12 patients, the 3 physical signs were assessed at study entry and at 2 months by the same observer and the intraobserver reliability for each of the signs was calculated.

RESULTS

All subjects were women (median age 58 years, range 36-75 years). The median duration of symptoms was 12 months (range 12-60 months). MRI findings were as follows: 11 patients (45.8%) had a gluteus medius tear, 15 patients (62.5%) had gluteus medius tendinitis (pure tendinitis in 9 patients and tendinitis with a tear in 6 patients), 2 patients had trochanteric bursal distension, and 1 patient had avascular necrosis of the femoral head. Trendelenburg's sign was the most accurate of the 3 physical signs in predicting a tendon tear, with a sensitivity of 72.7% and a specificity of 76.9%. Moreover, Trendelenburg's sign was the most reliable measure, with a calculated intraobserver kappa of 0.676 (95% confidence interval 0.270-1.08).

CONCLUSION

The results support the hypothesis that gluteus medius tendon pathology is important in defining GTPS. In this series, trochanteric bursal distension was uncommon and did not occur in the absence of gluteus medius pathology. The physical findings suggest that Trendelenburg's sign is the most sensitive and specific physical sign for the detection of gluteus medius tears, with an acceptable intraobserver reliability. Further delineation with MRI, especially in patients with a positive Trendelenburg's sign, is recommended prior to any consideration of surgery in this group of patients. Finally, with the pathology of this condition defined, the challenge will be to devise and assess, by randomized controlled trial, an appropriate treatment strategy for this group of patients.

Cytokine expression and synovial pathology in the initiation and spontaneous resolution phases of adjuvant arthritis: interleukin-17 expression is upregulated in early disease

The aim of this study was to understand the immune processes controlling the initiation and spontaneous resolution of adjuvant arthritis (AA). We investigated synovial T-cell recruitment and mRNA expression of IL-17 and other important disease related cytokines, IFN-gamma, IL-2, IL-4, TNF and TGF-beta in inguinal lymph node (ILN) and synovial membrane (SM). Arthritis severity was assessed by a numerical rating score and rats were sacrificed every 3--4 days postadjuvant induction. Further assessment involved quantitative radiology and histology of the ankle joints on each day, and the ILN and SM were removed for RNA extraction. Cytokine mRNA expression was measured using RT-PCR and densitometry. Paraffin sections of rat ankle joints were stained for T-cells (CD3) by immunohistochemistry. In the ILN, there was an increase in IL-17, TNF and IFN-gamma expression in the early stages of disease, with a secondary sustained increase in IFN-gamma expression. In the SM, there was expression of T-cell cytokines in early arthritis (day 13), and prolonged TNF and TGF-beta expression, which reflected disease progression. IL-4 mRNA expression increased in the later stages of AA. Synovial T-cell numbers transiently increased at day 6, and remained high from days 13--28. Increased pro-inflammatory cytokine expression, including IL-17, in the ILN reflects the initiating events in the early stage of disease. IL-17 may therefore play an important role in the pathogenesis of AA. The increase in IL-4 (an anti-inflammatory cytokine) in the SM in the later stages of AA suggests that IL-4 is involved in the spontaneous resolution of AA. The initial increase in IFN-gamma in the ILN may reflect a pro-inflammatory response, while the prolonged secondary increase may indicate activation of regulatory T-cells.

Effects of the peripherally selective kappa-opioid asimadoline, on substance P and CGRP mRNA expression in chronic arthritis of the rat

We have previously shown that the kappa-opioid agonist, asimadoline, produces time-dependent changes in neuropeptide concentrations in the joints of rats with chronic arthritis. We hypothesized that asimadoline acts on peripheral terminals to modulate substance P (SP) release. To address this hypothesis, here we have examined neuropeptide expression in their source cells in dorsal root ganglia (DRG) that innervate the joint, as well as in non-neuronal tissue, after treatment with asimadoline. We found an increased production of SP and CGRP in untreated chronic arthritic animals which supports our previous finding of increased SP content in the joint. More importantly, the kappa-opioid asimadoline reduced the expression of both SP and calcitonin gene-related peptide-alpha (alpha-CGRP) in DRG cells but had no effect on the very low expression of neuropeptides in non-neuronal tissue. The fact that SP synthesis is attenuated by asimadoline accords with our hypothesis that the increased tissue levels of SP result from kappa-mediated pre-synaptic inhibition of release leading to augmented tissue stores. These in vivo data confirm literature findings that opioids inhibit SP release from peripheral endings of primary afferent fibres.