Validity of the bath ankylosing spondylitis disease activity index for the evaluation of disease activity in axial psoriatic arthritis

Use of the Bath Ankylosing Spondylitis Disease Activity Index in Patients With Psoriatic Arthritis With and Without Axial Disease

OBJECTIVE

To evaluate whether the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) is a responsive instrument in psoriatic arthritis (PsA) and whether it differentiates between axial and peripheral disease activity in PsA.

METHODS

Individuals with PsA initiating therapy in a longitudinal cohort study based in the United States were included. Axial PsA (axPsA), most often also associated with peripheral disease, was defined as fulfillment of the Assessment of Spondyloarthritis international Society axial spondyloarthritis classification criteria or presence of axial disease imaging features. Baseline BASDAI, individual BASDAI items, patient global assessment, patient pain, and Routine Assessment of Patient Index Data 3, and score changes following therapy initiation were descriptively reported. Standardized response means (SRMs) were calculated as the mean change divided by the SD of the change.

RESULTS

The mean (SD) baseline BASDAI score at the time of therapy initiation was 5.0 (2.2) among those with axPsA (n = 40) and 4.8 (2.0) among those with peripheral-only disease (n = 79). There was no significant difference in patient-reported outcome scores between the groups. The mean change for BASDAI was similar among axial vs peripheral disease (-0.75 vs -0.83). SRMs were similar across axial vs peripheral disease for BASDAI (-0.37 vs -0.44) and the individual BASDAI items.

CONCLUSION

BASDAI has reasonable responsiveness in PsA but does not differentiate between axPsA and peripheral PsA. (ClinicalTrials.gov: NCT03378336).

Characteristics of patients with psoriatic arthritis in Korea: focusing on axial involvement

BACKGROUND/AIMS

We aimed to clarify the clinical characteristics of psoriatic arthritis (PsA) in Korean patients focusing on PsA with axial involvement.

METHODS

A retrospective medical chart review was performed to identify PsA patients at a single tertiary center. Cases of AS patients with psoriasis were recruited from a prospective AS registry of the same center. Demographics, laboratory findings, and radiologic characteristics were assessed.

RESULTS

A total of 69 PsA patients were identified. In PsA patients, spondylitis (46.4%) was the most common form. Compared to AS patients with psoriasis, PsA patients with radiographic axial involvement were older (50.9 vs. 32.4 years; p < 0.001) and showed greater peripheral disease activity (peripheral arthritis 78.1 vs. 12.5%, p < 0.001; enthesitis 50.0 vs. 6.3%, p = 0.003). AS patients with psoriasis presented a higher rate of HLA-B*27 positivity (81.3 vs. 17.2%; p < 0.001) and a more frequent history of inflammatory back pain (100.0 vs. 75.0%; p = 0.039) than PsA patients with radiographic axial involvement. Significant proportions of PsA patients with radiographic axial involvement had cervical spine involvement (10/18, 55.6%) and spondylitis without sacroiliitis (10/23, 43.5%).

CONCLUSION

We demonstrate that axial involvement is common in Korean PsA patients, and its characteristics can be distinct from those of AS.

Disease characteristics, pathogenesis, and treatment controversies of axial psoriatic arthritis

Axial psoriatic arthritis (axPsA) has considerable overlap with axial spondyloarthritis (axSpA) but has some unique features that sometimes preclude classification into axSpA. It has some clinical and radiographic differences compared to axSpA. Imaging typically shows asymmetric syndesmophytes, mainly in the cervical spine, with less frequent sacroiliitis. It more commonly presents later in life and is associated with less severe inflammatory back pain than axSpA. The interleukin (IL) IL-23/IL-17 axis is central to the pathogenesis of both diseases. However, the response to therapies targeting these cytokines has been different. IL-23 inhibitors are ineffective in axSpA but may be effective in psoriatic arthritis (PsA). Recent post hoc analyses of clinical trial data with IL-23 inhibitors in PsA have raised the possibility of their efficacy in axPsA and need evaluation in future clinical trials. Moreover, there is a need for classification criteria for axPsA and better tools to assess therapeutic response.

Is Axial Psoriatic Arthritis the Same as Ankylosing Spondylitis With Psoriasis: A Debate

During the Group for Research and Assessment of Psoriasis and Psoriatic Arthritis (GRAPPA) 2022 conference, Drs. Laura Coates and Atul Deodhar debated whether axial psoriatic arthritis (axPsA) is the same as ankylosing spondylitis (AS) with psoriasis. Dr. Coates argued that AS represents a spectrum of disease and that axPsA can be considered within that spectrum. Dr. Deodhar argued that axPsA and AS are 2 different diseases, using construct, content, face, and criterion validity. Their main arguments are described in this manuscript.

Management of Axial Disease in Patients With Psoriatic Arthritis: An Updated Literature Review Informing the 2021 GRAPPA Treatment Recommendations

OBJECTIVE

Axial involvement in patients with psoriatic arthritis (PsA) is a common subset of this condition, but a unanimous definition has yet to be established. It has been defined by using different criteria, ranging from the presence of at least unilateral grade 2 sacroiliitis to those used for ankylosing spondylitis (AS), or simply the presence of inflammatory low back pain (IBP). Our aim was to identify and evaluate the efficacy of therapeutic interventions for treatment of axial disease in PsA.

METHODS

This systematic review is an update of the axial PsA (axPsA) domain of the treatment recommendations project by the Group for Research and Assessment of Psoriasis and Psoriatic Arthritis (GRAPPA).

RESULTS

The systematic review of the literature showed that new biologic and targeted synthetic disease-modifying antirheumatic drug classes, namely interleukin (IL)-17A and Janus kinase inhibitors, could be considered for the treatment of axPsA. This would be in addition to previously recommended treatments such as nonsteroidal antiinflammatory drugs, physiotherapy, simple analgesia, and tumor necrosis factor inhibitors. Conflicting evidence still remains regarding the use of IL-12/23 and IL-23 inhibitors.

CONCLUSION

Further studies are needed for a better understanding of the treatment of axPsA, as well as validated outcome measures.

Axial involvement in psoriatic arthritis

Among the variety of clinical manifestations of psoriatic arthritis (PsA) – including peripheral arthritis, dactylitis, enthesitis, and axial disease – spondylitis is the least studied. There is no generally accepted definition of axial PsA (axPsA), nor is there any common terminology or diagnostic criteria for it. In the rheumatology community, there is also no consensus regarding radiological and MRI assessment of axial involvement in PsA patients, while disease activity indexes and the therapeutic tactics are borrowed from those used in treating axial spondyloarthritis (axSpA) and ankylosing spondylitis (AS). However, despite a range of similarities in immunopathogenetic mechanisms of axPsA and axSpA, there are also certain differences that may affect the treatment response in these patients. The aim of this review is the analysis of data on axial disease in PsA. The article discusses the genetic features, clinical presentations, imaging techniques, differential diagnostics and treatment options of axPsA.

Ex vivo cytokine production in psoriatic disease: Towards specific signatures in cutaneous psoriasis and peripheral psoriatic arthritis

Objectives

Psoriatic arthritis (PsA) and cutaneous psoriasis (PsO) are different phenotypes of psoriatic disease (PsD), whose underlying specific mechanisms remain incompletely understood. As cytokines are key elements to induce and tune up immune responses to drive inflammatory diseases, our objective was to assess whether clinical features, disease phenotype and PsA and PsO activity were associated with a particular ex vivo cytokine production profile.

Methods

Forty-eight patients (37 PsA and 11 PsO) and 11 healthy subjects (HS) were studied. Cytokine production by peripheral blood mononuclear cells (PBMC) that were either unstimulated, or stimulated with LPS or anti-CD3/CD28 antibodies, were analysed by multiplex assay in the culture supernatants.

Results

Cytokine signature of PsD includes a high level of TNFα in supernatants of LPS-stimulated PBMC, higher levels of IL-6 and lower levels of IFN-γ and IL-17A after CD3-CD28 stimulation, as well as higher spontaneous IL-1RA and TNFα production compared to HS. High body mass index (BMI) was associated with lower levels of IL-1β, and metabolic syndrome with lower levels of IFN-γ after LPS stimulation. In PsD, dermatological activity was related with higher IL-17A level, while rheumatic activity was linked with lower levels of IFN-γ and TNFα. Comparing each PsD subtype to HS, IL-1β and IL-6 productions are higher when using LPS stimulation in PsO patients with higher levels of IL-1β and IL-1α in peripheral PsA patients after CD3/CD28 stimulation. LPS stimulation induced high levels of IL-17A in peripheral PsA compared to axial PsA. PsA patients with axial PsA share some features with PsO but shows a distinct cytokine pattern compared to peripheral PsA.

Conclusion

PsO and the different PsA subtypes exhibit distinct ex vivo cytokine production profiles and common features of the so-called PsD. Analysis of IL-1 cytokine family and IL-6 seems to be of particular interest to distinguish PsO and peripheral PsA since it depends on monocytes in PsO and T-lymphocytes in peripheral PsA. Peripheral cytokine profiles are influenced by rheumatic and dermatological activity of the disease, and also by metabolic syndrome features. Our results highlight the crucial role of immune cell interactions with different patterns of interaction depending on clinical phenotype.

Outcome measures in psoriatic arthritis: Where next?

OBJECTIVE

To provide an overview of commonly used outcome measure in psoriatic arthritis (PsA).

BACKGROUND

PsA is a heterogenous inflammatory arthritis, associated with psoriasis that affects between 0.1% and 2% of the population and approximately one in three patients with psoriasis. Psoriatic arthritis places a significant burden on patients' overall quality of life and is associated with a range of comorbidities. Although assessment of patients and monitoring of symptoms has greatly improved over the last 2 decades, capturing disease activity in this multisystem disease remains challenging. Previous efforts have traditionally focussed on assessment of individual disease domains, however recent evidence suggests that composite measurements, particularly those incorporating patient reported outcomes may not only help monitor disease activity more accurately, but also help in accurately validating therapy outcomes in PsA patients.

PURPOSE

This review discusses currently used outcome measurements in PsA and also highlights the importance of emerging measurements such as biomarkers and their possible role in capturing treatment response.

An overview of psoriatic arthritis including clinical manifestations, assessment, diagnostic criteria, investigations, drug management and GRAPPA guidelines

Psoriatic arthritis (PsA) is a chronic and often progressive inflammatory disease, occurring in up to 30% of patients with psoriasis. Assessment of patients with PsA requires consideration of all disease domains, including peripheral arthritis, axial disease, enthesitis, dactylitis, skin psoriasis, psoriatic nail disease, uveitis and inflammatory bowel disease. Co-morbidities and related conditions should all be considered including: obesity, metabolic syndrome, cardiovascular disease, anxiety/depression, liver disease, chronic infections, malignancy, osteoporosis, fibromyalgia and reproductive health.

Predictors of response to secukinumab in patients with psoriatic arthritis and axial manifestations: a post-hoc analysis of the MAXIMISE trial

Objectives

To investigate patient characteristics predictive of response to secukinumab in patients with psoriatic arthritis (PsA) with axial manifestations.

Methods

In a post-hoc analysis from the MAXIMISE trial (NCT02721966) in patients with PsA and axial manifestations, we tested the hypothesis that the OR of the effect of treatment on the primary endpoint of the trial (Assessment of SpondyloArthritis international Society (ASAS) 20 responder status at week 12) would be different depending on 12 prespecified predictor variables. We applied a two-model logistic regression approach, a main effects and an interaction model.

Results

The OR (95% CI) for ASAS20 response for the presence of nail dystrophy was 3.2 (95% CI 0.93 to 10.99) in the secukinumab 150 mg group and 5.0 (95% CI 1.47 to 17.19) in the secukinumab 300 mg group compared with the placebo group (p=0.029). Odds of being a responder were similar in men and women in the secukinumab groups, though men fared worse than women in the placebo group (p=0.039). Current smokers were less likely to be ASAS20 responders compared with never smokers regardless of the treatment group (p=0.589).

Conclusion

Nail dystrophy was identified as a predictor of response to secukinumab in patients with PsA with axial manifestations in the MAXIMISE trial. These findings may be explained by the nail-entheseal concept as part of the axial phenotype in PsA.

Simulated Forest Immersion Therapy: Methods Development

Shinrin-yoku, forest bathing, may provide relief from chronic and breakthrough pain in patients with axial spondyloarthritis and improve immune function through increasing NK cell numbers and activity and their downstream effectors, perforin and granulysin, after chemo- or radiation therapy in breast and prostate cancer patients. The aim of this paper is to describe the study protocol for a simulated forest immersion therapy using virtual reality and atomized phytoncides, volatile organic compounds found in forested areas designed to effect positive change for these two patient populations. The setting, including the room set up and samples with inclusion/exclusion specific to this type of intervention, is outlined. Measures and calibration procedures pertinent to determining the feasibility of simulated forest immersion therapy are presented and include: ambient and surface room temperatures and relative humidity in real time, ambient ultrafine particulate matter, ambient droplet measurement that coincides with volatile organic compounds, specific phytoncides, and virtual reality and atomization of phytoncide set up. Particular lessons learned while training and setting up the equipment are presented. Simulated forest immersion therapy is possible with attention to detail during this early phase when development of methods, equipment testing, and feasibility in deploying the intervention become operational. The expected outcome of the development of the methods for this study is the creation of a standardized approach to simulating forest therapy in a controlled laboratory space.

The state of the art-psoriatic arthritis outcome assessment in clinical trials and daily practice

Psoriatic arthritis is a heterogeneous condition with substantial challenges in optimising outcome measures for both clinical trials and daily practice. As with other inflammatory arthritides, there is no gold standard instrument for measuring disease activity or impact, both of which are key to evaluate therapeutic approaches in trials and monitor disease in daily practice. A wide range of domains have been highlighted in the Outcome Measures in Rheumatology (OMERACT) core domain set for psoriatic arthritis; reflecting the disease involvement in multiple tissues (joints, tendons, skin, and spine) and the heterogenous impact of the disease on individuals. This Review summarises the current evidence around outcome measure selection, considering factors such as unidimensional versus multidimensional outcomes, continuous versus binary measures, and the feasibility of these approaches in trials compared with clinical practice.

How Should We Measure Peripheral Spondyloarthritis?

Spondyloarthritis (SpA) is recognized as an overarching spectrum of disease characterized by axial SpA (axSpA), peripheral arthritis, enthesitis, and dactylitis. Despite significant overlap, patients are often characterized as having predominantly peripheral or axial involvement.

No efficacy of anti-IL-23 therapy for axial spondyloarthritis in randomised controlled trials but in post-hoc analyses of psoriatic arthritis-related 'physician-reported spondylitis'?

The three monoclonal antibodies ustekinumab, guselkumab and risankizumab targeting the p 40 or the 19 subunit of interleukin -23 have now been approved for the indication psoriasis and the former two also for psoriatic arthritis (PsA). Ustekinumab and risankizumab have appeared ineffective in randomised controlled trials with patients with axial spondyloarthritis (axSpA), but post-hoc analyses of PsA trials have now suggested that they may improve back pain symptoms potentially induced by axial inflammation based on PsA. Here we argue that, based on the absence of efficacy in axSpA, this is unlikely and more probably due to generic, non-specific effects, which are not adequately covered by the tools developed for the assessment of inflammation in axSpA.

Outcome measures used in psoriatic arthritis registries and cohorts: A systematic literature review of 27 registries or 16,183 patients

INTRODUCTION

Psoriatic arthritis (PsA) is a multidimensional inflammatory disease for which multiple outcome measures can be used to assess disease activity. In 2006, the OMERACT has proposed the first core domain set in PsA. Since 2006, much work has been performed on outcome measures in PsA.

OBJECTIVES

The purpose of this study was to assess outcome measures collected in recent PsA registries or longitudinal cohorts.

METHODS

A systematic literature review was performed in Pubmed Medline (PROSPERO CRD42020175745) to identify all articles reporting on either registries or longitudinal cohorts in PsA, published between 2010 and March 2020. Registries centered on drugs or not PsA-specific, trials and long-term extension studies were excluded. The data collection comprised patient characteristics and the clinical outcome measures reported, including composite scores and patient reported outcomes (PROs). Statistics were descriptive.

RESULTS

Of 673 articles, 73 were analysed, reporting on 27 registries/cohorts. Overall, 16,183 patients were included, with a mean of 599 per study; 51% were men, weighted mean age was 49.7 ± 9.3 years and weighted mean disease duration was 6.8 ± 0.2 years. Overall, 58 different outcome measures were collected. Disease activity composite scores were used in 20/27 (74%) registries through 8 different scores (most frequently Minimal Disease Activity: 41%, DAS28: 33% and DAPSA: 30%). Among the domains of PsA, joint involvement was reported in 26/27 (96%) registries (through the 66/68 joint count: 85%) and skin psoriasis in 93% (through PASI: 72%), whereas enthesitis, dactylitis and axial involvement were less often reported (respectively, 77%, 74% and 52%). Furthermore, 22/27 (82%) studies reported HAQ; the other frequently reported PROs were patient global assessment (70%) and pain (63%).

CONCLUSIONS

Data collection in PsA is very heterogeneous, reflecting the need for international consensus on outcome measures.

Axial involvement in psoriatic arthritis: An update for rheumatologists

Psoriatic arthritis (PsA) is a heterogenous, chronic, inflammatory musculoskeletal disease that can lead to peripheral and axial damage and loss of function. Axial involvement occurs in 25% to 70% of patients with PsA, varying greatly depending on its definition, with the key manifestations being sacroiliitis and/or spondylitis. However, there are no agreed-upon classification or diagnostic criteria for axial involvement in PsA and no consensus on treatment paradigms, which complicates management of PsA. There have only been a few studies assessing biologics in patients with PsA with axial involvement, and most treatment plans are based on evidence from patients with axial spondyloarthritis. Rheumatologists therefore face many challenges in the management of axial PsA, including diagnosis, differential diagnosis, and choice of appropriate treatment. In this review, we summarize the clinical presentation, imaging characteristics, differential diagnoses, treatment options, and prognosis of axial PsA, with the aim of increasing rheumatologists' knowledge of this phenotype of PsA and thereby aiding its optimal management.

Axial Psoriatic Arthritis

PURPOSE OF REVIEW

To review current understanding of the prevalence, clinical features, outcome measures and recent therapeutic trials in axial psoriatic arthritis (axPsA).

RECENT FINDINGS

The prevalence of axPsA is estimated at 40-50%. However, the definition of axPsA remains unclear, therefore these estimates may be inaccurate. Ax PsA appears to be distinct from ankylosing spondylitis in demographic, clinical, genetic and therapeutic features. Because of the lack of widely accepted definition of axPsA it has been difficult to design therapeutic trials for this domain of PsA. Several studies have demonstrated the uniquness of axPsA. Few recent trials suggest that therapies that work for peripheral arthritis also work for axPsA.

Measurement properties of radiographic outcome measures in Psoriatic Arthritis: A systematic review from the GRAPPA-OMERACT initiative

BACKGROUND

Structural damage is as an important outcome in the Psoriatic Arthritis (PsA) Core Domain Set and its assessment is recommended at least once in the development of a new drug.

OBJECTIVES

To conduct a systematic review (SR) to identify studies addressing the measurement properties of radiographic outcome instruments for structural damage in PsA and appraise the evidence through the Outcome Measures in Rheumatology (OMERACT) Filter 2.1 Framework Instrument Selection Algorithm (OFISA).

METHODS

A SR was conducted using search strategies in EMBASE and MEDLINE to identify full-text English studies which aimed to develop or assess the measurement properties of radiographic outcome instruments in PsA. Determination of eligibility and data extraction was performed independently by two reviewers with input from a third to achieve consensus. Two reviewers assessed the methodology and results of eligible studies and synthesized the evidence using OMERACT methodology.

RESULTS

Twelve articles evaluating radiographic instruments were included. The articles assessed nine peripheral (hands, wrists and/or feet) and six axial (spinal and/or sacroiliac joints) radiographic instruments. The peripheral radiographic instruments with some evidence for reliability, cross-sectional construct validity and longitudinal construct validity were the Ratingen and modified Sharp van der Heijde scores. No instruments had evidence for clinical trial discrimination or thresholds of meaning. There was limited evidence for the measurement properties of all identified axial instruments.

CONCLUSION

There are significant knowledge gaps in the responsiveness of peripheral radiographic instruments. Axial radiographic instruments require further validation, and the need to generate novel instruments and utilise other imaging modalities should be considered.

Secukinumab in patients with psoriatic arthritis and axial manifestations: results from the double-blind, randomised, phase 3 MAXIMISE trial

Objectives

MAXIMISE (Managing AXIal Manifestations in psorIatic arthritis with SEcukinumab) trial was designed to evaluate the efficacy of secukinumab in the management of axial manifestations of psoriatic arthritis (PsA).

Methods

This phase 3b, double-blind, placebo-controlled, multi-centre 52-week trial included patients (≥18 years) diagnosed with PsA and classified by ClASsification criteria for Psoriatic Arthritis (CASPAR) criteria, with spinal pain Visual Analogue Score ≥40/100 and Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) score ≥4 despite use of at least two non-steroidal anti-inflammatory drugs (NSAIDs). Patients were randomised (1:1:1) to secukinumab 300 mg, secukinumab 150 mg or placebo weekly for 4 weeks and every 4 weeks thereafter. At week 12, placebo patients were re-randomised to secukinumab 300/150 mg. Primary endpoint was ASAS20 (Assessment of SpondyloArthritis international Society) response with secukinumab 300 mg at week 12.

Results

Patients were randomly assigned; 167 to secukinumab 300 mg, 165 to secukinumab 150 mg and 166 to placebo. Secukinumab 300 mg and 150 mg significantly improved ASAS20 response versus placebo at week 12 (63% and 66% vs 31% placebo). The OR (95% CI) comparing secukinumab 300 mg and 150 mg versus placebo, using a logistic regression model after multiple imputation, was 3.8 (2.4 and 6.1) and 4.4 (2.7 and 7.0; p<0.0001).

Conclusions

Secukinumab 300 mg and 150 mg provided significant improvement in signs and symptoms of axial disease compared with placebo in patients with PsA and axial manifestations with inadequate response to NSAIDs.

Trial registration number

NCT02721966.

Evaluating Inflammatory Versus Mechanical Back Pain in Individuals with Psoriatic Arthritis: A Review of the Literature

Psoriatic arthritis (PsA) is a chronic immune-mediated disease characterized by psoriatic skin and nail changes, peripheral joint inflammation, enthesitis, dactylitis, and/or axial involvement, either alone or in combination with each other. The presence of axial involvement has been shown to be a marker of PsA severity; however, there is no widely accepted definition of axial involvement in PsA (axPsA) or consensus on how or when to screen and treat patients with suspected axPsA. Chronic back pain is a prominent feature of axPsA and is thought to have a relevant role in early identification of disease. Chronic back pain can be caused by inflammatory back pain (IBP) or mechanical back pain (MBP). However, MBP can complicate recognition of IBP and delay diagnosis of axPsA. While MBP can also be associated with chronic back pain of ≥ 3 months in duration that is typical of IBP, IBP is characterized by inflammation of the sacroiliac joint and lower spine that is differentiated from MBP by key characteristic features, including insidious onset at age < 40 years, improvement with exercise but not with rest, and nighttime pain. This review discusses the differences in identification and management of IBP and MBP in patients with PsA with axPsA. The summary of available evidence highlights the importance of appropriate and timely screening, difficulties and limitations of differential diagnoses and treatment, and unmet needs in axPsA.

Psoriatic arthritis (PsA) is a long-term disease that may lead to psoriatic changes in skin and nails; inflammation of some joints, including finger and toe joints (dactylitis); inflammation of sites where tendons and ligaments connect to bone (enthesitis); and/or problems in the spine (axial involvement). Approximately 25–70% of patients with PsA have axial involvement (axPsA); this number varies because there is no widely accepted definition for axPsA. Chronic (long-lasting) back pain is a major feature of axSpA and can help doctors recognize axPsA early. Chronic back pain can be caused by inflammatory back pain (IBP) or mechanical back pain (MBP). IBP is described by back pain lasting ≥ 3 months, gradual onset at age < 40 years, improvement with exercise, no improvement with rest, pain at night (with improvement upon getting up), and changes in some laboratory test results. On the other hand, MBP is caused by a physical injury to the lower back. Both IBP and MBP can occur in patients with PsA, but they are treated in different ways. Being able to tell the difference between IBP and MBP is important to make sure that patients receive the right treatment. This review looks at the differences between IBP and MBP, screening for IBP, the difficulties and limitations of diagnosing and treating axPsA, and the needs of patients with axPsA for better diagnosis and treatment.

Axial Psoriatic Arthritis: A Distinct Clinical Entity in Search of a Definition

Axial involvement in psoriatic arthritis is a well-recognized manifestation with a prevalence between 12.5% and 78%. This huge heterogeneity is due to the different criteria used by authors to define psoriatic arthritis with axial involvement combining clinical features with radiographic evidence of disease. Specific genetic and clinical attributes of axial psoriatic arthritis might differentiate it from axial spondyloarthritis with concurrent skin psoriasis. Few studies address the specific management. The purpose of this review is to acknowledge the current understanding of axial involvement in psoriatic arthritis and highlight the need for a definition to facilitate research and clinical recognition.

Axial disease in psoriatic arthritis and ankylosing spondylitis: a critical comparison

Ankylosing spondylitis (AS) was first identified in the late 17th century. 250 years later, inflammatory spine disease was recognized to be one of the patterns of psoriatic arthritis (PsA). Isolated spondylitis is rare among patients with PsA, occurring in less than 5% of patients; however, many patients with PsA have axial disease that is concurrent with peripheral arthritis. At the other end of the spondyloarthritis spectrum, psoriasis is observed in 10% of patients with AS. Although axial involvement in PsA can be indistinguishable from axial disease in AS, it can also differ in several respects, raising the question of whether axial PsA and AS (with or without psoriasis) are different clinical presentations of the same disease, or whether they are separate diseases that have overlapping features. In this Review, the clinical presentation, metrology, radiographic characteristics, genetic factors, treatment options and axial prognosis of the two diseases are addressed. The aim of this Review is to capture all available comparisons made to date, to highlight the similarities and differences between AS and axial PsA and to propose a research agenda.

Should Methotrexate Have Any Place in the Treatment of Psoriatic Arthritis?

Methotrexate (MTX) is widely used in the treatment of psoriatic arthritis (PsA), despite the evidence base for this being limited. This narrative review summarizes the evidence to date of using MTX within different domains of psoriatic disease, including peripheral arthritis, axial disease, dactylitis, enthesitis, psoriasis, and nail disease. We also explore the role of MTX in combination therapy with tumor necrosis factor inhibitors, in addition to its safety and tolerability, to answer the question: should methotrexate have any place in the treatment of psoriatic arthritis?

Influence of Axial Involvement on Clinical Characteristics of Psoriatic Arthritis: Analysis from the Corrona Psoriatic Arthritis/Spondyloarthritis Registry

Objective.

We analyzed the characteristics of patients with psoriatic arthritis (PsA) with and without axial involvement in the US-based Corrona Psoriatic Arthritis/Spondyloarthritis Registry.

Methods.

All patients were included who had PsA and data on axial involvement, defined as physician-reported presence of spinal involvement at enrollment, and/or radiograph or magnetic resonance imaging showing sacroiliitis. Demographics, clinical measures, patient-reported outcomes, and treatment characteristics were assessed at enrollment.

Results.

Of 1530 patients with PsA, 192 (12.5%) had axial involvement and 1338 (87.5%) did not. Subgroups were similar in sex, race, body mass index, disease duration, presence of dactylitis, and prevalence of most comorbidities. However, patients with axial involvement were younger and more likely to have enthesitis, a history of depression, and more frequently used biologics at enrollment. They were also more likely to have moderate/severe psoriasis (body surface area ≥ 3%, 42.5% vs 31.5%) and significantly worse disease as measured by a lower prevalence of minimal disease activity (30.1% vs 46.2%) and higher nail psoriasis scores [visual analog scale (VAS) 11.4 vs 6.5], enthesitis counts (5.1 vs 3.4), Bath Ankylosing Spondylitis Disease Activity Index (4.7 vs 3.5) scores, Bath Ankylosing Spondylitis Functional Index (3.8 vs 2.5) scores, C-reactive protein levels (4.1 vs 2.4 mg/l), and scores for physical function (Health Assessment Questionnaire, 0.9 vs 0.6), pain (VAS, 47.7 vs 36.2), and fatigue (VAS, 50.2 vs 38.6).

Conclusion.

Presence of axial involvement was associated with a higher likelihood of moderate/severe psoriasis, with higher disease activity and greater effect on quality of life. These findings highlight the importance of monitoring patients with PsA for signs of axial symptoms or spinal involvement.

Patient-Reported Outcomes in Psoriatic Arthritis

Patient-reported outcome (PRO) measures are an important component to assessing disease impact and therapy response in patients with psoriatic arthritis (PsA). Overall, there are few PsA-specific PROs. Most PROs used in PsA are borrowed from other diseases (eg, rheumatoid arthritis and ankylosing spondylitis) or general population PROs. PROs are used in PsA clinical trials and in the clinical management of PsA. In this review, we discuss the most commonly used PRO in PsA, including their inclusion in composite measures. Future studies may be helpful to determine the best performing PROs in patients with PsA.

Assessment of Response to Treatment, Remission, and Minimal Disease Activity in Axial Psoriatic Arthritis Treated with Tumor Necrosis Factor Inhibitors

Objective.

To assess the response to treatment, remission, and minimal disease activity (MDA) in a group of patients with predominant axial psoriatic arthritis (axPsA). Predictors of response were also evaluated.

Methods.

Patients fulfilling the ClASsification of Psoriatic ARthritis (CASPAR) criteria and treated with anti-tumor necrosis factor (anti-TNF) agents adalimumab, etanercept, and golimumab were enrolled and prospectively followed every 4 months for 1 year in a clinical practice setting. Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) 50 was assessed as a set of response criteria to treatment; Composite Psoriatic Disease Activity Index (CPDAI) < 4, Disease Activity Index for Psoriatic Arthritis (DAPSA) score ≤ 3.3, and partial remission (PR) were also evaluated as remission criteria. Patients were considered in MDA when they met at least 5/7 of the criteria previously defined. Patients achieving BASDAI 50, PR, and MDA were compared to identify outcome predictor factors. Concordance between the outcome measures was also performed.

Results.

Of the 58 patients treated with anti-TNF, at baseline no patients were in PR or MDA. No patients had a CPDAI < 4 or a DAPSA score ≤ 3.3. After 12 months, BASDAI 50 was achieved in 15/48 patients (31.2%). CPDAI < 4, DAPSA score ≤ 3.3, PR, and MDA were achieved, respectively, in 17/48 (35.4%), 11/48 (22.9%), 11/48 (22.9%), and 24/48 (50%) patients. No difference was found among the 3 anti-TNF. Predictors for MDA were male sex, young age, low disease duration, low Health Assessment Questionnaire score, and absence of enthesitis.

Conclusion.

This longitudinal observational study, based on a clinical practice setting, showed that remission and MDA are achievable targets in axPsA treated with anti-TNF. Predictors of remission and MDA were also identified.

Patient involvement in outcome measures for psoriatic arthritis

Psoriatic arthritis (PsA) is a heterogeneous inflammatory arthritis with a varied clinical phenotype. There has been considerable international collaboration over recent years to develop and prioritise appropriate disease domains and outcome measures to capture all aspects of this complex disease. It has been recognised that patient-reported measures and physician assessments are complementary and, when used together, allow an improved reflection of disease burden. Taking this concept one step further, the experience in rheumatoid arthritis has demonstrated benefits of incorporating the patient perspective in the development of outcome measures. We report a systematic review demonstrating (1) that there has been little incorporation of the patient perspective in the development of outcome measures and domains in PsA, (2) the proceedings from the preliminary patient involvement in outcome measures for PsA (PIOMPSA) meetings, and (3) a proposed roadmap for improving patient involvement.

Construct validity and responsiveness of the simplified version of Ankylosing Spondylitis Disease Activity Score (SASDAS) for the evaluation of disease activity in axial spondyloarthritis

Background

Over the last decade, significant progresses have been achieved in the development and validation of new tools for the evaluation of disease activity in axial spondyloarthritis (SpA). Despite they play a key role in the assessment of these patients, the calculation scores are relatively complex and difficult to be quickly assessed in the busy daily clinical practice.

Objectives

To test the construct validity of the Simplified Ankylosing Spondylitis Disease Activity Score (SADSAS) to define disease activity and compare its internal and external responsiveness with the Ankylosing Spondylitis Disease Activity Score (ASDAS) and the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) in patients with axial SpA.

Methods

The patient cohort comprised 397 consecutive axial SpA patients who had never been treated with tumor necrosis factor (TNF) blockers. Clinical and laboratory outcome assessments were performed at baseline, and at week 24. The following parameters were evaluated: BASDAI, ASDAS-CRP, ASDAS-ESR, and SASDAS. Construct convergent validity was evaluated by correlating SASDAS with ASDAS CRP/ESR, BASDAI, Bath Ankylosing Spondylitis Functional Index (BASFI) and EuroQol five-dimensional (EQ-5D) questionnaire. One hundred and fifty-six patients were observed longitudinally for 6 months. Responsiveness was assessed after six months of treatment with sulfasalazine (SSZ) or biologics. Internal responsiveness was evaluated by using the effect size (ES) and standardized response mean (SRM). External responsiveness was investigated by receiver operating characteristic (ROC) analysis. Change scores were compared by calculating paired t-test statistic for the difference.

Results

In testing for convergent validity a strong correlations (p < 0.0001) were observed between both SASDAS and ASDAS-ESR (r = 0.835), and ASDAS-CRP (r = 0.805). Strong correlations (p < 0.0001) were also found between SASDAS and BASDAI score (r = −0.886), SASDAS and BASFI scores (rho = 0.588) and SASDAS and EQ-5D scores (rho = −0.579). The cross-classification showed a significant overall agreement (defined as the percentage of observed exact agreements) for SASDAS vs ASDAS-ESR (weighted k = 0.704) and for SASDAS vs ASDAS-CRP (k = 0.661). The most efficient composite measure in detecting change was the ASDAS-CRP (ES 1.95 and SRM 0.97). The responsiveness of SASDAS was slightly higher to ASDAS-ESR with an ES of 1.62 and 1.33, and an SRM of 0.88 and 0.71, respectively. The BASDAI appear to be the less responsive (ES = 0.93 and SRM = 0.52). The area under ROC curve of the SASDAS gives similar results to those provided by ASDAS CRP/ESR. The score changes of all combinations were highly correlated (p < 0.0001).

Conclusions

The new SASDAS is a highly effective measure in assessing disease activity and it showed comparable internal and external responsiveness with respect to the ASDAS ESR/CRP response criteria in patients with axial SpA. SASDAS is easy to calculate and, therefore, appear suitable for clinical decision making, epidemiologic research, and clinical trials.

Electronic supplementary material

The online version of this article (doi:10.1186/s12955-014-0129-9) contains supplementary material, which is available to authorized users.

Comparison of ASDAS and BASDAI as a measure of disease activity in axial psoriatic arthritis

The aim of this study was to compare the discriminative ability of Ankylosing Spondylitis Disease Activity Score (ASDAS) with Bath Ankylosing Spondylitis Activity Disease Activity Index (BASDAI) and other clinical disease activity parameters in patients with axial psoriatic arthritis (axPsA). Patients with axPsA were recruited from Erciyes Spondyloarthritis Cohort (ESPAC) and Anatolian Group for the Assessment in Rheumatic Disease (ANGARD) cohort and were assessed for BASDAI, ASDAS, BASFI (Bath Ankylosing Spondylitis Functional Index), Ankylosing Spondylitis Quality of Life (ASQoL), and visual analog scale (VAS) pain. The discriminant ability of ASDAS-C-reactive protein (-CRP) and ASDAS-erythrocyte sedimentation rate (-ESR) was assessed using standardized mean differences between patients with high and low disease activity. Fifty-four patients with axPsA were included in the study. Both ASDAS scores showed good discriminative ability between high and low disease activity states. Both ASDAS versions and BASDAI had relatively high area under the curve (AUC) according to ASAS partial remission, patient and physician global assessments in receiver operating characteristic (ROC) curve analysis. There was no significant difference between AUC scores for the models that compared ASDAS-CRP and ASDAS-ESR with BASDAI for each individual definition of disease activity states. ASDAS versions and BASDAI showed good similar discriminative ability between high and low disease activity as reflected by the AUC analysis in axPsA. The cutoff values for inactive disease and high disease activity were relatively similar to predefined cutoff values for AS. Further, prospective validation is now required to identify the appropriate assessment tools and cutoff values in axPsA.

Development of a disease activity and responder index for psoriatic arthritis--report of the Psoriatic Arthritis Module at OMERACT 11

This module reflected work within the Group for Research and Assessment of Psoriasis and Psoriatic Arthritis (GRAPPA) to develop and validate composite disease activity measures in psoriatic arthritis (PsA). At the Outcome Measures in Rheumatology (OMERACT) 8 Meeting, a core set of domains to be assessed in randomized controlled trials (RCT) and longitudinal observational studies of PsA was agreed upon. At OMERACT 10, 5 proposed composite responder definitions for PsA were reviewed and discussed, including new data from the GRACE (GRAppa Composite Exercise) study. At OMERACT 11, ongoing retrospective analyses of RCT data using the 3 proposed measures (Composite Psoriatic Disease Activity Index, Psoriatic Arthritis Disease Activity Score, and Arithmetic Mean of the Desirability Function) were discussed in detail. There was agreement that developing composite outcome measures for use in RCT and longitudinal observational studies in PsA was important. Concerns were expressed regarding development of a single measure that encompassed diverse domains, such as joint counts, quality of life (QOL), and disability measures. It was emphasized that the use of any composite measure should include the ability to differentiate between activity in individual domains, such as enthesitis or psoriasis, such that the effect of each could be assessed independently. It was also agreed that patients would be systematically involved in further development and refinement of composite measures. Future plans include qualitative work with patients to explore their experience of disease activity and statistical modeling to explore how each of the proposed measures will perform in different disease subgroups.

Measuring disease activity in psoriatic arthritis

Over the past decade, the assessment of the disease activity in psoriatic arthritis (PsA) has rapidly evolved in view of the need for valid, feasible, and reliable outcome measures that can be ideally employed in longitudinal cohorts, clinical trials, and clinical practice as well as the growing paradigm of tight disease control and treating to target in the management of PsA. This paper reviews the currently available measures used in the assessment of the disease activity in PsA. The composite measures for PsA that are under development are also discussed.

Phenotypic and clinical differences between Caucasian and South Asian patients with psoriatic arthritis living in North East London

To test for demographic and clinical differences between Caucasian and South Asian patients with psoriatic arthritis (PsA) living in the same environment and for differences between sexes. The demographic characteristics of patients attending outpatient clinics were obtained using a semi-structured questionnaire. Clinical parameters included disease activity (Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), erythrocyte sedimentation rate (ESR), C-reactive protein), function (Bath Ankylosing Spondylitis Functional Index (BASFI)) and visual analogue scale (VAS) scores for well-being and night pain (10 cm, where 10 = worst possible response). The first symptom experienced at disease onset and the main symptoms during the disease course were recorded in the questionnaire. A total of 217 patents were assessed of whom 151 were Caucasians and 66 were Asians. South Asian patients were significantly younger [(mean) 45.9 years [(SD)(±11.4)] for Asians and 53.1 years (±14.2) for Caucasians (p < 0.005)] and were diagnosed at an earlier age [40.7 years (±11.7) for Asians and 46.7 years (±15.8) for Caucasians (p < 0.05)] compared to Caucasians patients. Asian females with PsA had worse disease in terms of activity (ESR = 23.9 mmHg/h; BASDAI = 6.7), function (BASFI = 5.5), night pain (7.1 on VAS) and well-being (6.6 on VAS) compared with Asian males (13.2 mmHg/h, 5.3, 3.6, 4.1, 4.6, respectively) or Caucasian males and females (15.8 mmHg/h, 5.9, 5.3, 5.4, 5.4; 18.9 mmHg/h, 6.1, 6.1, 5.3, 5.8, respectively). There were no significant differences in symptoms at disease onset or the main symptoms during the disease course between Caucasian and Asian patients, although there was a trend towards more frequent enthesitis in Asian females during the course of disease suggested by pain with pressure compared to Asian males. South Asian patients may develop PsA earlier in life than Caucasian patients do, but their clinical characteristics are generally similar. Asian females with PsA have worse disease activity, function, night pain and well-being than Asian males and Caucasian males and females.

[Axial psoriatic arthritis]

Spinal involvement in PsA is a controversial issue. Currently, in spite of clinical recognition of axial involvement in axial PsA, there is a lack of consensus that impedes elaborating a definition for axial Psa. Recent advances in classification, clinical features, outcome measures and therapeutics are reviewed in this paper.