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

Evaluation of the Possibility of Axial Psoriatic Arthritis Patients Meeting Classification Criteria for Axial Spondyloarthritis and Ankylosing Spondylitis

The objective of the study was to analyze whether axial psoriatic arthritis (axPsA) patients meet classification criteria for axial spondyloarthritis (axSpA) and ankylosing spondylitis (AS). A total of 104 patients (66 men and 38 women) with PsA according to CASPAR criteria were examined, all patients had back pain. Patients were evaluated for presence of inflammatory back pain (IBP) by ASAS criteria. Back pain not meeting the ASAS criteria was taken to be chronic back pain (chrBP). Patients underwent hands, feet and pelvis, cervical spine and lumbar spine X-rays. Erosions, osteolysis, and juxta-articular new bone formation were evaluated. Definite radiographic sacroiliitis (d-rSI) was defined as bilateral grade ≥ 2 or unilateral grade ≥ 3. Nineteen patients without d-rSI underwent sacroiliac joints MRI. Ninety-three patients underwent HLA B27 examination. The number of patients who met the criteria for axSpA (ASAS) and the modified New York (mNY) criteria for AS was determined. IBP was identified in 67 (64.4%) patients; chrBP, in 37 (35.6%) patients; 31 (29.8%) patient were of older age (over 40) at the onset of IBP/chrBP; 57 (58.8%) patients had d-rSI; 6 (31.6%) patients had MRI-SI; syndesmophytes were detected in 57 (58.8%) cases. Among 40 patients without d-rSI, 19 (47.5%) had syndesmophytes. In 38/97 (39.2%) patients d-rSI was detected along with syndesmophytes, while 19/97 (19.6%) patients had isolated d-rSI without spondylitis, and 19/97 (19.6%) patients had isolated syndesmophytes without d-rSI. HLA B27 was present in 28 (30.1%) cases. 51 (55.4%) patients met criteria for axSpA. Forty-one (44.6%) patients did not meet criteria for axSpA; however, 27 (65.9%) of them had syndesmophytes. Forty-eight (48.5%) PsA patients met mNY criteria for AS. Among these patients, a set of specific features was revealed: 18 (37.5%) had no IBP, 18 (37.5%) were of older age (over 40) at the onset of IBP/chrBP, 34 (70.8%) had dactylitis, 38 (79.2%) had erosive polyarthritis, 23 (48.8%) had juxta-articular new bone formation, 14 (30.2%) had osteolysis, 23 (48.9%) had "chunky" non-marginal syndesmophytes, and 40 (82.6%) had nail psoriasis; 28 (66.6%) patients were HLA-B27 negative. Forty-five percent of axPsA patients do not meet criteria for axSpA. Characteristic features have been identified to differentiate axPsA from AS.

The ATTRACT study: screening for the early identification of axial psoriatic arthritis in a cohort of Italian psoriatic patients

OBJECTIVE

There is growing interest in the early identification of patients with axial PsA (axPsA). We aimed to evaluate whether a dermatology-based screening strategy could help to identify axPsA patients.

METHODS

The dermatologist-centred screening (DCS) questionnaire was administrated by dermatologists to consecutive patients fulfilling the inclusion criteria [(i) age ≥18 years and (ii) clinical diagnosis of psoriasis made by a dermatologist] to identify patients eligible (affirmative answers 1-3c of the DCS) for rheumatological evaluation. Clinical, laboratory, genetic and imaging data were collected from all referred patients.

RESULTS

Among the 365 patients screened, 265 fulfilled the inclusion criteria and 124/265 (46.8%) were eligible for rheumatological referral. Diagnosis of axPsA, with or without peripheral PsA (pPsA), was made in 36/124 (29.0%) patients; pPsA without axial involvement was found in 21/124 (16.9%) patients. Back pain at screening was recorded in 174 (66%) patients, with 158 (60%) reporting a back pain duration longer than 3 months and 140 (53%) reporting back pain onset before the age of 45 years. Active inflammatory and/or structural post-inflammatory changes in the sacroiliac joints and/or spine were observed in all axPsA patients. Patients with PsA showed a numerically longer duration of back pain and higher CRP levels in comparison with patients with psoriasis without PsA.

CONCLUSION

The DCS tool proved to be a valuable screening strategy for detecting and characterizing patients with axPsA in a real-life cohort of psoriasis patients in a dermatological setting and helped to identify a substantial number of patients affected by undiagnosed pPsA.

Axial Disease in Psoriatic Arthritis: A Challenging Domain in Clinical Practice

Psoriatic arthritis (PsA) is a chronic inflammatory condition affecting about one-third of individuals with psoriasis. Defining axial involvement in PsA (axPsA) remains debated. While rheumatologists guide clinical practice, consensus on axPsA is still lacking. This paper explores historical and upcoming definitions from the Axial Involvement in Psoriatic Arthritis (AXIS) study, which aims to establish a validated axPsA definition. Epidemiological data reveal diverse axPsA prevalence rates, emphasizing its complex relationship with peripheral arthritis and enthesitis. Unique genetic, clinical, and radiological features differentiate axPsA from ankylosing spondylitis (AS), necessitating refined classification criteria. The recommendations from the Assessment of Spondylarthritis international Society (ASAS) provide valuable guidance due to the limited direct evidence. Emerging therapies, including interleukin-23 (IL-23) inhibitors or Janus kinase (JAK) inhibitors, are under investigation for axPsA. Currently, secukinumab, an interleukin-17 (IL-17) inhibitor, is an evidence-based option for axPsA management. However, given the variability in individual patient responses and disease manifestations, personalized, evidence-based treatment approaches remain essential for optimizing patient outcomes. In the final section, two real-life cases illustrate the challenges in managing axPsA, emphasizing the importance of tailored therapies. Achieving precision in defining axPsA remains a formidable task, making detailed criteria essential for effective strategies and improving patient outcomes.

Determinants of health-related quality of life and global functioning and health in axSpA, pSpA and PsA: results from the ASAS-PerSpA study

OBJECTIVES

We aimed to identify determinants of health-related quality of life (HRQoL) and global functioning and health (GH) in axial SpA (axSpA), peripheral SpA (pSpA) and (PsA).

METHODS

The ASAS-perSpA study data were analysed. Models for the three patient groups were run separately to explore factors associated with HRQoL and GH, assessed by EQ-5D and ASAS-HI, respectively.

RESULTS

The analyses included 4185 patients: 2719 with axSpA, 433 with pSpA, and 1033 with PsA.In axSpA, disease activity (β = -0.061), physical function (β = -0.041), female sex (β = -0.019) and fibromyalgia (FM) (β = -0.068) were associated with worse HRQoL; age (β = 0.001) and university education (β = 0.014) were associated with better HRQoL. In pSpA, disease activity (β = -0.04) and physical function (β = -0.054) were associated with worse HRQoL. In PsA, disease activity (β = -0.045), physical function (β = -0.053), axial disease (β = -0.041) and female sex (β = -0.028) were associated with worse HRQoL. In axSpA, disease activity (β = 0.889), physical function (β = 0.887), peripheral disease (β = 0.564), female sex (β = 0.812) and FM (β = 1.639) were associated with worse GH; age (β = -0.013) and university education (β = -0.274) were associated with better GH. In pSpA, physical function (β = 1.142) and female sex (β = 1.060) were associated with worse GH; university education (β = -0.611) was associated with better GH. In PsA, disease activity (β = 0.703), physical function (β = 1.025), axial involvement (β = 0.659), female sex (β = 0.924) and FM (β = 1.387) were associated with worse GH; age (β = -0.024) and university education (β = -0.856) were associated with better GH.

CONCLUSION

Disease activity and physical function are major HRQoL and GH determinants across SpA types, and clinical characteristics and sociodemographic factors play an important role, highlighting the importance of a holistic approach for individual patients.

Work Productivity and General Health Through 2 Years of Guselkumab Treatment in a Phase 3 Randomized Trial of Patients With Active Psoriatic Arthritis

INTRODUCTION

To evaluate the effect of guselkumab on work productivity and nonwork daily activity impairment and general health status through 2 years in patients who were biologic-naïve with active psoriatic arthritis (PsA) in the phase 3 DISCOVER-2 clinical trial.

METHODS

Adult patients with PsA were randomized to subcutaneous injections of guselkumab 100 mg every 4 weeks (Q4W); at weeks 0, 4, then every 8 weeks (Q8W); or placebo (through week 24 with crossover to guselkumab Q4W). Work productivity and nonwork daily activity impairment were assessed using the Work Productivity and Activity Impairment Questionnaire for PsA (WPAI-PsA) and patient-reported general health status using the EuroQol 5-Dimension 5-Level (EQ-5D-5L) Index and EQ-Visual Analog Scale (EQ-VAS). Least-squares (LS) mean changes from baseline in WPAI-PsA domains and EQ-5D-5L/EQ-VAS were assessed through week 100. Changes in employment status were utilized to estimate potential indirect savings from improved work productivity.

RESULTS

Of 739 randomized patients, 738 had available baseline data for the analyses (Q4W 245; Q8W 248; placebo 245). At week 24, greater improvements in work productivity, nonwork daily activity, and EQ-5D-5L/EQ-VAS were observed in the Q4W and Q8W groups versus the placebo group. At week 100, LS mean reductions in work productivity impairment (- 23.8% to - 28.0%) and nonwork daily activity impairment (- 26.6% to - 29.2%) and improvements in EQ-5D-5L/EQ-VAS (0.14 to 0.15/21.2 to 25.0) were maintained in patients receiving guselkumab. Among patients employed at baseline, 12.1-16.4% were not employed at week 100, and 20.0-25.3% shifted from not employed at baseline to employed at week 100. Potential yearly indirect cost savings (USD) from improved work productivity at week 100 ranged from $16,529 to $19,409.

CONCLUSION

Patients with active PsA treated with guselkumab demonstrated reduced impairment in work productivity and nonwork daily activity, together with improvement in general health status and substantial potential cost savings, over a 2-year period.

TRIAL REGISTRATION

Clinicaltrials.gov identifier: NCT03158285.

Sex-specific differences in patients with psoriatic arthritis:a nationwide study from the Chinese Registry of Psoriatic Arthritis (CREPAR IV)

OBJECTIVES

To elucidate the sex-specific differences in demographic features, clinical characteristics, and quality of life in Chinese patients with psoriatic arthritis (PsA).

METHODS

A total of 1,074 patients with PsA registered between December 2018 and June 2021 from the Chinese REgistry of Psoriatic ARthritis (CREPAR) cohort were selected. The baseline data on demographics, clinical characteristics, commonly used laboratory tests, comorbidities, and quality of life assessments were collected for this cross-sectional analysis.

RESULTS

A total of 1,074 patients were included in this study, 585 (54.47%) of them were male and 489 (45.53%) were female. The age at PsA onset in male patients was earlier than that in female patients (38.10 ± 12.79 vs 40.37 ± 13.41, p = 0.005). For clinical characteristics, male patients presented with higher rates of axial involvement (43.89% vs 37.74%, p = 0.044) and nail involvement (66.15% vs 58.08%, p = 0.006), while female patients presented with higher rates of peripheral arthritis (89.57% vs 83.93%, p = 0.007). For laboratory tests, men presented with a higher percentage of HLA-B27 positivity than women (24.65% vs 16.70%, p = 0.002) and had higher levels of CRP (median 9.70 vs 5.65, p < 0.001). Regarding disease assessment indices, male patients scored higher in PASI and BASFI (median 5.00 vs 3.00, p = 0.007 and 1.80 vs 1.40, p = 0.012, respectively). No sex difference was found in rates of achieving remission. Factors associated with disease remission were also analyzed in both sexes.

CONCLUSION

Demographic and clinical characteristics tend to vary between male and female patients with PsA. Male patients reported more functional limitations in daily life. Key Points • The demographic and clinical features vary greatly between male and female patients with PsA. • Male patients reported more functional burden in daily life as measured by BASFI.

The activity of psoriatic arthritis with axial involvement correlates with the PsAID12

OBJECTIVE

To determine the impact of the disease in patients with PsA in daily clinical practice and to evaluate its relationship with its axial activity.

METHODS

A cross-sectional study was conducted in consecutive patients attended from January 2021 to December 2021 who met the CASPAR criteria, with clinical of inflammatory back pain and positive axial imaging, with or without peripheral involvement. Demographic, clinical, analytical data, HAQ index, PsAID12 and activity index (BASDAI and ASDAS-PCR) were also collected. Patients were divided into two groups, those with high impact and those with low impact according to PsAID results. Continuous variables are shown as median (Q1-Q3) and categorical variables as percentages and frequencies.

RESULTS

Of the 269 patients evaluated with PsA, 72 patients with axial involvement were included, 40 men (55.6%), with a median age of 54.1 years and disease duration of 7 years. 28.3% of the patients were obese and serum CRP level was 0.45 mg/dl (0.08-1.10). BASDAI was 4.2 (2.0-6.2) and ASDAS-PCR was 2.4 (1.5-3.2), which translates into 39.6% of patients in low activity or remission. The median PsAID total score was 3.9 (1.6-5.4), evaluated in 61 patients. The patients who achieved a PsAID12 ≤ 4 were 63%, mostly men and with lower CRP levels than PsAID ≥ 4 patients. In addition, low impact measured by the PsAID12 was associated with low results in BASDAI and ASDAS-PCR.

CONCLUSIONS

Axial involvement reflected lower impact of the disease measured by PsAID12 and it is correlated with low activity measured by BASDAI and ASDAS-PCR.

Specific descriptions of axial involvement are associated with radiographic damage development after 2 years in psoriatic arthritis patients

OBJECTIVES

Investigating the association between different definitions of axial involvement and syndesmophytes development over 2 years in patients with psoriatic arthritis (PsA).

METHODS

Patients from a prospective multicentre cohort (Belgian Epidemiological Psoriatic Arthritis Study) involving 17 Belgian rheumatology practices were recruited between December 2012 and July 2014 and included when fulfilling the Classification Criteria for Psoriatic Arthritis. Axial involvement included six clinical and two radiographic oriented definitions.Two calibrated central readers evaluated radiographic damage by assessing the modified Stoke Ankylosing Spondylitis Spinal Score and modified New York criteria. New syndesmophytes after 2 years were described conditional on axial involvement at baseline. Logistic regression analyses were used to investigate the association between syndesmophyte development and axial involvement. All definitions of axial involvement were evaluated separately.

RESULTS

From 150 patients, a 2-year follow-up of spinal radiographs was obtained. There are 11 patients with new syndesmophytes after 2 years. For the clinical definitions of axial involvement 'global assessment', 'detailed assessment', 'back pain (BP)' and 'inflammatory BP (IBP)' the probabilities of developing syndesmophytes ranged between 0.06 and 0.08 and were similar for the presence or absence of the definition. When including elevated C reactive protein (CRP) to the definitions the probability of developing syndesmophytes over 2 years increased two times for CBP and seven times for IBP.With radiographic axial involvement a similar trend was seen; radiographic sacroiliitis as definition showed a probability three times higher. When combined with elevated CRP there would be a 14 times higher chance to develop syndesmophytes in 2 years. The ORs varied from 0.83 to 13.80, though none of them were statistically significant.

CONCLUSIONS

The likelihood of syndesmophyte formation in PsA is low. The probability of developing syndesmophytes is much higher when axial involvement is determined radiographically rather than clinically, particularly in the context of high CRP.

A Patient Survey Exploring the Burden of Inflammatory Back Pain in Patients With Known Psoriasis

Background In the United Kingdom, diagnostic delay remains a challenge in axial spondyloarthritis (axSpA). Psoriasis is a frequently identified extra-musculoskeletal manifestation associated with axSpA. In this study, we aimed to determine the prevalence of inflammatory back pain (IBP) in psoriasis patients at a specialized psoriasis dermatology clinic in a London NHS Trust. Our primary goal was to identify psoriasis patients with IBP who were not referred to a rheumatologist, potentially leading to axSpA diagnostic delays. Additionally, we aimed to investigate factors contributing to these delays and strategies to address them. Methodology A patient survey consisting of 22 questions was used to assess the prevalence of IBP among 66 psoriasis patients attending a weekly specialized psoriasis dermatology clinic within a London NHS Trust between May and July 2023. The survey comprised patient demographic information along with inquiries about the existence of back pain exceeding three months. The Berlin Criteria was utilized to identify IBP among patients who reported experiencing back pain for over three months. Additionally, the survey sought information on prior diagnosis of axSpA and whether participants had consulted healthcare professionals regarding their back pain. Results Of the 66 patients invited, 51 (77%) completed the survey. The average age of the patients was 50 years (range = 19-74 years), with 58.8% being female. The mean duration of psoriasis was 15.7 years (range = 2-44 years). Overall, 45% (23/51) reported back pain lasting over three months. Among the patients who reported back pain for more than three months, 13 met the Berlin Criteria for IBP (25% of the total surveyed), and only four of these patients had a diagnosis of axSpA. Notably, seven patients (14% of the total surveyed) potentially had undiagnosed axSpA. General practitioners (GPs) were commonly consulted for back pain, yet only 39% of those with prolonged back pain had seen a rheumatologist. Despite experiencing prolonged back pain, 17% of patients had not sought healthcare advice for their symptoms. Conclusions This study highlights that IBP is a common yet underdiagnosed comorbidity in psoriasis patients. Dermatologists, GPs, and other allied healthcare professionals play a crucial role in detecting early axSpA. However, limited awareness of IBP hinders its identification in psoriasis patients and subsequent referral to rheumatologists. This highlights the need for improving awareness and education regarding axSpA among dermatologists and allied healthcare professionals as well as the public and patients to ensure timely diagnosis. The development of simple and easy-to-administer screening questionnaires to aid non-rheumatologists in identifying patients with IBP together with simplified referral pathways would increase onward referrals of appropriate patients to rheumatologists.

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.

Axial Involvement in Psoriatic Arthritis: A Cross-sectional Clinical and Radiologic Studies

OBJECTIVE

This study aimed to investigate spinal involvement in psoriatic arthritis (PsA) patients using clinical and radiographic methods.

METHODS

A cross-sectional clinical study was conducted on 50 PsA patients diagnosed according to the CASPAR criteria. Clinical examinations and functional assessments were performed. A radiographic assessment of the spine was performed.

RESULTS

Out of 50 PsA patients (mean age of 45.50 ± 9.90 years), (males and females constituted 27 (54.0%) and 23 (46.0%) respectively), 76% had radiological axial involvement; (26%) with inflammatory axial pain and (50%) without inflammatory axial pain (subclinical). Three axial radiographic patterns were detected including spondylitis without sacroiliitis (15.78%), spondylitis with sacroiliitis (78.94%), and sacroiliitis without spondylitis (5.26%). In axial PsA patients, males were more affected than females (χ2=11.679, p = 0.003), with older age (H = 15.817, p < 0.001) and higher body mass index (BMI) (F = 5.145, p = 0.010), increased psoriasis duration (H = 9.826, p = 0.007) and severity (Η=25.171, p < 0.001), and more spinal movement limitations than PsA patients without axial involvement (F = 26.568, p < 0.001). Cervical involvement was higher than lumbar involvement. Axial radiographic severity assessed by the PsA Spondylitis Radiology Index was associated with increased disability as assessed by the Health assessment questionnaire (rs = 0.533, p = 0.001) and decreased quality of life assessed by short form-36 score (rs = -0.321, p = 0.050).

CONCLUSION

This study shows that a high percentage of PsA patients had axial involvement with a high percentage of them having asymptomatic radiological findings. The cervical spine is more frequently and severely affected than the lumbar spine. Axial PsA occurs in males more than females with characteristic older age and higher BMI, increased psoriasis duration, and more limitation of spinal mobility.

Efficacy of Guselkumab on Axial-Related Symptoms Through up to 2 Years in Adults with Active Psoriatic Arthritis in the Phase 3, Randomized, Placebo-Controlled DISCOVER-2 Study

INTRODUCTION

Guselkumab previously showed greater improvements versus placebo in axial symptoms in patients with psoriatic arthritis (PsA) (assessed by Bath Ankylosing Spondylitis Disease Activity Index [BASDAI] and Ankylosing Spondylitis Disease Activity Score [ASDAS]), in post hoc analyses of the phase 3, placebo-controlled, randomized DISCOVER-1 and DISCOVER-2 studies. We now evaluate durability of response in axial-related outcomes through 2 years of DISCOVER-2.

METHODS

DISCOVER-2 biologic-naive adults with active PsA (≥ 5 tender/ ≥ 5 swollen joints, C-reactive protein ≥ 0.6 mg/dl) were randomized to guselkumab 100 mg every 4 weeks (Q4W) or at week 0, week 4, then Q8W, or placebo → guselkumab Q4W at week 24. Among patients with imaging-confirmed sacroiliitis (investigator-identified), axial symptoms were assessed through 2 years utilizing BASDAI, BASDAI Question #2 (spinal pain), modified BASDAI (mBASDAI; excludes Question #3 [peripheral joint pain]), and ASDAS. Mean changes in scores and proportions of patients achieving ≥ 50% improvement in BASDAI (BASDAI 50) and ASDAS responses, including major improvement (decrease ≥ 2.0), were determined through week 100. Treatment failure rules (through week 24) and nonresponder imputation of missing data (post-week 24) were utilized. Mean BASDAI component scores were assessed through week 100 (observed data). Exploratory analyses evaluated efficacy by sex and HLA-B*27 status.

RESULTS

Among 246 patients with PsA and imaging-confirmed sacroiliitis, guselkumab-treated patients had greater mean improvements in BASDAI, mBASDAI, spinal pain, and ASDAS scores, lower mean BASDAI component scores, and greater response rates in achieving BASDAI 50 and ASDAS major improvement vs. placebo at week 24. Differences from placebo were observed for guselkumab-treated patients in selected endpoints regardless of sex or HLA-B*27 status. At week 100, mean improvements were ~ 3 points for all BASDAI scores and 1.6-1.7 for ASDAS; 49-54% achieved BASDAI 50 and 39% achieved ASDAS major improvement at week 100.

CONCLUSIONS

Guselkumab treatment provided durable and meaningful improvements in axial symptoms and disease activity in substantial proportions of patients with active PsA and imaging-confirmed sacroiliitis.

TRIAL REGISTRATION

Clinicaltrials.gov NCT03158285.

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.

Diagnostic delay in axial spondylarthritis: A lost battle?

Diagnostic delay in axial spondylarthritis (axSpA) remains an unacceptable worldwide problem; with evidence suggesting significant detrimental impact both clinically on the individual, and economically on society. There is therefore, a need for global action across various healthcare professions that come into contact with patients living, and suffering, with undiagnosed axSpA. Recent estimates of the median diagnostic delay suggest that globally, individuals with axSpA wait between 2 and 6 years for a diagnosis - revealing a clear benchmark for improvement. This timespan presents a window of opportunity for earlier diagnosis and intervention, which will likely improve patient outcomes. This review describes the current diagnostic delay as estimated across countries and over time, before presenting evidence from published strategies that may be implemented to improve this delay across primary and secondary care, including for specialties treating extra-musculoskeletal manifestations of axSpA (ophthalmology, gastroenterology, dermatology). Ongoing campaigns tackling delayed diagnosis in axSpA are also highlighted.

The effect of ixekizumab on axial manifestations in patients with psoriatic arthritis from two phase III clinical trials: SPIRIT-P1 and SPIRIT-P2

Background

Psoriatic arthritis (PsA) is a chronic inflammatory condition predominantly affecting the peripheral joints. However, some patients with PsA can experience axial involvement which is manifested with back pain and associated with increased burden of illness.

Objectives

The aim of this post hoc analysis was to determine the efficacy of ixekizumab (IXE) up to 52 weeks in reducing axial symptoms in PsA patients, presenting with axial manifestations.

Design

This was a post hoc analysis of two pooled phase III clinical trials.

Methods

Patients with axial manifestations, from two placebo-controlled, randomized, double-blind, phase III trials (SPIRIT-P1 and SPIRIT-P2), were defined as Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) Question 2 (Q2; back pain)] total score ⩾4 and average of BASDAI Q5 + Q6 (morning stiffness) ⩾4 at baseline. For this post hoc analysis, the efficacy of IXE was evaluated at weeks 16, 24, and 52 using separate BASDAI questions (including back pain and morning stiffness), total BASDAI and modified BASDAI (mBASDAI; without Q3), Ankylosing Spondylitis Disease Activity Score (ASDAS), and 50% improvement in BASDAI (BASDAI50) response. Treatment comparisons were performed using logistic regression and analysis of covariance model for categorical and continuous end points, respectively.

Results

In the post hoc analysis among PsA patients with axial manifestations at baseline (N = 313), improvements in back pain and morning stiffness at weeks 16 and 24 were significantly greater in patients receiving IXE versus placebo (both p < 0.001). Improvements in BASDAI individual scores and total scores, mBASDAI, and ASDAS were significantly greater in patients receiving IXE compared with placebo. Similarly, significantly more IXE-treated patients achieved BASDAI50 at weeks 16 and 24 versus placebo. The effect of IXE was sustained at week 52. Similar effects were observed in sensitivity analyses subgroups.

Conclusion

IXE is effective in improving axial symptoms in patients with active PsA presenting with axial manifestations.

Extent of axial damage in psoriatic arthritis and spondyloarthritis: comparative data from the BEPAS and (Be-)GIANT multicentre cohorts

BACKGROUND

To examine radiographic axial damage of the sacroiliac joints and spine in patients with psoriatic arthritis (PsA) and spondyloarthritis (SpA) in private and academic Belgian practices.

METHODS

Patients with PsA with clinical diagnosis of PsA and fulfilling the Classification Criteria for Psoriatic Arthritis from the prospective Belgian Epidemiological Psoriatic Arthritis Study and patients with SpA fulfilling the Assessment of SpondyloArthritis international Society classification criteria for SpA originate from the Ghent and BelGian Inflammatory Arthritis and spoNdylitis cohorTs were included in this study. Baseline pelvic and spinal radiographs were analysed by two calibrated readers. Blinded for the origin of the cohort or clinical data readers assessed the modified Stoke Ankylosing Spondylitis Spine Score (mSASSS) and modified New York criteria on spinal and pelvic radiographs, respectively. Data were compared between both patient groups.

RESULTS

Of the 525 patients included (312 PsA and 213 SpA), most patients showed normal spinal radiographs: 87.5% of the patients with PsA and 92.0% of the patients with SpA. Patients with SpA with spinal damage show higher mSASSS than the patients with PsA (p<0.05). In patients with PsA, cervical spine is more often affected; 24/33 patients (72.7%) compared with lumbar spine 11/33 (33.3%). While in patients with SpA, syndesmophyte location was more evenly distributed; cervical 9/14 (64.3%) and lumbar 10/14 (71.4%).

CONCLUSION

Minimal radiographic spinal damage was observed in Belgian patients with PsA or SpA. Patients with SpA tend to have higher mSASSS values and more syndesmophytes compared with PsA. Syndesmophytes were more often located in the cervical spine of patients with PsA, while the location was equally distributed in axSpA.

Efficacy and safety of upadacitinib in patients with active psoriatic arthritis and axial involvement: results from two phase 3 studies

BACKGROUND

The objective of this post-hoc analysis was to assess the efficacy and safety of upadacitinib in psoriatic arthritis (PsA) patients with axial involvement.

METHODS

Post-hoc analysis of SELECT-PsA 1 and SELECT-PsA 2 in patients randomized to upadacitinib 15 mg (UPA15), placebo (switched to UPA15 at week 24), or adalimumab 40 mg (ADA; SELECT-PsA 1 only). Axial involvement was determined by investigator judgement (yes or no; based on the totality of available clinical information, such as duration and characteristics of back pain, age of onset, and previous lab investigations and imaging, if available) alone, or investigator judgement and patient-reported outcome (PRO)-based criteria (Bath Ankylosing Spondylitis Disease Activity Index [BASDAI] ≥ 4 and BASDAI Q2 ≥ 4). Efficacy outcomes that describe axial disease activity, including BASDAI endpoints, such as change from baseline in the overall BASDAI score or proportion of patients achieving BASDAI50 (≥ 50% improvement from baseline), as well as Ankylosing Spondylitis Disease Activity Score (ASDAS) endpoints, such as mean change from baseline in overall ASDAS or proportion of patients achieving ASDAS inactive disease or low disease activity, were evaluated at weeks 12, 24, and 56, with nominal P-values shown. Treatment-emergent adverse events (TEAEs) are summarized through week 56.

RESULTS

30.9% of patients in SELECT-PsA 1 and 35.7% in SELECT-PsA 2 had axial involvement by investigator judgement alone; 22.6% (SELECT-PsA 1) and 28.6% (SELECT-PsA 2) had axial involvement by investigator judgement and PRO-based criteria. Greater proportions of patients achieved BASDAI50 with UPA15 versus placebo using either criterion, and versus ADA using investigator judgement alone, at week 24 in SELECT-PsA 1 (investigator alone: UPA15, 59.0%, placebo, 26.9%, P < 0.0001, ADA, 44.1%, P = 0.015; investigator and PRO-based: UPA15, 60.4%, placebo, 29.3%, P < 0.0001, ADA, 47.1%, P = 0.074), with comparable findings in SELECT-PsA 2. Similar results were observed with UPA15 for additional BASDAI and ASDAS endpoints at weeks 12 and 24, with improvements maintained at week 56. Rates of TEAEs were generally similar across sub-groups irrespective of axial involvement status.

CONCLUSIONS

PsA patients with axial involvement determined by predefined criteria showed greater BASDAI and ASDAS responses with UPA15 versus placebo, and numerically similar/greater responses versus ADA. Safety results were generally comparable between patients with or without axial involvement.

TRIAL REGISTRATION

ClinicalTrials.gov: SELECT-PsA 1, NCT03104400; SELECT-PsA 2, NCT0310437.

Managing Psoriatic Arthritis Patients Presenting with Axial Symptoms

Axial symptoms (i.e., back pain) are common in the general population. At the same time 25-70% of patients with psoriatic arthritis (PsA) exhibit signs of inflammatory axial involvement (axial PsA). The presence of unexplained chronic (duration ≥ 3 months) back pain in a patient with psoriasis or PsA should trigger evaluation of the presence of axial involvement. Evaluation of axial involvement normally involves imaging of the axial skeleton (sacroiliac joints and/or spine) in addition to clinical and laboratory evaluation. Symptomatic patients with confirmed axial PsA are treated with a combination of non-pharmacologic and pharmacologic methods including the use of non-steroidal anti-inflammatory drugs, tumour necrosis factor, interleukin 17, and Janus kinase inhibitors. Interleukin 23 blockade might also be effective in the axial domain of PsA; a dedicated clinical study is ongoing at present. Safety considerations, patient preference, as well as the presence of other disease manifestations (especially of extra-musculoskeletal manifestations-clinically relevant psoriasis, acute anterior uveitis, inflammatory bowel disease), define the choice of a specific drug or drug class.

Comparison of patients with axial PsA and patients with axSpA and concomitant psoriasis: an analysis of the German register RABBIT-SpA

BACKGROUND

Psoriatic arthritis (PsA) and axial spondyloarthritis (axSpA) show certain overlaps: A subset of patients with PsA can develop axial involvement (axial PsA, axPsA), while a subset of patients with axSpA presents with psoriasis (axSpA+pso). Treatment strategy for axPsA is mostly based on axSpA evidence.

OBJECTIVES

To compare demographic and disease-specific parameters of axPsA and axSpA+pso.

METHODS

RABBIT-SpA is a prospective longitudinal cohort study. AxPsA was defined based on (1) clinical judgement by rheumatologists; (2) imaging (sacroiliitis according to modified New York criteria in radiographs or signs of active inflammation in MRI or syndesmophytes/ankylosis in radiographs or signs of active inflammation in spine MRI). axSpA was stratified into axSpA+pso and axSpA without pso.

RESULTS

Psoriasis was documented in 181/1428 axSpA patients (13%). Of 1395 PsA patients, 359 (26%) showed axial involvement. 297 patients (21%) fulfilled the clinical definition and 196 (14%) the imaging definition of axial manifestation of PsA. AxSpA+pso differed from axPsA regardless whether clinical or imaging definition was used. axPsA patients were older, more often female and less often HLA-B27+. Peripheral manifestations were more often present in axPsA than in axSpA+pso, whereas uveitis and inflammatory bowel disease were more common in axSpA+pso. Burden of disease (patient global, pain, physician global) was similar among axPsA and axSpA+pso patients.

CONCLUSIONS

AxPsA differs from axSpA+pso in its clinical manifestations, irrespective of whether axPsA is defined clinically or by imaging. These findings support the hypothesis that axSpA and PsA with axial involvement are distinct entities, so extrapolation of treatment data from randomised controlled trials in axSpA should be performed with caution.

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.

Impact of key manifestations of psoriatic arthritis on patient quality of life, functional status, and work productivity: Findings from a real-world study in the United States and Europe

OBJECTIVES

To determine the individual impact of key manifestations of psoriatic arthritis (PsA) on quality of life (QoL), physical function, and work disability.

METHODS

Data from the Adelphi 2018 PsA Disease-Specific Programme, a multinational, cross-sectional study of PsA patients, were used. PsA manifestations included peripheral arthritis (number of joints affected), psoriasis (body surface area [BSA]), axial involvement (inflammatory back pain [IBP] and sacroiliitis) enthesitis, and dactylitis. General, and disease-specific QoL, physical function, and work disability were measured with EQ-5D-5L, PsAID-12, HAQ-DI, and WPAI, respectively. Multivariate regression adjusting for potential confounders evaluated the independent effect of PsA manifestations on each outcome.

RESULTS

Among the 2222 PsA patients analysed, 77.0% had active psoriasis and 64.4% had peripheral arthritis; 5.9%, 6.8%, 10.2%, and 3.6% had enthesitis, dactylitis, IBP, or sacroiliitis, respectively. Mean EQ VAS scores were significantly poorer in patients with vs. without enthesitis (59.9 vs. 75.6), dactylitis (63.6 vs. 75.4), and with greater peripheral joint involvement (none: 82.5; 1-2 affected joints: 74.1; 3-6 joints: 74.2; >6 joints: 65.0). Significantly worse mean PsAID-12 scores were associated with vs. without enthesitis (4.39 vs. 2.34) or dactylitis (4.30 vs. 2.32), and with greater peripheral joint involvement (none: 1.21; 1-2 joints: 2.36; 3-6 joints: 2.74; >6 joints: 3.92), and BSA (none: 1.49; >3-10%: 2.96; >10%: 3.43). Similar patterns were observed with HAQ-DI and WPAI scores.

CONCLUSION

Most PsA manifestations were independently associated with worse general, and PsA-specific QoL, physical function, and work disability, highlighting the need for treatments targeting the full spectrum of PsA symptoms to lower the burden of disease.

18F-sodium fluoride PET-CT visualizes both axial and peripheral new bone formation in psoriatic arthritis patients

PURPOSE

As bone formation is associated with psoriatic arthritis (PsA), positron emission tomography (PET) using a ¹⁸F-Fluoride tracer may enable sensitive detection of disease activity. Our primary aim was to determine the feasibility of whole-body ¹⁸F-sodium fluoride PET-CT in clinically active PsA patients to depict new bone formation (as a reflection of disease activity) at peripheral joints and entheses. Our secondary aim was to describe ¹⁸F-sodium fluoride findings in the axial skeleton.

METHODS

Sixteen patients (female 10/16, age 50.6 ± 8.9 years) with PsA fulfilling CASPAR criteria or with a clinical diagnosis of PsA according to the treating rheumatologist and with ≥ 1 clinically active enthesitis site were included. Of each patient, a whole-body ¹⁸F-sodium fluoride PET-CT scan was performed. All scans were scored for PET-positive lesions at peripheral joints, enthesis sites and the spine. Clinical disease activity was assessed by swollen/tender joint count 44, enthesitis according to MASES and SPARCC scores.

RESULTS

Out of 1088 evaluated joints, 109 joints showed PET enhancement, mainly in the interphalangeal and metatarsal joints of the feet (14/109, 12.9%) and the distal interphalangeal joints of the hands (14/109, 12.9%). PET positivity was found at 44/464 enthesis sites, mainly at the patella tendon insertion (11/44, 25%) and quadriceps tendon insertion (10/44, 22.7%). Of the PET-positive joints and enthesis sites, respectively 18.2% and 29.5% were clinically positive; 81.8% and 70.5% of the PET-positive joints and entheses respectively were clinically asymptomatic. In 11 patients, ≥ 1 axial PET-positive lesion was observed, mainly in the cervical spine.

CONCLUSIONS

New molecular bone formation was observed on ¹⁸F-sodium fluoride PET-CT scans, in all domains in which PsA disease activity can be observed, with a substantial part showing no clinical symptoms.

CLINICAL TRIAL REGISTRATION

EudraCT: 2017-004,850-40, registered on 13 December 2017.

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.

Clinical Characteristics of Registry Participants with Psoriatic Arthritis Initiating Guselkumab: An Analysis from the CorEvitas Psoriatic Arthritis/Spondyloarthritis Registry

BACKGROUND

The monoclonal antibody guselkumab is the first selective inhibitor of the interleukin-23 p19 subunit approved to treat adults with moderate-to-severe plaque psoriasis and active psoriatic arthritis (PsA). Given its recent approval for active PsA, data describing patients with PsA initiating guselkumab outside of clinical trials are limited.

OBJECTIVE

This analysis describes characteristics of patients with rheumatologist-diagnosed PsA initiating guselkumab in the US-based, prospective, observational CorEvitas Psoriatic Arthritis/Spondyloarthritis Registry.

METHODS

Demographics, lifestyle/disease characteristics, comorbidities, prior treatment, and disease activity were summarized for patients with PsA initiating guselkumab from registry inception through 30 September, 2021.

RESULTS

Of 113 patients initiating guselkumab, the majority were female (63%), obese (67%), had psoriasis (89%), and initiated guselkumab as monotherapy (81%). Common comorbidities were hypertension (32%), depression (30%), and diabetes mellitus (26%). Mean tender (6.8) and swollen (2.0) joint counts, clinical Disease Activity Index for PsA score (19.1), and 57% of participants with ≥ 3% body surface area affected by psoriasis indicated moderate disease activity. Axial involvement was identified in 49% of patients. Median patient-reported pain and fatigue visual analog scale scores (0-100) were 60 and 59, respectively. Prior to guselkumab, 76% of patients had received two or more biologic disease-modifying antirheumatic drugs; the last therapy prior to guselkumab was a biologic disease-modifying antirheumatic drug in 81% of patients.

CONCLUSIONS

Registry participants with PsA initiating guselkumab had active peripheral joint and skin disease, with substantial pain and fatigue; a considerable proportion had axial involvement. Future studies will evaluate the effectiveness of guselkumab in this population.

Efficacy and safety of guselkumab in biologic-naïve patients with active axial psoriatic arthritis: study protocol for STAR, a phase 4, randomized, double-blinded, placebo-controlled trial

Background

Axial involvement constitutes a specific domain of psoriatic arthritis (PsA). Interleukin (IL)-23 inhibitors have demonstrated improvement in axial PsA (axPsA) symptoms, but have not shown efficacy in treating ankylosing spondylitis (AS), suggesting differences in axPsA processes and treatments. In a post hoc, pooled analysis of patients with investigator- and imaging-confirmed sacroiliitis in two phase 3, randomized, placebo-controlled studies (DISCOVER-1 and DISCOVER-2), patients treated with guselkumab, an IL-23p19 inhibitor, had greater axial symptom improvements compared with placebo. Confirmatory imaging at baseline was restricted to the sacroiliac (SI) joints, occurred prior to/at screening, and was locally read.

Methods

The STAR study will prospectively assess efficacy outcomes in PsA patients with magnetic resonance imaging (MRI)-confirmed axial inflammation. Eligible, biologic-naïve patients with PsA (N =  405) for ≥ 6 months and active disease (≥ 3 swollen and ≥ 3 tender joints, C-reactive protein [CRP] ≥ 0.3 mg/dL) despite prior non-biologic disease-modifying antirheumatic drugs, apremilast, and/or nonsteroidal anti-inflammatory drugs will be randomized (1:1:1) to guselkumab every 4 weeks (Q4W); guselkumab at week (W) 0, W4, then every 8 weeks (Q8W); or placebo with crossover to guselkumab at W24, W28, then Q8W. Patients will have Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) score ≥ 4, spinal pain component score (0–10 visual analog scale) ≥ 4, and screening MRI-confirmed axial involvement (positive spine and/or SI joints according to centrally read Spondyloarthritis Research Consortium of Canada [SPARCC] score ≥ 3 in ≥ 1 region). The primary endpoint is mean change from baseline in BASDAI at W24; multiplicity controlled secondary endpoints at W24 include AS Disease Activity Score employing CRP (ASDAS), Disease Activity Index for PsA (DAPSA), Health Assessment Questionnaire – Disability Index (HAQ-DI), Investigator’s Global Assessment of skin disease (IGA), and mean changes from baseline in MRI SI joint SPARCC scores. Centrally read MRIs of spine and SI joints (scored using SPARCC) will be obtained at W0, W24, and W52, with readers blinded to treatment group and timepoint. Treatment group comparisons will be performed using a Cochran-Mantel-Haenszel or chi-square test for binary endpoints and analysis of covariance, mixed model for repeated measures, or constrained longitudinal data analysis for continuous endpoints.

Discussion

This study will evaluate the ability of guselkumab to reduce both axial symptoms and inflammation in patients with active PsA.

Trial registration

This trial was registered at ClinicalTrials.gov, NCT04929210, on 18 June 2021.

Protocol version: Version 1.0 dated 14 April 2021.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13063-022-06589-y.

Clinical Characteristics of Patients With Psoriatic Spondylitis Versus Those With Ankylosing Spondylitis: Features at Baseline Before Biologic Therapy

BACKGROUND

Clinical characteristics and manifestations of psoriatic arthritis (PsA) have been extensively studied in western countries, yet data of Korean patients with PsA are very limited. We aimed to investigate the clinical traits of patients with PsA and dissect the characteristics of those with axial involvement.

METHODS

In this observational study, we analyzed clinical data of 109 patients with PsA who were enrolled in the Korean College of Rheumatology Biologics and Targeted Therapy registry between December 2012 and March 2022 at the time point of initiating or switching to a biologic agent. Data from 2,221 patients with ankylosing spondylitis (AS) registered during the same period were also analyzed. We divided patients with PsA into patients with or without axial involvement and then added AS patients with psoriasis (total three subgroups) for comparative analyses.

RESULTS

Asymmetric oligoarthritis was the most common clinical manifestation in patients with PsA, followed by symmetric polyarthritis and spondylitis. Our analysis indicated that methotrexate and sulfasalazine were the two most prescribed disease-modifying antirheumatic drugs for patients with PsA before starting biologic therapy. The patients with psoriatic spondylitis had more peripheral joint involvement (P = 0.016), less prior uveitis (P < 0.001), and lower human leukocyte antigen B27 (HLA-B27) positivity (P < 0.001) than the AS patients with psoriasis. Furthermore, syndesmophytes and radiographic sacroiliitis were prevalent among patients with PsA and AS patients with psoriasis who had the HLA-B27 gene.

CONCLUSION

Our study shows that the degree of peripheral arthritis is less severe in Korean patients with PsA who require biologics and reestablishes that psoriatic spondylitis is a common and important clinical pattern in Korean patients with PsA.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT01965132.

Isolated axial disease in psoriatic arthritis and ankylosing spondylitis with psoriasis

OBJECTIVES

To compare isolated axial psoriatic arthritis (PsA), axial PsA with peripheral involvement and isolated axial ankylosing spondylitis (AS) with psoriasis. To evaluate predictors for developing peripheral disease from isolated axial PsA over time.

METHODS

Two PsA and AS cohorts identified patients with PsA with axial disease and isolated axial patients with AS with psoriasis. Logistic regression compared isolated axial PsA to axial PsA with peripheral involvement and isolated axial AS with psoriasis. Cox proportional hazards model evaluated predictors for developing peripheral disease from isolated axial PsA.

RESULTS

Of 1576 patients with PsA, 2.03% had isolated axial disease and 29.38% had axial and peripheral disease. human leucocyte antigen HLA-B*27 positivity (OR 25.00, 95% CI 3.03 to 206.11) and lower Health Assessment Questionnaire scores (OR 0.004, 95% CI 0.00 to 0.28) were associated with isolated axial disease. HLA-B*27 also predicted peripheral disease development over time (HR 7.54, 95% CI 1.79 to 31.77). Of 1688 patients with AS, 4.86% had isolated axial disease with psoriasis. Isolated axial patients with PsA were older at diagnosis (OR 1.06, 95% CI 1.01 to 1.13), more likely to have nail lesions (OR 12.37, 95% CI 2.22 to 69.07) and less likely to have inflammatory back pain (OR 0.12, 95% CI 0.02 to 0.61) compared with patients with isolated axial AS with psoriasis.

CONCLUSIONS

Isolated axial PsA and AS with psoriasis are uncommon. HLA-B*27 positivity is associated with isolated axial PsA and may identify those who develop peripheral disease over time. Isolated axial PsA is associated with better functional status. Isolated axial PsA appears clinically distinct from isolated axial AS with psoriasis.

Sex- and gender-related differences in psoriatic arthritis

Psoriatic arthritis (PsA) is an inflammatory musculoskeletal disease with a chronic, progressive course. Various aspects of PsA, including its clinical features, disease course and response to treatment, are influenced by sociodemographic characteristics of the patient. This includes patient sex, the biological attributes associated with being male or female, and gender, a sociocultural construct that comprises attitudes, traits and behaviours associated with being a man or a woman. An understanding of sex- and gender-related differences in PsA, as well as their underlying mechanisms, is therefore important for individualized care. In this narrative review, the influence of sex and gender on PsA manifestation and course, patient function and quality of life, and their association with comorbidities are described. Sex- and gender-related disparities in response to advanced therapies and their potential underlying mechanisms are delineated. Differences in pathophysiological mechanisms between male and female patients including genetics, immune and hormonal mechanisms are discussed. Finally, fertility and pregnancy outcomes in PsA are outlined. By adopting sex and gender lenses, this review is aimed at highlighting key differences between male and female patients with PsA and uncovering mechanisms underlying these differences, ultimately promoting individualized care of men and women with PsA and informing future research in this area.

Early identification of axial psoriatic arthritis among patients with psoriasis: a prospective multicentre study

OBJECTIVES

To evaluate a dermatologist-centred screening tool followed by a structured rheumatological examination including MRI of sacroiliac joints and spine for the recognition of psoriatic arthritis with axial involvement (axPsA).

METHODS

This was a prospective multicentre study. Adult patients with a confirmed diagnosis of psoriasis who had chronic back pain (≥3 months), onset <45 years and had not been treated with any biologic or targeted synthetic disease-modifying antirheumatic drug in the 12 weeks before screening were referred to a specialised rheumatology clinic. A rheumatological investigation including clinical, laboratory and genetic assessments as well as imaging with conventional radiography and MRI of sacroiliac joints and spine was performed. The primary outcome of the study was the proportion of patients diagnosed with axPsA among all referred patients with PsO.

RESULTS

Rheumatologists examined 100 patients of those who qualified for referral. 14 patients (including 3 with both axial and peripheral involvement) were diagnosed with axPsA and 5 were diagnosed with peripheral PsA solely. All patients diagnosed with axPsA had active inflammatory and/or structural (post)inflammatory changes in the sacroiliac joints and/or spine on imaging. In five patients, MRI changes indicative of axial involvement were found only in the spine. All but one patient with PsA (13/14 with axPsA and 5/5 with pPsA) fulfilled the Classification Criteria for Psoriatic Arthritis criteria for PsA. The Assessment of SpondyloArthritis International Society criteria for axSpA were fulfilled in 9 (64.3%) patients diagnosed with axPsA.

CONCLUSIONS

Applying a dermatologist-centred screening tool may be useful for the early detection of axPsA in at-risk patients with psoriasis .

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.

The burden of progression of psoriatic arthritis. All-Russian register data

Background. Psoriatic arthritis (PsA) is a complex immune-mediated disease in which a third of patients with psoriasis (PsO) have a inflammatory lesion of both the musculoskeletal system (peripheral joints and axial structures) and extra-articular manifestations (dactylitis, enthesitis, nail PsO, uveitis and inflammatory bowel disease). Aim. To assess the burden of PsA progression in real practice according to the Russian register of PsA patients. Materials and methods. Seven hundred thirty seven M/F=350 (47.5%)/387 (52.5%) patients with PsA from the Russian register of PsA patients were included. Mean age 47.412.7 yrs., duration of PsO 200.6158.9 mo., PsA 79.681.9 mo. All patients were divided into 2 groups by PsA duration: 1st gr 36 mo 288 (39.1%) and 2nd gr 36 mo 449 (60.9%). All patients underwent standard clinical examination of PsA activity. Tender (68) and swelling (66) joint count (TJC, SJC), DAPSA, LEI, tenderness of the plantar fascia, PsO BSA (%), PASI, HAQ-DI, PsAID-12, BMI (kg/m2), ESR (mm/h), CRP (mg/l) and comorbidities by ICD-10 were evaluated. Parametric and non-parametric methods of statistical analysis were used. All p0.05 were considered to indicate statistical significance. Results. In patients with PsA duration 36 mo we found significant prevalence of erosions by X-Ray, axial PsA, BMI30 kg/m2, HAQ-DI1, PsAID-124, arterial hypertension, metabolic syndrome and overall comorbidity (p0.05). There were no significant differences between groups in PsO severity by BSA3%, PASI1, LEI1, TJC, SJC, dactylitis, ESR30 mm/h, CRP10 mg/l, DAPSA, diabetes mellitus, hyperlipidemia, coronary heart disease and liver damage (p0.05). Сonclusion. Long-standing stage PsA is associated with erosions, axial PsA, worst health related quality of life, functional disability and increased cardio-metabolic disorders and overall comorbidity. Our results support the idea to start bDMARDs at early stage of PsA, it can improve better outcomes.

Effect of upadacitinib on reducing pain in patients with active psoriatic arthritis or ankylosing spondylitis: post hoc analysis of three randomised clinical trials

Objective

Evaluate the effect of upadacitinib on pain outcomes in patients with active psoriatic arthritis (PsA) or ankylosing spondylitis (AS) across 3 randomised trials (SELECT-PsA 1 and 2 for PsA; SELECT-AXIS 1 for AS).

Methods

Patients were randomised to upadacitinib 15 mg once daily or placebo (all 3 studies), or adalimumab 40 mg every other week (SELECT-PsA 1 only). Pain outcomes included proportion of patients achieving ≥30%, ≥50% and ≥70% reduction from baseline in patient global assessment of pain and other end points.

Results

A higher proportion of patients receiving upadacitinib versus placebo achieved ≥30%, ≥50% and ≥70% reduction in pain end points as early as week 2; these improvements with upadacitinib were generally sustained or increased through year 1 (PsA 1/2 studies: 64%/48%, 58%/42% and 38%/22%, respectively; SELECT-AXIS 1 study: 76%, 72% and 54%). Results were similar with adalimumab in PsA 1 (59%, 49% and 32%). Patients who switched from placebo to upadacitinib 15 mg were able to reach a similar level of improvement as the continuous upadacitinib groups by year 1 (PsA 1/2 studies: 46%–60%, 35%–49% and 15%–34%; AS study: 83%, 72% and 46%). Results were similar with other pain end points.

Conclusion

Rapid and sustained improvements in pain outcomes across several end points were consistently shown with upadacitinib over 1 year in patients with active PsA or AS who had either inadequate response to prior non-biologic or biologic disease-modifying antirheumatic drugs (PsA studies) or were biologic-naïve with inadequate response to non-steroidal anti-inflammatory drugs (AS study).

Treatment Responses in Patients With Psoriatic Arthritis Axial Disease According to Human Leukocyte Antigen-B27 Status: An Analysis From the CorEvitas Psoriatic Arthritis/Spondyloarthritis Registry

OBJECTIVE

Axial disease is common and burdensome in patients with psoriatic arthritis (PsA). Human leukocyte antigen-B27 (HLA-B27) is a risk factor for axial PsA; treatment response by HLA-B27 status is inadequately characterized. This study evaluated responses to biologic disease-modifying antirheumatic drugs (bDMARDs) or targeted synthetic DMARDs (tsDMARDs) overall and by HLA-B27 status in patients with PsA axial disease.

METHODS

This observational study included participants in the CorEvitas (formerly Corrona) PsA/Spondyloarthritis Registry who initiated bDMARD or tsDMARD treatment at baseline, had a 6-month follow-up visit, fulfilled Classification Criteria for Psoriatic Arthritis, had a baseline Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) score of ≥4, and had known HLA-B27 status. Disease characteristics at baseline and 6 months were evaluated overall and by HLA-B27 status. Association between HLA-B27 status and treatment response was evaluated using an analysis of covariance model.

RESULTS

The analysis included 173 bDMARD or tsDMARD treatment initiations (54 [31.2%] among patients with HLA-B27+ status and 119 [68.8%] among patients with HLA-B27- status). BASDAI total and component scores decreased by ≤0.84 across groups after 6 months of bDMARD or tsDMARD therapy; these changes are not considered clinically meaningful. HLA-B27 status was not statistically significantly associated with changes in axial-related outcomes.

CONCLUSION

In patients with PsA axial disease, 6 months of bDMARD or tsDMARD therapy provided only mild improvements in axial-related outcomes, irrespective of HLA-B27 status. This continued high disease activity reflects a critical unmet need for focus on the axial domain of PsA and for additional safe and effective therapies for psoriatic axial disease.

Characterising axial psoriatic arthritis: correlation between whole spine MRI abnormalities and clinical, laboratory and radiographic findings

OBJECTIVE

To describe the prevalence of inflammatory and structural lesions using whole spine MRI in patients with psoriatic disease, and to assess their correlation with clinical features and with axial spondyloarthritis (axSpA) classification criteria.

METHODS

This retrospective analysis included patients with whole spine and sacroiliac joints (SIJ) MRI, selected from 2 populations: (1) active psoriatic arthritis (PsA), irrespective of axial symptoms; (2) psoriasis with confirmed or suspected PsA and axSpA symptoms. MRI spondylitis and/or sacroiliitis (MRI-SpA) was defined according to Assessment of Spondyloarthritis International Society (ASAS) consensus and by radiologist impression. Agreement between MRI-SpA and different inflammatory back pain (IBP) definitions (Berlin/ASAS/rheumatologist criteria) and the axSpA classification criteria were calculated considering MRI as gold standard. Logistic regression determined MRI-SpA-associated factors.

RESULTS

93 patients were analysed (69.9% PsA; 30.1% psoriasis). Back pain was present in 81.7%, defined as IBP in 36.6%-57%. MRI-SpA was found in 9.7% of patients by ASAS definition and in 12.9% by radiologist impression, of which 25% had isolated spondylitis.Low agreement was found between the three IBP definitions and MRI-SpA. Rheumatologist criteria was the most sensitive (50%-55.6%) while ASAS and Berlin criteria were the most specific (61.9%-63%). axSpA criteria had poor sensitivity for MRI-SpA (22.2%-25%). Late onset of back pain or asymptomatic patients accounted for most cases with MRI-SpA not meeting axSpA or IBP criteria. Male sex was associated with MRI-SpA (OR 6.91; 95% CI 1.42 to 33.59) in multivariable regression analysis.

CONCLUSION

Prevalence of MRI-defined axSpA was low and showed poor agreement with IBP and axSpA criteria.

Psoriatic Spondylitis: A Disease Manifestation in Debate: Evidences to Know for the Clinical Rheumatologist

ABSTRACT

With the advent of classification criteria for psoriatic arthritis (PsA) and axial spondyloarthritis (axSpA), patients with axial manifestations associated with psoriasis, initially described in the l950s as a specific entity termed psoriatic spondylitis (PS), are now categorized within PsA, ankylosing spondylitis (AS), and axSpA. Thus, different terms are used to describe axial disease in patients with PsA including PS, axial psoriatic arthritis (axPsA), and psoriatic spondyloarthritis. Patients with PS may present with inflammatory and/or mechanical back pain, but also may display axial disease on imaging despite not complaining of back pain. Cervical spondylitis has been reported in 35% to 75% of patients with PsA. Axial disease is silent in 20% and 25% of patients with axial PsA and PsA, respectively. The majority of axPsA patients have peripheral arthritis alongside the axial involvement, whereas only 2% to 5% of PsA patients have solely axial arthritis with no peripheral arthritis.A debate is currently underway as to whether inflammatory axial disease and psoriasis represent axSpA with psoriasis or a subset of PsA named axPsA. Studies have recognized that axial disease in PsA patients seems to be different demographically, genetically, clinically, and radiographically when compared with AS with or without psoriasis. This narrative review summarizes current knowledge regarding axial involvement of PsA in terms of history, terminology, classification, epidemiology, clinical presentation, imaging, diagnosis, and treatment, with the aim of providing advice for management of PS in clinical evidence-based practice. Data-driven studies are needed to develop clear, nonoverlapping classification criteria for spinal involvement in PsA.

Axial Involvement in Psoriatic Arthritis cohort (AXIS): the protocol of a joint project of the Assessment of SpondyloArthritis international Society (ASAS) and the Group for Research and Assessment of Psoriasis and Psoriatic Arthritis (GRAPPA)

BACKGROUND

Involvement of the axial skeleton (sacroiliac joints and spine) is a relatively frequent manifestation associated with psoriatic skin disease, mostly along with involvement of peripheral musculoskeletal structures (peripheral arthritis, enthesitis, dactylitis), which are referred to as psoriatic arthritis (PsA). Data suggest that up to 30% of patients with psoriasis have PsA. Depending on the definition used, the prevalence of axial involvement varies from 25% to 70% of patients with PsA. However, there are currently no widely accepted criteria for axial involvement in PsA.Objective: The overarching aim of the Axial Involvement in Psoriatic Arthritis (AXIS) study is to systematically evaluate clinical and imaging manifestations indicative of axial involvement in patients with PsA and to develop classification criteria and a unified nomenclature for axial involvement in PsA that would allow defining a homogeneous subgroup of patients for research.

DESIGN

Prospective, multicenter, multinational, cross-sectional study.

METHODS AND ANALYSES

In this multicenter, multinational, cross-sectional study, eligible patients [adult patients diagnosed with PsA and fulfilling Classification Criteria for Psoriatic Arthritis (CASPAR) with musculoskeletal symptom duration of ⩽10 years not treated with biological or targeted synthetic disease-modifying anti-rheumatic drugs] will be recruited prospectively. They will undergo study-related clinical and imaging examinations. Imaging will include radiography and magnetic resonance imaging examinations of sacroiliac joints and spine. Local investigators will evaluate for the presence of axial involvement based on clinical and imaging information which will represent the primary outcome of the study. In addition, imaging will undergo evaluation by central review. Finally, the central clinical committee will determine the presence of axial involvement based on all available information.

ETHICS

The study will be performed according to the ethical principles of the Declaration of Helsinki and International Council for Harmonisation Good Clinical Practice guidelines. The study protocol will be approved by the individual Independent Ethics Committee / Institutional Review Board of participating centers. Written informed consent will be obtained from all included patients.Registration: ClinicalTrials.gov ID: NCT04434885.

Evaluation of Clinical Diagnosis of Axial Psoriatic Arthritis or Elevated Patient-Reported Spine Pain in CorEvitas' Psoriatic Arthritis/Spondyloarthritis Registry

OBJECTIVE

To determine the presence of axial symptoms in patients with psoriatic arthritis (PsA) and examine differences between those with or without a diagnosis of axial PsA (axPsA).

METHODS

Patients with PsA at their CorEvitas' (formerly Corrona) Psoriatic Arthritis/Spondyloarthritis Registry enrollment visit were stratified into 4 mutually exclusive groups based on axial manifestations: physician-diagnosed axPsA only (Dx⁺Sx^-), patient-reported elevated spine symptoms only (Dx^-Sx⁺; defined as Bath Ankylosing Spondylitis Disease Activity Index ≥4 and spine pain visual analog scale ≥40), physician-diagnosed and patient-reported (Dx⁺Sx⁺), and no axial manifestations (Dx^-Sx^-). Patient characteristics, disease activity, and patient-reported outcomes (PROs) at enrollment in each axial manifestation group were compared with the Dx^-Sx^- group. Associations of patient characteristics with the odds of having axial manifestations were estimated using multinomial logistic regression (reference: Dx^-Sx^-).

RESULTS

Of 3393 patients included, 226 (6.7%) had Dx⁺Sx^-, 698 (20.6%) had Dx^-Sx⁺, 165 (4.9%) had Dx⁺Sx⁺, and 2304 (67.9%) had Dx^-Sx^-. Patients with Dx^-Sx⁺ or Dx⁺Sx⁺ were more frequently women and had a history of depression and fibromyalgia vs patients who had Dx^-Sx^-. Patients with Dx⁺Sx^- or Dx⁺Sx⁺ were more frequently HLA-B27 positive than those with Dx^-Sx^-. Fibromyalgia was significantly associated with increased odds of Dx⁺Sx^- or Dx⁺Sx⁺. Disease activity and PROs were worse in patients with Dx^-Sx⁺ or Dx⁺Sx⁺ than in those with Dx^-Sx^-.

CONCLUSION

Patients who had self-reported elevated spine symptoms, with or without physician-diagnosed axPsA, had worse quality of life and higher disease activity overall than patients without axial manifestations, suggesting an unmet need in this patient population.

Effect of adalimumab on axial manifestations in Japanese patients with psoriatic arthritis: a 24 week prospective, observational study

OBJECTIVES

PsA is characterized by enthesitis, synovitis and osseous involvement in the peripheral and axial joints. Few studies have examined axial involvement in PsA using imaging techniques. Here we examined axial involvement in PsA patients using MRI. In addition, we determined the efficacy of 24 week adalimumab treatment in improving the MRI findings of spondylitis and sacroiliitis.

METHODS

This was a prospective, open-label, single-arm study in patients with PsA. Adalimumab was administered to patients for a total of 24 weeks. MRI examinations were conducted at baseline and at week 24 of adalimumab treatment.

RESULTS

Thirty-seven patients with PsA were included in this study. Spondylitis was observed in at least one site of the positive scan in 91% (n = 31) of patients with PsA. The number of arthritic sites in the cervical, thoracic and lumbar regions of the spine was 48, 67 and 53, respectively. All patients had MRI-determined sacroiliitis of grade ≥1 severity while 28 patients (82%) had grade ≥2 sacroiliitis in at least one sacroiliac region. Sacroiliac arthritis was statistically more severe on the right side than on the left side (P < 0.05). In 34 patients with PsA, the thoracic spine was the most common site of spondylitis. In addition, 24 week adalimumab treatment led to an improvement in the mean number of spondylitis sites and the mean grade of sacroiliitis.

CONCLUSION

Treatment with adalimumab for 24 weeks resulted in improvement in spondylitis and sacroiliitis.

Factors Associated with Health-Related Quality of Life in Psoriatic Arthritis Patients: A Longitudinal Analysis

INTRODUCTION

Psoriatic arthritis (PsA) is considered a multifaceted disease, with patients reporting low health-related quality of life (HRQoL). Data on disease burden are substantial and there exists a need for properly designed studies to learn more about the evolution of HRQoL in this condition. This study aims to identify factors associated to HRQoL evolution in PsA patients followed-up in a real-world setting in Spain.

METHODS

We conducted a retrospective longitudinal observational study including incident patients from the rheumatology outpatient clinic of Hospital Clínico San Carlos (Madrid, Spain), diagnosed for the first time of PsA, defined as having received any ICD9/ICD10 diagnosis code of PsA, from 2007 to 2016, and followed-up until loss of follow-up, death, or November 2017. The influence of demographic and clinical variables in baseline HRQoL [assessed with the Rosser Classification Index (RCI)] was analyzed using bivariable and multivariable generalized linear models. The influence of those variables and of treatment-related factors in repeated measures of HRQoL was analyzed using bivariable and multivariable generalized estimating equations (GEE) models nested by patient.

RESULTS

Two hundred and thirty patients were included in the analysis, with 3384 registered visits. At baseline, older age, a previous diagnosis of obesity, and the presence of enthesitis were significantly associated with worse HRQoL. During follow-up, using an exchangeable working correlation structure, the presence of enthesitis was also associated with worse HRQoL, coefficient (95% CI) - 0.006 (- 0.01 to - 0.002), p = 1.00E-03; conversely, treatment with methotrexate or antimalarials was associated with better HRQoL with 0.007 (0.001-0.014), p = 0.020 and 0.003 (0.001-0.005), p = 3.00E-03, respectively.

CONCLUSIONS

Musculoskeletal manifestations and comorbidities exert a deleterious effect in HRQoL of PsA patients. Therefore, the optimal management of this condition needs to also address these manifestations in order to try to restore the QoL of these patients.

Hidden in plain sight: Is there a crucial role for enthesitis assessment in the treatment and monitoring of axial spondyloarthritis?

OBJECTIVE

To review the evidence surrounding the pathophysiology of enthesitis in axial spondyloarthritis (axSpA), its prevalence and contribution to the overall disease burden, and response to treatment at axial and peripheral sites.

METHODS

Literature searches of the Cochrane Library, PubMed, and Embase / Medline using the terms "enthesitis", "enthesopathy", "spondyloarthritis", "axial spondyloarthritis", and "ankylosing spondylitis" were conducted. Publications mentioning enthesitis or enthesopathy in the context of pathophysiology, diagnosis, or treatment were included.

RESULTS

Enthesitis is a common symptom of axSpA, occurring with high prevalence at axial and several peripheral sites. Inflammation at the site of enthesis is an early key manifestation of axSpA. Clinically evaluable enthesitis contributes significantly to the burden of disease, correlating with worse symptomatology and downstream structural damage. Despite its importance in driving axSpA disease processes, enthesitis is somewhat neglected in current approaches to disease assessment and management. Enthesitis is excluded from some commonly used disease activity measures, is not routinely assessed in clinical practice, and many methods of clinical assessment omit key accessible axial sites, such as the spinous processes.

CONCLUSION

Enthesitis plays a central role in driving the pathophysiology of axSpA. There is a need for a renewed focus on the early detection, measurement and treatment of enthesitis.

Axial Psoriatic Disease: Clinical and Imaging Assessment of an Underdiagnosed Condition

The frequent involvement of the spine and sacroiliac joint has justified the classification of psoriatic arthritis (PsA) in the Spondyloarthritis group. Even if different classification criteria have been developed for PsA and Spondyloarthritis over the years, a well-defined distinction is still difficult. Although the majority of PsA patients present peripheral involvement, the axial involvement needs to be taken into account when considering disease management. Depending on the definition used, the prevalence of axial disease may vary from 25 to 70% in patients affected by PsA. To date, no consensus definition has been reached in the literature and the definition of axial involvement in PsA has varied from isolated sacroiliitis to criteria used in ankylosing spondylitis. This article reviews the unmet needs in the clinical and radiological assessment of axial PsA, reporting the various interpretations of axial involvement, which have changed over the years. Focusing on both imaging and clinical standpoints, we reported the prevalence of clinical and radiologic features, describing the characteristics of axial disease detectable by X-rays, magnetic resonance imaging, and PET-CT, and also describing the axial symptoms and outcome measures in patients affected by axial disease.

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.

Unveiling axial involvement in psoriatic arthritis: An ancillary analysis of the ASAS-perSpA study

OBJECTIVE

To determine the clinical profile of axial psoriatic arthritis (PsA) in a worldwide setting. Secondly, to identify factors associated with the development of axial involvement in patients with PsA.

METHODS

Data from 3684 patients with axial spondyloarthritis (axSpA) or PsA from the ASAS-perSpA study were analysed. The ASAS-perSpA is a cross-sectional study that recruited consecutive patients with SpA (as diagnosed by their rheumatologist) from 68 centers worldwide and collected patient and disease data. First, 2651 axSpA patients and 367 PsA patients with any history of axial involvement (axPsA) were compared using logistic regression to later identify predictive factors for rheumatologist diagnosis of axPsA. Secondly, 367 axPsA patients were compared with 666 PsA patients lacking axial involvement (peripheral PsA [pPsA]) and the characteristics associated with axial manifestations were explored by logistic regression analysis.

RESULTS

Patients with axPsA were older and less frequently males or HLA*B27 positive in comparison with axSpA patients. Additionally, while patients with axPsA had more peripheral manifestations and psoriasis, other extra-musculoskeletal manifestations (IBD and uveitis) were more frequent in those with axSpA. In the multivariable analysis, older age at diagnosis (OR = 1.04), peripheral arthritis (OR = 7.32) and dactylitis (OR = 2.82) were significantly associated with the diagnosis of axPsA. However, uveitis (OR = 0.22), IBD (OR = 0.12), HLA*B27 carriership (OR = 0.26) or sacroiliitis on imaging (OR = 0.5) were inversely associated with axPsA diagnosis as compared to axSpA. Axial involvement in patients with PsA was significantly associated with male gender (OR = 1.68), elevated CRP (OR = 2.87) and the absence of psoriasis (OR = 0.33).

CONCLUSION

In this worldwide setting axPsA was defined by rheumatologists as a unique phenotype, with disease features lying between axSpA and pure pPsA.

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.

Clinical features of psoriatic arthritis

Psoriatic arthritis (PsA) is associated with decreased quality of life. As delayed diagnosis may lead to progressive joint destruction and long-term disability, the key clinical features of PsA should be recognizable to a wide range of clinicians to facilitate early diagnosis. In addition to assessment and identification of skin and nail lesions, which occur in up to 85% of those with musculoskeletal manifestations, clinicians should be aware of both the peripheral and axial manifestations of musculoskeletal disease reviewed here. Peripheral joint diseases include polyarticular, oligoarticular, distal, and arthritis mutilans subtypes, and cognizance of these patterns of disease, as well as periarticular manifestations, including dactylitis and enthesitis, is useful for swift diagnosis of PsA. Axial psoriatic arthritis (axial PsA), also known as the spondylitis subtype, may be limited to the spine and sacroiliac joints, but may also affect peripheral structures. Meticulous history-taking and physical examination and familiarity with appropriate imaging studies are often necessary to distinguish axial-PsA from other differential diagnoses. Swift diagnosis and treatment are necessary to both control PsA disease and mitigate the risks of the many associate comorbidities that may accompany it.

Patient characteristics and minimal disease activity in psoriatic arthritis: a transcontinental comparison

Psoriatic arthritis (PsA) is a heterogeneous disease with both environmental and genetic factors playing a role in this diversity. The aim of this study is to compare the patient profiles and outcomes in PsA patients in three countries from three continents. PsA patients from Turkey (n = 184), Canada (n = 200), and Italy (n = 177) from the Psoriatic Arthritis-International Database (PsArt-ID) were compared for patient demographics, disease features, treatments, and minimal disease activity (MDA) rates. Patient profiles were different across countries, patients from Italy being older [median (Q1-Q3): 59 (51-65)] than patients from Turkey [48 (37-58)] and Canada [55 (44-65)] and Italian patients having more frequent comorbidities and being more frequently smokers. For disease phenotypes, patients from Italy had axial disease less frequently (12%) than others (Turkey 23%, Canada 52%). Similarly, disease activity in patients from Italy was higher with higher tender and swollen joint counts and body surface area for psoriasis. The lowest rate of biologic use was observed in Italy [ Italy: 18.4%, Turkey: 26.1%, Canada: 33.9%]. MDA was achieved more in Canada [OR (CI): Canada vs Italy = 3.326 (1.983-5.577); Canada vs Turkey = 2.392 (1.498-3.818); Turkey vs Italy = 1.391 (0.786-2.460)]. PsA patient characteristics differ across countries which may be leading to differences in treatments and MDA rates. The differences can be a combination of genetic or geographical differences as well as the demographics of the general population in that area. Therefore, the unmet needs of PsA patients may vary globally. Key Points • PsA disease characteristics, phenotypes, activity levels and treatments differ across countries. • Unmet needs of PsA need to be determined individually.