Achilles tendon and enthesis assessment using ultrashort echo time magnetic resonance imaging (UTE-MRI) T1 and magnetization transfer (MT) modeling in psoriatic arthritis.

The purpose of this study is to investigate the use of ultrashort echo time (UTE) magnetic resonance imaging (MRI) techniques (T1 and magnetization transfer [MT] modeling) for imaging of the Achilles tendons and entheses in patients with psoriatic arthritis (PsA) compared with asymptomatic volunteers. The heels of twenty-six PsA patients (age 59 ± 15 years, 41% female) and twenty-seven asymptomatic volunteers (age 33 ± 11 years, 47% female) were scanned in the sagittal plane with UTE-T1 and UTE-MT modeling sequences on a 3-T clinical scanner. UTE-T1 and macromolecular proton fraction (MMF; the main outcome of MT modeling) were calculated in the tensile portions of the Achilles tendon and at the enthesis (close to the calcaneus bone). Mann-Whitney-U tests were used to examine statistically significant differences between the two cohorts. UTE-T1 in the entheses was significantly higher for the PsA group compared with the asymptomatic group (967 ± 145 vs. 872 ± 133 ms, p < 0.01). UTE-T1 in the tendons was also significantly higher for the PsA group (950 ± 145 vs. 850 ± 138 ms, p < 0.01). MMF in the entheses was significantly lower in the PsA group compared with the asymptomatic group (15% ± 3% vs. 18% ± 3%, p < 0.01). MMF in the tendons was also significantly lower in the PsA group compared with the asymptomatic group (17% ± 4% vs. 20% ± 5%, p < 0.01). Percentage differences in MMF between the asymptomatic and PsA groups (-16.6% and -15.0% for the enthesis and tendon, respectively) were higher than the T1 differences (10.8% and 11.7% for the enthesis and tendon, respectively). The results suggest higher T1 and lower MMF in the Achilles tendons and entheses in PsA patients compared with the asymptomatic group. This study highlights the potential of UTE-T1 and UTE-MT modeling for quantitative evaluation of entheses and tendons in PsA patients.

Assessment of the many faces of PsA: single and composite measures in PsA clinical trials.

PsA is a complex, heterogeneous disease that can place a large burden on patients' psychological and physical well-being. The multifaceted nature of PsA poses a significant assessment challenge, both in randomized control trials and in clinical practice. In recent years, there has been much progress in the development of unidimensional and composite measures of disease activity, as well as of questionnaires that capture the patient's perspective of the condition. Despite these advances, there remains uncertainty around which tools to implement within a research setting. This review aims to summarize the currently available clinical and patient-derived assessment tools, providing a practical and informative resource for the assessment of PsA. This review will also explore recent advancements in digital approaches to the assessment of rheumatological conditions. This will highlight the potential for digitalization in the assessment and monitoring of PsA, outlining innovative means of capturing disease activity and treatment response.

Treatment of Medicare Patients with Moderate-to-Severe Psoriasis who Cannot Afford Biologics or Apremilast.

Elderly patients are a group with a high frequency of psoriasis. Their disease burden has negative impacts on their quality of life. While there is a clear need to treat these patients, there are challenges in doing so. This work seeks to define the challenges that exist in treating elderly Medicare patients, as well as to provide treatment suggestions for providers to follow if they encounter one or more of these challenges. Providers face the following challenges when creating treatment plants for elderly patients with psoriasis: difficulty in obtaining drug coverage through Medicare, increased medical comorbidities, and polypharmacy. Providers aim for regimens that are affordable, safe, and efficacious, but it is not always clear how to achieve this combination, especially in elderly Medicare patients. This work is relevant in that it aims to explain the logistical roadblocks posed by Medicare coverage and provide solutions for commonly encountered issues in the treatment of a disabling and common disease in a high-risk population. Specifically, alternative treatment options to biologics and small-molecule inhibitors are discussed and include topical therapies, phototherapy, methotrexate, acitretin, and cyclosporine and for psoriatic arthritis include corticosteroids and leflunomide. The specific risks and benefits of these therapies in the elderly population are provided, allowing providers to make patient-specific decisions about optimal regimens.

Sustainability and switching of biologics for psoriasis and psoriatic arthritis at Fukuoka University Psoriasis Registry.

Biologics are efficacious for treating psoriasis vulgaris (PsV) and psoriatic arthritis (PsA), but sometimes must be terminated or changed for various reasons including ineffectiveness or adverse events. To find the optimal choice of biologics for treating psoriasis, we analyzed the real-world data on drug survival and the reason for terminating or switching biologics. Medical records from patients with PsV or PsA, who visited the Department of Dermatology, Fukuoka University Hospital from 2010 to 2017, were analyzed. Two hundred and eleven patients received biologics, and 147 patients (69.7%) were treated with only one biologic, while 64 patients (30.3%) were switched to different products. Frequently used biologics in PsV were ustekinumab (UST), infliximab and adalimumab when calculated by patient-year. Tumor necrosis factor inhibitor (TNFi) use decreased while UST and interleukin (IL)-17 inhibitors increased in newly introduced patients. UST showed the highest survival rate as a first-line drug, but the advantage was lost in the second reagent's group. The major reasons for terminating/switching biologics were as follows: primary ineffectiveness (26.4%), secondary loss of efficacy (36.5%), patient's preference, including referral to nearby hospital, or stopped visiting (22.6%), side-effects (7.7%), comorbidities (3.4%) and economic burden (2.4%). In PsA patients, TNFi are more frequently employed than in PsV patients, although switching to UST or IL-17 inhibitors showed an increasing trend. Biologic reagents were changed mostly because of primary or secondary loss of efficacy, which affected drug survival. Further research is needed to find the optimal choice of biologics with larger samples at multiple facilities.

Assessment and Clinical Relevance of Serum IL-19 Levels in Psoriasis and Atopic Dermatitis Using a Sensitive and Specific Novel Immunoassay.

Because development of reliable biomarkers in psoriasis and atopic dermatitis has lagged behind therapeutic progress, we created a blood-based test to fill the void in objective methods available for dermatological assessments. Our novel interleukin-19 (IL-19) immunoassay was initially tested to determine concentrations of IL-19 serum levels, then correlated with the psoriasis activity and severity index (PASI) in psoriasis, and the eczema area and severity index (EASI) in atopic dermatitis. Not only was IL-19 increased in psoriasis and correlated to PASI, but ixekizumab administration led to rapid, sustained IL-19 decreases to normal levels, with decreases at 2-weeks correlating with PASI improvement at 16-weeks. IL-19 increased upon ixekizumab withdraw, prior to relapse, and decreased following re-treatment. In baricitinib- and etanercept-treated psoriasis patients, IL-19 decreases also correlated with improvement. Many patients with limited skin disease, including genital psoriasis and psoriatic arthritis patients, also had increased IL-19, which was reduced to normal levels upon ixekizumab treatment, correlating with PASI improvement. We also measured IL-19 in baricitinib-treated atopic dermatitis patients. In atopic dermatitis, IL-19 was significantly elevated, correlated with EASI scores, and decreased with skin improvement. Therefore, measurement of serum IL-19 provides clinicians with an objective disease-activity assessment tool for psoriasis and atopic dermatitis patients.

Disease activity assessment in patients with psoriatic arthritis.

Psoriatic arthritis (PsA) is an inflammatory disease in patients with a personal or family history of psoriasis. While synovitis is the major hallmark, enthesitis, dactylitis, axial inflammation, and skin and nail involvement are variable in prevalence and severity. The assessment of disease activity is important to determine the treatment target ("Treat-to-Target") as well as early response to therapy, because a prolonged ineffective medication may not only be associated with an adverse disease outcome but constitutes a waste of individual and/or societal expenses. Various measures of disease activity have been established for all manifestations individually ('uni-dimensional approach') or by combining such measures into a single umbrella score ('multi-dimensional approach'). Because pathogeneses and therapeutic responsiveness differ among individual domains, a uni-dimensional approach is preferred. The major uni-dimensional index is the Disease Activity index for PSoriatic Arthritis, which provides a continuous scale and allows calculating disease activity at any point in time, determining response to therapy and defining disease activity states, such as remission, as a treatment target. The assessment of the various domains by individual and combined indices is discussed.

A two-phase model for chronic disease processes under intermittent inspection.

A model is developed for chronic diseases with an indolent phase that is followed by a phase with more active disease resulting in progression and damage. The time scales for the intensity functions for the active phase are more naturally based on the time since the start of the active phase, corresponding to a semi-Markov formulation. This two-phase model enables one to fit a separate regression model for the duration of the indolent phase and intensity-based models for the more active second phase. In cohort studies for which the disease status is only known at a series of clinical assessment times, transition times are interval-censored, which means the time origin for phase II is interval-censored. Weakly parametric models with piecewise constant baseline hazard and rate functions are specified, and an expectation-maximization algorithm is described for model fitting. Simulation studies examining the performance of the proposed model show good performance under maximum likelihood and two-stage estimation. An application to data from the motivating study of disease progression in psoriatic arthritis illustrates the procedure and identifies new human leukocyte antigens associated with the duration of the indolent phase. Copyright © 2017 John Wiley & Sons, Ltd.

Of patents and patent disputes: The TNFα patent files. Part 1: Humira.

This article discusses the patent strategy underlying the world's best selling drug, AbbVie's Humira®. Despite a non-optimal starting position, AbbVie has established an extensive portfolio to fend off biosimilar competition. This article is the first part of a trilogy that discusses IP issues related to anti-Tumor Necrosis factor α (TNFα) biologics.

Pharmacogenetics and pharmacogenomics in psoriasis treatment: current challenges and future prospects.

INTRODUCTION: Topical, systemic, oral disease modifying, and biologic agents are part of the armamentarium to manage psoriatic disease. The choice of therapy depends upon disease severity, relevant co-morbidities and patient preference. There is great variability in patient response with these agents, and there is still no clear method of selecting the preferred therapeutic agent for efficacy or lack of adverse events. AREAS COVERED: This article will review the pharmacogenetic and pharmacogenomic targets that are currently known with respect to psoriasis vulgaris, and the most frequent co-morbidity of psoriasis, psoriatic arthritis. EXPERT OPINION: Presently, no clinically actionable biomarker exists for any therapeutic agent used to treat psoriasis or psoriatic arthritis. The lack of validated outcome measures and conflicting results of open-label studies conducted may be attributed to a multitude of issues that confound discovery. Consequently, studies have been underpowered to identify genes or genetic variants worth translating to clinical practice. In order to achieve a pharmacogenetic/pharmacogenomic signature, improvements in study design of future investigations are required, including carefully designed prospective studies. It is imperative to combine known clinical, serological, and molecular markers with consistent outcomes and an adequate health economic evaluation before they can be adopted widely in clinical practice.

Interface Management between General Practitioners and Rheumatologists-Results of a Survey Defining a Concept for Future Joint Recommendations.

OBJECTIVE: To measure the views of general practitioners (GPs) and rheumatologists in a nationwide evaluation, so as to optimise their cooperation in managing patients with inflammatory rheumatic diseases. METHODS: A questionnaire covering aspects of collaboration was sent, both by mail and/or by email, to all GPs and rheumatologists in Austria. Topics covered were (i) examinations and interventions to be performed before referral, (ii) the spectrum of diseases to be referred, and (iii) the role of GPs in follow-up and continuous management of patients. RESULTS: 1,229 GPs of the 4,016 GPs (31%) and 110 of the 180 rheumatologists (61%) responded to the questionnaire. In cases of suspected arthritis, 99% of the GPs and 92% of the rheumatologists recommended specific laboratory tests, and 92% and 70%, respectively, recommended X-rays of affected joints before referral. Rheumatoid arthritis and spondyloarthritis, psoriatic arthritis and connective tissue disease were unanimously seen as indications for referral to a rheumatologist. Only 12% of rheumatologists felt responsible for the treatment of hand osteoarthritis and fibromyalgia. 80% of GPs and 85% of rheumatologists were of the opinion that treatment with disease-modifying drugs should be initiated by a specialist. Subsequent drug prescription and administration by GPs was supported by a majority of GPs and rheumatologists, with a concomitant rheumatologist follow-up every three to six months. CONCLUSION: The considerable consensus between the two professional groups constitutes a solid base for future joint recommendations, with the aim to accelerate the diagnostic process and the initiation of adequate therapy.

Single-joint Assessment for the Evaluation of Intraarticular Treatment: Responsiveness and Discrimination of the Composite Change Index.

OBJECTIVE: To investigate responsiveness, discrimination, and construct validity of a composite change index (CCI) for the assessment of single-joint involvement in inflammatory arthritis. METHODS: Evaluation of standardized response means (SRM), Guyatt effect size, and Spearman rank correlation coefficient in a randomized controlled trial investigating the effect of an intraarticular etanercept injection. RESULTS: The CCI showed a high SRM (1.68) and high Guyatt effect size (2.72). Both visual analog scale of pain and functionality had a moderate Guyatt effect size (2.06, 2.44) and high SRM (0.81, 0.97). CONCLUSION: This study supports the use of the CCI as a single-joint assessment after single-joint intervention. CLINICAL TRIAL REGISTRATION: NTR-1210.

A comparison of disease burden in rheumatoid arthritis, psoriatic arthritis and axial spondyloarthritis.

OBJECTIVE: The main objective of this study was to compare disease burden in rheumatoid arthritis (RA), psoriatic arthritis (PsA) and axial spondyloarthritis (ax-SpA). METHODS: In this cross-sectional study, all the RA (1093), PsA (365) and ax-SpA (333) patients who visited the out-patient clinic of the Hospital of Southern Norway Trust during the year 2013 were included; the RA patients all had a RA diagnosis verified by the treating rheumatologist, the PsA patients all fulfilled the ClASsification for Psoriatic ARthritis (CASPAR) criteria and the ax-SpA patients all fulfilled the Assessment of SpondyloArthritis international Society (ASAS) classification criteria for ax-SpA. Patient-reported health status, demographic variables, medications, and composite scores of disease activity were assessed. The main analyses were performed using General Linear Models adjusted for age, sex and multiple comparisons. Correlation analyses were performed using Spearman's rho. RESULTS: The reported pain, joint pain, patient's global assessment and fatigue were similar in PsA and ax-SpA, but significantly lower in RA. The 28-joint Disease Activity Score (DAS28) (0.3±0.1, p = 0.003), Clinical Disease Activity Index (CDAI) (1.0±0.4, p = 0.028) and Routine Assessment of Patient Index Data 3 (RAPID3) (0.4±0.1, p = 0.004) were all significantly higher in PsA vs. RA. RAPID3 showed moderate to high correlation with DAS28 (rho = 0.521, p<0.001) and CDAI (rho = 0.768, p<0.001) in RA and PsA, and with Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) (rho = 0.902, p<0.001) and Bath Ankylosing Spondylitis Functional Index (BASFI) (0.865, p<0.001) in ax-SpA and PsA. CONCLUSION: In conclusion, patient- reported outcome measures were similar in our population of PsA and ax-SpA patients, but significantly lower for the RA patients. Composite disease activity measures were lower in RA than in PsA and ax-SpA, but the magnitude of these differences was small and probably not of clinical significance. Our study indicates that disease burden in RA, PsA and ax-SpA may be more similar than previously demonstrated.

High-resolution MRI assessment of dactylitis in psoriatic arthritis shows flexor tendon pulley and sheath-related enthesitis.

OBJECTIVE: Dactylitis is a hallmark of psoriatic arthritis (PsA) where flexor tenosynovitis is common. This study explored the microanatomical basis of dactylitis using high-resolution MRI (hrMRI) to visualise the small entheses around the digits. METHODS: Twelve patients with psoriatic dactylitis (4 fingers, 8 toes), and 10 healthy volunteers (6 fingers, 4 toes) had hrMRI of the digits using a 'microscopy' coil and contrast enhancement. All structures were evaluated including the tendons and ligaments, related enthesis organs, pulleys, volar/plantar plates and tendon sheaths. RESULTS: In dactylitis, collateral ligament enthesitis was seen in nine digits (75%), extensor tendon enthesitis in six digits (50%), functional enthesitis (5 digits, 42%), abnormal enhancement at the volar plates (2/5 joints, 40%) and the plantar plate (1/5 joints, 20%). Nine cases (75%) demonstrated flexor tenosynovitis, with flexor tendon pulley/flexor sheath microenthesopathy observed in 50% of all cases. Less abnormalities which were milder was observed in the normal controls, none of whom had any signal changes in the tendon pulleys or fibrous sheaths. CONCLUSIONS: This study provides proof of concept for a link between dactylitis and 'digital polyenthesitis' including disease of the miniature enthesis pulleys of the flexor tendons, further affirming the concept of enthesitis in PsA.

Optimisation of rheumatology indices: dactylitis and enthesitis in psoriatic arthritis.

Outcome measures are a key part of study design and clinical assessment. Enthesitis and dactylitis are typical features of psoriatic arthritis (PsA) and the spondyloarthritides but traditionally scoring systems for enthesitis have mainly been validated in ankylosing spondylitis (AS). There are many scoring systems which are not validated used for dactylitis although newer validated scores are now available. Recently there have been advances in composite scores that include enthesitis and dactylitis to assess disease activity. These are currently being validated further and have not yet been tested in routine clinical practice.

Ultrasound composite scores for the assessment of inflammatory and structural pathologies in Psoriatic Arthritis (PsASon-Score).

INTRODUCTION: This study was performed to develop ultrasound composite scores for the assessment of inflammatory and structural lesions in Psoriatic Arthritis (PsA). METHODS: We performed a prospective study on 83 PsA patients undergoing two study visits scheduled 6 months apart. B-mode and Power Doppler (PD) findings were semi-quantitatively scored at 68 joints (evaluating synovia, perisynovial tissue, tendons and bone) and 14 entheses. We constructed bilateral and unilateral (focusing the dominant site) ultrasound composite scores selecting relevant sites by a hierarchical approach. We tested convergent construct validity, reliability and feasibility of inflammatory and structural elements of the scores as well as sensitivity to change for inflammatory items. RESULTS: The bilateral score (termed PsASon22) included 22 joints (6 metacarpophalangeal joints (MCPs), 4 proximal interphalangeal joints (PIPs) of hands (H-PIPs), 2 metatarsophalangeal joints (MTPs), 4 distal interphalangeal joints (DIPs) of hands (H-DIPs), 2 DIPs of feet (F-DIPs), 4 large joints) and 4 entheses (bilateral assessment of lateral epicondyle and distal patellar tendon). The unilateral score (PsASon13) compromised 13 joints (2 MCPs, 3 H-PIPs, 1 PIP of feet (F-PIP), 2 MTPs, 1 H-DIP and 2 F-DIPs and 2 large joints) and 2 entheses (unilateral lateral epicondyle and distal patellar tendon). Both composite scores revealed a moderate to high sensitivity (bilateral composite score 43% to 100%, unilateral 36% to 100%) to detect inflammatory and structural lesions compared to the 68-joint/14-entheses score. The inflammatory and structural components of the composite scores correlated weakly with clinical markers of disease activity (corrcoeffs 0 to 0.40) and the health assessment questionnaire (HAQ, corrcoeffs 0 to 0.39), respectively. Patients with active disease achieving remission at follow-up yielded greater reductions of ultrasound inflammatory scores than those with stable clinical activity (Cohen's d effect size ranging from 0 to 0.79). Inter-rater reliability of bi- and unilateral composite scores was moderate to good with ICCs ranging from 0.42 to 0.96 and from 0.36 to 0.71, respectively for inflammatory and structural sub-scores. The PsASon22 and PsASon13 required 16 to 26 and 9 to 13 minutes, respectively to be completed. CONCLUSION: Both new PsA ultrasound composite scores (PsASon22 and PsASon13) revealed sufficient convergent construct validity, sensitivity to change, reliability and feasibility.

Validation of the Thai version of the Health Assessment Questionnaire for patients with psoriatic arthritis.

OBJECTIVE: To validate the Thai version of the Health Assessment Questionnaire (HAQ) for patients with psoriatic arthritis (PsA). METHODS: The Thai version of the HAQ was administered to 47 patients with PsA attending our rheumatology clinic. Clinical assessments included the measures of disease activity, disease severity and functional status. The correlation of the single items and total score of the Thai HAQ with the measures of disease activity, disease severity and functional status was assessed using Pearson's correlation or Spearman rank correlation, as appropriate. RESULTS: Of 47 patients who fulfilled the Classification Criteria for Psoriatic Arthritis (CASPAR), 21 were male. Their mean age ± standard deviation (SD) and mean disease duration ± SD were 49 ± 10 years and 6.97 ± 6.17 years, respectively. Spondylitis was the most common manifestation (38%). The mean Thai HAQ score was 0.47. The single items and total score of the Thai HAQ were moderately to highly correlated with several measures of disease activity (r = 0.32­0.81, P < 0.01), except for swollen joint count (r = 0.16). For functional status and disease severity, the Thai HAQ was moderately correlated with grip strength (r = -0.39, P < 0.01), but poorly correlated with the range of spinal movement and the number of damaged joints.(r = -0.01 to 0.17). Cronbach's alpha coefficient for internal consistency reliability was 0.88. These results were comparable to the original version. CONCLUSION: The Thai version of the HAQ is valid for assessing functional status in patients with PsA; however, its validity may be limited in patients who have axial involvement or permanent joint damage.

Undertreatment, treatment trends, and treatment dissatisfaction among patients with psoriasis and psoriatic arthritis in the United States: findings from the National Psoriasis Foundation surveys, 2003-2011.

IMPORTANCE: Psoriasis and psoriatic arthritis inflict significant morbidity. Data on undertreatment, treatment use, and treatment satisfaction are paramount to identify priority areas for advocacy, education, and research to improve patient outcomes. OBJECTIVES: To determine the extent of nontreatment and undertreatment of psoriatic diseases, trends in treatment use, treatment satisfaction, and reasons for medication discontinuation among patients with psoriasis and psoriatic arthritis. DESIGN, SETTING, AND PARTICIPANTS: We used the national survey data collected by the National Psoriasis Foundation via biannual surveys conducted from January 1, 2003, through December 31, 2011, in the United States. Survey data were collected from randomly sampled patients with psoriasis and psoriatic arthritis in the US population from a database of more than 76,000 patients with psoriatic diseases. MAIN OUTCOMES AND MEASURES: Nontreatment, undertreatment, and treatment trends determined by the use of prescription medication (topical, phototherapeutic, oral systemic, and biologic), as well as treatment satisfaction and reasons for medication discontinuation. RESULTS: A total of 5604 patients with psoriasis or psoriatic arthritis completed the survey. From 2003 through 2011, patients who were untreated ranged from 36.6% to 49.2% of patients with mild psoriasis, 23.6% to 35.5% of patients with moderate psoriasis, and 9.4% to 29.7% of patients with severe psoriasis. Among those receiving treatment, 29.5% of patients with moderate psoriasis and 21.5% of patients with severe psoriasis were treated with topical agents alone. The most frequently used phototherapy modality is UV-B, whereas methotrexate is the most commonly used oral agent. Although adverse effects and a lack of effectiveness were primary reasons for discontinuing biological agents, the inability to obtain adequate insurance coverage was among the top reasons for discontinuation. Overall, 52.3% of patients with psoriasis and 45.5% of patients with psoriatic arthritis were dissatisfied with their treatment. CONCLUSIONS AND RELEVANCE: Nontreatment and undertreatment of patients with psoriasis and psoriatic arthritis remain a significant problem in the United States. While various treatment modalities are available for psoriasis and psoriatic arthritis, widespread treatment dissatisfaction exists. Efforts in advocacy and education are necessary to ensure that effective treatments are accessible to this patient population.

Burden of disease: psoriasis and psoriatic arthritis.

Psoriatic arthritis (PsA) increases the disease burden associated with psoriasis by further diminishing quality of life, increasing health care costs and cardiovascular risk, and potentially causing progressive joint damage. The presence of PsA influences psoriasis treatment by increasing overall disease complexity and, within the framework of current guidelines and recommendations, requiring the use of conventional disease-modifying anti-rheumatic drugs or tumor necrosis factor-α inhibitors in order to prevent progressive joint damage. Despite its important impact, PsA is still under-diagnosed in dermatology practice. Dermatologists are well positioned to recognize and treat PsA, given that it characteristically presents, on average, 10 years subsequent to the appearance of skin symptoms. Regular screening of psoriasis patients for early evident joint symptoms should be incorporated into daily dermatologic practice. Although drugs effective in PsA are available, not all patients may respond to treatment, and others may lose their initial response over time. New investigational therapies, such as inhibitors of interleukin-17A, interleukin-12/23, Janus kinase 3, or phosphodiesterase-4, may address unmet needs in psoriatic disease, with further research needed to determine the role of these agents in reducing joint damage and other comorbidities.

Magnetic resonance imaging assessment of axial psoriatic arthritis: extent of disease relates to HLA-B27.

OBJECTIVE: To determine the prevalence, on magnetic resonance imaging (MRI), of bone marrow edema lesions in symptomatic axial psoriatic arthritis (PsA), and to compare this prevalence with that in nonradiographic axial spondyloarthritis (SpA) and ankylosing spondylitis (AS) and its relationship to HLA-B27 status. METHODS: We performed a cross-sectional audit of MRI scans of lumbar spine (L-spine) and sacroiliac (SI) joints. Using the semiquantitative Leeds Scoring System in which bone marrow edema is graded from 0 to 3 according to severity of the lesions, MRI scans were scored independently by 2 expert readers who were blinded to the clinical characteristics of the patients. Concordant data from the 2 readers were used to report on definite lesions. RESULTS: MRIs from 76 patients with comparable age ranges were categorized into 3 groups: those from PsA patients, those from patients with nonradiographic axial SpA, and those from AS patients. HLA-B27 positivity was similar in PsA patients (10 of 33) and patients with nonradiographic axial SpA (10 of 24) and higher in AS patients (18 of 19). Total MRI scores (L-spine plus SI joints) were higher in AS patients than in PsA patients (P = 0.025) or in patients with nonradiographic axial SpA (P = 0.007). A relationship was seen between the severity and extent of disease and HLA-B27 positivity in PsA patients, which was comparable to that in AS patients. HLA-B27-negative PsA patients had lower MRI scores than HLA-B27-positive PsA patients (P = 0.03) and AS patients (P = 0.006), whereas scores were similar in HLA-B27-positive PsA patients and AS patients. Similarly, MRI scores of HLA-B27-negative patients with nonradiographic axial SpA were lower than those of AS patients (P = 0.01). CONCLUSION: HLA-B27 positivity defines a group of patients with more severe axial bone marrow edema that is likely related to the classic AS phenotype. Clinically, HLA-B27-negative PsA is more likely to be reported as a "negative" MRI examination result.