Imaging in psoriatic arthritis

Association of disease duration and PASI response rates at week 12 in patients with moderate-to-severe plaque psoriasis receiving biologics in the real-world psoriasis study of health outcomes (PSoHO)

PURPOSE

Currently, in the treatment of moderate-to-severe psoriasis (PsO) there is a lack of evidence demonstrating optimal biologic treatment response with respect to disease duration. The aim of this post-hoc analysis, using real world data from the Psoriasis Study of Health Outcomes (PSoHO), is to provide evidence if early intervention with biologics is associated with better treatment outcomes and if there is any difference among drug classes or individual biologics.

MATERIALS AND METHODS

For this post-hoc analysis patients were categorised into two subgroups according to shorter (≤2 years) or longer (>2 years) disease duration. Analysis was performed on anti-interleukin (IL)-17A cohort vs other biologics cohort, anti-IL-17A vs other drug classes, and pairwise comparisons of ixekizumab vs individual biologics, provided that the statistical models converged. Analysis investigated the association of disease duration with the proportion of patients achieving 100% improvement in Psoriasis Area Severity Index score (PASI 100) at week 12. Adjusted comparative analyses, reported as odds ratio (OR), were performed using Frequentist Model Averaging (FMA) for each cohort or treatments within each subcategory of the subgroups.

RESULTS

At week 12, anti-IL-17A and other biologics cohorts displayed minimal differences in numerical response rate for PASI 100 with respect to disease duration. The anti-IL-17A cohort showed a higher numerical PASI 100 response rate compared to the other biologic cohort irrespective of disease duration (≤2 years: 36.7% vs 21.8%; >2 years: 35.8% vs 21.9%).

CONCLUSION

Overall, the results do not clearly indicate that treating patients early is critical in achieving optimal patient outcomes. Furthermore, patients treated with ixekizumab show numerically higher response rates relative to other individual biologics irrespective of disease duration.

An Unusual Case of Psoriatic Arthritis With Secondary Lingual Lesions, Resembling Geographic Tongue

Psoriatic arthritis (PsA) is a chronic inflammatory condition that impacts a significant proportion of individuals diagnosed with psoriasis. This report presents a rare case of a patient diagnosed with PsA who never had active psoriatic skin lesions but only a family history of psoriasis, with secondary lingual lesions, resembling geographic tongue (GT). A male patient, 24 years old, was referred with two painless erythematous areas resembling (without whitish borders, as in GT) rounded atrophic lesions on the dorsal surface of the tongue, resistant to any kind of antimicrobial/antifungal treatment for more than six months. The patient was diagnosed with PsA two years ago fulfilling the CASPAR (ClASsification for Psoriatic ARthritis) criteria. The patient never had active psoriatic skin lesions, but his father had psoriasis. The biopsy of lingual lesions showed moderate hyperkeratosis, spongiosis, and diffuse inflammatory infiltration of lymphocytes and neutrophils in the lamina propria as well as in the stratified squamous epithelium forming Munro's microabscesses at the superficial layers. The manifestation of the atypical psoriasiform, GT-like lingual lesions was considered as part of psoriasis manifestations and the patient was advised to follow regular checkups so that any major exacerbation of the systematic symptoms could be preemptively avoided. Not only GT but also atypical lingual GT-like reddish oral lesions may be considered as transient forms of psoriasis supporting an early diagnosis and monitoring of psoriasis/PsA.

Prospective double-blind study on the value of musculoskeletal ultrasound by dermatologists as a screening instrument for psoriatic arthritis

OBJECTIVES

This study evaluated musculoskeletal ultrasound (MSUS) use by dermatologists previously trained on a novel handheld, chip-based ultrasound device (HHUD) to screen for early PsA.

METHODS

Twelve dermatologists were recruited to screen psoriasis patients for PsA using the novel HHUD in one major hospital in Bonn (Germany) and six private practices in surrounding regions. Patient screening was based on medical history, clinical examination, and the GEPARD questionnaire paired with an MSUS examination of up to three painful joints. All screened patients were then referred to rheumatologists, who determined the final diagnosis. The screening effect of MSUS was assessed according to its sensitivity and specificity before and after its application.

RESULTS

Between 1 October 2020 and 26 May 2021, a total of 140 psoriasis patients with arthralgia participated in this study. PsA was diagnosed in 19 (13.6%) cases. Before applying MSUS, dermatologists' screening sensitivity and specificity were recorded as 88.2% and 54.4%, respectively, while after applying MSUS the sensitivity and specificity changed to 70.6% and 90.4%, respectively. MSUS led to a change of PsA suspicion in 46 cases, with PsA no longer being suspected in 45 of them.

CONCLUSION

This study was able to demonstrate that PsA screening using MSUS by previously trained dermatologists can lead to more precise PsA detection and potentially decreased rheumatologist referral rates.

Differential Diagnosis of Inflammatory Arthritis from Musculoskeletal Ultrasound View

Diagnostic imaging in rheumatology has evolved over the centuries, and novel imaging modalities, including musculoskeletal ultrasonography (MSUS) and magnetic resonance imaging (MRI), are being widely used in the 21st century. With the increase in availability of molecular target-specific therapies, including biologic agents and Janus kinase (JAK) inhibitors, the therapeutic outcome of inflammatory arthritis has changed, and early and accurate diagnosis of inflammatory rheumatic diseases has become more important. Given this situation, MSUS, which is a portable, convenient, noninvasive, and cost-effective imaging technique, plays an important role in the diagnosis of rheumatic diseases. MSUS can be used to detect subclinical inflammation and to accurately determine the distribution of joint involvement and inflammation sites in each joint. Definitive diagnosis for patients with early arthritis should be made after noting their history and performing clinical examination, laboratory testing, and additional procedures. However, MSUS is an extension of physical examination and it can provide a further opportunity and motivation to consider differential diagnoses rather than a conclusive diagnosis. This review aims to describe the usefulness of MSUS in differential diagnoses of the phenotype of early inflammatory arthritis.

Diagnosis and Intervention in Early Psoriatic Arthritis

Psoriatic arthritis (PsA) is a chronic inflammatory disorder that affects approximately 20–30% of patients with psoriasis. PsA causes deformities and joint damage, impairing quality of life and causing long-term functional disability. Several recent studies demonstrated that early diagnosis and intervention for PsA prevents permanent invalidity. However, the clinical features of PsA vary and are shared with other differential diseases, such as reactive arthritis, osteoarthritis, and ankylosing spondylitis. The common and overlapping features among these diseases complicate the accurate early diagnosis and intervention of PsA. Therefore, this review focuses on the current knowledge of the diagnosis of early PsA and discusses the meaning of early intervention for early PsA.

Enthesitis in psoriatic arthritis (Part 2): imaging

Enthesitis is a hallmark finding in PsA and may predate the onset of synovitis. Clinical examination of enthesitis provides no structural information, relies on eliciting tenderness at entheseal sites and may not be sensitive or specific. Soft tissue imaging techniques such as musculoskeletal ultrasound and MRI can depict ultrastructural and inflammatory changes. Although these imaging techniques are complimentary, ultrasound can image superficial entheses with high fidelity and examine vascularity with the use of Doppler but cannot image subchondral bone. MRI depicts bone and can visualize bone marrow edema as well as soft tissue edema. However, due to short relaxation times, entheseal structures are not easily differentiated. There has been increasing recognition of biomechanical confounding, especially since the majority of the entheses examined are in the lower extremity. Imaging entheseal indices are being developed to minimize the effect of body weight and activity. In the following article, contemporary concepts of entheses in relation to imaging will be reviewed as well as important confounders in assessing entheseal alterations. The role and limitations of imaging techniques will be discussed.

Prevalence and factors associated with osteoporosis and bone mineral density testing in psoriatic arthritis

OBJECTIVES

To determine bone mineral density (BMD) in psoriatic arthritis (PsA) patients, factors associated with undergoing BMD testing, and the effect of PsA clinical activity on BMD.

METHODS

Patients attending the University of Toronto PsA Clinic with a BMD from cohort inception to January 2019 were included. Descriptive statistics summarized lumbar spine, femoral neck and total hip T-scores. Cox proportional hazard regression identified predictors for BMD testing. Logistic regression analysis determined odds of having normal (T-score ≥ -1.0) versus osteoporotic range BMD (T-score ≤ -2.5). A multi-state model determined factors associated with BMD state changes over time.

RESULTS

Of the 1479 patients, 214 had BMDs. Mean T-scores at the lumbar spine, femoral neck and total hip were -0.30±0.32, -1.10±1.04 and -0.45±0.42 respectively. Osteopenia and osteoporosis occurred in 45.27% and 12.94% of patients. Increasing age, menopause, elevated acute phase reactants, biologic, methotrexate and systemic glucocorticoid use were associated with a higher chance of undergoing BMD testing. Increased BMI and biologic use were associated with a lower chance of having osteoporotic range BMD. In multi-state analysis, polyarthritis may portend lower BMDs over time, although this did not achieve statistical significance due to low patient numbers.

CONCLUSIONS

The prevalence of osteopenia and osteoporosis in the PsA cohort were similar to the general population. Clinicians are using osteoporosis risk factors and PsA disease severity markers to select patients for BMD testing. Polyarticular disease may portend worse BMDs. Biologic use and increased BMI appear to have a protective effect.

High-resolution MRI of flexor tendon pulleys using a 16-channel hand coil: disease detection and differentiation of psoriatic and rheumatoid arthritis

Background

To evaluate the value of 3 Tesla (T) magnetic resonance imaging (MRI) changes of flexor tendon pulleys for the differentiation of psoriatic (PsA) and rheumatoid arthritis (RA), using a novel 16-channel high-resolution hand coil.

Methods

Seventeen patients with active PsA, 20 patients with active RA, and 16 healthy controls (HC) underwent high-resolution 3 T MRI using the dedicated 16-channel hand coil. Images were analyzed by three independent readers for the degree of inflammatory changes, thickness of flexor tendon pulleys, and comparison to the outcome measures for RA clinical trials (OMERACT) PsA MRI score (PsAMRIS) and to its sub-scores. For correlation analyses, Spearman rho correlation was calculated.

Results

Flexor tendon pulleys were thicker in PsA than in RA patients (mean difference 0.16 mm, p < 0.001) and HC (mean difference 0.2 mm, p < 0.001) and showed a higher degree of associated inflammatory changes (mean difference from RA 4.7, p = 0.048; mean difference from HC 14.65, p < 0.001). Additionally, there was a strong correlation of accessory pulley inflammation and PsAMRIS and its acute-inflammatory sub-scores, flexor tenosynovitis, synovitis, and periarticular inflammation (for the second digit synovitis ρ = 0.72, flexor tenosynovitis ρ = 0.7, overall PsAMRIS ρ = 0.72, p < 0.01). Similar robust correlations were evident in digits 3–5. Weaker correlations were evident in RA (synovitis ρ = 0.49, flexor tenosynovitis ρ = 0.49, periarticular inflammation ρ = 0.4).

Conclusion

The assessment of MRI changes of flexor tendon pulleys is potentially beneficial for disease detection in PsA, as well as for its distinction from RA and HC.

Trial registration

2014123117, December 2014.

The importance of ultrasound in identifying and differentiating patients with early inflammatory arthritis: a narrative review

Early differentiation between different types of inflammatory arthritis and subsequent initiation of modern treatments can improve patient outcomes by reducing disease activity and preventing joint damage. Routine clinical evaluation, laboratory testing, and radiographs are typically sufficient for differentiating between inflammatory and predominantly degenerative arthritis (e.g., osteoarthritis). However, in some patients with inflammatory arthritis, these techniques fail to accurately identify the type of early-stage disease. Further evaluation by ultrasound imaging can delineate the inflammatory arthritis phenotype present. Ultrasound is a noninvasive, cost-effective method that enables the evaluation of several joints at the same time, including functional assessments. Further, ultrasound can visualize pathophysiological changes such as synovitis, tenosynovitis, enthesitis, bone erosions, and crystal deposits at a subclinical level, which makes it an effective technique to identify and differentiate most common types of inflammatory arthritis. Limitations associated with ultrasound imaging should be considered for its use in the differentiation and diagnosis of inflammatory arthritides.

Distinguishing rheumatoid arthritis from psoriatic arthritis

Rheumatoid arthritis (RA) and psoriatic arthritis (PsA) have key differences in clinical presentation, radiographic findings, comorbidities and pathogenesis to distinguish between these common forms of chronic inflammatory arthritis. Joint involvement is typically, but not always, asymmetric in PsA, while it is predominantly symmetric in RA. Bone erosions, without new bone growth, and cervical spine involvement are distinctive of RA, while axial spine involvement, psoriasis and nail dystrophy are distinctive of PsA. Patients with PsA typically have seronegative test findings for rheumatoid factor (RF) and cyclic citrullinated peptide (CCP) antibodies, while approximately 80% of patients with RA have positive findings for RF and CCP antibodies. Although there is overlap in the pathogenesis of PsA and RA, differences are also present that affect the efficacy of treatment. In PsA, levels of interleukin (IL)-1β, IL-6, IL-17, IL-22, IL-23, interferon-γ and tumour necrosis factor-α (TNF-α) are elevated, and in RA, levels of IL-1, IL-6, IL-22, IL-33, TNF-α, chemokine ligand 11 and chemokine C-X-C motif ligand 13 are elevated. Differences in the pathogenesis of RA and PsA translate into some variances in the specificity and efficacy of therapies.

ENTHESITIS AND PSORIATIC ONYCHOPATHY AS A FACTOR FOR PREDICTION OF PSORIATIC ARTHRITIS IN PSORIASIS

Psoriatic arthritis is a psoriasis-related spondyloarthropathy that occurs in 20–30 % of patients with psoriasis. Psoriatic arthritis affects the patient’s quality of life indicators and are more often associated with disabilities of working age than psoriasis skin form. Nail psoriasis has been proposed as a predictor for the development of psoriatic arthritis. The inflammation involving the entheses, called enthesitis, is an early inflammatory change seen in psoriatic arthritis, and nail changes appear to result from the close relationship between the nail and the enthesis of the distal interphalangeal extensor tendon, one of the main entheseal compartments affected in psoriatic arthritis. Various imaging studies have demonstrated that there is a considerable proportion of undiagnosed psoriatic arthritis among patients with psoriasis. Since early detection and treatment of psoriatic arthritis could, ultimately, allow the prevention of clinical and radiologic progression of the disease, there is the need to establish clinical indicators to detect this risk.

Considerations for the definition of remission criteria in psoriatic arthritis

OBJECTIVES

Psoriatic arthritis (PsA) is an autoimmune disease that can cause progressive structural damage of the joints and irreversible disability. The potentially achievable results of biologic therapy for PsA has led to the view that disease remission should be the goal of treatment. However, the heterogeneity of disease manifestations and need for validated outcome measures makes defining remission in PsA challenging. This article evaluates proposed criteria for defining remission in PsA and discusses how these criteria can be applied in clinical practice.

METHODS

A primary literature search was conducted in PubMed to identify articles discussing potential PsA treatment goals or targets, including minimal disease activity. English-language publications from the last 10 years were included in this assessment.

RESULTS

There are 5 clinical domains in PsA that must be considered when evaluating remission: synovitis, enthesitis, dactylitis, spondylitis, and psoriasis/nail psoriasis. Due to variability in the completeness of remission and time to achieve remission with different therapies between these domains, remission should be measured clinically through a combination of objective measures, or a composite assessment tool. Composite measures are more efficient than unidimensional instruments in measuring remission, but remission rates differ between the available composite indices.

CONCLUSION

Although the concept of remission as a treatment goal in PsA is gaining acceptance among rheumatologists, further work is necessary to develop a broadly acceptable definition of remission.

Basic radiological assessment of synovial diseases: a pictorial essay

The synovium is a specialized tissue lining the synovial joints, bursae, and tendon sheaths of the body. It is affected by various localized or systemic disorders. Synovial diseases can be classified as inflammatory, infectious, degenerative, traumatic, hemorrhagic, and neoplastic. Damage in other intraarticular structures, particularly cartilages, generally occurs as a part of pathologic processes involving the synovium, leading to irreversible joint destruction. Imaging has an essential role in the early detection of synovial diseases prior to irreversible joint damage. Obtaining and understanding characteristic imaging findings of synovial diseases enables a proper diagnosis for early treatment. This article focuses on the recent literature that is related with the role of imaging in synovial disease.

Psoriatic arthritis for the dermatologist

Psoriatic arthritis (PsA) is a chronic, progressive, inflammatory spondyloarthropathy that affects approximately one-third of patients with all types of psoriasis. Dermatologists are in a unique position to recognize early symptoms of PsA, initiate appropriate therapy, and prevent development of further disability. The course of PsA can be modulated by immunosuppressive therapy; patients with moderate-to-severe disease require aggressive management with medications proven to halt disease progression. It is essential for the dermatologist to understand the safety, tolerability, efficacy, cost, and potential to halt disease progression with available medications for this relatively common and potentially disabling disease.

Gene Expression Profiling in Peripheral Blood Cells and Synovial Membranes of Patients with Psoriatic Arthritis

Background

Psoriatic arthritis (PsA) is an inflammatory arthritis whose pathogenesis is poorly understood; it is characterized by bone erosions and new bone formation. The diagnosis of PsA is mainly clinical and diagnostic biomarkers are not yet available. The aim of this work was to clarify some aspects of the disease pathogenesis and to identify specific gene signatures in paired peripheral blood cells (PBC) and synovial biopsies of patients with PsA. Moreover, we tried to identify biomarkers that can be used in clinical practice.

Methods

PBC and synovial biopsies of 10 patients with PsA were used to study gene expression using Affymetrix arrays. The expression values were validated by Q-PCR, FACS analysis and by the detection of soluble mediators.

Results

Synovial biopsies of patients showed a modulation of approximately 200 genes when compared to the biopsies of healthy donors. Among the differentially expressed genes we observed the upregulation of Th17 related genes and of type I interferon (IFN) inducible genes. FACS analysis confirmed the Th17 polarization. Moreover, the synovial trascriptome shows gene clusters (bone remodeling, angiogenesis and inflammation) involved in the pathogenesis of PsA. Interestingly 90 genes are modulated in both compartments (PBC and synovium) suggesting that signature pathways in PBC mirror those of the inflamed synovium. Finally the osteoactivin gene was upregulared in both PBC and synovial biopsies and this finding was confirmed by the detection of high levels of osteoactivin in PsA sera but not in other inflammatory arthritides.

Conclusions

We describe the first analysis of the trancriptome in paired synovial tissue and PBC of patients with PsA. This study strengthens the hypothesis that PsA is of autoimmune origin since the coactivity of IFN and Th17 pathways is typical of autoimmunity. Finally these findings have allowed the identification of a possible disease biomarker, osteoactivin, easily detectable in PsA serum.

Altered bone biology in psoriatic arthritis

Psoriatic arthritis (PsA) is characterized by focal bone erosions mediated by osteoclasts at the bone-pannus junction. The bulk of research over the past decade has centered on mechanisms that underlie osteoclastogenesis along with new insights into osteoimmunology; however, recent advances that focus on steps that lead to new bone formation are beginning to emerge. New revelations about bone formation may have direct relevance to PsA given the presence of enthesophytes, syndesmophytes, and bony ankylosis frequently observed in patients with this disorder. In this review, we discuss current developments in the pathogenesis of new bone formation, novel imaging approaches to study bone remodeling and highlight innovative approaches to study the effect of inflammation on bone. Lastly, we discuss promising therapies that target joint inflammation and osteitis with the potential to mediate pathologic bone formation.