Power Doppler enhancement of accessory pulleys confirming disease localization in psoriatic dactylitis

Validation and incorporation of digital entheses into a preliminary GLobal OMERACT Ultrasound DActylitis Score (GLOUDAS) in psoriatic arthritis

OBJECTIVES

The main objective was to generate a GLobal OMERACT Ultrasound DActylitis Score (GLOUDAS) in psoriatic arthritis and to test its reliability. To this end, we assessed the validity, feasibility and applicability of ultrasound assessment of finger entheses to incorporate them into the scoring system.

METHODS

The study consisted of a stepwise process. First, in cadaveric specimens, we identified enthesis sites of the fingers by ultrasound and gross anatomy, and then verified presence of entheseal tissue in histological samples. We then selected the entheses to be incorporated into a dactylitis scoring system through a Delphi consensus process among international experts. Next, we established and defined the ultrasound components of dactylitis and their scoring systems using Delphi methodology. Finally, we tested the interobserver and intraobserver reliability of the consensus- based scoring systemin patients with psoriatic dactylitis.

RESULTS

32 entheses were identified in cadaveric fingers. The presence of entheseal tissues was confirmed in all cadaveric samples. Of these, following the consensus process, 12 entheses were selected for inclusion in GLOUDAS. Ultrasound components of GLOUDAS agreed on through the Delphi process were synovitis, tenosynovitis, enthesitis, subcutaneous tissue inflammation and periextensor tendon inflammation. The scoring system for each component was also agreed on. Interobserver reliability was fair to good (κ 0.39-0.71) and intraobserver reliability good to excellent (κ 0.80-0.88) for dactylitis components. Interobserver and intraobserver agreement for the total B-mode and Doppler mode scores (sum of the scores of the individual abnormalities) were excellent (interobserver intraclass correlation coefficient (ICC) 0.98 for B-mode and 0.99 for Doppler mode; intraobserver ICC 0.98 for both modes).

CONCLUSIONS

We have produced a consensus-driven ultrasound dactylitis scoring system that has shown acceptable interobserver reliability and excellent intraobserver reliability. Through anatomical knowledge, small entheses of the fingers were identified and histologically validated.

High-resolution ultrasound imaging of elementary lesions in dactylitis

OBJECTIVE

The aim of the present study was to illustrate the (potential) diagnostic role of high resolution US images in assessing the elementary lesions of dactylitis.

METHODS

Using high-frequency US machines/probes, we matched the micro-anatomical cadaveric architecture of the digit with multiple sonographic findings of dactylitis. High-sensitive color/power Doppler assessments have also been performed to evaluate the digital microvasculature.

DISCUSSION

Modern US equipment/features guarantee prompt and in-depth B-mode and color/power Doppler imaging of tiny anatomical structures of the digit which are usually not properly visible with standard US machines. More specifically, hypervascularization of the digital subcutaneous tissue, fibrous pulleys of flexor tendons, dorsal synovial pads as well as pathological changes of the distal entheseal anchorage network can be accurately detected.

CONCLUSION

In clinical practice, high-end US equipment can be used to accurately assess the digits in patients with dactylitis. This way, simple and convenient sonographic diagnosis of different elementary lesions can be timely established.

Ultrasonographic Insights into Peripheral Psoriatic Arthritis: Updates in Diagnosis and Monitoring

Psoriatic arthritis (PsA) is a chronic inflammatory arthritis associated with psoriasis, characterized by heterogeneous clinical manifestations and variable disease progression. Ultrasonography has emerged as a valuable tool in the diagnosis and monitoring of PsA, providing real-time visualization of joint and soft tissue abnormalities. This review highlights recent advancements in ultrasonographic techniques for the assessment of PsA, including the identification of typical features, the role of power Doppler imaging in detecting active inflammation, and the potential of ultrasound for guiding treatment decisions. Additionally, we discuss the utility of ultrasound in assessing treatment response and monitoring disease progression in patients with PsA, with a focus on novel imaging modalities. By elucidating the evolving role of ultrasonography in PsA management, this article aims to enhance clinicians' understanding of its utility in facilitating early diagnosis, optimizing treatment strategies, and improving patient outcomes.

Ankle retinacula abnormalities as features of psoriatic arthritis: An ultrasound study

OBJECTIVE

To compare the ultrasonography (US) assessment of the retinacula of ankles in patients with rheumatoid arthritis (RA) and psoriatic arthritis (PsA).

METHODS

This cross-sectional study included RA or PsA patients with ankle pain and healthy controls. The following US features were recorded: presence of synovitis, tenosynovitis and abnormalities of two retinacula (the superior peroneal retinaculum [SPR] and the flexor retinaculum [FR] evaluated in mode B and power Doppler).

RESULTS

Among the 80 included patients, 37 (46%) and 23 (29%) had RA and PsA; 20 (25%) patients were healthy controls. The FR was thicker in PsA than RA ankles 0.96±0.39 vs. 0.64±0.15, P<0.001 with no difference between RA patients and HCs. Other FR abnormalities such as hypoechogenicity, PD positivity or periostosis were more frequent in PsA than RA patients, P<0.001. On receiver-operating-characteristic curve analysis, a cut-off of 1mm FR thickness provided a sensitivity of 49% and specificity of 97% for the diagnosis of PsA. Overall, 39 and 3% of PsA and RA ankles exhibited retinaculitis of FR (thickness≥1mm with hypervascularization or hypoechogenicity). The two disease groups did not differ in the evaluation of SPR.

CONCLUSIONS

US abnormalities of FR were more frequent in PsA than RA and appeared to be specific for PsA. US assessment of FR might be useful to distinguish RA and PsA.

Guselkumab, a Selective Interleukin-23 p19 Subunit Inhibitor, Resolves Dactylitis in Patients With Active Psoriatic Arthritis: Pooled Results Through Week 52 From Two Phase 3 Studies

OBJECTIVE

Previous analyses of pooled DISCOVER-1 and DISCOVER-2 data through Week 24 showed significantly higher rates of dactylitis resolution in patients treated with guselkumab compared with placebo. Here, we investigate associations between dactylitis resolution and other outcomes through 1 year.

METHODS

Patients were randomized 1:1:1 to receive subcutaneous injections of guselkumab 100 mg at Week 0, Week 4, and then every 4 or 8 weeks, or placebo with crossover to guselkumab at Week 24. Independent assessors determined dactylitis severity score (DSS; 0-3/digit; total = 0-60). Dactylitis resolution (DSS = 0) (prespecified) and at least 20%, at least 50%, and at least 70% DSS improvement from baseline (post hoc) were determined through Week 52 (nonresponder imputation for treatment failure through Week 24 and for missing data through Week 52). ACR50, tender/swollen joints, low disease activity (LDA) as assessed by composite indices, and radiographic progression (DISCOVER-2 only) were assessed in patients with dactylitis versus without dactylitis resolution at Week 24 and Week 52.

RESULTS

Patients with dactylitis at baseline (473 of 1118) had more severe joint and skin disease than those without dactylitis (645 of 1118). At Week 52, approximately 75% of guselkumab-randomized patients with dactylitis at baseline had complete resolution; approximately 80% had at least 70% DSS improvement. Through Week 52, new-onset dactylitis (DSS ≥1) was uncommon among patients with a DSS of 0 at baseline. Guselkumab-randomized patients with dactylitis resolution were more likely to achieve ACR50, at least 50% reduction in tender and swollen joints, and LDA at Week 24 and Week 52 than those without resolution. At Week 52, patients with dactylitis resolution had numerically less radiographic progression from baseline (DISCOVER-2).

CONCLUSION

Through 1 year, approximately 75% of guselkumab-randomized patients had complete resolution of dactylitis; patients exhibiting resolution were more likely to achieve other important clinical outcomes. Given the high burden of dactylitis, resolution may be associated with better long-term patient outcomes.

Fluorescence, ultrasonic and photoacoustic imaging for analysis and diagnosis of diseases

Biomedical imaging technology, which allows us to peer deeply within living subjects and visually explore the delivery and distribution of agents in living things, is producing tremendous opportunities for the early diagnosis and precise therapy of diseases. In this feature article, based on reviewing the latest representative examples of progress together with our recent efforts in the bioimaging field, we intend to introduce three typical kinds of non-invasive imaging technologies, i.e., fluorescence, ultrasonic and photoacoustic imaging, in which optical and/or acoustic signals are employed for analyzing various diseases. In particular, fluorescence imaging possesses a series of outstanding advantages, such as high temporal resolution, as well as rapid and sensitive feedback. Hence, in the first section, we will introduce the latest studies on developing novel fluorescence imaging methods for imaging bacterial infections, cancer and lymph node metastasis in a long-term and real-time manner. However, the issues of imaging penetration depth induced by photon scattering and light attenuation of biological tissue limit their widespread in vivo imaging applications. Taking advantage of the excellect penetration depth of acoustic signals, ultrasonic imaging has been widely applied for determining the location, size and shape of organs, identifying normal and abnormal tissues, as well as confirming the edges of lesions in hospitals. Thus, in the second section, we will briefly summarize recent advances in ultrasonic imaging techniques for diagnosing diseases in deep tissues. Nevertheless, the absence of lesion targeting and dependency on a professional technician may lead to the possibility of false-positive diagnosis. By combining the merits of both optical and acoustic signals, newly-developed photoacoustic imaging, simultaneously featuring higher temporal and spatial resolution with good sensitivity, as well as deeper penetration depth, is discussed in the third secretion. In the final part, we further discuss the major challenges and prospects for developing imaging technology for accurate disease diagnosis. We believe that these non-invasive imaging technologies will introduce a new perspective for the precise diagnosis of various diseases in the future.

The role of trauma and isomorphic reaction in the pathogenesis of psoriatic arthritis

The role of biomechanical stress and trauma in the initiation of inflammation of the joints and periarticular structures in psoriatic arthritis (PA) is currently not fully understood. Soft tissues and joints are the target for constant biomechanical stress and microtrauma, leading to inflammation. There is an opinion that this inflammation in PA is due to an analogue of the skin isomorphic reaction that develops in the skin of psoriatic patients in response to trauma. Some authors have called this reaction the deep Koebner phenomenon. It is assumed that the early, preclinical phase of psoriatic arthritis may be based on inflammation of the enthesis as a response to microtrauma, and explained by the proximity of the entheses and the articular membranes. Detection of early changes in entheses in psoriatic patients, including those who do not have complaints from the musculoskeletal system, is of great importance for the early diagnosis of psoriatic arthritis. In the literature review, the sources for the period 20102021 were studied, devoted to the role of the isomorphic reaction and microtraumatization in the pathogenesis of PA, as well as the role of various imaging methods for the early diagnosis of enthesitis in psoriatic patients.

Enthesitis in Psoriatic Arthritis, the Sonographic Perspective

Purpose of Review

To provide an overview of the ultrasound (US) studies focusing on enthesitis in psoriatic arthritis (PsA).

Recent Findings

Last-generation US equipment has demonstrated the ability to detect subtle morphostructural and vascular abnormalities at entheseal level. US is able to identify pathologic changes in both “classical” (i.e., the site of attachment of tendons, ligaments, and joint capsules into the bone) and “functional” entheses (i.e., anatomical regions where tendons or ligaments wrap around bony pulleys).

Summary

US has the potential to be the first-line method in the assessment of enthesitis. In the present review we critically discussed the current definitions of US enthesitis, the scoring systems, and the main fields of application (i.e., the detection of enthesitis in PsA and psoriasis, the identification of different disease subsets, and the assessment of response to treatment).

The transition from enthesis physiological responses in health to aberrant responses that underpin spondyloarthritis mechanisms

PURPOSE OF REVIEW

Despite immunology and translational therapeutics advances in inflammatory arthritis over the past two decades, the enthesis, which is the epicentric of the spondyloarthritis family pathological process, retains many mysteries because of tissue inaccessibility that hampers direct immune study. As entheses are subject to almost continuous mechanical stress and spondyloarthritis is linked to microdamage or injury and joint stress, it is cardinal to understand the physiological changes occurring within the entheses not only to be able to differentiate disease from health but also to understand the transition normal physiology break down and its merges into spondyloarthritis-related disease.

RECENT FINDINGS

Imaging has played a major role in understanding the enthesis in human. Remarkable insights from enthesis functioning and microdamage in normal and with ageing including those linked to body mass index is emerging. The impact of mechanical stress and degenerative conditions on the development of the secondary entheseal vascular changes is not understood. Of note, ultrasound studies in psoriasis have shown higher power Doppler changes compared to controls pointing towards a role for vascular changes in the development of enthesitis in psoriatic arthritis.

SUMMARY

The literature pertaining to normal entheses changes with age, microdamage and vascular changes in health is providing a roadmap for understanding of the enthesis and its potential role in evolution of spondyloarthritis including psoriatic arthritis.

Psoriatic Dactylitis: Current Perspectives and New Insights in Ultrasonography and Magnetic Resonance Imaging

Dactylitis, one of the most typical features of psoriatic arthritis (PsA), is the diffuse swelling of the digits and is determined by the involvement of different anatomic structures, including: the subcutaneous fibrous tissue “accessory pulley” system; flexor tendons, with their related structures; the articular synovium; the small enthesis of the hands. Dactylitis is currently considered both a marker of disease activity and severe prognosis and its importance in PsA is emphasized by the inclusion in the classification criteria of PsA. This review focuses on the role of imaging in the management of PsA patients with dactylitis in clinical practice and in a research setting. Furthermore, imaging could be a valuable tool to assist in unravelling some of the underlying mechanisms of the onset and chronicization of dactylitis in PsA patients.

Sensitivity to change and clinical correlations of the novel DACtylitis glObal Sonographic (DACTOS) score in psoriatic arthritis

OBJECTIVE

The aim of the study is to assess the performance of the DACTOS (DACtylitis glObal Sonographic) score in a PsA dactylitis clinical setting. In particular, we evaluated the ability of DACTOS to identify the affected fingers, its sensitivity to change after treatment, the correlations between DACTOS and clinical parameters, and the capacity of the score to identify the treatment responders.

METHODS

Forty-six consecutive patients with symptomatic PsA hand dactylitis were enrolled. A total of seventy-three dactylitic digits were evaluated clinically and sonographically before and after treatment in this observational and prospective study. Clinical assessment included the Leeds Dactylitis Index-basic (LDI-b) score and visual analogue scales for pain (VAS-p) and functional impairment (VAS-FI). Sonographic lesions were investigated using high-frequency ultrasound with grey scale and power Doppler features according to the DACTOS score. Correlations between the DACTOS score and the clinical parameters were assessed at baseline, 1 month (T1) and 3 months (T3).

RESULTS

We observed significant improvements in all of the assessed clinical parameters and the DACTOS scores after dactylitis treatment. There was a statistically significant correlation between the variation of all clinical parameters (VAS-p, VAS-FI and LDI-b) and the DACTOS score at T1 and T3 evaluations. We found statistically significant differences in the DACTOS score between clinical responder and non-responder groups (P < 0.001) and between clinical remission and non-remission groups (P < 0.001).

CONCLUSION

The DACTOS score performs well in real-life clinical settings in terms of sensitivity to change and correlations with clinical features in PsA dactylitis.

Which ultrasound lesions contribute to dactylitis in psoriatic arthritis and their reliability in a clinical setting

OBJECTIVES

To explore the frequency of ultrasound elementary lesions in dactylitis in psoriatic arthritis (PsA), and the reliability of scoring these lesions in a clinical setting.

METHODS

In 31 patients with PsA and clinical dactylitis, ultrasound assessment of the affected finger or toe was performed using greyscale and color Doppler mode. One examiner scanned all patients and a second examiner scanned 10 patients for inter-reader reliability. For each digit, the following lesions were evaluated: subcutaneous edema; soft tissue thickening; synovitis of the digital joints; tenosynovitis of the flexor tendon; enthesitis at the deep flexor tendon and the extensor tendon entheses; and paratenonitis of the extensor tendon. A dactylitis sum-score was calculated. Findings in clinically tender and non-tender digits were compared.

RESULTS

The most frequent lesions were soft tissue thickening (81%) and subcutaneous edema (74%) followed by synovitis (56-68%) and flexor tenosynovitis (52%). Color Doppler was most frequently found subcutaneously (55%) and around the flexor tendons (45%). All lesions were typically found in combinations, most commonly subcutaneous edema and synovitis (71%), subcutaneous edema and flexor tenosynovitis (52%), and all three in combination (52%). Tender digits had a higher dactylitis sum-score and numerically higher prevalence of most lesions than non-tender digits. Intra- and inter-reader agreements were moderate to excellent, though lower for few components of digital enthesitis, especially hypoechogenicity.

CONCLUSION

Dactylitis in PsA appears to encompass several lesions, most often subcutaneous changes combined with synovitis and/or flexor tenosynovitis. Reliability of scoring established ultrasound lesions of dactylitis in a clinical setting is moderate-excellent. Key Points • Dactylitis in psoriatic arthritis consists of multiple ultrasound lesions • A dactylitis ultrasound sum-score gives an impression of severity by including all lesions • Reliability of ultrasound scoring of dactylitis components is good.

Recent Advances in Imaging for Diagnosis, Monitoring, and Prognosis of Psoriatic Arthritis

Psoriatic arthritis (PsA) is an inflammatory condition characterized by a strong heterogeneity and multifaceted behavior. PsA manifests in two types—axial and peripheral—which may be present at the same time. Peripheral manifestations can be further divided into the articular (arthritis) and extra-articular (i.e., enthesitis and dactylitis) subgroups. In such a complex disease, imaging is often required to characterize the type of involvement and to evaluate the radiological damage and progression of PsA. In addition, imaging plays a pivotal role in clinical practice; that is, for axial involvement. Conventional radiology has been the main standard of reference for many years. However, in recent years, there has been growing interest in different imaging modalities, such as ultrasonography (US) and magnetic resonance imaging (MRI). All these techniques play a role in the diagnosis and follow-up of patients with PsA and cover all the types of the disease. US and MRI have good sensitivities and specificities for detecting synovitis, and this may be helpful for differential diagnosis with other musculoskeletal diseases and useful in the early or preclinical phases of the disease. However, US is not useful in the diagnosis of axial PsA. In addition, other modalities have been investigated in the field of PsA imaging. Computed tomography (CT), in particular, dual energy-CT and high-resolution peripheral CT (HRpQ-CT) might play an important role in the assessment of bone damage, erosions, and new bone formation. Regarding advanced functional imaging, FDG PET/CT is another interesting technique for exploring disease activity.

Imaging in the diagnosis and management of peripheral psoriatic arthritis

Psoriatic arthritis is a heterogenous disease affecting peripheral and axial joints, tendons, ligaments, and their insertions, in addition to the skin and the nails. The complexity of the involved structures has puzzled clinicians trying to understand the underlying pathology that leads to symptoms in order to choose the appropriate medications with different modes of actions. Imaging, mainly ultrasound and magnetic resonance imaging, allows of accurate detection of inflammatory changes in the musculoskeletal structures, which helps to avoid false positive and negative assessments. The linking of different anatomical structures' involvement using imaging also provides insights into the pathogenesis of psoriatic arthritis. In this review, ultrasound and magnetic resonance imaging will be discussed in depth with regard to their use in the field of peripheral psoriatic arthritis, with a focus on the literature from the last 4 years and recent advances.

Musculoskeletal Ultrasound in Monitoring Clinical Response to Treatment in Acute Symptomatic Psoriatic Dactylitis: Results from a Multicentre Prospective Observational Study

This observational and prospective study evaluated the clinical correlations of sonographic lesions in consecutive psoriatic arthritis (PsA) dactylitis cases. Eighty-three dactylitic digits were evaluated clinically and sonographically before treatment and at one-month (T1) and three-month (T3) follow-up. Clinical evaluation included the Leeds Dactylitis Index-basic (LDI-b) score and the visual analogue scales for pain (VAS-p) and functional impairment (VAS-FI). High-frequency ultrasound with grey scale (GS) and power Doppler (PD) assessed flexor tenosynovitis (FT), soft tissue oedema (STO), extensor tendon paratenonitis, and joint synovitis. There was a statistically significant correlation between the clinical parameters (VAS-p, VAS-FI, and LDI-b) and FT and STO at T1 and T3. We found statistically significant improvement in FT and STO for the cases with clinically meaningful treatment responses (p < 0.001). After a multiple conditional logistic regression analysis, the only variables that correlated with a T1 clinical response were the resolutions of PD FT (OR 15.66) and PD STO (OR 6.23), while the resolution of PD FT (OR 27.77) and of GS STO (OR 7.29) correlated with a T3 clinical response. The clinical improvements of active dactylitis are linked to the regression of sonographic evidence of extracapsular inflammation (particularly FT and STO).

Ultrasound Imaging in Psoriatic Arthritis: What Have We Learnt in the Last Five Years?

Psoriatic arthritis (PsA) is a complex heterogeneous disease with multiple inter-related pathologies such as synovitis, enthesitis, tendinopathy, and dactylitis. Clinical assessment is limited in its detail to assess pathology, thus in recent years, ultrasound (US) has become more popular, given its high sensitivity to detect inflammatory arthritis and ability to inform clinical decisions. Although a qualitative technique, US findings can be graded semi-quantitatively for grayscale (GS) and power Doppler (PD). Synovitis is frequently present in inflammatory arthritis pathologies, and in PsA, recent evidence shows a propensity for tendon and entheseal lesions. The presence of flexor tenosynovitis and flexor tendon insertional enthesopathy at accessory pulleys is supportive of the “Deep Koebner” concept. Peri-tendinous inflammation—mutual to PsA or rheumatoid arthritis (RA), is associated with soft tissue oedema with PD signal frequently at the flexor tendon compartments in PsA. Research on enthesitis in PsA/PsO has improved understanding in subclinical and clinical PsA, explored associations with progression to PsA, and investigated links to prognosis assessment. Dactylitis is a pathognomonic PsA lesion where US has enhanced knowledge of the disease course and pathology of lesions such as: flexor tenosynovitis; synovitis; and soft tissue oedema. Increased US sensitivity has also brought innovation including promising automated ultrasound scanning techniques. So, what have we learnt in recent years and what are the unmet needs to focus future research initiatives in this disabling disease? This narrative review article assesses the neoteric evidence, bringing into context the knowledge gained and highlighting potential areas of research.

The Role of Musculoskeletal Ultrasound in the Rheumatoid Arthritis Continuum

PURPOSE OF REVIEW

Rheumatoid arthritis (RA) is no longer considered a fixed phenotype but rather a disease continuum. This review outlines the current and potential value of applying ultrasound (US) along this continuum: from the prediction of progression to RA in at-risk individuals, to confirmation of the early diagnosis of RA, as well as the consideration of differential diagnoses, and the use in disease monitoring and defining remission.

RECENT FINDINGS

In individuals at-risk of RA (i.e., positive autoantibodies with symptoms but without synovitis), US has shown a promising predictive value for the development of clinical arthritis, providing the opportunity to improve risk stratification (and disease prevention) of these individuals. The detection of inflammation on US in patients with early undifferentiated arthritis, in which a definite diagnosis cannot be reached, could predict evolution to persistent arthritis, mostly RA. This, in addition to the US potential ability to identify disease specific patterns for different rheumatic conditions, might facilitate early diagnosis and, therefore, improve the management of patients with RA, or other types of inflammatory arthritides. US has also demonstrated the capability to predict radiographic progression, and relapse risk after treatment discontinuation, in RA patients in remission according to the clinical instruments, raising implications in the management, including therapy discontinuation, of these patients. US has an undeniable value in the management of patients at different stages along the RA continuum. Further research is needed to identify which groups of patients benefit the most from US imaging.

Power Doppler Ultrasound Assessment of A1 Pulley. A New Target of Inflammation in Psoriatic Arthritis?

Objective: To determine the prevalence of grey scale and power Doppler (PD) ultrasound (US) features of A1 pulley inflammation in a cohort of psoriatic arthritis (PsA) patients compared with rheumatoid arthritis (RA) patients.

Methods: Sixty patients (30 with PsA and 30 with RA) were consecutively enrolled. The main clinimetric indexes were recorded, and US assessment of A1 pulleys from second to fifth fingers bilaterally was carried out. The presence of A1 pulley inflammation, defined as PD signal within a thickened pulley, was registered.

Results: A1 pulley inflammation was found in 15 of 240 fingers (6.3%) of eight PsA patients (26.7%) and in one of 240 fingers (0.4%) of one RA patient (3.3%) (p < 0.01 and p = 0.03, respectively). Seven of eight PsA patients (88%) with at least one inflamed A1 pulley had a moderate/high disease activity score. The regression linear analysis (R² = 0.36, adjusted R² = 0.31) showed that A1 pulley inflammation was correlated with Disease Activity Index for Psoriatic Arthritis (DAPSA) (β = 0.43, p = 0.03).

Conclusion: US A1 pulley inflammation appears to be relatively common at patient level in PsA, seems to be a characteristic feature of PsA compared to RA, and correlates with DAPSA.