Predominant ultrasonographic extracapsular changes in symptomatic psoriatic dactylitis: results from a multicenter cross-sectional study comparing symptomatic and asymptomatic hand dactylitis

Early psoriatic arthritis: clinical and therapeutic challenges

INTRODUCTION

Psoriatic arthritis (PsA) is a chronic immunoinflammatory disease of the enthesis and adjacent synovium, skin, and nail, which early diagnosis may be crucial for starting a prompt therapeutic intervention. Theoretically, early treatment offers the advantage of acting on the reduction of the articular damage progression since initial phases of the disease.

AREAS COVERED

This review explores the challenges of clinical-diagnostic aspects and the underlying pathophysiology of early PsA phases, as well as the evidence evaluating the impact of early intervention on disease outcomes.

EXPERT OPINION

Main instruments for early PsA diagnosis include recognizing synovial-entheseal inflammatory signs at onset, improving screening PsA high-risk subjects, and increasing disease knowledge of physicians and patients with psoriasis or familial history. PsA continues to significantly impact on the Quality of Life of patients affected by the disease, making necessary to deeply study clinical manifestations, risk factors, and underlying immunoinflammatory mechanisms, as well as to identify biomarkers for early identification. Additionally, it remains a need to increase more evidence on understanding how early treatment of PsA and of psoriasis might influence the course of the disease.

Advantages of ultrasound imaging for the early diagnosis of psoriatic arthritis in patients with moderate to severe psoriasis

Background

Psoriatic arthritis (PsA) is an immune-mediated form of chronic inflammatory arthritis associated with psoriasis (PsO). It constitutes a significant comorbidity of PsO and is distinguished by the presence of widespread musculoskeletal inflammation.

Objective

The aim of this study is to precisely detect asymptomatic PsA using ultrasound (US) examinations and to distinguish between various stages of PsO.

Methods

All patients with moderate-to-severe PsO, who consented to undergo musculoskeletal US examinations during their hospitalization between September 2020 and January 2022, were enrolled in the study. We compared patients' demographic characteristics, comorbidities, disease duration, relevant laboratory parameters, and musculoskeletal US findings.

Results

A total of 547 patients with PsO were included in the study, and 114 of them received a diagnosis of PsA. Furthermore, 16.45 % of patients with moderate to severe PsO displayed subclinical PsA. We observed a significantly higher frequency of abnormal US findings in patients with PsA compared to those without PsA, with a sensitivity of 95.61 % and a specificity of 79.22 %. Additionally, the incidence of enthesitis and synovitis varied significantly between PsA and non-PsA patients, and they were identified as independent variables predicting the presence of PsA. Furthermore, the interphalangeal joint, knee joint, and calcaneal tendon were the most frequently affected areas in PsA, as indicated by the observed US changes.

Conclusion

Ultrasound examination proves to be a valuable tool for detecting subclinical PsA, facilitating early screening of the condition. Particular attention should be directed towards changes in the interphalangeal joint, knee joint, and calcaneal tendon when reviewing ultrasound images of asymptomatic patients.

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.

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.

How Variable Is the Volar Subcutaneous Tissue of the Digits on B-Mode and Color Doppler Ultrasound in Non-Psoriatic Individuals and Could It Be Included in a Dactylitis Score?

BACKGROUND

 Digital subcutaneous tissue (SCT) changes are involved in dactylitis, a hallmark feature of psoriatic arthritis (PsA). There are no studies on the ultrasound (US) characteristics of the digital SCT in the general population.

OBJECTIVES

 To investigate the variability in US-measured thickness (TH) and color Doppler (CD)-detected blood flow of the SCT of the volar aspects of the fingers in a non-psoriatic population and to investigate the impact of the scanning method and demographics and clinical features on these measurements.

METHODS

 SCT TH and semiquantitative (SQD) and quantitative (QD) Doppler signals were measured in the bilateral second finger at the proximal and middle phalanges in 81 non-psoriatic volunteers [49 female, 32 men; 18-78 years]. Two scanning methods with and without (thick gel layer interposition) probe-skin contact were used. Demographics and clinical features were collected.

RESULTS

 There was high variability of SCT TH and Doppler measurements between individuals. All US measurements obtained without probe-skin contact were significantly greater than their corresponding measurements obtained with the probe contacting the skin (p < 0.001). SCT TH was positively related to dominant hand, age, masculine gender, weight, height, body mass index, and alcohol consumption while Doppler measurements were positively related to age and non-dominant hand.

CONCLUSIONS

 US-measured SCT thickness and Doppler-detected SCT blood flow of the volar aspect of the fingers seem to be highly variable in the non-psoriatic population as well as highly dependent on the US scanning method. This variability is of utmost importance for assessing dactylitis in PsA.

Ultrasound Effectiveness of Steroid Injection for hand Psoriatic Dactylitis: Results from a Longitudinal Observational Study

Introduction

To assess clinical and ultrasound effectiveness of steroid injection (local treatment, LT) into the digital flexor tendon sheath for the treatment of psoriatic dactylitis compared to systemic treatment (ST) alone.

Methods

In this observational, multicentre, prospective study, 88 cases of symptomatic hand dactylitis were evaluated clinically and sonographically by high-frequency ultrasound (US) probe in both greyscale (GS) and power Doppler (PD). The presence of flexor tenosynovitis (FT), soft tissue oedema (STO), peritendon extensor inflammation and synovitis was assessed (including DACtylitis glObal Sonographic—DACTOS—score) before treatment, at 1-month (T1) and 3-months (T3) follow-up. LT was proposed to all patients. Patients refusing LT were treated with oral NSAIDs. Patients continued the same baseline csDMARDs and/or corticosteroid therapy during the whole follow-up period. US response was defined for DACTOS score < 3 and US remission for DACTOS score = 0.

Results

At T3 evaluation the ST group showed a significantly higher persistence (grade > 1) of FT and STO (p < 0.001 for all) and MCP synovitis (p = 0.001). US remission was achieved only in the LT group (at T3 31% vs. 0, p < 0.001). The percentage of patients with DACTOS < 3 was significantly greater in the LT group compared with ST group, at both T1 (49% vs. 5%, p < 0.001) and T3 evaluation (76% vs. 7%, p < 0.001). In multiple conditional logistic regression analysis, the only factor associated with US remission was LT (T3 odds ratio = 41.21, p < 0.001).

Conclusions

US confirmed the effectiveness of steroid injection for dactylitis by demonstrating that it involves the resolution of extra-articular inflammation, in particular FT and STO.

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.

Regulation of entheseal IL-23 expression by IL-4 and IL-13 as an explanation for arthropathy development under dupilumab therapy

OBJECTIVES

Dupilumab blocks the IL-4 receptor (IL-4R) and thus signalling of the 'Th2' cytokines IL-4 and IL-13. It has a license to treat atopic eczema and was recently linked to emergent enthesitis and psoriasis. We investigated the cellular and functional basis for how IL-4/IL-13 regulates the IL-23-IL-17 axis in entheseal stromal, myeloid and lymphocyte cells.

METHODS

Immunohistochemistry was performed on healthy enthesis samples from patients undergoing elective spinal surgery to investigate entheseal tissue IL-4R expression and cytokine expression by intracellular flow cytometry for IL-4 and IL-13. Digested human enthesis samples were stimulated with lipopolysaccharide (LPS) for IL-23 induction, either alone or with IL-4 or IL-13. Enthesis fibroblasts were stimulated with TNF and IL-17 with and without IL-4 or IL-13 to assess the effect on CCL20 secretion. Synovial fluid samples from PsA patients were also analysed by ELISA for levels of IL-4 and IL-13.

RESULTS

The IL-4/IL-13 receptor was present in both the peri-entheseal bone and enthesis soft tissue, and entheseal-derived T cells produced basal levels of IL-4, but not IL-13. Both IL-4 and IL-13 attenuated LPS-induced entheseal IL-23 production. IL-4 also downregulated secretion of TNF/IL-17A-induced CCL20 from entheseal fibroblasts. Both IL-13 and IL-4 were also detectable in the synovial fluid of PsA patients. We also noted a seronegative inflammatory oligoarthritis whilst under dupilumab therapy.

CONCLUSION

Our findings suggest a previously unknown protective role for IL-4/IL-13 in entheseal induction of the IL-23-IL-17 axis. These findings point towards a novel explanation for IL-13 pathway single nucleotide polymorphisms in PsA and also a molecular explanation for why anti-IL-4/IL-13 therapy may induce musculoskeletal entheseal pathology as recently reported.

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.

Diagnosis, classification, and assessment in psoriatic arthritis

There have been considerable advances in the classification and assessment of psoriatic arthritis (PsA). In this report, we give an overview of historic and current classification criteria and discuss its role and limitations in research and clinical practice. We discuss the most commonly used assessment instruments for arthritis, psoriasis, onychodystrophy, enthesitis, dactylitis and axial PsA with a focus on clinical practice. We pay particular attention to the current evidence for the use of composite outcome measures, and their use in randomised controlled trials and routine care.

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.

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.

Novel and reliable DACTylitis glObal Sonographic (DACTOS) score in psoriatic arthritis

OBJECTIVES

Dactylitis is one of the most typical features of psoriatic arthritis (PsA), with a high lifetime prevalence and inclusion in PsA clinical indices. Musculoskeletal ultrasonography (Msk-US) can readily detect inflammatory involvement of finger anatomical structures particular to dactylitis and monitor therapeutic effects. In this study, we aim to identify the characteristic lesions in PsA dactylitis of the hands, assess the reliability of Msk-US in scoring those lesions and develop a DACTylitis glObal Sonographic (DACTOS) score.

METHODS

After a systematic literature review on the use of Msk-US in PsA dactylitis, 12 rheumatologists participated in a three-round Delphi procedure and consensus meeting to agree on the sonographic elementary lesions characterising dactylitis and on the composition of a global sonographic score. Then, a web-based and a patient-based intra-rater and inter-rater reliability exercise was performed to assess those lesions included in the score.

RESULTS

DACTOS score was obtained by summing the scores of each lesion selected in the Delphi survey: subcutaneous soft tissue oedema, flexor tenosynovitis, peritendon extensor inflammation and synovitis. The DACTOS score ranges from 0 to 25. In the reliability exercises, we obtained moderate-to-excellent agreement for the sonographic lesions included in the score.

CONCLUSIONS

The novel DACTOS score is a reliable measure to interpret the multiple characteristic sonographic features of dactylitis. The DACTOS score provides a useful global analysis of dactylitis of the hand and can represent a support to clinical diagnosis as well as a useful tool for the management and research in patients with PsA with dactylitis.

Effectiveness of steroid injection for hand psoriatic dactylitis: results from a multicentre prospective observational study

OBJECTIVE

To assess the effectiveness of steroid injection (local treatment, LT) into the digital flexor tendon sheath of dactylitis in psoriatic arthritis (PsA) patients as compared with systemic treatment (ST).

METHODS

Forty-six PsA patients with a total of 73 dactylitic fingers were assessed in an observational, multicentre, prospective study by the Leeds Dactylitis Index basic (LDI-b) score and evaluated for local pain (visual analogue scale-VAS pain) and functional impairment (VAS-FI). Steroid injection was proposed to all patients. Patients refusing LT were treated with oral NSAIDs. Both the groups continued baseline csDMARDs and/or corticosteroids therapy. The clinical outcomes were measured at baseline, 1 month (T1) and 3 months (T3).

RESULTS

The reduction of VAS-pain, VAS-FI and LDI-b values was statistically significant higher in the LT group (24 patients, 38 dactylitic fingers) as compared with the ST group (22 patients, 35 dactylitic fingers), both at T1 (p < 0.001, p < 0.001 and p = 0.008, respectively) and at T3 (p < 0.001, p < 0.001 and p < 0.001, respectively). A clinically meaningful treatment response (defined as a contemporary reduction of at least 5 points in VAS-pain and VAS-FI or as values of VAS-pain and VAS-FI were both ≤ 2) was observed at T1 in 33 (87%) digits in LT group and in 6 (17%) digits in ST group (p < 0.001). At T3, clinical response improved significantly in both the groups, with significant difference (94% vs 31%, p < 0.001).

CONCLUSIONS

For the first time, we show the effectiveness of steroid injection into the digital flexor tendon sheath in improving clinical aspects of hand psoriatic dactylitis. Key Points • Therapy with steroid injection (local treatment, LT), into the digital flexor tendon sheath for the treatment of active dactylitis in psoriatic arthritis patients, is more effective when compared with systemic treatment (ST) alone. • The reduction of VAS-pain, VAS-functional impairment (VAS-FI) and Leeds Dactylitis Index basic values was statistically significant higher in the LT group as compared with the ST group, both at T1and at T3. • A clinically meaningful response was observed at T1 in 87% of digits of patients treated with steroid injection and in 17% of digits of the systemic treatment group (p < 0.001). At T3, clinical response improved significantly in both the groups, with significant difference. • For the first time, findings from this study show that the use of steroid injections into the digital flexor tendon sheath for psoriatic dactylitis could be an effective and safe first-line therapy for psoriatic dactylitis.

Metabolic Syndrome and psoriatic arthritis: considerations for the clinician

Introduction: Metabolic Syndrome (MetS) is strictly interconnected with systemic inflammation, and increased evidence has described a close link between this condition and Psoriatic Arthritis (PsA).Areas covered: This review summarizes main studies exploring clinical aspects and prevalence of MetS in PsA cohorts. Further, there is accumulating evidence showing shared inflammatory pathways between MetS, its components, and PsA.Expert opinion: The high prevalence of MetS in PsA highlights the need for screening, evaluation, and close monitoring of MetS and its components (namely, diabetes mellitus, obesity, hypertension, and dyslipidemia) in psoriatic patients.Further studies should focus on the pathogenetic link between MetS and PsA. More studies are required to identify appropriate algorithms for the assessment and management of MetS in PsA patients.

Targeted synthetic pharmacotherapy for psoriatic arthritis: state of the art

INTRODUCTION

In recent years, different studies regarding psoriatic arthritis (PsA) have shown the pathogenetic role of dysfunction of signaling pathways involving the phosphodiesterase-4 enzyme and transcription factors or enzymes belonging to the kinase (JAK)-signal family pathway. These also represent the target of several drugs known as targeted synthetic disease-modifying antirheumatic drugs (tsDMARDs).

AREAS COVERED

The authors performed a systematic literature search using the PubMed database, as well as through retrieving data from randomized controlled trials, their post-hoc analysis, and pooled data analysis on the efficacy and safety profile of the PDE4 inhibitor (PDE4i), apremilast, and the inhibitors of JAK (JAKis), tofacitinib, filgotinib, baricitinib, and upadacitinib, in PsA.

EXPERT OPINION

In PsA, the PDE4i, apremilast, and the JAKi, tofacitinib, are effective across multiple clinical domains and have an acceptable tolerability profile, thus expanding the treatment options available for PsA patients. Apremilast and tofacitinib show several advantages mainly represented by their oral administration, a fast onset of action, and a short half-life. Data on tsDMARDs in PsA are still limited, and randomized trials and real-life studies are advocated.