Multimodal imaging of the distal interphalangeal-joint synovio-entheseal complex in psoriatic arthritis (MIDAS): a cross-sectional study on the diagnostic accuracy of different imaging modalities comparing psoriatic arthritis to psoriasis and osteoarthritis

Combined semiquantitative nail-enthesis complex ultrasonography and capillaroscopy in psoriasis and psoriatic arthritis

This pilot study investigates distinctive features within the nail-enthesis complex among Psoriatic arthritis (PsA), Psoriasis (PSO), Rheumatoid Arthrit is (RA), and Healthy Control (HC) groups, utilizing a combined approach of ultrasound (US) and nailfold videocapillaroscopy (NVC). Clinical assessments and comprehensive US and NVC evaluations of the nail-enthesis complex were conducted on 72 subjects (18 PsA, 16 PSO, 19 RA, 19 HC). Unsupervised clustering models and factor analysis were employed to identify patterns and interrelationships between US and NVC parameters. Significant structural differences were detected, emphasizing the discriminatory power of semiquantitative US scores (GS BUNES, Wortsman type). Trends in vascularization aligned with literature, showcasing dysregulated angiogenesis in PsA and PSO. The clustering model effectively distinguished HC from PsA subjects, revealing a potential continuum between PSO and PsA. RA subjects exhibited subsets with features akin to both HC and PsA/PSO, underscoring the complexity of its manifestations. This study provides insights into nail-enthesis complex alterations, highlighting distinctions among PsA, PSO, RA, and HC subjects. The clustering model emphasizes potential overlap between PSO and PsA. Factor analysis elucidates collinearity in US-detected characteristics, while suggesting limited discriminative power of some quantitative parameters. These findings advocate for further exploration in prospective trials, potentially predicting the evolution of undifferentiated early arthritis and arthritis onset in PSO patients.

Clinical, genetic and omics-based biomarkers that might support the identification of the development of psoriatic arthritis in individuals with psoriasis: a narrative review of the literature

It is known that 25%-30% of individuals with cutaneous psoriasis (PsC) will develop psoriatic arthritis (PsA). To date, the reasons for the development of PsA in individuals with PsC have not been identified. Furthermore, there are considerable delays in the diagnosis and treatment of PsA, which lead to joint and bone deformation and chronic pain. It is therefore important to develop more precise diagnostic and screening tools. In this narrative review of the literature, clinical risk factors and novel molecular biomarkers (genetic markers, blood and inflammatory markers, lipid, metabolite and protein biomarkers) have been evaluated. The review included 38 publications that were reported between May 2020 and May 2024. Similar to previous reviews, nail involvement was one of the strongest clinical risk factors for the development of PsA, while molecular biomarkers did not provide a clear and robust differentiation between PsC and PsA groups. The seemingly poor performance of molecular markers may be largely attributed to small study populations and heterogeneity in study designs. Data and sample sharing in large consortia such as HIPPOCRATES (Health initiatives in Psoriasis and PsOriatic arthritis ConsoRTium European States) could help to overcome the limitations of small studies and enable the development of more robust diagnostic and screening tools for PsA.

Pivotal role of the synovioentheseal complex in the imaging of arthritis and rheumatic diseases

Imaging plays a key role in the diagnosis and management of rheumatic diseases. Although joints and periarticular tissue are commonly involved in rheumatic diseases, entheses further away from joints, such as in the Achilles tendon or plantar fascia insertion onto the calcaneus, as well as skin and subcutaneous tissue, are among other -sometimes overlooked- targets. The link of enthesitis, which describes inflammation at the insertions of ligaments, tendons, or joint capsules, with spondyloarthritis (SpA) was established just before the turn of the century as a characteristic feature based on imaging studies with histopathological correspondence. To highlight the association between enthesitis and synovitis in SpA, the anatomical unit of the “synovioentheseal complex” (SEC) and the concepts of “functional enthesis” and “articular enthesis,” apart from the better known “insertional enthesis,” were introduced to encompass other inflammatory lesions associated with SpA. Studies from the last two decades revealed the involvement of the SEC in rheumatic and non-rheumatic disorders with different pathogeneses. Although such involvement is sometimes distinctive, it does not necessarily point to a specific diagnosis at other times. Nevertheless, the potential of SEC inflammation in the differentiation of SpA from other forms of arthritis remains important. The purpose of this review was to provide essential information concerning the involvement of the SEC in the diagnosis of rheumatic diseases and arthritis, focusing on imaging characteristics.

Association of the clinical components in the distal interphalangeal joint synovio-entheseal complex and subsequent response to ixekizumab or adalimumab in psoriatic arthritis

OBJECTIVES

To assess the frequency of simultaneous distal interphalangeal (DIP) joint disease and adjacent nail psoriasis (finger unit) among patients with psoriatic arthritis (PsA) and compare the efficacy of the IL-17A antagonist ixekizumab (IXE) and the TNF-α inhibitor adalimumab (ADA).

METHODS

This post hoc analysis evaluated the simultaneous occurrence of DIP joint involvement (tenderness and/or swelling) and adjacent nail psoriasis among patients with PsA from the SPIRIT-H2H (NCT03151551) trial comparing IXE to ADA. Among patients with simultaneous DIP joint involvement and adjacent nail psoriasis in ≥1 digit at baseline, treatment effects were assessed through week 52 for each affected finger unit; 'finger unit' defines the connected DIP joint and adjacent nail of an individual digit.

RESULTS

A total of 354 patients had simultaneous DIP joint involvement and adjacent nail psoriasis in ≥1 finger unit at baseline. Among them, 1309 (IXE: 639; ADA: 670) finger units had baseline DIP joint tenderness and/or swelling and adjacent nail psoriasis. Proportions of affected finger units achieving complete resolution were significantly higher with IXE vs ADA as early as week 12 (38.8% vs 28.4%, P < 0.0001) and at all post-baseline assessments through week 52 (64.9% vs 57.5%, P = 0.0055).

CONCLUSION

In this study cohort, patients with DIP joint involvement almost always had adjacent nail psoriasis. Greater resolution of DIP joint tenderness, swelling and adjacent nail psoriasis was achieved at all time points over 52 weeks through targeting IL-17A with IXE than TNF-α with ADA, which is noteworthy given prior comparable musculoskeletal outcomes for both drug classes.

Nail Ultrasound in Psoriasis and Psoriatic Arthritis-A Narrative Review

Ultrasonography has advantages for assessing psoriatic arthritis (PsA) due to its ability to evaluate several targets, including joints, entheses, and tendons, but also skin and nails. Although ultrasound is widely used in PsA, nail ultrasound, despite its potential as a non-invasive method for the early detection of inflammation in the nail apparatus, has low applicability in medical practice, as probes with a higher frequency are needed compared with the frequency of probes usually used. In the present article, we have narratively evaluated the studies published in the last 5 years (19 February 2018-18 February 2023) on nail ultrasound value in the diagnosis and monitoring of PsA. The studies published during this period share common measurement parameters, such as the OMERACT definition of enthesis published in 2018. We included original articles published in PubMed and Web of Science using the following search terms in all possible combinations: psoriatic arthritis, psoriasis, ultrasound, and nail. Articles were declared relevant if they presented data on nail morphology, power Doppler evaluation and nearby structure evaluation, while focusing on digitorum extensor enthesitis. In most of the studies, common morphological parameters were generally increased in patients with psoriasis or PsA and were demonstrated to change with medication. The thickness of the extensor tendon was greater in patients with PsA and psoriasis versus controls and it was correlated with nail clinical changes, especially the presence of onycholysis. The presence of PD showed large variability in healthy individuals. The link between enthesitis and nail involvement is still a subject of controversy, taking into account the latest histological findings. The use of ultrasound in the evaluation of nail and DIP enthesitis remains a challenge and an area of research in the coming years.