Detection of subclinical skin manifestation in patients with psoriasis and psoriatic arthritis by fluorescence optical imaging

Metabolic and molecular imaging in inflammatory arthritis

It is known that metabolic shifts and tissue remodelling precede the development of visible inflammation and structural organ damage in inflammatory rheumatic diseases such as the inflammatory arthritides. As such, visualising and measuring metabolic tissue activity could be useful to identify biomarkers of disease activity already in a very early phase. Recent advances in imaging have led to the development of so-called 'metabolic imaging' tools that can detect these changes in metabolism in an increasingly accurate manner and non-invasively.Nuclear imaging techniques such as 18F-D-glucose and fibroblast activation protein inhibitor-labelled positron emission tomography are increasingly used and have yielded impressing results in the visualisation (including whole-body staging) of inflammatory changes in both early and established arthritis. Furthermore, optical imaging-based bedside techniques such as multispectral optoacoustic tomography and fluorescence optical imaging are advancing our understanding of arthritis by identifying intra-articular metabolic changes that correlate with the onset of inflammation with high precision and without the need of ionising radiation.Metabolic imaging holds great potential for improving the management of patients with inflammatory arthritis by contributing to early disease interception and improving diagnostic accuracy, thereby paving the way for a more personalised approach to therapy strategies including preventive strategies. In this narrative review, we discuss state-of-the-art metabolic imaging methods used in the assessment of arthritis and inflammation, and we advocate for more extensive research endeavours to elucidate their full field of application in rheumatology.

[Can rheuma be scanned? : Review of the current study situation on fluorescence optical imaging]

BACKGROUND

The novel technique of indocyanine green (ICG)-based fluorescence optical imaging (FOI) using the Xiralite® system (Rheumascan) has been the subject of many different studies worldwide since approval for clinical use in the European Union (2009), USA (2014) and Asia. The FOI depicts the disturbed microcirculation in the joints of both hands caused by inflammation.

OBJECTIVE

The aim of this article is to provide an overview of the current state of studies on ICG-based FOI in different rheumatologic indications.

METHODS

A narrative literature review of publications on ICG-based FOI in the diagnosis of various inflammatory rheumatic joint diseases since 2010 is presented, its use in treatment monitoring is explained, and its value in systemic sclerosis is outlined.

RESULTS

In summary, studies have extensively demonstrated the accuracy of FOI in inflammation detection. Therefore, it can be concluded that FOI is a good supplement to existing imaging modalities. Due to characteristic patterns of both skin and nails, FOI is an indicated procedure especially in psoriatic arthritis and can be very helpful in the diagnostic process in early undifferentiated arthritis. The FOI has shown its usefulness in children (juvenile idiopathic arthritis), for monitoring the course of treatment, and for demonstrating disturbed microcirculation in patients with systemic sclerosis.

CONCLUSION

The presented data imply that FOI should be considered as a valuable complementary imaging tool in the diagnostic algorithm of daily rheumatologic practice, both for diagnosis and for follow-up monitoring. In particular, the automated analyses should be able in the future to objectify measurements of inflammatory activity as well as monitoring the response to treatment.

Fluorescence-optical imaging as a promising easy-to-use imaging biomarker to increase early psoriatic arthritis detection in patients with psoriasis: a cross-sectional cohort study with follow-up

OBJECTIVES

To evaluate the ability of fluorescence-optical imaging (FOI) to detect preclinical musculoskeletal inflammatory signs in patients with skin psoriasis at risk of developing psoriatic arthritis (PsA).

METHODS

This investigator-initiated prospective exploratory study evaluated adult patients with psoriasis with musculoskeletal complaints and/or nail psoriasis within the last 6 months. Patients underwent a comprehensive rheumatological clinical examination (CE) along with musculoskeletal ultrasound (MSUS) and FOI of both hands at a single visit. Patients with CE-/MSUS-/FOI+ findings had MRI performed on the symptomatic or dominant hand within 7 days. If MRI was negative, the patients were followed over 2 years for the onset of clinically manifest PsA.

RESULTS

A total of 389 patients were referred from dermatology centres and evaluated at 14 rheumatology sites in Germany. Seventy-seven (20%) patients with CE-/US-/FOI- were considered to have psoriasis only. PsA was diagnosed in 140/389 patients (36%) based on CE alone and in another 55 patients (14%) by additional MSUS; overall, 50% of the patient cohort was diagnosed with PsA. One hundred sixteen patients (30%) were FOI+ (CE-) of which 40 (37%) were FOI+/MRI+. In the 2-year follow-up of the FOI+/CE- patients, clinical PsA was confirmed in another 12%.

CONCLUSION

FOI is a promising method for the detection of signs of musculoskeletal inflammation in hands that may serve as an early imaging biomarker for transitions from psoriasis to PsA. This imaging technique has the potential to detect PsA in at-risk patients with psoriasis, reduce time to PsA diagnosis and improve patient outcomes.

Polydopamine/IR820 nanoparticles as topical phototheranostics for inhibiting psoriasiform lesions through dual photothermal and photodynamic treatments

Dual photothermal and photodynamic therapy (PTT and PDT) is an attractive approach that generates a synergistic effect for inhibiting keratinocyte hyperproliferation in the treatment of psoriasis. Here, we developed phototheranostic nanocarriers capable of producing hyperthermia and reactive oxygen species (ROS) in response to near-infrared (NIR) illumination. To this end, IR820 with photothermal and photodynamic features was embedded in nano-sized polydopamine (PDA) acting as a PTT agent. A comprehensive characterization of the PDA/IR820 nanosystem was performed according to its morphology, size, zeta potential, UV absorbance, and heat generation. Its therapeutic efficacy was assessed by a keratinocyte-based study and using an imiquimod (IMQ)-stimulated psoriasiform murine model. PDA/IR820 nanoparticles were facilely internalized into keratinocytes and mainly resided in lysosomes. Upon irradiation with NIR light, ROS were generated inside the keratinocytes to cause a photodynamic effect. The live/dead cell assay and cytotoxicity assay demonstrated that PDA and IR820 acted as effective photoabsorbers to induce keratinocyte death. The highest cytotoxic effect was detected in the group of NIR-irradiated PDA/IR820 nanoparticles, which killed 52% of keratinocytes. The nanosystem acted through the caspase and poly ADP-ribose polymerase (PARP) pathways to induce keratinocyte apoptosis. In vitro and in vivo skin permeation indicated the selective accumulation of the topically applied PDA/IR820 nanoparticles within psoriasiform skin, suggesting their skin-targeting capability. The combination of PDA/IR820 nanoparticles and NIR irradiation increased the skin temperature by 11.7 °C. PTT/PDT eliminated psoriasiform plaques in mice by decreasing hyperplasia, inhibiting cytokine overexpression, and recovering the barrier function. The epidermal thickness of the IMQ-treated skin was reduced from 134 to 34 μm by the nanocarriers plus NIR. The IR820 nanoparticles were largely deposited on the inflamed areas of psoriasiform lesions for monitoring the severity of inflammation. The image-guided phototheranostic nanoparticles showed their potential for applications in psoriasis management via noninvasive topical administration.

Epidemiology of Psoriasis and Comorbid Diseases: A Narrative Review

Psoriasis is a chronic autoimmune inflammatory disease that remains active for a long period, even for life in most patients. The impact of psoriasis on health is not only limited to the skin, but also influences multiple systems of the body, even mental health. With the increasing of literature on the association between psoriasis and extracutaneous systems, a better understanding of psoriasis as an autoimmune disease with systemic inflammation is created. Except for cardiometabolic diseases, gastrointestinal diseases, chronic kidney diseases, malignancy, and infections that have received much attention, the association between psoriasis and more systemic diseases, including the skin system, reproductive system, and oral and ocular systems has also been revealed, and mental health diseases draw more attention not just because of the negative mental and mood influence caused by skin lesions, but a common immune-inflammatory mechanism identified of the two systemic diseases. This review summarizes the epidemiological evidence supporting the association between psoriasis and important and/or newly reported systemic diseases in the past 5 years, and may help to comprehensively recognize the comorbidity burden related to psoriasis, further to improve the management of people with psoriasis.

Follow-Up Comparison of Fluorescence Optical Imaging With Musculoskeletal Ultrasound for Early Detection of Psoriatic Arthritis

Objectives

Early diagnosis of psoriatic arthritis (PsA) is crucial for a patient outcome but hampered by heterogenous manifestation and a lack of specific biomarkers. We recently showed that fluorescence optical imaging (FOI) can differentiate between patients with confirmed and suspected PsA. This study aims to follow-up (FU) patients with confirmed and suspected PsA focusing on patients with a change from suspected to confirmed PsA by the use of FOI in comparison with musculoskeletal ultrasound (MSUS).

Methods

Follow-up examination of patients included in the study performed by Erdmann-Keding et al. in which FOI of both hands was performed in a standardized manner using three predefined phases (p1–p3) and PrimaVista Mode (PVM). The comparison was drawn to grayscale–power Doppler (GS/PD) MSUS of the clinically dominant hand (wrist, MCP, PIP, DIP 2–5) from dorsal or palmar.

Results

Patients with a change from suspected to diagnosed PsA showed an increased prevalence of joints with pathological enhancement in FOI (p = 0.046) with an unchanged joint distribution pattern, especially with a dominant involvement of DIP joints. Compared to the baseline, these patients were three times more common to show enhancement in FOI p3 at FU. Newly detected pathologic joints by FOI (PVM, p2) and MSUS at FU were positively associated with the change of diagnosis from suspected to confirmed PsA (FOI: AUC 0.78; GSUS: AUC 0.77).

Conclusion

Fluorescence optical imaging appears to be a helpful tool to detect early PsA and to distinguish between acute and chronic disease stages. It could thereby become a suitable tool as a screening method to select psoriasis patients with an indication for further rheumatological evaluation.

New Perspectives on Diagnosing Psoriatic Arthritis by Imaging Techniques

Psoriatic arthritis is a chronic inflammatory condition that can lead to severe functional impairment and irreversible damage. The diagnosis can be difficult in early cases where the clinical exam is often scarce. The lack of a serological biomarker can lead to a considerable delay in diagnosis. In this review, we discuss the existent imaging methods that have improved the diagnosis of psoriatic arthritis (PsA). The degree and type of musculoskeletal involvement cannot be assessed by only one imaging method. We think that a combination of methods is the best approach to evaluate both structural damage and inflammatory lesions and that ultrasound (US) could be the best tool to screen a patient when considering the diagnosis of PsA. US is an accessible, non-ionizing technique that offers information regarding active inflammation in joints, entheses, and soft tissues.

Brodalumab Is Associated with High Rates of Complete Clearance and Quality of Life Improvement: A Subgroup Analysis of Patients with Psoriasis and Concomitant Psoriatic Arthritis

Background

Psoriatic arthritis (PsA) is a chronic inflammatory disease associated with psoriasis that significantly impairs physical function and quality of life (QoL). Prompt therapeutic intervention is crucial for limiting PsA progression and preventing disability.

Objectives

The aim of this study was to compare the efficacy of brodalumab versus ustekin­umab and the impact on QoL in patients with moderate-to-severe plaque psoriasis, by concomitant PsA status.

Methods

This post hoc analysis of pooled data from the phase 3 AMAGINE-2 and −3 trials evaluated complete skin clearance (100% improvement of Psoriasis Area and Severity Index [PASI 100]), improvement in symptom severity (Psoriasis Symptom Inventory [PSI] response), and QoL (Dermatology Life Quality Index [DLQI] score of 0/1) by concomitant PsA status. A competing risk model assessed cumulative incidence over 52 weeks with outcomes of PASI 100 or inadequate response.

Results

This analysis included 929 patients with moderate-to-severe psoriasis. Concomitant PsA was present in 79/339 (23%) and 110/590 (19%) patients receiving brodalumab 210 mg and ustekinumab, respectively. At Week 52, odds ratios (ORs) (95% confidence intervals [CIs]) for complete clearance with brodalumab versus ustekin­umab were 3.15 (1.52–6.55, p = 0.0015) in patients with concomitant PsA and 3.05 (2.19–4.26, p < 0.0001) in patients without concomitant PsA. Corresponding Week 52 ORs (95% CIs) for DLQI 0/1 with brodalumab versus ustekinumab were 2.05 (1.07–3.90, p = 0.0277) and 1.83 (1.32–2.53, p = 0.0002); Week 52 ORs (95% CIs) for PSI ≤8 with brodalumab versus ustekinumab were 3.42 (1.43–8.18, p = 0.0036) and 1.40 (1.01–1.95, p = 0.0434). The 52-week cumulative incidence of patients achieving PASI 100 was significantly higher for brodalumab versus ustekinumab in patients with concomitant PsA (p = 0.0001) and in those without concomitant PsA (p < 0.0001).

Conclusions

Treatment with brodalumab rapidly results in high levels of complete and sustained skin clearance and greater cumulative treatment benefit in patients with moderate-to-severe psoriasis versus ustekinumab, regardless of concomitant PsA status.

Fluorescence optical imaging: ready for prime time?

The novel technique of fluorescence optical imaging (FOI, Xiralite), which is approved in the European Union and the USA for clinical use, has been the object of studies since 2009. Indocyanine green-based FOI can demonstrate an impaired microcirculation caused by inflammation in both hands in one examination. Several studies have investigated FOI for detection of joint inflammation by comparing FOI to magnetic resonance imaging (MRI) and/or musculoskeletal ultrasound (MSUS). The results have shown a generally good agreement (>80%) between FOI and clinical examination, MRI and MSUS by power Doppler in inflammatory joint diseases. Moreover, characteristic enhancements in skin and nails are seen in PsA, which potentially can be useful in the diagnostic process of early undifferentiated arthritis. Furthermore, FOI has been investigated for the visualisation of a disturbed microcirculation in the hands and fingers of patients with systemic sclerosis (SSc), highlighting the potential of monitoring vascular changes in SSc and other vasculopathies. The available data indicate that it is time to consider FOI as a useful part of the imaging repertoire in rheumatology clinical practice, particularly where MSUS and MRI are not easily available.