Utility of multi-biomarker panel on discriminating disease activity in patients with psoriatic arthritis

OBJECTIVE

To investigate the correlation of serum protein biomarkers and disease activity in patients with PsA.

METHODS

176 patients fulfilled the CASPAR (ClASsification criteria for Psoriatic ARthritis) were recruited in this cross-sectional study. The level of 48 protein biomarkers, cartilage and bone turn-over markers were assessed. The patients were randomly divided into a derivation-cohort and a validation-cohort at a ratio of 7:3. Patients were further categorized based on their disease activity states using cDAPSA (remission/low disease activity and moderate/high disease activity). Least absolute shrinkage and selection operator (LASSO) was used to select biomarkers which were associated with moderate/high disease activity in the derivation cohort. Receiver operating characteristic (ROC) curve, GiViTI calibration belt were used to assess the performance of the model in both cohorts.

RESULTS

The cohort [age: 55.5 (44.0-62.75) years, male: 80 (45.5 %)] had moderate disease activity [DAPSA: 15.9 (8.3-26.9); PASI: 3.2 (0.5-6.8)]. 101 PsA patients (57.4 %) had clinical DAPSA moderate/high disease activity. Biomarker levels associated with moderate/high disease activity included SAA (Serum amyloid A), IL-8 (Interleukin 8), IP10 (Interferon gamma-induced protein 10)/CXCL10, M-CSF (Macrophage colony-stimulating factor), SCGF-β (Stem cell growth factor), SDF-1α (Stromal cell-derived factor 1α)/CXCL12. The model's equation including the 6 biomarker levels was applied to the validation-cohort. The area under the ROC curve (AUC) for discriminating moderate/high disease activity was 0.802 and 0.835 for the derivation-and-validation-cohorts, respectively. The multi-biomarkers panel model had higher-AUC when compared with that of C-reactive protein (CRP) (AUC = 0.727, p = 0.022). The P-values of calibration charts in the two sets were 0.902 and 0.123.

CONCLUSIONS

The multi-biomarkers panel demonstrated the ability to discriminate patients with moderate/high disease activity from those with low disease activity/remission.

Serum Interleukin (IL)-6, Lipid Profile, and Association With Disease Severity in Patients With Psoriasis: A Cross-Sectional Study

OBJECTIVES

This study estimated the lipid profile and inflammatory biomarker (interleukin-6, IL-6) levels in patients with psoriasis and explored the association between lipid profiles and inflammatory biomarkers (IL-6) in assessing the severity of the disease.

METHODOLOGY

This cross-sectional study was conducted in the Department of Biochemistry, in association with the Department of Dermatology, at the Veer Surendra Sai Institute of Medical Sciences and Research, Burla, from November 2022 to June 2023. A fully automated analyzer (Cobas C311, Roche Diagnostics, Mannheim, Germany) was used to estimate the lipid profile, while the enzyme-linked immunosorbent assay (Erba, Transasia Bio-medicals Ltd., Mumbai, India) was used to estimate the inflammatory marker (IL-6). Data were analyzed using Statistical Package for the Social Sciences version 21.0 (IBM Corp., Armonk, NY). An unpaired t-test was conducted to examine the relationship between two variables. A p value of <0.05 was considered significant. The correlation among IL-6, lipid profile, and psoriasis area severity index (PASI) score was analyzed using Pearson's correlation coefficient. Quantitative data were expressed as means and standard deviations.

RESULTS

Of the 102 study participants, 68 had psoriasis alone, and 34 had psoriasis with arthritis (psoriatic arthritis, PsA). Higher mean serum concentrations of IL-6, total cholesterol (TC), low-density lipoprotein, and triglycerides were found in patients with PsA compared to those with psoriasis alone. In patients with PsA, TC and IL-6 showed a strong positive correlation with the PASI score. In contrast, high-density lipoprotein showed a negative correlation with PASI (r = -0.036, p < 0.05).

CONCLUSION

In conclusion, our study revealed lipid profile abnormalities and increased IL-6 activity in PsA patients. By measuring inflammatory markers (IL-6) and lipid profiles early in the disease process, we can employ preventive strategies to better manage and improve survival and quality of life in patients with psoriasis.

The association between endoplasmic reticulum aminopeptidase 2 gene single nucleotide polymorphisms and the risk of psoriasis and psoriatic arthritis in Egyptians

BACKGROUND

Psoriasis (Ps) is a disorder attributed to the immune system that involves inflammation of the skin and joints. Psoriasis is a multifactorial disorder in which genetic factors represent about 70% of the disease risk. This study aims to establish the correlation between the ERAP2 gene's single nucleotide polymorphisms (SNPs) rs2910686 and rs2248374 with the susceptibility to Ps and/or psoriatic arthritis (PsA) among the Egyptian population.

METHODS AND RESULTS

Genotyping of ERAP2 gene SNPs (rs2910686 and rs2248374) in 120 psoriatic patients with and without arthritis and 100 controls was done using real-time PCR. The genotype frequency and distribution of the ERAP2 SNP (rs2910686 and rs2248374) were in Hardy-Weinberg equilibrium (HWE). For rs2910686, the TC and CC genotypes and C allele frequency were significant risk factors for PsA compared to the controls (OR = 5.708, OR = 10.165, and OR = 4.282, respectively). They also were significant risk factors for Ps compared to the controls (OR = 5.165, OR = 5.040, and OR = 3.258, respectively). For rs2248374, the AG genotype significantly increased the risk of PsA (OR = 2.605) and Ps (OR = 3.768) compared to controls. The AG genotype was significantly related to the risk of Ps (OR = 3.369) G allele with PsA (OR = 1.608) and Ps (OR = 1.965) compared to controls.

CONCLUSION

In Egyptian individuals, the ERAP2 gene polymorphisms (rs2248374 and rs2910686) may contribute genetically to the pathophysiology of psoriasis and PsA.

Differences between psoriatic arthritis and psoriasis in multi-omics

We aim to systemically review the genomics, transcriptomics, epigenetics, proteomics, metabonomics and microbiota of psoriatic arthritis and psoriasis, illustrating the differences of these two diseases, broadening our understanding of the pathogenesis of them and providing important clues for valuable biomarkers of earlier diagnosis and treatments. To our knowledge, this is the first study that combine all omics studies from genomics to microbiota and may serve as a reference for future studies to identify the key underlying pathways in psoriatic arthritis.

Certolizumab pegol effectiveness, survival and safety in patients with psoriasis: A multicenter retrospective analysis in daily clinical practice by the Spanish Psoriasis Group

BACKGROUND

Certolizumab is an Fc-free PEGylated tumor necrosis factor-alpha (TNFα) inhibitor recently approved for the treatment of moderate-to-severe plaque psoriasis, although there is limited real-world evidence on the effectiveness and safety in patients with plaque psoriasis treated with certolizumab. The objective of this article is to determine the effectiveness, drug survival, and safety, including pregnancy, childbirth, and lactation, of certolizumab in moderate-to-severe plaque psoriasis under real-world conditions.

METHODS

This is a retrospective, multicenter, observational study performed in 15 hospitals in Spain. It evaluates the effectiveness and safety of certolizumab in plaque psoriasis in the clinical practice setting.

RESULTS

A total of 67 patients (73% female) were evaluated with a mean baseline Psoriasis Area Severity Index (PASI) of 8.9. At Week 12, the mean PASI was 2.3 (n = 67), 1.3 (n = 57) at Week 24 and 1.3 at Week 52 (n = 34). Absolute PASI < 3 was achieved in 69, 86, and 92% of patients at Weeks 12, 24, and 52, respectively, as observed. For its part, using the under-response imputation analysis, PASI < 3 at Weeks 12, 24, and 52 were achieved by 69, 73, and 49% of the patients, respectively. A total of 35 patients (52%) had concomitant psoriatic arthritis, and, in 24 of them, Disease Activity in Psoriatic Arthritis Score (DAPSA) was recorded at baseline, with a mean value of 17.9 which decreased to 8.2 at Week 12 (n = 22) and to 3.6 at Week 24 (n = 18). Certolizumab treatment was discontinued in 14 out of 67 patients (21%), due to lack/loss of cutaneous or articular effectiveness (n = 11) or patient decision (n = 2) or adverse event in only one patient who developed active tuberculosis. A lower baseline PASI [hazard ratio (HR): 1.12 (1.02-1.23); P = 0.023] and a more significant reduction in PASI at Week 12 [HR: 1.16 (1.07-1.27); P < 0.001] and Week 52 [HR: 1.47 (1.11-1.96); P = 0.007] was shown to be significantly related with better survival for the entire follow-up period. Fourteen patients were treated during pregnancy and/or lactation without reporting adverse events in either the patient or the newborn.

CONCLUSIONS

Certolizumab consistently showed high effectiveness and drug survival rates in this real-life cohort. The safety demonstrated in clinical trials during pregnancy and lactation seems to be confirmed in clinical practice.

Dynamics of inflammation-associated plasma proteins following faecal microbiota transplantation in patients with psoriatic arthritis and healthy controls: exploratory findings from the FLORA trial

OBJECTIVES

The gut microbiota can mediate both pro and anti-inflammatory responses. In patients with psoriatic arthritis (PsA), we investigated the impact of faecal microbiota transplantation (FMT), relative to sham transplantation, on 92 inflammation-associated plasma proteins.

METHODS

This study relates to the FLORA trial cohort, where 31 patients with moderate-to-high peripheral PsA disease activity, despite at least 3 months of methotrexate treatment, were included in a 26-week, double-blind, randomised, sham-controlled trial. Participants were allocated to receive either one gastroscopic-guided healthy donor FMT (n=15) or sham (n=16). Patient plasma samples were collected at baseline, week 4, 12 and 26 while samples from 31 age-matched and sex-matched healthy controls (HC) were collected at baseline. Samples were analysed using proximity extension assay technology (Olink Target-96 Inflammation panel).

RESULTS

Levels of 26 proteins differed significantly between PsA and HC pre-FMT (adjusted p<0.05), of which 10 proteins were elevated in PsA: IL-6, CCL20, CCL19, CDCP1, FGF-21, HGF, interferon-γ (IFN-γ), IL-18R1, monocyte chemotactic protein 3, and IL-2. In the FMT group, levels of 12 proteins changed significantly across all timepoints (tumour necrosis factor (TNF), CDCP1, IFN-γ, TWEAK, signalling lymphocytic activation molecule (SLAMF1), CD8A, CD5, Flt3L, CCL25, FGF-23, CD6, caspase-8). Significant differences in protein levels between FMT and sham-treated patients were observed for TNF (p=0.002), IFN-γ (p=0.011), stem cell factor (p=0.024), matrix metalloproteinase-1 (p=0.038), and SLAMF1 (p=0.042). FMT had the largest positive effect on IFN-γ, Axin-1 and CCL25 and the largest negative effect on CCL19 and IL-6.

CONCLUSIONS

Patients with active PsA have a distinct immunological plasma protein signature compared with HC pre-FMT. FMT affects several of these disease markers, including sustained elevation of IFN-γ.

TRIAL REGISTRATION NUMBER

NCT03058900.

Conundrum for Psoriasis and Thyroid Involvement

Strategies concerning thyroid anomalies in patients confirmed with psoriasis, either on clinical level or molecular levels, and their genetic findings remain an open issue. Identification of the exact subgroup of individuals that are candidates to endocrine assessments is also controversial. Our purpose in this work was to overview clinical and pathogenic data concerning psoriasis and thyroid comorbidities from a dual perspective (dermatologic and endocrine). This was a narrative review of English literature between January 2016 and January 2023. We included clinically relevant, original articles with different levels of statistical evidence published on PubMed. We followed four clusters of conditions: thyroid dysfunction, autoimmunity, thyroid cancer, and subacute thyroiditis. A new piece of information in this field was the fact that psoriasis and autoimmune thyroid diseases (ATD) have been shown to be related to the immune-based side effects of modern anticancer drugs-namely, immune checkpoint inhibitors (ICP). Overall, we identified 16 confirmatory studies, but with heterogeneous data. Psoriatic arthritis had a higher risk of positive antithyroperoxidase antibodies (TPOAb) (25%) compared to cutaneous psoriasis or control. There was an increased risk of thyroid dysfunction versus control, and hypothyroidism was the most frequent type of dysfunction (subclinical rather than clinical), among thyroid anomalies correlated with >2-year disease duration, peripheral > axial and polyarticular involvement. With a few exceptions, there was a female predominance. Hormonal imbalance included, most frequently, low thyroxine (T4) and/or triiodothyronine (T3) with normal thyroid stimulating hormone (TSH), followed by high TSH (only one study had higher total T3). The highest ratio of thyroid involvement concerning dermatologic subtypes was 59% for erythrodermic psoriasis. Most studies found no correlation between thyroid anomalies and psoriasis severity. Statistically significant odds ratios were as follows: hypothyroidism: 1.34-1.38; hyperthyroidism: 1.17-1.32 (fewer studies than hypo); ATD: 1.42-2.05; Hashimoto's thyroiditis (HT): 1.47-2.09; Graves' disease: 1.26-1.38 (fewer studies than HT). A total of 8 studies had inconsistent or no correlations, while the lowest rate of thyroid involvement was 8% (uncontrolled studies). Other data included 3 studies on patients with ATD looking for psoriasis, as well as 1 study on psoriasis and thyroid cancer. ICP was shown to potentially exacerbate prior ATD and psoriasis or to induce them both de novo (5 studies). At the case report level, data showed subacute thyroiditis due to biological medication (ustekinumab, adalimumab, infliximab). Thyroid involvement in patients with psoriasis thus remained puzzling. We observed significant data that confirmed a higher risk of identifying positive antibodies and/or thyroid dysfunction, especially hypothyroidism, in these subjects. Awareness will be necessary to improve overall outcomes. The exact profile of individuals diagnosed with psoriasis who should be screened by the endocrinology team is still a matter of debate, in terms of dermatological subtype, disease duration, activity, and other synchronous (especially autoimmune) conditions.

Matrix Metalloproteinases; A Biomarker of Disease Activity and Prognosis in Spondyloarthritis: A Narrative Review

BACKGROUND

Matrix metalloproteinases, as components of the proteolytic system, are deemed to be implicated in the pathogenesis and progression of several rheumatic diseases. Their role in spondyloarthritis has been investigated by several studies.

OBJECTIVE

This article aims to review and summarize the current knowledge related to metalloproteinases in patients with spondyloarthritis.

METHODS

To examine the association between matrix metalloproteinases and spondyloarthritis, we conducted a narrative review using a literature search in SCOPUS for English-language sources. The search included studies published from the database inception to December 2020.

RESULTS

A total number of 74 articles were included. It was found that levels of matrix metalloproteinases 3 were higher in radiographic axial spondyloarthritis patients and seemed to play a role in the progression of joint damage. The levels of matrix metalloproteinases 1, 2, and 9 were upregulated in psoriatic arthritis patients compared to psoriasis and could identify psoriasis patients who would develop rheumatic manifestations. The levels of matrix metalloproteinases correlated significantly with disease activity in ankylosing spondylitis and decreased upon treatment with Tumor Necrosis Factor inhibitors (TNFi).

CONCLUSION

Excessive matrix metalloproteinases activity is associated with articular destruction. Their levels can reflect disease activity, structural damage, and response to TNFi in patients with spondyloarthritis. Nevertheless, further studies are needed to confirm these results.

Women in rheumatology: major contributions and key discoveries of the twentieth century

In the twentieth century, rheumatology saw an exponential growth. Discoveries in the pathophysiology of rheumatic diseases, progress in research methodology and novel treatments cardinally changed the natural course of rheumatic diseases and revolutionized patient management. Although underrepresented in this field, women have made considerable input in advancing our specialty towards the new era. In this article we acknowledge key scientific discoveries and major contributions made by 18 brilliant women scientists that shaped the field of rheumatology in the twentieth century. We hope that the achievements of these remarkable women will inspire young rheumatologists and researchers.

Validity and reliability of the Turkish version of Psoriasis Epidemiology Screening Tool for the detection of psoriatic arthritis in patients with psoriasis

Objectives

The Psoriasis Epidemiology Screening Tool (PEST) is a simple and useful questionnaire designed to screen arthritis in patients with psoriasis. This study aims to evaluate the validity and reliability of the PEST questionnaire in Turkish patients with psoriasis.

Patients and methods

Between August 2019 and September 2019, a total of 158 adult patients with psoriasis (61 males, 68 females; mean age: 43.1±13.3 years; range, 29.8 to 56.4 years) who were not previously diagnosed with PsA were included. The testing procedure for translation and cultural adaptation was carried out according to the following steps: preparation, forward translation, reconciliation, back-translation/back-translation review, harmonization, finalization, and proofreading. Patients' demographic parameters, comorbidities, PEST, and Toronto Psoriatic Arthritis Screen (ToPAS 2) results were recorded. The patients were, then, assessed by a rheumatologist who was blinded to their PEST scores. The diagnosis of PsA was made according to the Classification criteria for Psoriatic Arthritis (CASPAR). The receiver operating characteristic (ROC) was assessed to obtain the sensitivity and specificity of the PEST questionnaire.

Results

Of the patients, 42 had PsA, while 87 did not. Each parameter of PEST showed a low-high internal consistency ranging from 0.366 to 0.781. When the Question 3 was excluded, Cronbach alpha value increased to 0.866. The Cronbach alpha value of the whole scale was 0.829. The test-retest reliability of the Turkish version of PEST was determined as 0.86 for the total score (ICC=0.866 95% CI: 0.601-0.955; p<0.0001). There was a strong positive correlation between PEST and ToPAS 2 (r=0.763; p<0.001) and a moderate positive correlation between PEST and CASPAR (r=0.455; p<0.001). A cut-off value of ≥3 yielded a sensitivity of 93% and a specificity of 89% for the diagnosis of PsA with the highest Youden's index. The PEST scale was found to have a higher sensitivity, but lower specificity in the head-to-head comparison with ToPAS 2.

Conclusion

The Turkish version of PEST is a reliable and valid tool for screening PsA in Turkish patients with psoriasis.

Biomarkers in psoriatic arthritis: A meta-analysis and systematic review

Introduction

Psoriatic arthritis (PsA) is a chronic inflammatory disease that frequently develops in patients with psoriasis (PsO) but can also occur spontaneously. As a result, PsA diagnosis and treatment is commonly delayed, or even missed outright due to the manifold of clinical presentations that patients often experience. This inevitably results in progressive articular damage to axial and peripheral joints and entheses. As such, patients with PsA frequently experience reduced expectancy and quality of life due to disability. More recently, research has aimed to improve PsA diagnosis and prognosis by identifying novel disease biomarkers.

Methods

Here, we conducted a systematic review of the published literature on candidate biomarkers for PsA diagnosis and prognosis in MEDLINE(Pubmed), EMBase and the Cochrane library with the goal to identify clinically applicable PsA biomarkers. Meta-analyses were performed when a diagnostic bone and cartilage turnover biomarker was reported in 2 or moredifferent cohorts of PsA and control.

Results

We identified 1444 publications and 124 studies met eligibility criteria. We highlighted bone and cartilage turnover biomarkers, genetic markers, and autoantibodies used for diagnostic purposes of PsA, as well as acute phase reactant markers and bone and cartilage turnover biomarkers for activity or prognostic severity purposes. Serum cartilage oligometrix metalloproteinase levels were significantly increased in the PsA sera compared to Healthy Control (HC) with a standardized mean difference (SMD) of 2.305 (95%CI 0.795-3.816, p=0.003) and compared to osteoarthritis (OA) with a SMD of 0.783 (95%CI 0.015-1.551, p=0.046). The pooled serum MMP-3 levels were significantly higher in PsA patients than in PsO patients with a SMD of 0.419 (95%CI 0.119-0.719; p=0.006), but no significant difference was highlighted when PsA were compared to HC. While we did not identify any new genetic biomarkers that would be useful in the diagnosis of PsA, recent data with autoantibodies appear to be promising in diagnosis, but no replication studies have been published.

Conclusion

In summary, no specific diagnostic biomarkers for PsA were identified and further studies are needed to assess the performance of potential biomarkers that can distinguish PsA from OA and other chronic inflammatory diseases.

The causal relationship between psoriasis, psoriatic arthritis, and inflammatory bowel diseases

Psoriasis is more common in patients with inflammatory bowel disease (IBD) than in the general population. Similarly, patients with psoriasis or psoriatic arthritis (PsA) have a higher incidence of IBD. However, whether this association is causal remains unknown. Therefore, we used a two-sample bidirectional Mendelian randomization (MR) analysis to identify this relationship. According to MR analysis, psoriasis and PsA causally increased the odds of developing Crohn's disease (OR = 1.350 (1.066-1.709) P = 0.013; OR = 1.319 (1.166-1.492) P < 0.001). In contrast, MR estimates gave little support to a possible causal effect of psoriasis, PsA, on ulcerative colitis (OR = 1.101 (0.905-1.340) P = 0.335; OR = 1.007 (0.941-1.078) P = 0.831). Similarly, the reverse analysis suggested the Crohn's disease causally increased the odds of psoriasis and PsA (OR = 1.425 (1.174-1.731) P < 0.001; OR = 1.448 (1.156-1.182) P = 0.001), whereas there are no causal association between ulcerative colitis and psoriasis, PsA (OR = 1.192 (0.921-1.542) P = 0.182; OR = 1.166 (0.818-1.664) P = 0.396). In summary, our MR analysis strengthens the evidence for the bidirectional dual causality between psoriasis (including PsA) and Crohn's disease.

Biomarkers of disease progression in people with psoriasis: a scoping review

BACKGROUND

Identification of those at risk of more severe psoriasis and/or associated morbidities offers opportunity for early intervention, reduced disease burden and more cost-effective healthcare. Prognostic biomarkers of disease progression have thus been the focus of intense research, but none are part of routine practice.

OBJECTIVES

To identify and catalogue candidate biomarkers of disease progression in psoriasis for the translational research community.

METHODS

A systematic search of CENTRAL, Embase, LILACS and MEDLINE was performed for relevant articles published between 1990 and December 2021. Eligibility criteria were studies involving patients with psoriasis (any age, n ≥ 50) reporting biomarkers associated with disease progression. The main outcomes were any measure of skin severity or any prespecified psoriasis comorbidity. Data were extracted by one reviewer and checked by a second; studies meeting minimal quality criteria (longitudinal design and/or use of methods to control for confounding) were formally assessed for bias. Candidate biomarkers were identified by an expert multistakeholder group using a majority voting consensus exercise, and mapped to relevant cellular and molecular pathways.

RESULTS

Of 181 included studies, most investigated genomic or proteomic biomarkers associated with disease severity (n = 145) or psoriatic arthritis (n = 30). Methodological and reporting limitations compromised interpretation of findings, most notably a lack of longitudinal studies, and inadequate control for key prognostic factors. The following candidate biomarkers with future potential utility were identified for predicting disease severity: LCE3D, interleukin (IL)23R, IL23A, NFKBIL1 loci, HLA-C*06:02 (genomic), IL-17A, IgG aHDL, GlycA, I-FABP and kallikrein 8 (proteomic), tyramine (metabolomic); psoriatic arthritis: HLA-C*06:02, HLA-B*27, HLA-B*38, HLA-B*08, and variation at the IL23R and IL13 loci (genomic); IL-17A, CXCL10, Mac-2 binding protein, integrin b5, matrix metalloproteinase-3 and macrophage-colony stimulating factor (proteomic) and tyramine and mucic acid (metabolomic); and type 2 diabetes mellitus: variation in IL12B and IL23R loci (genomic). No biomarkers were supported by sufficient evidence for clinical use without further validation.

CONCLUSIONS

This review provides a comprehensive catalogue of investigated biomarkers of disease progression in psoriasis. Future studies must address the common methodological limitations identified herein to expedite discovery and validation of biomarkers for clinical use. What is already known about this topic? The current treatment paradigm in psoriasis is reactive. There is a need to develop effective risk-stratified management approaches that can proactively attenuate the substantial burden of disease. Prognostic biomarkers of disease progression have therefore been the focus of intense research. What does this study add? This review is the first to scope, collate and catalogue research investigating biomarkers of disease progression in psoriasis. The review identifies potentially promising candidate biomarkers for further investigation and highlights common important limitations that should be considered when designing and conducting future studies in this area.

Combined – whole blood and skin fibroblasts- transcriptomic analysis in Psoriatic Arthritis reveals molecular signatures of activity, resistance and early response to treatment

Background

An interplay between immune cells and resident skin and joint stromal cells is implicated in psoriatic arthritis (PsA), yet the mechanisms remain elusive with a paucity of molecular biomarkers for activity and response. Combined transcriptomic and immunophenotypic analysis of whole blood and skin fibroblasts could provide further insights.

Methods

Whole blood RNA-seq was performed longitudinally in 30 subjects with PsA at the beginning, one and six months after treatment, with response defined at six months. As control groups, 10 healthy individuals and 10 subjects with rheumatoid arthritis (RA) were recruited combined with public datasets from patients with psoriasis (PsO) and systemic lupus erythematous (SLE). Differential expression analysis and weighted gene co-expression network analysis were performed to identify gene expression signatures, while deconvolution and flow cytometry to characterize the peripheral blood immune cell profile. In a subset of affected and healthy individuals, RNA-seq of skin fibroblasts was performed and subjected to CellChat analysis to identify the blood-skin fibroblast interaction network.

Results

PsA demonstrated a distinct “activity” gene signature in the peripheral blood dominated by TNF- and IFN-driven inflammation, deregulated cholesterol and fatty acid metabolism and expansion of pro-inflammatory non-classical monocytes. Comparison with the blood transcriptome of RA, PsO, and SLE revealed a “PsA-specific signature” enriched in extracellular matrix remodeling. This was further supported by the skin fibroblast gene expression profile, displaying an activated, proliferating phenotype, and by skin-blood interactome analysis revealing interactions with circulating immune cells through WNT, PDGF and immune-related semaphorins. Of note, resistance to treatment was associated with upregulation of genes involved in TGFβ signaling and angiogenesis and persistent increase of non-classical monocytes. Differentially expressed genes related to platelet activation and hippo signaling discriminated responders and non-responders as early as one month after treatment initiation.

Conclusion

Transcriptome analysis of peripheral blood and skin fibroblasts in PsA reveals a distinct disease activity signature and supports the involvement of skin fibroblasts through their activation and interaction with circulating immune cells. Aberrant TGFβ signaling and persistently increased non-classical monocytes characterize treatment-resistant PsA, with pro-inflammatory pathways related to platelet activation and Hippo signaling predicting early response to treatment.

Cartilage Oligomeric Matrix Protein, Diseases, and Therapeutic Opportunities

Cartilage oligomeric matrix protein (COMP) is an extracellular matrix (ECM) glycoprotein that is critical for collagen assembly and ECM stability. Mutations of COMP cause endoplasmic reticulum stress and chondrocyte apoptosis, resulting in rare skeleton diseases. The bouquet-like structure of COMP allows it to act as a bridging molecule that regulates cellular phenotype and function. COMP is able to interact with many other ECM components and binds directly to a variety of cellular receptors and growth factors. The roles of COMP in other skeleton diseases, such as osteoarthritis, have been implied. As a well-established biochemical marker, COMP indicates cartilage turnover associated with destruction. Recent exciting achievements indicate its involvement in other diseases, such as malignancy, cardiovascular diseases, and tissue fibrosis. Here, we review the basic concepts of COMP and summarize its novel functions in the regulation of signaling events. These findings renew our understanding that COMP has a notable function in cell behavior and disease progression as a signaling regulator. Interestingly, COMP shows distinct functions in different diseases. Targeting COMP in malignancy may withdraw its beneficial effects on the vascular system and induce or aggravate cardiovascular diseases. COMP supplementation is a promising treatment for OA and aortic aneurysms while it may induce tissue fibrosis or cancer metastasis.

Molecular and cellular regulation of psoriatic inflammation

This review highlights the molecular and cellular mechanisms underlying psoriatic inflammation with an emphasis on recent developments which may impact on treatment approaches for this chronic disease. We consider both the skin and the musculoskeletal compartment and how different manifestations of psoriatic inflammation are linked. This review brings a focus to the importance of inflammatory feedback loops that exist in the initiation and chronic stages of the condition, and how close interaction between the epidermis and both innate and adaptive immune compartments drives psoriatic inflammation. Furthermore, we highlight work done on biomarkers to predict the outcome of therapy as well as the transition from psoriasis to psoriatic arthritis.

Assessment of serum and synovial fluid MMP-3 and MPO as biomarkers for psoriatic arthritis and their relation to disease activity indices

Research on biomarkers for the diagnosis and monitoring of psoriatic arthritis (PsA) is ongoing. The purpose of this study was to assess the potential of serum and synovial fluid matrix metalloproteinase-3 (MMP-3) and myeloperoxidase (MPO) as biomarkers for PsA and their relation to disease activity indices. This case-control study involved 156 psoriatic arthritis patients, 50 gonarthrosis patients, and 30 healthy controls. The target parameters were measured with the enzyme-linked immunosorbent assay (ELISA) kits. Serum MMP-3 and MPO levels were elevated in the PsA patients in comparison to the two control groups (p < 0.001) and distinguished PsA from GoA patients and healthy controls with 100% accuracy. Synovial MMP-3 discriminated PsA from GoA patients irrespective of the presence of crystals (AUC = 1.00). PsA patients with crystals in the synovial fluid had elevated synovial MPO (p < 0.001) and were distinguished from PsA patients without crystals with accuracy of 88.50% and from GoA patients with accuracy of 88.30%. Synovial fluid MPO was positively associated with the following indicators of disease activity: VAS (r_s = 0.396); DAPSA (r_s = 0.365); mCPDAI (r_s = 0.323). Synovial MMP-3 showed a weaker positive association with DAPSA (r_s = 0.202) and mCPDAI (r_s = 0.223). Our results suggest that serum MMP-3 and MPO could serve as biomarkers for PsA. Synovial fluid MMP-3 showed a potential as a biomarker for PsA versus GoA. Synovial MPO could be utilized as a marker for the presence of crystals in PsA patients.

Comorbidity in Adult Psoriasis: Considerations for the Clinician

Psoriasis is associated with several comorbidities ranging from cardiovascular comorbidity and mental disorders to other immune mediated inflammatory diseases. However, most of these co-morbidities are often overlooked or diagnosed late. Furthermore, evidence suggests that comorbidities are undertreated. Here, we provide an overview of comorbidities in psoriasis and present a simple rundown of considerations of relevance to the clinician. We hope that this review may raise clinicians' awareness of comorbidities in psoriasis and provide simple guidance regarding screening tools and treatment decisions in psoriasis with comorbidities.

Psoriatic arthritis: prospects for the future

Psoriatic arthritis (PsA) is a form of chronic inflammatory arthritis associated with psoriasis and a multitude of other symptoms, most commonly arthritis, dactylitis, enthesitis and axial involvement. PsA is significantly heterogeneous, with a highly variable clinical course of PsA. Patients may experience significant or mild skin and joint symptoms, with some patients developing rapidly progressing joint destruction and skin symptoms. Despite the range of symptom severity, PsA is frequently associated with significantly impaired quality of life from joint destruction, as well as chronic pain and a range of comorbidities such as depression and cardiovascular disease. Currently, there are no definitive diagnostic tests for PsA, with diagnosis remaining challenging owing to the heterogeneous presentation and course of the disease. Presently, the CASPAR criteria are often used to aid rheumatologists in distinguishing PsA from other inflammatory arthritides. Treatment options for patients have been expanded over the last two decades with the emerging clinical utility of biological therapies. However, early identification and diagnosis of patients and effective disease control remain unmet medical needs within the PsA community. In addition, predicting response to treatment also remains a challenge to rheumatologists. This review highlights the current hurdles faced by healthcare professionals in the diagnosis and management of PsA patients and provides future action points for consideration by the members of the multidisciplinary team who treat PsA patients.

A Systematic Review Characterizing Psoriatic Arthritis Onset and Exacerbation in Patients Receiving Biologic Therapy

Background

While biologic therapies revolutionized treatment of immune-mediated inflammatory diseases (IMIDs), some adverse effects have been noted. This includes the development and exacerbation of PsA in patients on biologic agents, however the outcomes were not extensively explored.

Objective

To perform a systematic review to characterize the outcomes of PsA onset or exacerbation secondary to biologic use.

Methods

MEDLINE and EMBASE search conducted on March 23, 2021 resulted in 18 studies comprised of 64 patients.

Results

Of the 64 patients, 57 (89.1%) experienced new-onset PsA and 7 (10.9%) experienced exacerbation of preexisting PsA following exposure to a biologic; most commonly a TNF-α inhibitor (42.2%, n = 27/64) and IL-12/23 inhibitors (39.1%, n = 25/64). The mean durations of biologic use before PsA onset and exacerbation were 14.8 months and 5.2 months, respectively. Twenty-four patients (44.4%) subsequently switched to an alternate biologic without further reports of PsA-related adverse events. All 64 patients reported a specific treatment for PsA; most commonly discontinuation of the associated biologic agent (32.8%, n = 21/64). Complete resolution of PsA was reported in 35.9% (n = 23/64) of cases, of which 91.3% (n = 21/23) resulted after discontinuation of biologic.

Conclusion

Although we characterized outcomes of PsA induction and exacerbation secondary to biologic use, large-scale studies are required.

Combined Single Cell Transcriptome and Surface Epitope Profiling Identifies Potential Biomarkers of Psoriatic Arthritis and Facilitates Diagnosis via Machine Learning

Early diagnosis of psoriatic arthritis (PSA) is important for successful therapeutic intervention but currently remains challenging due, in part, to the scarcity of non-invasive biomarkers. In this study, we performed single cell profiling of transcriptome and cell surface protein expression to compare the peripheral blood immunocyte populations of individuals with PSA, individuals with cutaneous psoriasis (PSO) alone, and healthy individuals. We identified genes and proteins differentially expressed between PSA, PSO, and healthy subjects across 30 immune cell types and observed that some cell types, as well as specific phenotypic subsets of cells, differed in abundance between these cohorts. Cell type-specific gene and protein expression differences between PSA, PSO, and healthy groups, along with 200 previously published genetic risk factors for PSA, were further used to perform machine learning classification, with the best models achieving AUROC ≥ 0.87 when either classifying subjects among the three groups or specifically distinguishing PSA from PSO. Our findings thus expand the repertoire of gene, protein, and cellular biomarkers relevant to PSA and demonstrate the utility of machine learning-based diagnostics for this disease.

Psoriasis as an Immune-Mediated and Inflammatory Systemic Disease: From Pathophysiology to Novel Therapeutic Approaches

Psoriasis is an immune-mediated inflammatory disease, with a chronic relapsing-remitting course, which affects 2–3% of the worldwide population. The progressive acquisitions of the inflammatory pathways involved in the development of psoriasis have led to the identification of the key molecules of the psoriatic inflammatory cascade. At the same time, psoriasis therapy has radically evolved with the introduction of target molecules able to modify the natural history of the disease, acting specifically on these inflammatory pathways. For these reasons, biologics have been demonstrated to be drugs able to change the disease’s natural history, as they reduce the inflammatory background to avoid irreversible organ damage and prevent systemic complications. However, several issues related to the use of biologics in patients with systemic comorbidities, remain open. All these data reflect the extraordinary potentiality of biologics, but also the unmet medical need to improve our knowledge on the long-term risk related to continuous use of these drugs, and their administration in special populations. This narrative review aims to highlight both the efficacy and safety profile of biologics in psoriasis, starting from pathophysiology and moving towards their clinical application.

Early Origins of Psoriatic Arthritis: Clinical, Genetic and Molecular Biomarkers of Progression From Psoriasis to Psoriatic Arthritis

Greater than 90% of patients with psoriatic arthritis (PsA) first develop their arthritis on a background of known psoriasis (Pso). Thus, having skin/nail Pso certainly is an important risk factor for PsA but as PsA develops in <30% of those affected with Pso, the presence of Pso alone is insufficient as a means of identifying which patients with Pso will develop PsA. It is hoped that with further molecular assessment of Pso patients who do not have any evidence of inflammatory musculoskeletal disease compared to those with early PsA features, that the “at risk” profile of Pso patients destined to develop PsA can be refined such that disease prevention studies can be designed and a new era of treatment for PsA can emerge. In this article, the early stages in the development of PsA are outlined and what is currently known about clinical features, genetic factors and soluble or tissue biomarkers associated with the development of PsA in patients with Pso is reviewed in detail. Finally, proposals are outlined regarding the approaches required in order to address this important research area.

Clinical, laboratory, and genetic markers for the development or presence of psoriatic arthritis in psoriasis patients: a systematic review

Twenty to thirty percent of psoriasis (Pso) patients will develop psoriatic arthritis (PsA). Detection of Pso patients that are (at risk for) developing PsA is essential to prevent structural damage. We conducted a systematic search of five bibliographic databases, up to May 2020. We searched for studies assessing markers (clinical, laboratory, genetic) associated with the development or presence of PsA in Pso patients. Study selection and quality assessment of the included studies was performed, followed by a qualitative best evidence synthesis to determine the level of evidence for a marker and its association with concomitant/developing PsA in Pso. Overall, 259 possible markers were identified in 119 studies that met the inclusion criteria. Laboratory markers related to inflammation and bone metabolism reached a strong level of evidence for the association (not prediction) of PsA in Pso. Only CXCL10 showed strong evidence for a positive predictive value for PsA in Pso. The importance of timely detecting PsA in a Pso population, and finding more (bio)markers contributing to early detection, remains high.

Identification and Evaluation of Serum Protein Biomarkers Which Differentiate Psoriatic from Rheumatoid Arthritis

OBJECTIVES

To identify serum protein biomarkers which might separate early inflammatory arthritis (EIA) patients with psoriatic arthritis (PsA) from those with rheumatoid arthritis (RA) and may be used to support appropriate early intervention.

METHODS

The serum proteome of patients with PsA and RA was interrogated using nano-flow liquid chromatography mass spectrometry (nLC-MS/MS) (n=64 patients), an aptamer-based assay (SOMAscan) targeting 1,129 proteins (n=36 patients) and a multiplexed antibody assay (Luminex) for 48 proteins (n=64 patients). Multiple reaction monitoring assays (MRM) were developed to evaluate the performance of putative markers using the discovery cohort (n=60) and subsequently an independent cohort of PsA and RA patients (n=167).

RESULTS

Multivariate machine learning analysis of the protein discovery data from the three platforms revealed that it was possible to discriminate PsA from RA patients with an area under the curve (AUC) of 0.94 for nLC-MS/MS, 0.69 for bead based immunoassay measurements and 0.73 for aptamer based analysis. Subsequently in the separate verification and evaluation studies, random forest models revealed that a subset of proteins measured by MRM could differentiate PsA and RA patients with AUCs of 0.79 and 0.85 respectively.

CONCLUSION

We report a serum protein biomarker panel which can separate EIA patients with PsA from those with RA. With continued evaluation and refinement using additional and larger patient cohorts including those with other arthropathies we suggest the panel identified here could contribute toward improved clinical decision making.

Unmet needs in psoriatic arthritis

Psoriatic arthritis (PsA) is a chronic inflammatory arthritis with a highly variable clinical presentation that does not have a validated molecular or imaging test, making accurate diagnosis a challenge. Consequences of diagnostic delay include irreversible joint damage and significant morbidity. Over the past few decades, there have been major advances in the understanding and treatment of PsA, leading to more targeted therapies. However, there is no current method to predict optimal treatment strategy to achieve minimal disease activity and prevent medication-related adverse events in the management of early disease. PsA is also associated with other comorbidities that include metabolic syndrome and psychosocial burden; two areas that are often unaddressed in the clinical setting and have associated sequelae. This chapter focuses on key domains of unmet needs, which include diagnostic challenges, delay in diagnosis, prognostication systems and stratified medicine approaches and precision medicine strategies for established and emerging therapies.

Clinical Burden of Concomitant Joint Disease in Psoriasis: A US-Linked Claims and Electronic Health Records Database Analysis

BACKGROUND

Few studies have evaluated the clinical burden of concomitant joint disease in patients with psoriasis (PSO). The objective of this study was to assess comorbidity rates in patients with psoriatic arthritis (PsA) compared with PSO alone.

METHODS

This was a retrospective study of US patients with prevalent PSO. Linked medical claims and electronic health records (EHR) in Optum's de-identified Integrated Claims-Clinical dataset were analyzed from 2007 to 2018. Patients were followed for up to 5 years after the first claim/diagnostic code for PSO (index date). Baseline comorbidity prevalence and follow-up rates (cases per 1000 person-years) were assessed using descriptive statistics. Comorbidity rate analysis included patients with the respective comorbidity at baseline.

RESULTS

Baseline demographics and comorbidity prevalence were numerically similar between patients with concomitant joint disease (PSO-PsA) and those with PSO alone (PSO-only). During follow-up, comorbidity rates were higher in patients in the PSO-PsA group than patients in the PSO-only group. Ratios of PSO-PsA comorbidity rates relative to PSO-only ranged from 1.1 for allergies and infections to 1.7 for fatigue, diabetes, and obesity. Comorbidity rate ratios increased from year 1 to year 5 for hypertension (1.05-1.34), hyperlipidemia (0.94-1.13), diabetes (1.00-1.49), cardiovascular disease (1.03-1.66), depression (0.97-1.19), and anxiety (0.87-0.98).

CONCLUSIONS

Patients with PsA have a larger clinical burden, characterized by higher comorbidity rates, than those with PSO. Future research should explore PsA risk factors and how physicians can monitor and treat patients with PSO to reduce the risk of PsA and the associated clinical burden.

Psoriatic arthritis screening: A systematic literature review and experts' recommendations

OBJECTIVE

To analyze the performance of psoriatic arthritis (PsA) screening tools, examine their implementation in daily practice, and reach a consensus about the best screening tool for implementation in daily practice in different medical settings.

METHODS

A systematic literature review (SLR), structured telephone interviews to hospitals, and a multidisciplinary nominal group meeting were all conducted. The SLR employed sensitive search strategies using Medline, Embase, and the Cochrane Library up to January 2020. Two reviewers independently selected articles that reported data on PsA screening tools and that included sufficient data to at least calculate the sensitivity and specificity of those tools (e.g., questionnaires, algorithms, specific questions, and biomarkers). The hospital interviews collected data regarding the process of suspected PsA diagnosis and referral to rheumatology, the implementation of PsA screening tools, and barriers and facilitators to implementation of those tools. In the nominal group meeting, a multidisciplinary team of experts discussed all these data and subsequently recommended a screening tool for implementation.

RESULTS

The SLR included 41 moderate-quality studies that analyzed 14 PsA screening tools, most of which were questionnaire-based tools. All of these studies reported a moderate-good performance but presented different characteristics regarding the time to completion or the number and type of items or questions. The implementation of screening tools was low (30.5%). The experts ultimately recommended regular use of a PsA screening tool, preferably the PURE-4 questionnaire.

CONCLUSIONS

The implementation of PsA screening tools like the PURE-4 questionnaire in daily practice likely improves the prognosis of PsA patients.

Broad proteomic screen reveals shared serum proteomic signature in patients with psoriatic arthritis and psoriasis without arthritis

OBJECTIVE

To identify novel serum proteins involved in the pathogenesis of PsA as compared with healthy controls, psoriasis (Pso) and AS, and to explore which proteins best correlated to major clinical features of the disease.

METHODS

A high-throughput serum biomarker platform (Olink) was used to assess the level of 951 unique proteins in serum of patients with PsA (n = 20), Pso (n = 18) and AS (n = 19), as well as healthy controls (HC, n = 20). Pso and PsA were matched for Psoriasis Area and Severity Index (PASI) and other clinical parameters.

RESULTS

We found 68 differentially expressed proteins (DEPs) in PsA as compared with HC. Of those DEPs, 48 proteins (71%) were also dysregulated in Pso and/or AS. Strikingly, there were no DEPs when comparing PsA with Pso directly. On the contrary, hierarchical cluster analysis and multidimensional scaling revealed that HC clustered distinctly from all patients, and that PsA and Pso grouped together. The number of swollen joints had the strongest positive correlation to ICAM-1 (r = 0.81, P < 0.001) and CCL18 (0.76, P < 0.001). PASI score was best correlated to PI3 (r = 0.54, P < 0.001) and IL-17 receptor A (r = -0.51, P < 0.01). There were more proteins correlated to PASI score when analysing Pso and PsA patients separately, as compared with analysing Pso and PsA patients pooled together.

CONCLUSION

PsA and Pso patients share a serum proteomic signature, which supports the concept of a single psoriatic spectrum of disease. Future studies should target skin and synovial tissues to uncover differences in local factors driving arthritis development in Pso.

Serum Biomarkers of Inflammation and Turnover of Joint Cartilage Can Help Differentiate Psoriatic Arthritis (PsA) Patients from Osteoarthritis (OA) Patients

The aim of this study was to find characteristic biomarkers in the serum of patients with osteoarthritis (OA) and psoriatic arthritis (PsA) responsible for inflammation and destruction of joint cartilage, which could differentiate these two diseases. The study included 67 people: 22 patients with knee OA, 22 patients with PsA, and 23 individuals who were the control group of healthy individuals (HC). The concentration of IL-18, IL-20, IL-6, MMP-1, MMP-3, COMP, PG-AG, and YKL-40 in serum were determined. Among the OA and PsA patients group, the radiological assessment and clinical assessment were also performed. The concentration of 7 out of 8 of examined biomarkers (except MMP-1) was statistically significantly higher in the serum of patients with OA and PsA than in the control group. Compering OA and PsA groups only, the serum PG-AG level in OA patients was statistically significantly higher than in PsA patients (p < 0.001). The results of univariate and multivariate logistic regression analysis comparing OA and PsA biomarker serum levels identified PG-AG and COMP as markers that are significantly different between patients with OA and PsA (odds ratio 0.995 and 1.003, respectively). The ROC curve constructed using the model with age showed PG-AG and COMP had an AUC of 0.907. The results of this study show that COMP and PG-AG may be sensitive markers differentiating patients with osteoarthiritis from psoriatic arthritis.

Bone phenotypes in rheumatology - there is more to bone than just bone

Osteoarthritis, rheumatoid arthritis, psoriatic arthritis, and ankylosing spondylitis, all have one clear common denominator; an altered turnover of bone. However, this may be more complex than a simple change in bone matrix and mineral turnover. While these diseases share a common tissue axis, their manifestations in the area of pathology are highly diverse, ranging from sclerosis to erosion of bone in different regions. The management of these diseases will benefit from a deeper understanding of the local versus systemic effects, the relation to the equilibrium of the bone balance (i.e., bone formation versus bone resorption), and the physiological and pathophysiological phenotypes of the cells involved (e.g., osteoblasts, osteoclasts, osteocytes and chondrocytes). For example, the process of endochondral bone formation in chondrocytes occurs exists during skeletal development and healthy conditions, but also in pathological conditions. This review focuses on the complex molecular and cellular taxonomy of bone in the context of rheumatological diseases that alter bone matrix composition and maintenance, giving rise to different bone turnover phenotypes, and how biomarkers (biochemical markers) can be applied to potentially describe specific bone phenotypic tissue profiles.

Is there any association between psoriasis, psoriatic arthritis and thyroid autoimmunity?

BACKGROUND

Autoimmune diseases share a significant part of their genetic background and tend to coexist in the same patient. Some studies have investigated the possible association between autoimmune thyroiditis and psoriasis or psoriatic arthritis (PsA), with conflicting results. This study aimed to investigate the prevalence of autoimmune thyroiditis in psoriatic patients with (PsA) or without (PsC) joint involvement.

METHODS

208 patients with psoriasis and/or PsA were recruited. These patients were divided into two groups: psoriasis patients (without PsA) (PsC group: 100 patients; mean age of 50.1 ± 11.7 years) and subjects with psoriasis and psoriatic arthritis (PsA group: 108 subjects: mean age of 39.8 ± 10.8 years). Assessment of psoriasis severity was conducted using the Psoriasis Area and Severity Index (PASI) score. The diagnosis of psoriatic arthritis was made according to CASPAR criteria. All patients had thyroid evaluation through evaluation of thyroid function, thyroperoxidase antibodies and thyroid ultrasound examination.

RESULTS

A statistically significant difference was found between the prevalence of autoimmune thyroiditis in the PsA group than the PsC group (25.9 vs 9.0 %; P = 0.018) with higher trends to hypothyroidism in the PsA group compared to the PsC group (13.9% vs 2.0%, P = 0.0018).

CONCLUSIONS

The higher prevalence of autoimmune thyroiditis in the PsA group may be due to an immune dysfunction pathway in patients with psoriatic arthritis with a higher risk to develop other autoimmune diseases. This evidence confirms that psoriatic arthritis is an autoimmune disease with an overactive immune system that can involve multiple organs. Thyroid function evaluation should be part of the clinical and laboratory examination of patients with psoriatic arthritis.

Applying precision medicine to unmet clinical needs in psoriatic disease

Psoriatic disease (PsD) is a heterogeneous condition that can affect peripheral and axial joints (arthritis), entheses, skin (psoriasis) and other structures. Over the past decade, considerable advances have been made both in our understanding of the pathogenesis of PsD and in the treatment of its diverse manifestations. However, several major areas of continued unmet need in the care of patients with PsD have been identified. One of these areas is the prediction of poor outcome, notably radiographic outcome in patients with psoriatic arthritis, so that stratified medicine approaches can be taken; another is predicting response to the numerous current and emerging therapies for PsD, so that precision medicine can be applied to rapidly improve clinical outcome and reduce the risk of toxicity. In order to address these needs, novel approaches, including imaging, tissue analysis and the application of proteogenomic technologies, are proposed as methodological solutions that will assist the dissection of the critical immune-metabolic pathways in this complex disease. Learning from advances made in other inflammatory diseases, it is time to address these unmet needs in a multi-centre partnership aimed at improving short-term and long-term outcomes for patients with PsD.

Ab locks for improving the selectivity and safety of antibody drugs

Monoclonal antibodies (mAbs) are a major targeted therapy for malignancies, infectious diseases, autoimmune diseases, transplant rejection and chronic inflammatory diseases due to their antigen specificity and longer half-life than conventional drugs. However, long-term systemic antigen neutralization by mAbs may cause severe adverse events. Improving the selectivity of mAbs to distinguish target antigens at the disease site from normal healthy tissue and reducing severe adverse events caused by the mechanisms-of-action of mAbs is still a pressing need. Development of pro-antibodies (pro-Abs) by installing a protease-cleavable Ab lock is a novel and advanced recombinant Ab-based strategy that efficiently masks the antigen binding ability of mAbs in the normal state and selectively "turns on" the mAb activity when the pro-Ab reaches the proteolytic protease-overexpressed diseased tissue. In this review, we discuss the design and advantages/disadvantages of different Ab lock strategies, focusing particularly on spatial-hindrance-based and affinity peptide-based approaches. We expect that the development of different masking strategies for mAbs will benefit the local reactivity of mAbs at the disease site, increase the therapeutic efficacy and safety of long-term treatment with mAbs in chronic diseases and even permit scientists to develop Ab drugs for formerly undruggable targets and satisfy the unmet medical needs of mAb therapy.

Beyond skin deep: addressing comorbidities in psoriasis

Psoriasis is a chronic inflammatory disease that is commonly encountered in primary care and is associated with significant morbidity that extends beyond the skin manifestations. Psoriasis is associated with an elevated risk of psoriatic arthritis, cardiovascular disease, obesity, insulin resistance, mental health disorders, certain types of malignancy, inflammatory bowel disease and other immune-related disorders, and hepatic and renal disease. Enhanced recognition of these comorbidities may lead to earlier diagnosis and potentially better overall health outcomes. Psoriatic nail involvement, severe skin disease and obesity are associated with a greater risk of psoriatic arthritis. Individuals with psoriasis should be routinely screened for psoriatic arthritis to allow for early intervention to improve long term prognosis. Life expectancy is reduced in people with psoriasis due to a variety of causes, with cardiovascular disease and malignancy being the most common aetiologies. Psoriasis affects several factors that contribute to worsened quality of life and increased risk of depression and anxiety. Effective therapies are now available that have been shown to concurrently improve skin disease, quality of life and psychiatric symptoms. As the concordance between psychosocial impact and objective disease severity does not always correlate, it is essential to tailor management strategies specifically to the needs of each individual. Cigarette smoking and excess alcohol consumption are among the most important modifiable risk factors that increase the likelihood of psoriasis development and severity of skin disease. This provides a compelling rationale for smoking cessation and limiting alcohol intake in people with psoriasis beyond their traditional harmful health consequences.

Interleukin-18, interleukin-20, and matrix metalloproteinases (MMP-1, MMP-3) as markers of psoriatic arthritis disease severity and their correlations with biomarkers of inflammation and turnover of joint cartilage

Introduction

Psoriatic arthritis (PsA) is a chronic, seronegative spondyloarthropathy characterised by joint inflammation and psoriatic skin changes. Recent data indicate that interleukin-18 (IL-18) and interleukin-20 (IL-20) may be involved in the aetiopathogenesis of PsA.

Aim

To evaluate the potential role of IL-18, IL-20, and matrix metalloproteinases (MMP-1, MMP-3) in the pathogenesis of PsA and their correlations with other markers of inflammation and destruction of joint cartilage, as well as clinical changes.

Material and methods

The study included 24 patients with PsA and 26 healthy volunteers as a control group. The concentration of IL-18 and IL-20, c-reactive protein (CRP), metalloproteinase-1 and -3 (MMP-1, MMP-3), cartilage oligomeric matrix protein (COMP), aggrecan (PG-AG), and human cartilage glycoprotein (YKL-40) in serum was determined. Clinical severity of the disease according to the BSA, PASI, and DLQI as well as tender and swollen joint count (TJC, SJC) were also evaluated.

Results

The concentration of IL-18 was statistically significantly higher in the serum of patients with PsA than in the control group (62.87 pg/ml vs. 16.73 pg/ml, p < 0.0049). Serum IL-20 levels in PsA patients were also higher than in the control group, but without statistical significance (p = 0.2939). The ROC curves showed: AUC = 0.81 for IL-18, AUC = 0.75 for IL-20, AUC = 0.96 for COMP, and AUC = 0.89 for MMP-3.

Conclusions

IL-18 and IL-20 as well as MMP-3 and COMP may be sensitive markers in the diagnosis of PsA.

Challenges in the clinical diagnosis of psoriatic arthritis

Psoriatic arthritis (PsA) is a chronic heterogeneous inflammatory musculoskeletal disease. The non-specific and often subtle manifestations make early diagnosis and subsequent treatment challenging. In the absence of diagnostic criteria and biomarkers, the diagnosis is often delayed leading to poor long-term outcomes. In addition, the differential diagnosis of a patient presenting with arthritis in the setting of skin psoriasis is wide due to symptom overlap with many other diseases. Peripheral arthritis, dactylitis, enthesitis and axial arthritis are the 4 domains of musculoskeletal involvement in PsA and careful examination of each domain by a rheumatologist is the first step for a correct diagnosis. Other extra-musculoskeletal features such as the presence of uveitis, inflammatory bowel disease, nail psoriasis and elevated acute phase reactants aid in the diagnosis of PsA. Screening patients with skin psoriasis using validated questionnaires might help in early diagnosis especially when coupled with imaging.

Circulating microRNAs in extracellular vesicles as potential biomarkers for psoriatic arthritis in patients with psoriasis

BACKGROUND

Psoriatic arthritis (PsA) develops in ~30% of patients with psoriasis. The diagnosis of PsA is challenging, and there are no reliable molecular markers in clinical use. MicroRNAs are short non-coding regulatory RNAs, which can be actively packaged into extracellular vesicles (EVs) and secreted to the circulation.

OBJECTIVES

To explore whether plasma-derived EV microRNAs may serve as biomarkers for PsA in patients with psoriasis.

METHODS

Plasma samples were obtained from patients with cutaneous-only psoriasis (PsC) and patients with psoriasis and PsA. Plasma EVs were isolated using miRCURY™ Exosome Isolation Kit. RNA sequencing was used to identify differentially expressed EV miRNAs in the discovery phase (PsC, n = 15; PsA, n = 14). In the validation phase (PsC, n = 29; PsA, n = 28), 41 selected miRNAs were analysed in plasma EVs by qPCR. The association of the identified miRNAs with PsA was assessed by logistic regression analysis.

RESULTS

RNA sequencing identified 19 plasma EV miRNAs with significantly different levels between PsA and PsC in the discovery cohort. Significantly lower levels of plasma EV let-7b-5p and miR-30e-5p in PsA vs. PsC were confirmed in the validation cohort, and their decreased levels were found to be associated with the presence of PsA. ROC analysis revealed an AUC of 0.68 (95% CI 0.53-0.83) for let-7b-5p and 0.69 (95% CI 0.55-0.84) for miR-30e-5p.

CONCLUSIONS

Circulating EV microRNA levels are altered in patients with PsA as compared with PsC. Findings of this exploratory study suggest that circulating EV microRNAs may serve as biomarkers for arthritis in psoriasis patients.

A set of serum markers detecting systemic inflammation in psoriatic skin, entheseal, and joint disease in the absence of C-reactive protein and its link to clinical disease manifestations

Background

C-reactive protein (CRP) is often normal in patients with psoriatic disease. Herein, we aimed to define markers of systemic inflammation in patients with monomorphic and polymorphic psoriatic skin, entheseal, and joint disease.

Methods

Three-step approach: (i) selection of serum markers elevated in psoriatic arthritis compared healthy controls from a panel of 10 different markers reflecting the pathophysiology of psoriatic disease; (ii) testing of these selected markers as well as C-reactive protein (CRP) in a larger cohort of 210 individuals- 105 healthy controls and 105 patients with psoriatic disease with either monomorphic skin (S), entheseal (E) or joint (A) involvement or polymorphic disease with various combinations of skin, entheseal and joint disease (SE, SA, EA, SEA); (iii) testing whether tumor necrosis factor (TNF) and interleukin (IL)-17 inhibitor therapy normalizes these markers.

Results

CRP was not elevated or was rarely elevated in the subgroups (S 0%, E 0%, A 20%, SE 7%, SA 33%, EA 27%, SEA 33%) despite active psoriatic disease. In sharp contrast, beta-defensin 2 and lipocalin-2 levels were elevated in the majority of patients with monomorphic skin (93% and 73%) and entheseal (both 53%), but not joint disease (27% and 20%). Conversely, elevations of calprotectin and IL-8 were found in the majority of patients with monomorphic joint disease (both 73%). IL-22 was elevated in all three monomorphic disease manifestations (S 60%, E 46%; A 60%). Furthermore, the vast majority of patients with polymorphic psoriatic disease (SE, SA, EA, SEA) showed widespread marker elevation. IL-17- and TNF inhibitor treatment significantly lowered all 5 markers of inflammation in PsA patients.

Conclusions

Systemic inflammation is detectable in the majority of patients with psoriatic disease, even if CRP is normal. The respective marker pattern depends on the manifestation of psoriatic disease with respect to skin, entheseal, and joint involvement.

Differences in Osteoimmunological Biomarkers Predictive of Psoriatic Arthritis among a Large Italian Cohort of Psoriatic Patients

(1) Background: In literature it is reported that 20–30% of psoriatic patients evolve to psoriatic arthritis over time. Currently, no specific biochemical markers can either predict progression to psoriatic arthritis or response to therapies. This study aimed to identify osteoimmunological markers applicable to clinical practice, giving a quantitative tool for evaluating pathological status and, eventually, to provide prognostic support in diagnosis. (2) Methods: Soluble (serum) bone and cartilage markers were quantified in 50 patients with only psoriasis, 50 psoriatic patients with psoriatic arthritis, and 20 healthy controls by means of multiplex and enzyme-linked immunoassays. (3) Results: Differences in the concentrations of matrix metalloproteases (MMPs), tissue inhibitors of metalloproteinases (TIMPs), receptor activator of nuclear factor kappa-B- ligand (RANK-L), procollagen type I N propeptide (PINP), C-terminal telopeptide of type I collagen (CTx-I), dickkopf-related protein 1 (DKK1), and sclerostin (SOST) distinguished healthy controls from psoriasis and psoriatic arthritis patients. We found that MMP2, MMP12, MMP13, TIMP2, and TIMP4 distinguished psoriasis from psoriatic arthritis patients undergoing a systemic treatment, with a good diagnostic accuracy (Area under the ROC Curve (AUC) > 0.7). Then, chitinase-3-like protein 1 (CHI3L1) and MMP10 distinguished psoriasis from psoriatic arthritis not undergoing systemic therapy and, in the presence of onychopathy, MMP8 levels were higher in psoriasis than in psoriatic arthritis. However, in these latter cases, the diagnostic accuracy of the identified biomarkers was low (0.5 < AUC < 0.7). (4) Conclusions. By highlighting never exploited differences, the wide osteoimmunological biomarkers panel provides a novel clue to the development of diagnostic paths in psoriasis and psoriasis-associated arthropathic disease.

The Reliability of Laboratory Testing in Diagnosing Psoriatic Arthritis: A Case Report

Psoriatic arthritis is an uncommon, chronic inflammatory disease. Laboratory testing for psoriatic arthritis, although necessary for a complete work-up, is generally nondiagnostic for most patients. We present a case of a 26-year-old woman with unilateral plantar forefoot pain and swelling that was diagnosed as psoriatic arthritis. The diagnosis was made without the benefit of skin manifestations or definitive laboratory results, other than those from laboratory tests performed for an initial evaluation of acute-phase reactants. Radiographs showed nonspecific subchondral bone changes at a few metatarsophalangeal joints of the involved foot that suggested an inflammatory arthropathy. This case illustrates that the absence of specific serum markers for psoriatic arthritis can make its diagnosis challenging, especially in the absence of dermatologic changes of psoriasis.

Effects of secukinumab on metabolic and liver parameters in plaque psoriasis patients

BACKGROUND

Psoriasis is associated with metabolic, liver and cardiovascular comorbidity. Secukinumab, a fully human monoclonal antibody that selectively neutralizes interleukin-17A, has shown significant and sustained efficacy in the treatment of moderate to severe psoriasis.

OBJECTIVES

This was an exploratory post hoc analysis of pooled data from three phase 3 studies in plaque psoriasis patient populations. The objective was to show the course of metabolic and liver parameters under secukinumab, etanercept or placebo treatment over time. A further objective was to assess the impact of selected comorbidities and metabolic characteristics on high-sensitivity C-reactive protein (hs-CRP), as a surrogate marker of systemic inflammation.

METHODS

Data from the phase 3 randomized controlled trials [FIXTURE (NCT01358578), ERASURE (NCT01365455) and SCULPTURE (NCT01406938); n = 3010] were included in this analysis. Patients were treated with secukinumab 150 mg or 300 mg, placebo or etanercept 50 mg (FIXTURE only) as active comparator. A set of metabolic and liver parameters was longitudinally assessed over 52 weeks. Multivariate regression analyses assessed the impact of selected comorbidities and metabolic characteristics on hs-CRP levels at baseline and under treatment.

RESULTS

Secukinumab treatment reduced hs-CRP levels. Body weight and uric acid levels tended to decrease over 52 weeks with secukinumab. Secukinumab showed a neutral effect on fasting plasma glucose, lipid parameters and liver enzymes. Psoriatic arthritis, metabolic syndrome, obesity, impaired glucose metabolism, and hyperuricemia were each associated with increased hs-CRP levels at baseline. Concomitant obesity attenuated the decline in hs-CRP under treatment.

CONCLUSIONS

These analyses suggest neutral to favourable long-term trends in metabolic and liver parameters under secukinumab treatment. Metabolic comorbidities were associated with increased hs-CRP levels, reflecting the role of systemic inflammatory processes in their pathophysiology.

Psoriatic arthritis

Psoriasis is a multisystemic, inflammatory skin condition that can affect many areas of the body, but most commonly the extensor surfaces of the elbows and knees, and sometimes the intergluteal and umbilical area. It has a prevalence of 2–4% in western adults, and 20­–30% of psoriasis patients will develop psoriatic arthritis (PsA). PsA is an inflammatory musculoskeletal disease associated with cutaneous psoriasis. It affects men and women almost equally with a peak age at onset of 40 and 50 years. It is a diverse disease that affects multiple organ systems includes peripheral and axial joints, entheses, skin, and nails. PsA is associated with comorbidities such as osteoporosis, uveitis, subclinical bowel inflammation, and cardiovascular disease. Given this heterogeneity, its diagnosis has been difficult. Here we present an updated review of its classification criteria CASPAR (classification criteria for PsA), use of screening tools to aid in early diagnosis, recent findings on pathogenesis, and new therapeutic approaches including new biologic medications.

Integrative Approach to Reveal Cell Type Specificity and Gene Candidates for Psoriatic Arthritis Outside the MHC

We recently conducted a large association analysis to compare the genetic profiles between patients with psoriatic arthritis (PsA) and cutaneous-only psoriasis (PsC). Despite including over 7,000 genotyped patients, only the MHC achieved genome-wide significance. In this study, we hypothesized that appropriate epigenomic elements (H3K27ac marks for active enhancers) can guide us to reveal valuable information about the loci with suggestive evidence of association. Our aim is to investigate these loci and explore how they may lead to the development of PsA. We evaluated this potential by investigating the genes connected with these loci from the perspective of pharmacogenomics and gene expression. We illustrated that markers with suggestive evidence of association outside the MHC region are enriched in H3K27ac marks for osteoblast and chondrogenic differentiated cells; using pharmacogenomics resources, we showed that genes near these markers are targeted by existing drugs used to treat psoriatic arthritis. Significantly, six of the ten suggestive significant loci overlapping the regulatory elements encompass genes differentially expressed (FDR < 5%) in differentiated osteoblasts, including genes participating in the Wnt signaling such as RUNX1, FUT8, and CTNNAL1. Our approach shows that epigenomic information can be used as cost-effective approach to enhance the inferences for GWAS results, especially in situations when few genome-wide significant loci are available. Our results also point the way to more directed investigations comparing the genetics of PsA and PsC.

Utilization of the validated Psoriasis Epidemiology Screening Tool to identify signs and symptoms of psoriatic arthritis among those with psoriasis: a cross-sectional analysis from the US-based Corrona Psoriasis Registry

Background

Despite increasing awareness of the disease, rates of undiagnosed psoriatic arthritis (PsA) are high in patients with psoriasis (PsO). The validated Psoriasis Epidemiology Screening Tool (PEST) is a five‐item questionnaire developed to help identify PsA at an early stage.

Objectives

To assess the risk of possible undiagnosed PsA among patients with PsO and characterize patients based on PEST scores.

Methods

This study included all patients enrolled in the Corrona PsO Registry with data on all five PEST questions. Demographics, clinical characteristics and patient‐reported outcomes were compared in Corrona PsO Registry patients with PEST scores ≥3 and <3 using t‐tests for continuous variables and chi‐squared tests for categorical variables; scores ≥3 may indicate PsA.

Results

Of 1516 patients with PsO, 904 did not have dermatologist‐reported PsA; 112 of these 904 patients (12.4%) scored ≥3 and were significantly older, female, less likely to be working, and had higher BMI than patients with scores <3. They also had significantly longer PsO duration, were more likely to have nail PsO and had worse health status, pain, fatigue, Dermatology Life Quality Index and activity impairment.

Conclusions

Improved PsA screening is needed in patients with PsO because the validated PEST identified over one‐tenth of registry patients who were not noted to have PsA as having scores ≥3, who could have had undiagnosed PsA. Appropriate, earlier care is important because these patients were more likely to have nail PsO, worse health‐related quality of life and worse activity impairment.