Psoriatic disease--from skin to bone

Wnt signaling regulates chemokine production and cell migration of circulating human monocytes

The β-catenin dependent canonical Wnt signaling pathway plays a crucial role in maintaining normal homeostasis. However, when dysregulated, Wnt signaling is closely associated with various pathological conditions, including inflammation and different types of cancer.Here, we show a new connection between the leukocyte inflammatory response and the Wnt signaling pathway. Specifically, we demonstrate that circulating human primary monocytes express distinct Wnt signaling components and are susceptible to stimulation by the classical Wnt ligand-Wnt-3a. Although this stimulation increased the levels of β-catenin protein, the expression of the classical Wnt-target genes was not affected. Intriguingly, treating circulating human monocytes with Wnt-3a induces the secretion of cytokines and chemokines, enhancing monocyte migration. Mechanistically, the enhanced monocyte migration in response to Wnt stimuli is mediated through CCL2, a strong monocyte-chemoattractant.To further explore the physiological relevance of these findings, we conducted ex-vivo experiments using blood samples of patients with rheumatic joint diseases (RJD) - conditions where monocytes are known to be dysfunctional. Wnt-3a generated a unique cytokine expression profile, which was significantly distinct from that observed in monocytes obtained from healthy donors.Thus, our results provide the first evidence that Wnt-3a may serve as a potent stimulator of monocyte-driven immune processes. These findings contribute to our understanding of inflammatory diseases and, more importantly, shed light on the role of a core signaling pathway in the circulation.

Investigating causal associations among gut microbiota, metabolites, and psoriatic arthritis: a Mendelian randomization study

Background

Currently, there has been observed a significant alteration in the composition of the gut microbiome (GM) and serum metabolites in patients with psoriatic arthritis (PsA) compared to healthy individuals. However, previous observational studies have shown inconsistent results regarding the alteration of gut microbiota/metabolites. In order to shed light on this matter, we utilized Mendelian randomization to determine the causal effect of GM/metabolites on PsA.

Methods

We retrieved summary-level data of GM taxa/metabolites and PsA from publicly available GWAS statistics. Causal relationships between GM/metabolites and PsA were determined using a two-sample MR analysis, with the IVW approach serving as the primary analysis method. To ensure the robustness of our findings, we conducted sensitivity analyses, multivariable MR analysis (MVMR), and additional analysis including replication verification analysis, LDSC regression, and Steiger test analysis. Furthermore, we investigated reverse causality through a reverse MR analysis. Finally, we conducted an analysis of expression quantitative trait loci (eQTLs) involved in the metabolic pathway to explore potential molecular mechanisms of metabolism.

Results

Our findings reveal that eight GM taxa and twenty-three serum metabolites are causally related to PsA (P < 0.05). Notably, a higher relative abundance of Family Rikenellaceae (ORIVW: 0.622, 95% CI: 0.438-0.883, FDR = 0.045) and elevated serum levels of X-11538 (ORIVW: 0.442, 95% CI: 0.250-0.781, FDR = 0.046) maintain significant causal associations with a reduced risk of PsA, even after adjusting for multiple testing correction and conducting MVMR analysis. These findings suggest that Family Rikenellaceae and X-11538 may have protective effects against PsA. Our sensitivity analysis and additional analysis revealed no significant horizontal pleiotropy, reverse causality, or heterogeneity. The functional enrichment analysis revealed that the eQTLs examined were primarily associated with glycerolipid metabolism and the expression of key metabolic factors influenced by bacterial infections (Vibrio cholerae and Helicobacter pylori) as well as the mTOR signaling pathway.

Conclusion

In conclusion, our study demonstrates that Family Rikenellaceae and X-11538 exhibit a strong and negative causal relationship with PsA. These particular GM taxa and metabolites have the potential to serve as innovative biomarkers, offering valuable insights into the treatment and prevention of PsA. Moreover, bacterial infections and mTOR-mediated activation of metabolic factors may play an important role in this process.

Combination of methotrexate with oral disease-modifying antirheumatic drugs in psoriatic arthritis: a systematic review

Background: Oral conventional synthetic disease-modifying antirheumatic drugs (csDMARDs), especially methotrexate, are the cornerstone of treating psoriatic arthritis (PsA). The use of csDMARDs with biologics has increased their efficacy in psoriasis. However, the combination of two oral DMARDs in patients with PsA has not been adequately reviewed. In this study, we explore the combinational use of methotrexate with DMARDs in PsA patients. Materials & methods: A review was conducted using Medline (PubMed), Embase, Web of Science and the Cochrane Library, covering articles up to February 2023. Results & conclusion: Nine studies comprising 1993 participants were included. The evidence supporting combination therapy remains limited. Combinational therapy could be considered in patients with inadequate response to monotherapy or no access to biologics.

The role and application of three IFN-related reactions in psoriasis

The pathophysiology of psoriasis is a highly complicated one. Due to the disease's specificity, it not only affects the patient's skin negatively but also manifests systemic pathological changes. These clinical symptoms seriously harm the patient's physical and mental health. IFN, a common immunomodulatory factor, has been increasingly demonstrated to have a significant role in the development of psoriatic skin disease. Psoriasis is connected with a variety of immunological responses. New targets for the therapy of autoimmune skin diseases may emerge from further research on the mechanics of the associated IFN upstream and downstream pathways. Different forms of IFNs do not behave in the same manner in psoriasis, and understanding how different types of IFNs are involved in psoriasis may provide a better notion for future research. This review focuses on the involvement of three types of IFNs in psoriasis and related therapeutic investigations, briefly describing the three IFNs' production and signaling, as well as the dual effects of IFNs on the skin. It is intended that it would serve as a model for future research.

Dickkopf-Related Protein 1 (DKK-1) as a Possible Link between Bone Erosions and Increased Carotid Intima-Media Thickness in Psoriatic Arthritis: An Ultrasound Study

Psoriatic arthritis (PsA) is a heterogenous systemic inflammatory disorder that affects peripheral joints and skin, but also causes inflammation at entheseal sites, digits (dactylitis) and the axial skeleton. Despite considerable advances, our understanding of the pathogenesis and management of PsA is hampered by its complex clinical expression. We enrolled patients who met the ClASsification for Psoriatic Arthritis (CASPAR) criteria for PsA (n = 17), and healthy controls (n = 13). The lipid profile, C-reactive protein (CRP) and Dickkopf-related protein 1 (DKK-1) circulating levels were measured for all subjects. For the patients with PsA, (1) the erosive character of the articular disease was assessed by a musculoskeletal ultrasound and (2) the cardiovascular risk was evaluated using the Systematic Coronary Risk Evaluation (SCORE) chart and the ultrasound measurement of the carotid intima-media thickness. A higher titer of serum DKK-1 was associated with the presence of erosions (p < 0.005) and the cIMT correlated with DKK-1 levels in patients with PsA (r = 0.6356, p = 0.0061). Additionally, we observed a positive correlation between increased cIMT and CRP (r = 0.5186, p = 0.0329). Our results suggest that DKK-1 could be used as an early biomarker for the erosive character of the articular disease and for the assessment of the cardiovascular risk in PsA patients.

Comorbidities in Psoriatic Arthritis: A Narrative Review

PURPOSE

Psoriatic arthritis (PsA) is a common type of inflammatory arthritis. Patients with PsA present with certain extra-articular manifestations and comorbidities (often collectively called psoriatic disease). The purpose of the present review was to highlight the main comorbidities in the setting of PsA.

METHODS

A narrative review was performed using data from articles found in a search of PubMed and Scopus using the terms psoriatic arthritis and comorbidities.

FINDINGS

Cardiovascular disease (CVD), as well as metabolic and mental health disorders, are the most common comorbidities in patients with PsA. In most cases, underlying inflammation seems to be involved in the increased risk for CVD in PsA, while a bidirectional relationship seems to operate between mental health disorders and psoriatic disease. The treatment of patients with PsA, especially with biologic disease-modifying antirheumatic drugs, has been shown to lead to favorable outcomes regarding the CVD risk. However, it is debatable whether specific drug classes are more effective than others or should be avoided in patients with CVD risk factors. Comorbidity of mental health disorders is even more complex, given the difficulties in measuring and reporting these comorbidities in clinical trials and in clinical practice.

IMPLICATIONS

Future studies are needed for a better understanding of the pathogenic mechanisms of, and the development of better protocols for the identification and treatment of patients with, comorbidities in patients with PsA. The education of clinicians, health care professionals in rheumatology, and patients could be useful in achieving this goal.

Ex vivo cytokine production in psoriatic disease: Towards specific signatures in cutaneous psoriasis and peripheral psoriatic arthritis

Objectives

Psoriatic arthritis (PsA) and cutaneous psoriasis (PsO) are different phenotypes of psoriatic disease (PsD), whose underlying specific mechanisms remain incompletely understood. As cytokines are key elements to induce and tune up immune responses to drive inflammatory diseases, our objective was to assess whether clinical features, disease phenotype and PsA and PsO activity were associated with a particular ex vivo cytokine production profile.

Methods

Forty-eight patients (37 PsA and 11 PsO) and 11 healthy subjects (HS) were studied. Cytokine production by peripheral blood mononuclear cells (PBMC) that were either unstimulated, or stimulated with LPS or anti-CD3/CD28 antibodies, were analysed by multiplex assay in the culture supernatants.

Results

Cytokine signature of PsD includes a high level of TNFα in supernatants of LPS-stimulated PBMC, higher levels of IL-6 and lower levels of IFN-γ and IL-17A after CD3-CD28 stimulation, as well as higher spontaneous IL-1RA and TNFα production compared to HS. High body mass index (BMI) was associated with lower levels of IL-1β, and metabolic syndrome with lower levels of IFN-γ after LPS stimulation. In PsD, dermatological activity was related with higher IL-17A level, while rheumatic activity was linked with lower levels of IFN-γ and TNFα. Comparing each PsD subtype to HS, IL-1β and IL-6 productions are higher when using LPS stimulation in PsO patients with higher levels of IL-1β and IL-1α in peripheral PsA patients after CD3/CD28 stimulation. LPS stimulation induced high levels of IL-17A in peripheral PsA compared to axial PsA. PsA patients with axial PsA share some features with PsO but shows a distinct cytokine pattern compared to peripheral PsA.

Conclusion

PsO and the different PsA subtypes exhibit distinct ex vivo cytokine production profiles and common features of the so-called PsD. Analysis of IL-1 cytokine family and IL-6 seems to be of particular interest to distinguish PsO and peripheral PsA since it depends on monocytes in PsO and T-lymphocytes in peripheral PsA. Peripheral cytokine profiles are influenced by rheumatic and dermatological activity of the disease, and also by metabolic syndrome features. Our results highlight the crucial role of immune cell interactions with different patterns of interaction depending on clinical phenotype.

Real-world evidence of biologic treatments in psoriatic arthritis in Italy: results of the CHRONOS (EffeCtiveness of biologic treatments for psoriatic artHRitis in Italy: an ObservatioNal lOngitudinal Study of real-life clinical practice) observational longitudinal study

Background

Biologics have demonstrated efficacy in PsA in randomized clinical trials. More evidence is needed on their effectiveness under real clinical practice conditions. The aim of the present work is to provide real-world evidence of the effectiveness of biologics for PsA in the daily clinical practice.

Methods

CHRONOS was a multicenter, non-interventional, cohort study conducted in 20 Italian hospital rheumatology clinics.

Results

399 patients were eligible (56.9% females, mean (SD) age: 52.4 (11.6) years). The mean (SD) duration of PsA and psoriasis was 7.2 (6.9) and 15.3 (12.2) years, respectively. The mean (SD) duration of the biologic treatment under analysis was 18.6 (6.5) months. The most frequently prescribed biologic was secukinumab (40.4%), followed by adalimumab (17.8%) and etanercept (16.5%). The proportion of overall responders according to EULAR DAS28 criteria was 71.8% (95% CI: 66.7–76.8%) out of 308 patients at 6 months and 68.0% (95% CI: 62.7–73.3%) out of 297 patients at 1 year. Overall, ACR20/50/70 responses at 6 months were 41.2% (80/194), 29.4% (57/194), 17.1% (34/199) and at 1-year were 34.9% (66/189), 26.7% (51/191), 18.4% (36/196), respectively. Secondary outcome measures improved rapidly already at 6 months: mean (SD) PASI, available for 87 patients, decreased from 3.2 (5.1) to 0.6 (1.3), the proportion of patients with dactylitis from 23.6% (35/148) to 3.5% (5/142) and those with enthesitis from 33.3% (49/147) to 9.0% (12/133).

Conclusions

The CHRONOS study provides real-world evidence of the effectiveness of biologics in PsA in the Italian rheumatological practice, confirming the efficacy reported in RCTs across various outcome measures.

Supplementary Information

The online version contains supplementary material available at 10.1186/s41927-022-00284-w.

The Digital Way to Intercept Psoriatic Arthritis

Psoriasis (PsO) and Psoriatic Arthritis (PsA) are chronic, immune-mediated diseases that share common etiopathogenetic pathways. Up to 30% of PsO patient may later develop PsA. In nearly 75% of cases, skin psoriatic lesions precede arthritic symptoms, typically 10 years prior to the onset of joint symptoms, while PsO diagnosis occurring after the onset of arthritis is described only in 15% of cases. Therefore, skin involvement offers to the rheumatologist a unique opportunity to study PsA in a very early phase, having a cohort of psoriatic “risk patients” that may develop the disease and may benefit from preventive treatment. Progression from PsO to PsA is often characterized by non-specific musculoskeletal symptoms, subclinical synovio-entheseal inflammation, and occasionally asymptomatic digital swelling such as painless toe dactylitis, that frequently go unnoticed, leading to diagnostic delay. The early diagnosis of PsA is crucial for initiating a treatment prior the development of significant and permanent joint damage. With the ongoing development of pharmacological treatments, early interception of PsA has become a priority, but many obstacles have been reported in daily routine. The introduction of digital technology in rheumatology may fill the gap in the physician-patient relationship, allowing more targeted monitoring of PsO patients. Digital technology includes telemedicine, virtual visits, electronic health record, wearable technology, mobile health, artificial intelligence, and machine learning. Overall, this digital revolution could lead to earlier PsA diagnosis, improved follow-up and disease control as well as maximizing the referral capacity of rheumatic centers.

Real-world evidence of biologic treatments in moderate-severe psoriasis in Italy: Results of the CANOVA (EffeCtiveness of biologic treAtmeNts for plaque psOriasis in Italy: An obserVAtional longitudinal study of real-life clinical practice) study

EffeCtiveness of biologic treAtmeNts for plaque psOriasis in Italy: An obserVAtional (CANOVA) study was aimed at providing real-world evidence of the effectiveness of biologics in Italian patients with moderate-severe psoriasis. It was an observational, retro-prospective cohort study conducted in 17 Italian dermatology clinics. Adult patients with moderate-severe plaque psoriasis, who started a biologic treatment between 24 weeks and 24 months before enrolment, were included. With a follow-up visit at 6 months after enrolment, each patient had at least 12 months of observation. The primary objective was to describe the clinical response rates (PASI 75) after 16/24/52 weeks from biologic treatment start. Secondary outcomes were sustained response, quality of life, and treatment satisfaction. Of the 669 eligible patients (64% males), 52% were naïve to biologics, though a mean duration of psoriasis since first diagnosis of 18.6 years (SD 13.2). The most frequently prescribed biologics were secukinumab (41%), ustekinumab (25%), TNF-inhibitors (22%) and ixekizumab (12%). PASI 75 was achieved by 86% of patients (95% CI: 82%-89%) at 16 weeks, 90% (87%-93%) at 24 weeks, and 91% (89%-94%) at 52 weeks. Patients achieving PASI 90 and PASI 100 at 52 weeks were 75% (71%-79%) and 53% (49%-57%), respectively. Sustained PASI 75 response after 1 year from treatment start was achieved by 78% (74%-82%) of patients. Mean DLQI total score was 2.3 (SD 3.9) at enrollment and decreased at the final visit to 1.8 (3.6). A high level of treatment satisfaction was expressed by patients over the study period. This large real-world study confirms in the clinical practice the good effectiveness and acceptability of biologics in psoriasis patients.

Quality of life and its relation to periarticular bone changes in psoriatic patients with or without joint involvement

OBJECTIVES

To assess periarticular bone changes in psoriasis patients with or without joint involvement and its effect on patients' quality of life (QoL).

METHODS

This cross-sectional study enrolled 50 patients with psoriasis (25 only with skin psoriasis (PsO) and 25 with psoriatic arthritis (PsA)), as well as 25 healthy controls. All participants were analyzed by high-resolution computed tomography (HR-CT) scans of the dominant hand (second and third metacarpophalangeal joints) for detection of new bone formation (enthesophytes) and erosions. Demographic, laboratory, clinical, and disease-specific data, including physical function and QoL, were collected.

RESULTS

Physical function and QoL scores were significantly worse in the PsA patients than in the PsO patients. All 25 PsA patients (100%), 18 PsO patients (72%), and 5 healthy individuals (20%) had periarticular bone changes. Statistically significant higher erosion number and volume as well as higher enthesophyte number and height were found in PsA patients compared to both PsO patients and controls, and in PsO patients compared to controls. In PsO patients, the number of erosions and enthesophytes had a negative correlation with some Short Form (SF)-36 sub-scores. In the PsA patients, the number of erosions had a positive correlation with psoriasis disability index, while the number of enthesophytes had a negative correlation with the general health SF-36 sub-score.

CONCLUSION

In PsO patients, there may be subclinical periarticular inflammation (erosions and enthesophytes) that raise the suspicion of occult PsA or the possibility of PsO transition to PsA and these periarticular bone changes may worsen QoL in PsO patients. Key Points • Skin psoriasis patients may have subclinical PsA. • Periarticular bone changes in PsO patients may be the early sign for uploading PsA disease. • Quality of life is highly affected in PsA than in PsO patients.

Systematic literature review of non-topical treatments for early, untreated (systemic therapy naïve) psoriatic disease: a GRAPPA initiative

BACKGROUND

Psoriatic disease (PsD) is a complex systemic disorder with cutaneous and musculoskeletal manifestations. Current evidence on pharmacological interventions, effective across the spectrum of clinical manifestations of early, systemic treatment-naïve PsD, is limited. This review aims to appraise such evidence.

METHODS

This systematic review examined seven patient-intervention-comparator-outcome research questions to address the efficacy of the interventions on the following: across the spectrum of clinical manifestations PsD activity; peripheral arthritis; dactylitis; spondylitis; enthesitis; skin; and nails. Early PsD was defined as a disease duration of ≤2 years, except for studies investigating outcomes restricted to the skin. Eligible references were clinical trials or well-designed prospective studies/series reporting on adult humans, untreated, with cutaneous and/or musculoskeletal features of PsD.

RESULTS

Nine references (out of 160 319, publication range 1946-2019) fulfilled the eligibility criteria. No study adopted comprehensive (that is, simultaneous assessment of different PsD manifestations) composite indices as primary outcome measures. Individual studies reported that apremilast and biologics successfully improved outcomes (disease activity index for PsA, minimal disease activity, PsA DAS, psoriasis area and severity index, PsA response criteria) when efficacy analyses were restricted to single manifestations of untreated PsD. Only qualitative synthesis of evidence was possible, owing to the following factors: data heterogeneity (disease classification criteria, outcome measures); unavailable data subsets (focused on early, untreated PsD) at the single study level; and insufficient data on the exposure of participants to previous treatment.

CONCLUSION

Effective interventions, albeit limited in scope, were found for early, treatment-naïve PsD. No study provided evidence about the management of co-occurring cutaneous and musculoskeletal manifestations in early, treatment-naïve PsD. This review highlights an unmet need in research on early PsD.

Psoriatic arthritis under the influence of IFNγ

Psoriasis is a common multifactorial autoimmune disease of the skin, and in a large percentage of patients, immune responses involve nail and joint pathology, which develop psoriatic arthritis (PsA). Historically, T helper 1 (Th1)-derived-IFN-γ was abundantly detected in psoriatic skin and its correlation with development and severity of PsO, led to an early classification of psoriasis as a Th1-mediated disease. Investigations of the cellular and molecular mechanisms of PsO pathogenesis in recent years, together with impressive results of biologics against interleukin 17A (IL-17) have shifted focus on IL-17A. However, the contributions of IFN-γ in IL-17 induced pathology and its involvement in the development of PsA have been largely overshadowed. This review summarizes the current knowledge on IFN-γ and provides new insights on the contribution of IFN-γ to PsO and PsA disease pathogenesis and development.

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.

Transition phase towards psoriatic arthritis: clinical and ultrasonographic characterisation of psoriatic arthralgia

Objective

Non-specific musculoskeletal pain is common in subjects destined to develop psoriatic arthritis (PsA). We evaluated psoriatic patients with arthralgia (PsOAr) compared with psoriasis alone (PsO) and healthy controls (HCs) using ultrasonography (US) to investigate the anatomical basis for joint symptoms in PsOAr and the link between these imaging findings and subsequent PsA transition.

Methods

A cross-sectional prevalence analysis of clinical and US abnormalities (including inflammatory and structural lesions) in PsOAr (n=61), PsO (n=57) and HCs (n=57) was performed, with subsequent prospective follow-up for PsA development.

Results

Tenosynovitis was the only significant sonographic feature that differed between PsOAr and PsO (29.5% vs 5.3%, p<0.001), although synovitis and enthesitis were numerically more frequent in PsOAr. Five patients in PsOAr and one in PsO group developed PsA, with an incidence rate of 109.2/1000 person-years in PsOAr vs 13.4/1000 person-years in PsO (p=0.03). Visual Analogue Scale pain, Health Assessment Questionnaire, joint tenderness and US active enthesitis were baseline variables associated with PsA development.

Conclusion

Tenosynovitis was associated with arthralgia in subjects with psoriasis. Baseline US evidence of enthesitis was associated with clinical PsA development in the longitudinal analysis. These findings are relevant for enriching for subjects at risk of imminent PsA development.

The "green nail" phenomenon in ICG-enhanced fluorescence optical imaging - a potential tool for the differential diagnosis of psoriatic arthritis

BACKGROUND AND OBJECTIVES

Early diagnosis of psoriatic arthritis poses a particular challenge. A novel fluorescence optical imaging technique, the Xiralite® system is very useful in this regard as it allows for visualization of microvasculature and perfusion. The present study is the first to systematically examine fluorescence optical signals in a large psoriatic arthritis cohort.

PATIENTS AND METHODS

In the primary study, we reviewed and analyzed extra-articular fluorescence optical signal patterns in 241 imaging sequences obtained from 187 psoriatic arthritis patients; 36 fluorescence optical sequences from 31 patients with rheumatoid arthritis served as controls. In a follow-up study, 203 consecutive fluorescence optical sequences from 54 psoriatic arthritis patients and 149 control subjects with various inflammatory rheumatic disorders were retrospectively evaluated in order to validate the primary study results in terms of the patterns previously identified.

RESULTS

Psoriatic arthritis patients exhibited three different fluorescence optical signal patterns in projection of the nails that have not been previously described. One of these patterns was the "green nail" sign, which was highly specific (97 %) for psoriatic arthritis. In the follow-up study, the specificity of this phenomenon in psoriatic arthritis was 87 % in comparison to the control cohort.

CONCLUSIONS

In the present study, fluorescence optical signals in the nail region proved to be highly specific for psoriatic arthritis. The "green nail" phenomenon seems to be of particular diagnostic interest as a potential sign of impaired microcirculation of the nail bed.

Current treatment options for psoriatic arthritis: spotlight on abatacept

Psoriatic arthritis (PsA) is a chronic inflammatory disease of joints, tendon sheaths, and entheses affecting patients with established skin psoriasis, or, less frequently, patients without a personal history of psoriasis with a positive familial history. Many treatment options are now available to deal with the different aspects of the disease, including traditional and biological disease-modifying antirheumatic drugs and the recently released targeted synthetic disease-modifying antirheumatic drugs. However, ~40% of patients still fail to achieve a meaningful clinical response to first-line biologic therapy advocating the development of novel medications. It is now well accepted that T-cells participate in the immunopathogenesis of several autoimmune diseases. For this reason, the potential intervention on T-cells represented an attractive therapeutic target for a long time, becoming a clinical reality with the development of abatacept. Abatacept is a biologic agent selectively targeting the T-cell costimulatory signal delivered through the CD80/86-CD28 pathway and was approved in December 2005 by the US Food and Drug Administration and in May 2007 by European Medicines Agency for the treatment of patients with rheumatoid arthritis in combination with methotrexate. Based on the relevant role of T-cells in PsA pathogenesis and following the positive results obtained in a phase III clinical trial, abatacept recently received approval for treatment of patients with PsA. In this review, we will focus on the current knowledge about the emerging role of abatacept in treatment of PsA.

Psoriasis therapy by Chinese medicine and modern agents

Psoriasis is a chronic, painful, disfiguring and non-contagious skin disease that has globally affected at least 200 million patients. In general, mild to moderate psoriasis patients will be treated by chemical drugs or Chinese medicine, while targeting systemic biological drugs have been successfully developed with good efficacy but high cost burden to patients with severe psoriasis. Since the underlying mechanisms of psoriasis are not well understood, in this review, psoriasis pathogenesis and clinical therapeutic principles by modern medicine and Chinese medicine are extensively described. Based on the data from the China Food and Drug Administration, the majority of chemical drugs are utilized as the topical formulations, while Chinese medicines are mainly delivered by an oral route, suggesting that the market for topical preparations of Chinese medicine to treat psoriasis is worth to exploration. Moreover, considering the unique clinical therapeutic theory and successful clinical application of Chinese medicine in the treatment of psoriasis, we believe that development of new small molecule drugs based on Chinese medicine will be a promising strategy to reduce therapeutic costs and improve safety for psoriatic patients.

The evidence for microbiome manipulation in inflammatory arthritis

The human body consists of millions of commensal bacteria (the microbiome), with the intestinal tract being the most prevalent site of colonization. This colonization process begins at birth, and despite numerous factors such as ageing, diet and drug use affecting the microbiome make-up, by adulthood the composition of the gut bacteria is relatively consistent across local populations. The recent advent of new scientific techniques has enabled us to explore how the microbiome affects health and, in particular, has shed light on the involvement of the microbiome in the pathogenesis of inflammatory disease. In this review we highlight the current evidence for microbiome manipulation in inflammatory arthritis in animal and human models and discuss potential therapeutics targeting the microbiome as treatment for these diseases.

Carotid plaque and bone density and microarchitecture in psoriatic arthritis: the correlation with soluble ST2

Psoriatic arthritis (PsA) patients have increased risk of both atherosclerosis and osteoporosis. Previous studies revealed that IL-33/ST2 axis may be related to both conditions; however, these associations were never evaluated in a single patients’ group. Here we explored the association among plasma levels of IL-33 and its decoy receptor soluble ST2 (sST2), carotid plaque determined by ultrasound, and volumetric bone mineral density (vBMD)/microstructure of distal radius measured by high-resolution peripheral quantitative computed tomography (HR-pQCT) in 80 PsA patients (55% male; 53.0 ± 10.1 years). Plasma sST2 levels were significantly higher in 33 (41%) patients with carotid plaques (11.2 ± 4.5 vs 7.7 ± 3.7 ng/ml, P < 0.001). In multivariate analysis, sST2 was an independent explanatory variable associated with carotid plaques (OR = 1.296, 95% CI: [1.091,1.540]; P = 0.003). After adjustment for the osteoporotic risk factors, sST2 was significantly associated with higher cortical porosity (β = 0.184, [0.042,0.325]; P = 0.012) and cortical pore volume (2.247, [0.434,4.060]; P = 0.016); and had a trend to be associated with lower cortical vBMD (−2.918, [−6.111,0.275]; P = 0.073). IL-33 was not associated with carotid plaque or vBMD/microstructure. In conclusion, plasma sST2 levels were independently correlated with both carotid plaque and compromised cortical vBMD/microstructure in PsA patients. IL-33/ST2 axis may be a link between accelerated atherosclerosis and osteoporosis in PsA.

Orthopaedic interventions in patients with psoriatic arthritis: a descriptive report from the SPAR cohort

Objectives

To evaluate the current needs for joint surgery in patients with psoriatic arthritis (PsA).

Methods

The patient database at the Rheumatology Department of the University Hospitals Leuven, was cross-sectionally analysed using demographic, medical, laboratory, radiological and surgical data of 269 patients with PsA. Patients were grouped by the presence or absence of orthopaedic surgery and compared for gender, age, mean health assessment questionnaire (HAQ) score, current medication and disease duration. The data were assessed using descriptive statistics and Student's t-tests.

Results

Overall 48.33% of the patients underwent 1 or more orthopaedic surgeries at some point of time. A total of 280 surgical interventions were flagged in the database, including both joint sacrificing and non-joint sacrificing procedures. Mean disease duration±SD at the time of surgery was 1.58 years±12.05. Age of the patients with surgeries was 54.13 years±11.03 SD and not different from those without surgeries (53.73 years±12.81 SD; p=0.78). 41.54% of the patients underwent a single surgery while 58.46% had multiple surgeries. A significant difference in the mean HAQ score was observed among the patients with and without surgeries (p<0.001). Of all the surgeries 63.92% were performed after diagnosis whereas 36.07% were performed before a diagnosis of PsA was made. Among the surgeries performed before diagnosis 40.59% were arthroscopies including 9.90% of diagnostic arthroscopies.

Conclusions

The number of surgical interventions has significantly increased in patients with PsA compared with historical cohorts even with a relatively shorter disease duration. There was a significant difference in HAQ score between the patients with or without surgeries.

Spondyloarthritis and the microbiome: new insights from an ancient hypothesis

The human microbiome, which represents the total collection of microorganisms (and their genes) inhabiting the human body, has increasingly been recognized as a potential key factor in the development of autoimmune disease. Multiple studies suggest that the microbiome has significant influence on immune homeostasis, while disruptions in local microbiome composition can result in a heightened systemic inflammatory response. The intestinal microbiome, in particular, harbors the densest assembly of bacteria and appears to influence the immune system in the context of inflammatory arthropathies. Although studies are still sparse, this review will examine the role of the microbiome in the pathogenesis of spondyloarthritis (SpA), particularly in enteropathic arthritis (EA), reactive arthritis (ReA), ankylosing spondylitis (AS), and psoriatic arthritis (PsA).

Economic and comorbidity burden among moderate-to-severe psoriasis patients with comorbid psoriatic arthritis

OBJECTIVE

To compare the prevalence of comorbidities, health care utilization, and costs between moderate-to-severe psoriasis (PsO) patients with comorbid psoriatic arthritis (PsA) and matched controls.

METHODS

Adults ages 18-64 years with concomitant diagnoses of PsO and PsA (PsO+PsA) were identified in the OptumHealth Reporting and Insights claims database between January 2007 and March 2012. Moderate-to-severe PsO was defined based on the use of at least one systemic or phototherapy during the 12-month study period after the index date (randomly selected date after the first PsO diagnosis). Control patients without PsO and PsA were demographically matched 1:1 with PsO+PsA patients. Multivariate regressions were employed to examine PsO/PsA-related comorbidities, medications, health care utilization, and costs between PsO+PsA patients and controls, adjusting for demographics, index year, insurance type, and non-PsO/PsA-related comorbidities.

RESULTS

Among 1,230 matched pairs of PsO+PsA patients and controls, PsO+PsA patients had significantly more PsO/PsA-related comorbidities, with the top 3 most common in both groups being hypertension (35.8% versus 23.5%), hyperlipidemia (34.6% versus 28.5%), and diabetes mellitus (15.9% versus 10.0%). Compared with controls, PsO+PsA patients had a higher number of distinct prescriptions filled (incidence rate ratio 2.3, P < 0.05); were more likely to have inpatient admissions (odds ratio [OR] 1.6), emergency room visits (OR 1.3), and outpatient visits (OR 62.7) (all P < 0.05); and incurred significantly higher total, pharmacy, and medical costs (adjusted annual cost differences per patient $23,160, $17,696, and $5,077, respectively; all P < 0.01).

CONCLUSION

Compared with matched PsO- and PsA-free controls, moderate-to-severe PsO patients with comorbid PsA had higher comorbidity and health care utilization and costs.

Reactive oxygen species in psoriasis and psoriasis arthritis: relevance to human disease

Psoriasis (Ps) is a chronic, immune-mediated, skin inflammatory disease affecting up to 3% of the population worldwide. Different environmental triggers initiate this complex multifactorial syndrome. Many individuals affected by Ps (6-26%) develop inflammatory disease in other organs, often in the joints as in psoriasis arthritis (PsA). Animal models that reflect the typical Ps syndrome, including both skin and joint pathology as in Ps and PsA, are valuable tools for dissecting disease pathways leading to clinical manifestations. In this context, we developed a new acute Ps and PsA-like disease model that appears after exposure to Saccharomyces cerevisiae mannan in certain mouse strains. The disease was found to be triggered by mannan-activated macrophages, leading to the activation of a pathogenic interleukin-17 pathway involving innate lymphocytes. Interestingly, the production of reactive oxygen species protected the mice from the triggering of this pathway and ameliorated Ps and PsA development.

Density, structure, and strength of the distal radius in patients with psoriatic arthritis: the role of inflammation and cardiovascular risk factors

We investigated the densitometric and microstructural features of the distal radius in psoriatic arthritis (PsA) patients using high-resolution peripheral quantitative computed tomography. PsA patients have unique bone microstructural deficits, manifested as lower cortical bone density and higher cortical porosity, which are associated with a propensity to bone fragility.

INTRODUCTION

The aim of this study was to investigate the densitometric, geometric, microstructural, and biomechanical features of the distal radius in psoriatic arthritis (PsA) patients.

METHODS

This study cohort consisted of 53 PsA patients (24 males and 29 females), with an average age of 53.1 years and 53 gender- and age-matched controls. Areal bone mineral density (aBMD) of the hip, lumbar spine, and ultradistal radius was measured by dual-energy X-ray absorptiometry. High-resolution peripheral quantitative computed tomography (HR-pQCT) was performed at the distal radius to obtain measures of volumetric BMD (vBMD), microstructure, and derived biomechanical indices.

RESULTS

There were no significant between-group differences in aBMD at the femoral neck, total hip, and ultradistal radius, while aBMD at the lumbar spine was significantly higher in patients. The only indices indicating compromised bone quality in PsA patients were related to cortical bone quality. Cortical vBMD were -3.8% significantly lower, while cortical pore volume, porosity index, and pore diameter were 108, 79.5, and 8.6%, respectively, significantly higher in patients. Cortical stress was marginally lower (-1.3%, p = 0.077) in patients with stress significantly more unevenly distributed (4.9%, p = 0.035). Endocortical perimeter and cortical pore volume were significantly higher in patients with vertebral fracture. Deficits in cortical bone quality were associated with indices of disease activity/severity and were more prominent in patients with type 2 diabetes mellitus or hypertension.

CONCLUSIONS

There is an intertwined relationship between chronic inflammation, cardiovascular risk factors, and bone loss in PsA. PsA patients seem to have unique bone microstructural deficits which are associated with a propensity to bone fragility.

Interleukin-17 is a critical target for the treatment of ankylosing enthesitis and psoriasis-like dermatitis in mice

Ankylosis is a major pathological manifestation of spondyloarthropathy. The aim of this study was to evaluate the effects of anti-IL-17 therapy on spontaneous ankylosing enthesitis in mice. In this study, we used male DBA/1 mice as a spontaneous ankylosis model. Serum IL-17 concentrations were determined using enzyme-linked immunosorbent assay. Male DBA/1 mice from different litters were mixed and caged together preceding the treatment at 10 weeks (wk) of age (prophylaxis) or 21 wk of age (intervention). Treatment with anti-IL-17 antibodies or saline was initiated after caging in groups of mice and administered weekly. The onset of tarsal ankylosis was assessed by ankle swelling and histopathological examination. Pathological changes and mRNA expression levels were assessed in joints and ears obtained at the experimental end-point. We found that circulating IL-17 increased with the onset of ankylosis in male DBA/1 mice, coinciding with the onset of dermatitis. The symptoms of dermatitis corresponded to the pathological characteristics of psoriasis: acanthosis with mild hyperkeratosis, scaling, epidermal microabscess formation and augmented expression of K16, S100A8 and S100A9. Prophylactic administration of anti-IL-17 antibodies significantly prevented the development of both ankylosis and dermatitis in male DBA/1 mice caged together. On the other hand, administration of anti-IL-17 antibodies after disease onset had a lesser but significant effect on ankylosis progression but did not affect dermatitis progression. In conclusion, IL-17 is a key mediator in the pathogenic process of tarsal ankylosis and psoriasis-like dermatitis in male DBA/1 mice caged together. Thus, IL-17 is a potential therapeutic target in ankylosing enthesitis and psoriasis in humans.

Peripheral spondyloarthritis and psoriatic arthritis; overlaps and distinctions: a report from the GRAPPA 2012 annual meeting

For over 40 years the concept of psoriatic arthritis (PsA) has slowly evolved as new knowledge has emerged. This has been facilitated by the development of new criteria for classification, improvement on existing criteria by the use of updated methodologies, and new information about the disease. At the same time, there has been discussion about categorization within the generic term spondyloarthritis. At the 2012 annual meeting of the Group for Research and Assessment of Psoriasis and Psoriatic Arthritis (GRAPPA), some of this history was reviewed, along with the current thinking about the taxonomy of PsA within spondyloarthritis.

Role of IL-17 in psoriasis and psoriatic arthritis

The role of T cell subpopulations in human disease is in a transition phase due to continuous discovery of new subsets of T cell, one of which is Th17, characterized by the production of signature cytokine IL-17. In the last couple of years, many articles are coming out on the role of Th17 and its signature cytokine IL-17 in different autoimmune diseases like rheumatoid arthritis, psoriasis, psoriatic arthritis (PsA), SLE and multiple sclerosis. Psoriasis and PsA are immune-mediated diseases, affecting the skin and joints, respectively. Initially, it was thought that psoriasis and PsA were Th1-mediated diseases; however, studies in knockout animal models (IL-17 knockout mice) as well as human experimental data indicate that Th17 and its signature cytokine IL-17 have a critical role in the pathogenesis of psoriatic disease. Th17 cells have been identified from the dermal extracts of psoriatic lesions. Subsequently, our research group has substantiated this observation that Th17 cells are enriched in the papillary dermis of psoriatic plaques and in freshly isolated effector T lymphocytes from the synovial fluid of PsA patients, and we have reported that the majority of these CD4 + IL-17+ T cells are of memory phenotype (CD4RO(+)CD45RA(-)CD11a(+)). Recent reports also suggest that the synovial tissue in psoriatic arthritis is enriched with IL-17R, and its most well recognized receptor IL-17RA is functionally active in psoriatic arthritis. In this review article, we have discussed the role of IL-17 in psoriatic disease and have narrated about the novel IL17/IL-17R antibodies currently in preparation for its therapeutic uses in autoimmune diseases.

Characterization of DC-STAMP+ Cells in Human Bone Marrow

Osteoclasts (OC), specialized cells derived from monocytes, maintain skeletal homeostasis under normal conditions but degrade bone in patients with rheumatoid (RA) and psoriatic arthritis (PsA). Monocytes initially develop in the bone marrow (BM), circulate in peripheral blood, and differentiate into distinct cell types with diverse functions. Imaging studies in (RA) patients and murine arthritis models demonstrate that bone marrow edema detected on MRI is the result of enhanced myelopoiesis which precedes the development of bone erosions detected on plain radiographs several years later. A major knowledge gap, however, is whether OC develop in the BM and circulate to the joint and if the differentiation to OC takes place in the joint space in response to differentiation signals such as RANKL and TNF. We have previously demonstrated that osteoclast precursors (OCP) are increased in the circulaton of patients with RA and PsA. We showed that DC-STAMP (Dendritic Cell-Specific Transmembrane protein), a 7-pass transmembrane protein expressed on the surface of monocytes, is essential for cell-to-cell fusion during OC differentiation and is a valid biomarker of OCP. Herein, we examined OCP in human bone marrow and identified one novel subset of DC-STAMP+CD45intermediate monocytes which was absent in the blood. We also found that OCPs reside in human BM with a higher frequency than in the peripheral blood. These findings support the notion that the BM is a major reservoir of circulating OCPs. In addition, we demonstrated that a higher frequency of DC-STAMP+ cells in the BM have detectable intracellular IFN-γ, IL-4 and IL-17A than DC-STAMP+ cells circulating in the peripheral blood. Finally, the frequency of DC-STAMP+ monocytes and T cells is signficantly higher in PsA BM compared to healthy controls, suggesting an enhanced myelopoiesis is a central event in inflammatory arthritis.

The functional MICA-129 polymorphism is associated with skin but not joint manifestations of psoriatic disease independently of HLA-B and HLA-C

A methionine/valine polymorphism at amino acid 129 of the major histocompatibility complex class I chain-related gene A (MICA-129) categorizes alleles into strong and weak binders of the natural killer (NK) and T-cell receptor NKG2D. We investigated whether MICA-129 is differentially associated with skin and joint manifestations of psoriatic disease (PsD) independently of human leukocyte antigen (HLA)-C and HLA-B in patients and controls from Toronto and St. John's. The MICA-129 methionine (Met) allele, particularly Met/Met homozygosity, was strongly associated with both cutaneous psoriasis (PsC) and psoriatic arthritis (PsA) independently of HLA-B and HLA-C in Toronto patients, and was also associated with PsA in St. John's patients, but with no additional effect of Met/Met homozygosity. No association remained after adjustment for HLA alleles in St. John's patients. MICA-129 was not associated with PsA when compared with PsC. We conclude that MICA-129 is a marker of skin manifestations of PsD that is independent of HLA class I in Toronto patients.

Intervertebral disc and macrophage interaction induces mechanical hyperalgesia and cytokine production in a herniated disc model in rats

OBJECTIVE

The expression of proinflammatory factors such as tumor necrosis factor α (TNFα), interleukin-6 (IL-6), IL-8, and prostaglandin E(2) (PGE(2) ) is significantly correlated with the symptoms of herniated disc disease. Among the different types of immune cells, macrophages are frequently noted in the herniated disc tissue. We undertook this study to clarify the interaction of the intervertebral disc (IVD) and macrophages with regard to the production of TNFα, IL-6, IL-8, and PGE(2) .

METHODS

We developed 2 animal models to assess the interactions of IVDs with macrophages in terms of TNFα, IL-6, IL-8, and PGE(2) production and pain-related behavior. We also cocultured IVDs and macrophages to assess the role of TNFα in IL-6, IL-8, and PGE(2) production.

RESULTS

IVD autografts induced TNFα, IL-6, IL-8, and cyclooxygenase 2 (COX-2) messenger RNA (mRNA) up-regulation; macrophage infiltration was seen shortly after the autograft was implanted. A significant decrease was noted in the mechanical threshold of the ipsilateral paw following the up-regulation of TNFα, IL-6, IL-8, and COX-2 mRNA. Only IVD and macrophage cocultures resulted in IL-8 and PGE(2) up-regulation. TNFα up-regulation was maximized before that of IL-6 and IL-8. TNFα neutralization attenuated production of IL-6 and PGE(2) , but not that of IL-8. Neutralization of TNFα and IL-8 significantly increased the paw withdrawal mechanical threshold in the IVD autograft and spinal nerve ligation model.

CONCLUSION

IVD-macrophage interaction plays a major role in sciatica and in the production of TNFα, IL-6, IL-8, and PGE(2) . TNFα is required for IL-6 and PGE(2) production, but not for IL-8 production, during IVD-macrophage interaction. Neutralization of TNFα and IL-8 can be a valuable therapy for herniated disc disease.

Pathological role of interleukin-6 in psoriatic arthritis

Psoriatic arthritis (PsA) is a clinical manifestation of psoriatic disease. Although the pathogenesis of PsA remains unknown, PsA can be managed by treatments similar to those used for rheumatoid arthritis (RA). Because interleukin-(IL-) 6 has been suggested to have a pathogenic role in PsA, a humanized anti-IL-6 receptor antibody tocilizumab treatment for PsA was recently tried. However, the efficacy of tocilizumab for PsA was not favorable. This suggests that the pathogenic roles of IL-6 in PsA and RA are different. In RA, tumor necrosis factor (TNF) primarily contributes to the arthritis effector phase and IL-6 contributes to the arthritis priming phase. In PsA, the TNF-related effector phase is similar to that in RA, but the IL-6-related priming phase might not be critical. This paper discusses the role of IL-6 in PsA.

Biomarkers of subclinical atherosclerosis in patients with autoimmune disorders

Atherosclerosis is accelerated in rheumatoid arthritis (RA) and psoriatic arthritis (PsA). We investigated a possible association of oxidized low-density lipoproteins (ox-LDLs), nitric oxide (NO), 3-nitrotyrosine, vitamin A, vitamin E, and β-carotene serum levels with subclinical atherosclerosis in RA and PsA. By the use of ELISA, we observed higher ox-LDL levels in patients with intima-media thickness (IMT) > 1 than in patients with IMT ≤ 1 and a negative correlation between NO levels and IMT values. By the use of high-performance liquid chromatography, we determined higher levels of vitamin A in patients with PsA and IMT ≤ 1 than in controls and lower levels of β-carotene in patients with RA and PsA than in controls. β-carotene concentrations were negatively correlated to the duration of disease in RA. Our study confirms that ox-LDLs and NO may be markers of accelerated atherosclerosis in RA and PsA whereas vitamins seem to be associated only to the presence of the autoimmune disorders.

Clinical symptoms of skin, nails, and joints manifest independently in patients with concomitant psoriasis and psoriatic arthritis

This study correlated assessment tools for evaluating the severity of skin, nail, and joint symptoms in patients with psoriasis (Pso) and psoriatic arthritis (PsA). Adults with plaque Pso (with or without PsA) were enrolled from four U.S. institutions. Patients were evaluated using a novel 10-area Linear Psoriasis Area and Severity Index (XL-PASI), Psoriatic Arthritis Assessment (PsAA), Psoriatic Arthritis Screening and Evaluation Questionnaire (PASE), Nail Assessment (NA) and Joint Assessment (JA) tools, Psoriasis Weighted Extent and Severity Index (PWESI), and Lattice Physician Global Assessment (LS-PGA). Correlations between assessment tools and individual items in the assessment tools were performed. Data from 180 patients (55 with PsA) were analyzed. Highest correlations between tools (r = 0.77-0.88) were between the XL-PASI, PWESI and LS-PGA. Individual items in the XL-PASI correlated with items in the PWESI for extent skin symptoms, but not for all body areas. Overall, correlations were seen between hands and feet, between face and scalp, and between buttocks, chest, and back. Only low correlation was seen between items assessing joint symptoms with items assessing skin symptoms. These data support the notion that the complex phenotype of psoriatic disease requires instruments that assess the severity of skin, nails, and joints separately.

Therapeutic considerations in spondyloarthritis patients who fail tumour necrosis factor antagonists

The tumour necrosis factor (TNF) antagonists have significantly improved quality of life and functional status in patients with spondyloarthritis (SpA). The excitement regarding the remarkable success of these agents is justified but challenges remain. In particular, alternative systemic therapies with proven efficacy for patients who fail TNF antagonists have been developed in rheumatoid arthritis but are not yet available in SpA. In this article, the approach to patients with psoriatic arthritis (PsA) or ankylosing spondylitis (AS) who fail TNF antagonists will be discussed with the goal of providing a path to the clinician, who must manage these patients amidst uncertainty. Three central questions will be addressed. Why does a particular SpA patient not respond to a TNF antagonist? How can the clinician improve the probability of treatment response in patients who fail a TNF antagonist? What specific approaches can be taken to control disease activity in PsA or AS following treatment failure with a TNF antagonist? Data from controlled trials, registries and pilot studies will be combined with expert opinion to address these important questions.

Epidemiology and comorbidities of psoriasis patients in a national database in Taiwan

BACKGROUND

Recent findings in psoriasis research have shown that psoriasis is frequently associated with systemic comorbidities.

OBJECTIVES

This study aims to describe the epidemiology of psoriasis and the prevalence of comorbidities in patients with psoriasis in Taiwan.

METHODS

Patients who had at least one outpatient visit or admission with ICD-9-CM diagnosis code 696.0-1 in the Taiwan National Health Insurance (NHI) claims database during 2006 were identified as psoriasis cases. The cases were further classified into moderate to severe psoriasis (sPsO) for those who had previously received systemic therapy during the study period and mild psoriasis (mPsO) for those who had not. The cases were matched in a 1:4 ratio with controls from a sample cohort of 997,771 enrolees representative of the Taiwan population. Matching variables included age, gender and residential area. Prevalence of comorbidities was assessed using prevalence relative risk (RR) based upon a Cox proportional regression model.

RESULTS

51,800 psoriasis cases were identified (prevalence=0.235%; mean age=46.4±18.6; male:female=1.6:1) and 17.5% of cases were sPsO type. Psoriasis was associated with a significantly increased prevalence ratio (RR; [95% confidence interval]) for hypertension (1.51; [1.47, 1.56]), diabetes (1.64; [1.58, 1.70]), hyperglyceridaemia (1.61; [1.54, 1.68]), heart disease (1.32; [1.26, 1.37]), hepatitis B viral infection (1.73; [1.47, 2.04]), hepatitis C viral infection (2.02; [1.67, 2.44]), rheumatoid arthritis (3.02; [2.68, 3.41]), systemic lupus erythematosus (6.16; [4.70, 8.09]), vitiligo (5.94; [3.79, 9.31]), pemphigoid (14.75; [5.00, 43.50]), pemphigus (41.81; [12.41, 140.90]), alopecia areata (4.71; [2.98, 7.45]), lip, oral cavity and pharynx cancer (1.49; [1.22, 1.80]), digestive organs and peritoneum cancer (1.57; [1.41, 1.74]), depression (1.50; [1.39, 1.61]), fatty liver (2.27; [1.90, 2.71]), chronic airways obstruction (1.47; [1.34, 1.61]), sleep disorder (3.89; [2.26, 6.71]), asthma (1.29; [1.18, 1.40]), and allergic rhinitis (1.25; [1.18, 1.33]). Conversely, psoriasis was not associated with an increased risk of Crohn's disease.

CONCLUSIONS

Psoriasis was associated with a significantly increased risk of comorbidities, especially for those patients with moderate to severe disease. These health associations should be taken into consideration when evaluating the burdens of psoriasis and designing effective treatment plans.