Pathogenesis of psoriatic arthritis

Prevalence and Clinical Predictors of Psoriatic Arthritis in Saudi Patients With Psoriasis: A Single-Center Retrospective Cohort Study

Background Among psoriatic patients, psoriatic arthritis is the most common and most impactful comorbidity. In most cases, it occurs after the onset of psoriasis. Detecting and treating it early is crucial for rheumatologists and dermatologists. Objectives The study aimed to determine the prevalence of psoriatic arthritis among recognized cases of psoriasis, as well as to determine the clinical features of psoriasis that are linked to a greater prevalence of psoriatic arthritis at King Abdulaziz Medical City (KAMC), Riyadh. Methods A retrospective cohort study of 487 psoriatic patients diagnosed between 2015 and 2023 was conducted at KAMC, Riyadh. The study included subjects aged 18 years or older with a psoriasis diagnosis documented by a dermatologist and a psoriatic arthritis diagnosis documented by a rheumatologist based on the Classification Criteria for Psoriatic Arthritis (CASPAR). Patients younger than 18 years, diagnosed with psoriatic arthritis concurrently with psoriasis, or within 90 days of psoriasis diagnosis, or who lack a documented diagnosis of psoriasis by a dermatologist were excluded. The study evaluated demographic data and medical variables concerning psoriasis (age at onset, type of psoriasis, site of psoriasis, and nail dystrophy) and psoriatic arthritis. SPSS Statistics version 25 (IBM Corp., Armonk, NY) was used to conduct statistical analysis. The p-value of 0.05 was used to evaluate statistical significance. Results Overall, 487 patients had psoriasis in this study. Of these, 49 (10%) were diagnosed with psoriatic arthritis. The mean ± standard deviation of the age of the psoriasis group was 41.7 ± 15.6 years, with 264 (54.2%) females and 223 (44.8%) males. The clinical features of psoriasis that were linked to a greater frequency of psoriatic arthritis in our study included female gender (71.4%), plaque psoriasis (95.9%), psoriatic lesions involving the extremities (75%), scalp (42.9%), and trunk (36.7%), nail dystrophy (28.6%), as well as the involvement of three or more sites (40.8%) at the time of their initial diagnosis of psoriasis. Conclusion Our study indicated that 10% of Saudi patients with psoriasis had psoriatic arthritis. Moreover, the present study shows that patients with greater psoriatic lesions at initial presentation are more likely to develop psoriatic arthritis.

The Influence of Vitamin D Receptor Gene Polymorphisms in Spondyloarthritis

Spondyloarthritis (SpA) is an inflammatory rheumatic disease related to low bone mineral density. Because vitamin D plays an important role in bone metabolism and immune system modulation, the aim of this study was to evaluate the influence of polymorphisms in vitamin D receptor genes (VDR) in the development of SpA. In this case-control study, a total of 244 patients with SpA and 197 individuals with no SpA were included. Among the patients, 174 had ankylosing spondylitis (AS) and 66 had psoriatic arthritis (PsA). Genotyping of FokI (rs2228570 C > T), BsmI (rs1544410 C > T), ApaI (rs7975232 A > C), and TaqI (rs731236 T > C) was performed using PCR-RFLP, while genotyping of HLA-B∗27 was performed using PCR-SSP. Serum levels for hydroxy (OH) vitamin D and the clinical activity index of the disease (BASDAI) were also evaluated. SNPStats and OpenEpi software were used for statistical analysis. The ApaI a allele and ApaI a/a genotype were less frequent in PsA compared with controls. The ApaI a/a genotype was associated with a protecting factor for PsA in females, and ApaI A/a was associated with a protecting factor for the disease in HLA-B∗27 positive patients. Notwithstanding, the ApaI a/a genotype was a risk factor for SpA and AS in males. The FokI f/f genotype was associated with a better clinical activity in PsA. When considering the covariates, vitamin D sufficiency, and gender, the FokI F/F genotype was associated with a risk factor in males with SpA and AS compared with females with this same genotype. In conclusion, the ApaI rs7975232 polymorphism was associated with PsA, and the FokI rs2228570 polymorphism was associated with better clinical PsA activity. ApaI and FokI were associated with SpA and AS when considering gender and vitamin D sufficiency.

Metabolic Syndrome and psoriatic arthritis: considerations for the clinician

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

The skin microbiome in psoriatic disease: A systematic review and critical appraisal

Background

Psoriasis affects 1–3% of the Canadian population. Psoriatic arthritis (PsA), the most common comorbidity of psoriasis, affects up to 30% of psoriasis patients. The skin microbiome is hypothesized to play a role in the pathogenesis of psoriatic disease (PsD-psoriasis and PsA).

Objective

To summarize the current state of literature on the skin microbiome in PsD.

Methods

A systematic review was performed using searches in Ovid, Medline, Embase, Medline Epub Ahead of Print and In-Process & Other Non-Indexed Citations, and Cochrane Central Register of Controlled Trials (CENTRAL). Search was limited to humans and English language, with no limits for date or publication type.

Results

Of 4,032 citations identified, 9 studies met inclusion criteria (7 on psoriasis only and 2 studies compared the microbiome characteristics between psoriasis and PsA). Compared to healthy controls, lesions demonstrated a decreased alpha diversity, higher relative abundances of Firmicutes, and lower relative abundances of Actinobacteria. Less conclusive were genus-level results, which nonetheless demonstrated trends towards increased Streptococcus, Staphylococcus, and Corynebacterium and decreased Propionibacterium in lesions vs. control.

Limitations

Study designs were heterogeneous, including sampling technique and exclusion criteria.

Conclusions

Phyla- and selected genus-level characteristic of the psoriatic microbiome are presented; further research is warranted.

•

Psoriatic lesion demonstrates decreased alpha diversity compared to healthy skin.

•

Relative abundance of Firmicutes is higher in psoriatic compared to healthy skin.

•

Relative abundance of Actinobacteria is lower in psoriatic compared to healthy skin.

•

Studies vary in methodology, including sampling technique and exclusion criteria.

Cardiovascular Risk in Psoriasis Patients: Clinical, Functional and Morphological Parameters

BACKGROUND

Psoriasis correlates with metabolic disorders, early atheromatosis and increased cardiovascular risk.

OBJECTIVES

To assess markers of cardiovascular disease in psoriatic patients.

METHODS

Cross-sectional, observational study involving 11 psoriatic participants and 33 controls. Anthropometric, biochemical, hemodynamic and imaging parameters were evaluated. Arterial stiffness was assessed by oscillometric measurement of the brachial artery. Intima-media thickness (IMT) and left ventricular diastolic function were assessed by Doppler echography and echocardiography. Between-group comparisons of numerical variables were performed by the Student's t-test or Wilcoxon Mann-Whitney test for independent samples. Significance level was set at 5%.

RESULTS

Psoriatic patients showed increased pulse wave velocity (PWV) (9.1 ± 1.8 vs 8.0 ± 2 m/s, p = 0.033), IMT of the left common carotid artery (p = 0.018) and a higher percentage of patients above the 75th percentile according to the ELSA table when compared with controls (54.5 vs 18.2%, p = 0.045). Psoriatic patients also showed an increase in peripheral/central systolic blood pressure (137.1 ± 13.2 vs 122.3 ± 11.6 mmHg, p = 0.004)/(127 ± 13 vs 112.5 ± 10.4 mmHg, p = 0.005), peripheral/central diastolic blood pressure (89.9 ± 8.9 vs 82.2 ± 8, p = 0.022)/(91 ± 9.3 vs 82.2 ± 8.3, p = 0.014), total cholesterol (252 ± 43.5 vs 198 ± 39.8 mg/dL, p < 0.001), LDL cholesterol (167 ± 24 vs 118 ± 40.8 mg/dL, p < 0.001) and C-reactive protein (7.6 ± 35.4 vs 1 ± 1.2 mg/L p < 0.001) compared with controls.

CONCLUSION

Psoriasis patients show increased PWV, IMT, peripheral and central blood pressures, and serum cholesterol and C-reactive protein levels, denoting a higher cardiovascular risk.

T Cell Hierarchy in the Pathogenesis of Psoriasis and Associated Cardiovascular Comorbidities

The key role of T cells in the pathogenesis of cutaneous psoriasis has been well described in the last decade and the knowledge of the relative role of the different subsets of T cells in psoriasis pathogenesis has considerably evolved. Now, it is clear that IL-17A-producing T cells, including Th17/Tc17, have a central role in the pathogenesis of cutaneous psoriasis and therapies blocking the IL-17A pathway show high clinical efficacy. By contrast, the contribution of IFNγ-producing T cells has progressively become less clear because of the lack of efficacy of anti-IFNγ antibodies in clinical studies. In parallel, the role of CD8⁺ T cells specific for self-antigens has been revived and increasing evidence now indicates that in psoriatic skin the majority CD8⁺ T cells are present in the form of epidermal tissue-resident memory T cells. In the last years it also emerged the possibility of a contribution of T cell recirculation in the pathogenesis of psoriasis and its systemic manifestations. The aim of this review is to define a hierarchy for the different subsets of T cells in the T cell-mediated inflammatory cascade in psoriatic skin. This analysis will possibly help to distinguish the subsets that initiate the disease, those involved in the establishment of the self-sustaining amplification loop that leads to the cutaneous clinical manifestations and finally the subsets that act as downstream players in established lesions. Specific T cell subpopulations finally will be considered for their possible role in propagating inflammation at distant sites and for representing a link with systemic inflammation and cardiovascular comorbidities.

Clinical Risk Factors for the Development of Psoriatic Arthritis Among Patients with Psoriasis: A Review of Available Evidence

Psoriatic arthritis (PsA), a chronic inflammatory arthritis, affects about 10% of patients with psoriasis with higher prevalence seen in patients with more extensive skin disease. Early identification of PsA may result in improved outcomes. While it remains unclear which patients with psoriasis will develop PsA, several studies have identified potential risk factors for PsA among patients with psoriasis. This review examines the basic epidemiologic principles of identifying risk factors and reviews the evidence to date about risk factors for PsA among patients with psoriasis.

T cell responses in psoriasis and psoriatic arthritis

According to the current view the histological features of psoriasis arise as a consequence of the interplay between T cells, dendritic cells and keratinocytes giving rise to a self-perpetuating loop that amplifies and sustains inflammation in lesional skin. In particular, myeloid dendritic cell secretion of IL-23 and IL-12 activates IL-17-producing T cells, Th22 and Th1 cells, leading to the production of inflammatory cytokines such as IL-17, IFN-γ, TNF and IL-22. These cytokines mediate effects on keratinocytes thus establishing the inflammatory loop. Unlike psoriasis the immunopathogenic features of psoriatic arthritis are poorly characterized and there is a gap in the knowledge of the pathogenic link between inflammatory T cell responses arising in the skin and the development of joint inflammation. Here we review the knowledge accumulated over the years from the early evidence of autoreactive CD8 T cells that was studied mainly in the years 1990s and 2000s to the recent findings of the role of Th17, Tc17 cells and γδ T cells in psoriatic disease pathogenesis. The review will also focus on common and distinguishing features of T cell responses in psoriatic plaques and in synovial fluid of patients with psoriatic arthritis. The integration of this information could help to distinguish the role played by T cells in the initiation phase of the disease from the role of T cells as downstream effectors sustaining inflammation in psoriatic plaques and potentially leading to disease manifestation in distant joints.

The prevalence of obesity is increased in patients with late compared with early onset psoriasis

PURPOSE

We compared the clinical and epidemiologic characteristics of early and late onset psoriasis with an emphasis on potential differences in the comorbidities associated with each subtype.

METHODS

An observational, multicenter study was performed, and associations between the age at the time of diagnosis and binary comorbidity outcomes were evaluated using multiple logistic regression analysis adjusted for age and other relevant confounders.

RESULTS

An increased prevalence of positive family history, psoriatic arthritis, and depression was observed in patients with early onset psoriasis. On the other hand, late onset psoriasis was more frequently associated with obesity and elevated waist circumference compared with early onset form. Elderly psoriatic patients (at the age of 75 years) with late onset psoriasis are at an especially high risk for obesity compared with individuals at the same age with an early onset disease.

CONCLUSIONS

The increased frequency of psoriasis in the family of early onset patients may suggest that manifestation of psoriasis at younger age is driven by strong genetic influence. However, such a remarkable association of abdominal obesity with late onset psoriasis may suggest that obesity can be one of the acquired factors that may predispose for the development of psoriasis in the elderly.

Adipokines in psoriatic arthritis patients: the correlations with osteoclast precursors and bone erosions

Significant bone remodeling with disordered osteoclastogenesis has been implicated in the pathogenesis of psoriatic arthritis (PsA). And there is a high prevalence of the metabolic syndrome (MS) in PsA patients. Adipokines, especially leptin and adiponectin, have recently been reported to be involved in the development and regulation of some autoimmune diseases. In this study, we examined the alternation of circulating osteoclastogenesis related cytokines [tumor necrosis factor-α (TNF-α), osteoprotegerin (OPG) and receptor activator of nuclear factor-κB ligand (RANKL)] and adipokines (leptin, adiponectin, resistin, chemerin, omentin) in PsA patients, and analysed the correlations between these factors and osteoclast precursors numbers, radiographic damage scores, and disease activity index. 41 PsA patients, 20 psoriasis patients, and 24 healthy controls were recruited. Blood samples were obtained for detecting the levels of TNF-α, OPG, RANKL and the adipokines. The numbers of osteoclast precursors (OCs) in peripheral blood were assessed. Radiographs of affected joints in PsA patients were scored for erosion, joint-space narrowing, osteolysis, and new bone formation. Compared with healthy controls, patients with PsA had higher TNF-α, RANKL, OCs, leptin and omentin but lower adiponectin and chemerin. Increased serum levels of TNF-α, RANKL, leptin, and omentin were positively correlated with OCs numbers. In contrast, serum adiponectin levels were decreased in PsA patients and negatively correlated with OCs numbers. TNF-α, RANKL and leptin were positively correlated with Psoriatic Arthritis Joint Activity Index (PsAJAI). Only TNF-α was positively correlated with radiographic damage scores. Our data demonstrated that systemic expression of soluble mediators of osteoclastogenesis and adipokines were disordered in PsA. Certain adipokines were elevated in the circulation of patients with PsA and might contribute to pathogenesis of arthritis. Prospective studies will be of interest to determine the pluripotent effects of adipokines on osteoclastogenesis in chronic inflammatory rheumatic diseases. Future studies may lead to novel therapeutic strategies.

Psoriatic arthritis is associated with increased arterial stiffness in the absence of known cardiovascular risk factors: a case control study

The objective of the study was the evaluation of arterial stiffness, a cardiovascular risk factor, in patients with psoriatic arthritis (PsA). Twenty PsA patients classified on the basis of the CASPAR criteria (M/W, 14/6; mean age, 38.6 years; range, 22-53), attending our out-patient clinic, and 20 healthy control subjects (M/W, 14/6; mean age, 38.7 years; range, 22-53) matched for age, weight, height and with similar cardiometabolic profile entered the study. An exclusion criterion was the presence of known cardiovascular risk factors. Central hemodynamic parameters and aortic pulse wave velocity (aPWV) were assessed non-invasively by a SphygmoCor device. A significantly higher aPWV was recorded in PsA patients when compared to controls. The difference remained statistically significant after adjustment for age, weight, height, heart rate (HR) and central mean pressure (mean±SE; PsA, 8.3 ± 0.2 versus control, 6.8 ± 0.2 m/s; p < 0.0001). Among PsA patients, aPWV was related to known duration of disease (r = 0.63; p = 0.003). This result was confirmed after adjustment for the main confounders (β = 0.011; p = 0.013). These results support the concept of psoriatic disease as a systemic condition involving not only the skin, joints and gastrointestinal tract but also arterial vessels. The involvement of the vascular system indicates the presence of pathogenetic mechanisms that could accelerate the atherosclerotic process in this condition.

Inhibitors of tumor necrosis factor-alpha for treatment ofpsoriatic patients

The article describes current concepts of the role of cytokines in the pathogenesis of inflammatory diseases. The authors describe the biological action of tumor necrosis factor-alpha and its soluble receptors on body cells. They also provide data on the role of tumor necrosis factor-alpha in the formation of skin and joint inflammatory affections at psoriasis. The authors substantiate treatment of medium to severe forms of psoriasis with biological gene-engineered anti-cytokine drugs, and provide and their comparative characteristics.

Responses to adalimumab in patients with active psoriatic arthritis who have not adequately responded to prior therapy: effectiveness and safety results from an open-label study

OBJECTIVE

To evaluate the effectiveness and safety of adalimumab in patients with active psoriatic arthritis (PsA) and an inadequate response to prior therapy.

METHODS

Patients were treated with subcutaneous injections of adalimumab 40 mg every other week in addition to their standard antirheumatic therapies in a 12-week, open-label study. Effectiveness evaluations at Week 12 included American College of Rheumatology (ACR) and Psoriasis Area and Severity Index (PASI) response rates, Psoriatic Arthritis Response Criteria (PsARC), active dactylitis, enthesitis, and target lesion assessment. Physical function was evaluated using the Health Assessment Questionnaire Disability Index (HAQ-DI).

RESULTS

A total of 127 patients were enrolled. At Week 12, patients achieved ACR20, ACR50, and ACR70 response rates of 78.0%, 55.9%, and 21.3%, respectively. PASI50 and PASI75 response rates were 64.7% and 47.1%. A PsARC response was experienced by 70.1% of patients. Between baseline and Week 12, clinically and statistically significant reductions occurred in the mean total plaque score of the target lesion as well as in the percentages of patients with active dactylitis and enthesitis. A mean improvement in HAQ-DI was also observed (-0.44; p < 0.001). Three serious adverse events were reported, but none was considered related to adalimumab therapy.

CONCLUSION

Adalimumab-treated patients achieved significant improvements in both skin and joint manifestations of PsA, as well as in physical function. Adalimumab was well tolerated and had a safety profile similar to that observed in other clinical trials of adalimumab for the treatment of PsA. ClinicalTrials.gov identifier: NCT00427362.

Patient-reported outcomes in a randomized trial of etanercept in psoriatic arthritis

OBJECTIVE

To evaluate the effects of etanercept treatment on patient-reported outcomes (PRO) in patients with psoriatic arthritis (PsA).

METHODS

A 24-week double-blind comparison to placebo was followed by a 48-week open-label phase in which all eligible patients received etanercept. PRO were measured using the Stanford Health Assessment Questionnaire Disability Index (HAQ-DI), the Medical Outcomes Study Short-Form (SF-36), the EQ-5D visual analog scale (VAS), and the American College of Rheumatology (ACR) patient pain assessment.

RESULTS

Beginning at Week 4 and continuing through Week 24 of double-blind treatment, patients treated with etanercept had significantly higher mean percentage improvement in HAQ-DI relative to baseline than patients given placebo (53.6% vs 6.4% at Week 24; p < 0.001). After 48 weeks of open-label treatment with etanercept, the mean percentage change from study baseline was 52.8% for the original etanercept group and 46.9% for the original placebo group, with 41.2% of patients overall achieving a HAQ-DI of 0. Mean changes relative to baseline for SF-36 physical component summary scores, EQ-5D VAS, and ACR pain assessment were also significant in the double-blind period for etanercept compared with placebo (p < 0.001 for all 3 measures). Patients taking placebo achieved similar improvements once they began treatment with etanercept in the open-label period.

CONCLUSION

Patients with PsA treated with etanercept reported significant improvements in physical function that were almost 10 times the improvement seen with placebo and were maintained for up to 2 years. Almost half of patients treated with etanercept reported no disability by the end of the study.

The diagnosis and treatment of early psoriatic arthritis

Psoriatic arthritis (PsA) is a chronic inflammatory musculoskeletal disorder associated with a heterogeneous disease presentation, varied disease expression and an unpredictable but often chronically destructive clinical course. Joint damage can occur early in the disease; indeed, several imaging modalities have demonstrated subclinical joint involvement in psoriasis patients without musculoskeletal signs or symptoms. Efforts are underway to validate questionnaires that will enable dermatologists to screen patients with psoriasis for the presence of musculoskeletal disease. To date, the use of therapies in patients with early PsA has not been reported in randomized controlled trials. Moreover, conventional agents are partially effective in established PsA but, in general, trials with DMARDS have not included validated outcome measures for the different manifestations of PsA. Tumor necrosis factor antagonists can alleviate the signs and symptoms of established psoriatic arthritis and inhibit radiographic progression, but the therapeutic impact of early intervention with these agents requires further study. The extent of disease and the presence of comorbidities should be used to guide treatment decisions and to minimize adverse events.

Incidence and clinical predictors of psoriatic arthritis in patients with psoriasis: a population-based study

OBJECTIVE

To determine the incidence and disease-specific predictors of clinically recognized psoriatic arthritis (PsA) in patients with psoriasis.

METHODS

We identified an incidence cohort of psoriasis subjects age >/=18 years diagnosed between January 1, 1970 and December 31, 1999 in a population-based setting. Psoriasis diagnoses were validated by confirmatory diagnosis in the medical record. Incident and clinically recognized PsA subjects were classified according to the Classification of Psoriatic Arthritis (CASPAR) criteria. Cox proportional hazards models were used to identify predictors of PsA within the psoriasis cohort.

RESULTS

The psoriasis incidence cohort comprised 1,633 subjects. Of these, 40 were diagnosed with PsA concurrently with psoriasis and were excluded from analysis. The remaining 1,593 psoriasis subjects had a mean age of 43 years and 50% were men. Over 20,936 person-years of followup, 57 subjects were clinically recognized with new-onset PsA, with a cumulative incidence of 1.7% (95% confidence interval [95% CI] 1.0-2.3%), 3.1% (95% CI 2.2-4.1%), and 5.1% (95% CI 3.7-6.6%) at 5, 10, and 20 years following psoriasis incidence, respectively. Psoriasis features associated with higher risk of PsA were scalp lesions (hazard ratio [HR] 3.89, 95% CI 2.18-6.94), nail dystrophy (HR 2.93, 95% CI 1.68-5.12), and intergluteal/perianal lesions (HR 2.35, 95% CI 1.32-4.19). Calendar year was not associated with risk of PsA (P = 0.15), indicating that the likelihood of PsA in psoriasis subjects did not change over time.

CONCLUSION

In this population-based study, <10% of patients with psoriasis developed clinically recognized PsA during a 30-year period. Psoriasis features associated with a higher likelihood of PsA were nail dystrophy, scalp lesions, and intergluteal/perianal psoriasis.

Time trends in epidemiology and characteristics of psoriatic arthritis over 3 decades: a population-based study

OBJECTIVE

To determine time trends in incidence, prevalence, and clinical characteristics of psoriatic arthritis (PsA) over a 30-year period.

METHODS

We identified a population-based incidence cohort of subjects aged 18 years or over who fulfilled ClASsification of Psoriatic ARthritis (CASPAR) criteria for PsA between January 1, 1970, and December 31, 1999, in Olmsted County, Minnesota, USA. PsA incidence date was defined as the diagnosis date of those who fulfilled CASPAR criteria. Age- and sex-specific incidence rates were estimated and age- and sex-adjusted to the 2000 US White population.

RESULTS

The PsA incidence cohort comprised 147 adult subjects with a mean age of 42.7 years, and 61% were men. The overall age- and sex-adjusted annual incidence of PsA per 100,000 was 7.2 [95% confidence interval (CI) 6.0, 8.4] with a higher incidence in men (9.1, 95% CI 7.1, 11.0) than women (5.4, 95% CI 4.0, 6.9). The age- and sex-adjusted incidence of PsA per 100,000 increased from 3.6 (95% CI 2.0, 5.2) between 1970 and 1979 to 9.8 (95% CI 7.7, 11.9) between 1990 and 2000 (p for trend < 0.001). The point prevalence per 100,000 was 158 (95% CI 132, 185) in 2000, with a higher prevalence in men (193, 95% CI 150, 237) than women (127, 95% CI 94, 160). At incidence, most PsA subjects had oligoarticular involvement (49%) with enthesopathy (29%).

CONCLUSION

The incidence of PsA has been rising over 30 years in men and women. Reasons for the increase are unknown, but may be related to a true change in incidence or greater physician awareness of the diagnosis.

Normal levels and function of endothelial progenitor cells in patients with psoriatic arthritis

Endothelial progenitor cells (EPCs) are a population of bone marrow derived cells which have been attributed with the ability to migrate into areas of tissue ischemia and to posses reparative qualities. EPCs have been shown to be decreased in level and function in various inflammatory disorders. Psoriasis and psoriatic arthritis are associated with an increase in cardiovascular morbidity. The aim of the study was to investigate the number of EPCs among patients suffering from psoriasis and psoriatic arthritis. Patients suffering from active psoriasis and psoriatic arthritis were recruited as well as healthy controls. Disease activity was assessed with the DAS-28, BASDAI and PASI scores. Peripheral blood mononuclear cells were isolated and EPC numbers evaluated by FACS analysis using the CD34/133 and CD34/KDR. No significant difference was found between numbers of EPCs between healthy controls, patients with psoriasis and psoriatic arthritis. A significant correlation was found between levels of VGEF and the BASDAI score. The results of the current study do not support a significant role for EPCs in the pathogenesis of psoriasis and psoriatic arthritis.

Development of psoriasis after B cell depletion with rituximab

The B cell-depleting monoclonal antibody rituximab is a novel therapy for the rheumatic diseases, with an increasing body of evidence regarding its safety and efficacy in an expanding range of indications. However, there is uncertainty over its potential use in, and impact on, autoantibody-negative diseases. We describe 3 patients, with no known risk factor for psoriasis, who developed psoriasis (and 1 who also developed features of psoriatic arthritis) after receiving rituximab for a variety of indications, namely, seropositive and seronegative rheumatoid arthritis and systemic lupus erythematosus. In all cases, the underlying disease responded well to rituximab. The interpretation of this possible side effect of rituximab remains unclear, but a B cell-depleted environment may induce abnormal T cell responses, possibly provoked either by subclinical infection or by the removal of mechanisms whereby B cells regulate T cells. These cases suggest that the pathogenesis of psoriasis may not require normal numbers of B cells and that proposed treatment of psoriasis and psoriatic arthritis with rituximab may result in unpredictable responses.

Gene expression profiling in human autoimmunity

Human autoimmune diseases are well suited for the application of gene expression profiling. Sampling of blood cells and target tissues has already revealed many important pathways contributing to this spectrum of disorders, and many commonalities are emerging. For instance, clinically distinct diseases such as systemic lupus erythematosus, Sjögren's syndrome, dermatomyositis, and psoriasis all show evidence for dysregulation of the type I interferon pathway. These data suggest that autoimmune diseases will eventually be categorized at the level of gene expression. This work has led to advances in our understanding of disease pathogenesis and in the future promises to facilitate assessments of disease activity and improve targeting of therapies. Here, we review the literature on gene profiling in human autoimmune diseases and provide perspective on the current state of the art.

Dysregulation of interleukin-10-dependent gene expression in rheumatoid arthritis synovial macrophages

OBJECTIVE

The inflammatory cytokines tumor necrosis factor alpha (TNFalpha) and interleukin-1 (IL-1) are produced by activated macrophages, are key mediators of pathogenesis, and are validated therapeutic targets in rheumatoid arthritis (RA) and seronegative spondylarthritis (SpA). IL-10 is a potent antiinflammatory cytokine that suppresses macrophage TNFalpha and IL-1 production, yet is not effective in suppressing inflammatory arthritis. To gain insight into IL-10 responses in inflammatory arthritis, we used microarray analysis to determine the patterns of IL-10-inducible gene expression in freshly isolated RA and seronegative SpA synovial macrophages.

METHODS

Macrophages from the synovial fluid of 5 patients with RA and 3 with seronegative SpA (2 with psoriatic arthritis and 1 with ankylosing spondylitis) were isolated by positive selection and stimulated ex vivo with IL-10 or interferon-gamma (IFNgamma). Gene expression was analyzed using Affymetrix microarrays and protocols. Real-time polymerase chain reaction was used to confirm changes in gene expression.

RESULTS

The number of genes induced by IL-10 in arthritic macrophages was markedly smaller than that induced in control macrophages, and the strength of induction was lower in arthritic macrophages for most genes. The residual response of arthritic macrophages to IL-10 stimulation was qualitatively altered, such that IL-10 preferentially increased expression of IFNgamma-inducible genes. In contrast, arthritic macrophages expressed many IFNgamma-inducible genes prior to stimulation, and their response to IFNgamma remained mostly intact.

CONCLUSION

These results demonstrate that IL-10 responses are dysregulated in RA synovial macrophages. An altered biologic response to IL-10, with attenuation of its antiinflammatory function and a concomitant retention of IFNgamma-like activating functions, provides a basis for the lack of efficacy of IL-10 in suppressing inflammatory arthritis.

Hyperoxia causes angiopoietin 2-mediated acute lung injury and necrotic cell death

The angiogenic growth factor angiopoietin 2 (Ang2) destabilizes blood vessels, enhances vascular leak and induces vascular regression and endothelial cell apoptosis. We considered that Ang2 might be important in hyperoxic acute lung injury (ALI). Here we have characterized the responses in lungs induced by hyperoxia in wild-type and Ang2-/- mice or those given either recombinant Ang2 or short interfering RNA (siRNA) targeted to Ang2. During hyperoxia Ang2 expression is induced in lung epithelial cells, while hyperoxia-induced oxidant injury, cell death, inflammation, permeability alterations and mortality are ameliorated in Ang2-/- and siRNA-treated mice. Hyperoxia induces and activates the extrinsic and mitochondrial cell death pathways and activates initiator and effector caspases through Ang2-dependent pathways in vivo. Ang2 increases inflammation and cell death during hyperoxia in vivo and stimulates epithelial necrosis in hyperoxia in vitro. Ang2 in plasma and alveolar edema fluid is increased in adults with ALI and pulmonary edema. Tracheal Ang2 is also increased in neonates that develop bronchopulmonary dysplasia. Ang2 is thus a mediator of epithelial necrosis with an important role in hyperoxic ALI and pulmonary edema.

Newer Therapeutic Approaches: Spondyloarthritis and Uveitis

Over the last 5 years considerable progress has taken place in the therapeutic approach to spondyloarthritis (SpA). This progress is due in large part to the development of effective biologic therapies and to improved clinical trial design and implementation. This article summarizes treatment advances in SpA with emphasis on the efficacy and safety of biologic agents in the treatment of psoriatic arthritis, ankylosing spondylitis, undifferentiated spondyloarthropathy, and uveitis.

Activating killer cell immunoglobulin-like receptor gene KIR2DS1 is associated with psoriatic arthritis

Killer cell immunoglobulin-like receptor genotyping was performed on a cohort of American Caucasian patients with psoriasis to investigate any possible relationship between these chromosome 19 genes and autoimmune-linked disease. This patient cohort also contained a subgroup of patients who had been additionally diagnosed as positive for psoriatic arthritis (PsA). Because of the known association of human leucocyte antigen (HLA)-Cw*06 with psoriasis, the study concentrated on the five KIR genes that have HLA-C as their recognized ligand (i.e., KIR2DL1, -2DL2, -2DL3, -2DS1, and -2DS2). An increase in the frequency of the activating KIR2DS1 gene was detected in the PsA patients, compared with psoriasis patients negative for PsA and an unaffected American Caucasian control group.

Genetic factors in psoriatic arthritis

The genetic factors that are associated with psoriatic arthritis (PsA) are intricately linked with those that predispose to psoriasis itself. The strongest association is with human leukocyte antigen-Cw*0602, although true susceptibility may lie with one of the neighboring genes along a disease-associated haplotype. There are a number of interesting candidate genes within the major histocompatibility complex (MHC) region with strong functional relevance that have been investigated in PsA. In addition, several areas outside the MHC complex have been highlighted as a result of genetic linkage studies in psoriasis. PsA is a complex, multifactorial disease where multiple genes are likely to influence disease susceptibility, severity, and clinical phenotype. The current evidence for genetic factors in psoriasis and PsA will be reviewed.

Psoriatic arthritis therapy advances

PURPOSE OF REVIEW

This paper will review the data published in 2004 on the treatment of psoriatic arthritis, which arthritis affects 6 to 39% of all patients with psoriasis.

RECENT FINDINGS

New data from placebo-controlled trials of anti-tumor necrosis factor agents, etanercept, infliximab, and adalimumab continue to show sustained effectiveness of these therapies in their ability to control the symptoms and signs of both arthritis and psoriasis, improve quality of life and function, and inhibit disease progression as measured by radiologic changes. Medications that inhibit T cells have been approved for the treatment of psoriasis and have been studied in psoriatic arthritis. The effectiveness of one of these agents, efalizumab, did not achieve statistical significance in the treatment of psoriatic arthritis. The results of a trial with a second agent, alefacept are pending public review.

SUMMARY

There has been a persistent increased focus on the diagnosis and treatment of psoriatic arthritis as newer and more effective drugs than traditional disease-modifying agents have become available.

Treatment update on spondyloarthropathy

PURPOSE OF REVIEW

The unexpected success of the tumor necrosis factor antagonists in ankylosing spondylitis and psoriatic arthritis has generated considerable enthusiasm regarding the therapeutic potential of these drugs. By contrast, concerns regarding the high cost and long-term safety of the tumor necrosis factor blocking agents have prompted investigators to take a closer look at more traditional anti-inflammatory agents and to explore novel therapeutic targets. The purpose of this review is to summarize treatment advances in spondylarthropathy over the past year and to discuss potential future therapies.

RECENT FINDINGS

Recent studies indicate that the morbidity of ankylosing spondylitis and PsA are considerably higher than previously reported. Etanercept, infliximab and adalimumab safely and effectively relieved the signs and symptoms of psoriatic arthritis patients in phase III trials. Etanercept and infliximab were also effective in phase III trials in ankylosing spondylitis. Etanercept slowed radiographic progression in psoriatic arthritis trials, but it is not known whether tumor necrosis factor antagonists can prevent structural damage in ankylosing spondylitis. One trial showed that methotrexate may be effective for relieving the pain of axial disease in ankylosing spondylitis but these findings contradict two previous studies. For reactive arthritis and undifferentiated spondylarthropathy, a combination of antibiotics may be more effective than a single antibiotic for the relief of musculoskeletal symptoms. Last, potential therapeutic targets include interleukin-1, interleukin-12, B lymphocytes, accessory molecules on T lymphocytes, and angiogenic factors.

SUMMARY

Phase III trials have confirmed that tumor necrosis factor antagonists are effective and safe for the treatment of ankylosing spondylitis and psoriatic arthritis. For patients who do not respond to tumor necrosis factor blockade, several treatment options are under study. Information from these trials will more clearly define the role of disease-modifying antirheumatic drugs, novel therapeutic agents, and antibiotics in the treatment of spondylarthropathy.

Pathogenesis of psoriatic arthritis

PURPOSE OF REVIEW

Heterogeneity in clinical presentation and disease course has hindered understanding of disease mechanisms in psoriatic arthritis, but recent studies have provided insights into pathogenesis. This review examines relevant animal models and genetic factors implicated in disease susceptibility. Also, recent reports on mechanisms related to synovial and entheseal inflammation are discussed.

RECENT FINDINGS

Two transgenic mouse models (amphiregulin, STAT-3) were reported that have features of psoriatic arthritis and psoriasis respectively. Genetic studies did not find associations between psoriatic arthritis and several class I major histocompatibility complex alleles, the caspase-activating recruitment domain 15 domain, or the major histocompatibility complex class I chain-related gene A9 allele, in sharp contrast to previous reports. The striking association of psoriatic arthritis with mutations in the killer immunoglobulin receptors on natural killer cells is particularly exciting but needs further study. Psoriatic arthritis has histopathologic features that are more characteristic of other forms of spondyloarthritis than rheumatoid arthritis. Moreover, several of these features correlate with clinical disease activity. Matrix metalloproteinases are strongly expressed in psoriatic arthritis synovium, and serum matrix metalloproteinases-3 may be a reliable biomarker for monitoring disease response. Finally, the concept of an 'enthesis organ' may explain the magnetic resonance imaging findings and clinical signs of psoriatic enthesitis and dactylitis.

SUMMARY

Recent findings highlight the importance of innate immune mechanisms in disease pathogenesis. Moreover, psoriatic arthritis and rheumatoid arthritis synovium have divergent histopathologic features that indicate distinct disease mechanisms. The generation of appropriate animal models coupled with reliable biomarkers will result in a deeper understanding of disease pathogenesis and will facilitate the identification of new therapeutic targets.

Angiogenesis as an immunopharmacologic target in inflammation and cancer

Many pathological processes including wound healing, chronic inflammation and cancer require angiogenesis, i.e., the formation of new vasculature in the lesions. Accumulating evidence indicates that angiogenesis is crucial for both chronic inflammation and the growth of malignant tumors with the participation of diverse cytokines, chemokines and growth factors. It is nevertheless believed that differences exist in angiogenesis between cancer and chronic inflammatory diseases. The aim of this review is to outline the characteristics of angiogenesis in chronic inflammation and cancer. A better understanding of the angiogenic processes may facilitate the design of more effective therapies for chronic inflammation and cancer.