Systemic and vascular inflammation in patients with moderate to severe psoriasis as measured by [18F]-fluorodeoxyglucose positron emission tomography-computed tomography (FDG-PET/CT): a pilot study

Psoriasis as a systemic disease

Psoriasis is an inflammatory immune-mediated disease that affects the skin and has pathogenic effects with systemic impact. The relationship between psoriasis and comorbidities remains controversial. The hypothesis of a causative role of psoriasis in its cardiovascular and metabolic comorbidities is based on pathophysiologic concepts establishing a link between chronic inflammation in psoriasis, endothelial dysfunction, formation of atherosclerotic plaques, and the different compounds of metabolic syndrome. Psoriasis management has to be multidisciplinary. It implicates identification and treatment of psychological disorders, addictions, and associated cardiovascular and metabolic diseases, together with improvement of quality of life of patients.

Cardiometabolic biomarkers in chronic plaque psoriasis before and after etanercept treatment

OBJECTIVE

To assess cardiometabolic biomarkers in patients with psoriasis before and after etanercept treatment.

METHODS

Patients with moderate-to-severe plaque psoriasis were randomized to etanercept 50 mg once or twice weekly, double-blinded. Cardiometabolic biomarkers were assessed at baseline and after 12 weeks of treatment (n = 273).

RESULTS

At baseline, 42% of patients had metabolic syndrome. Etanercept was not associated with any clinically relevant adverse effects on cardiometabolic biomarkers. In the once-weekly subgroup, significant mean percentage changes from baseline (p < 0.05) were observed for the quantitative insulin-sensitivity check index (QUICKI; -2.2%), apolipoprotein (Apo) A1 (3.2%), Apo B:Apo A1 ratio (-3.5%), leptin (8.6%) and high-sensitivity C-reactive protein (hsCRP) (-65.5%); and in the twice-weekly subgroup for plasma insulin (15.9%), QUICKI (-2.7%), high-density lipoprotein cholesterol (HDL-C; 2.9%), apolipoprotein (Apo) A1 (2.8%), Apo B:Apo A1 (-4.6%) and hsCRP (-74.4%).

CONCLUSION

Metabolic syndrome was common in these patients with moderate-to-severe psoriasis. Etanercept treatment may provide some potentially favorable modulation of insulin sensitivity, HDL-C, Apo A1 and Apo B:Apo A1 ratio.

A comparison of vascular inflammation in psoriasis, rheumatoid arthritis, and healthy subjects by FDG-PET/CT: a pilot study

OBJECTIVE

Psoriasis (PSO) and rheumatoid arthritis (RA) increase cardiovascular diseases (CVD) beyond traditional risk factors. Vascular inflammation has previously been demonstrated to be present in PSO and RA using [18F]-fluorodeoxyglucose-positron emission tomography/computed tomography (FDG-PET/CT) imaging. However, vascular inflammation has not been compared in these two disorders relative to a healthy reference population. Thus, vascular inflammation was quantitatively assessed in patients with PSO (n=10), RA (n=5), and healthy subjects (n=10) using FDG-PET/CT.

METHODS

FDG-PET/CT mean standardized uptake value (SUVmean) was determined slice by slice within the ascending, aortic arch, descending thoracic, suprarenal abdominal, and infrarenal abdominal aorta, and the mean metabolic volumetric product (MVPmean) was then calculated for each aortic subsegment. Plasma lipids and metabolic and inflammatory markers were also assessed.

RESULTS

CVD risk profiles were largely similar across groups. After adjustment for CV risk factors, regional aortic vascular inflammation based on MVPmean was elevated for both PSO (beta coefficients 0.31-1.47, p<0.001) and RA (beta coefficients 0.15-0.69, p<0.05) compared to healthy subjects.

CONCLUSIONS

These observations using FDG-PET/CT to estimate vascular inflammation support epidemiological findings of premature atherosclerosis in PSO and RA. The use of FDG-PET/CT to investigate vascular inflammation across systemic inflammatory diseases warrants further examination in larger study populations.

Impact of effective tumor necrosis factor-alfa inhibitor treatment on arterial intima-media thickness in psoriasis: results of a pilot study

BACKGROUND

Psoriasis is associated with higher incidence of atherosclerotic comorbidities. Sustained arterial wall inflammation mediated by common cytokines of psoriasis and atherogenesis precedes atherosclerotic plaque development. Increased intima-media thickness (IMT) is an accepted indicator of subclinical atherosclerosis and has been reported in severe psoriasis.

OBJECTIVE

This pilot study aimed to clarify whether effective long-term tumor necrosis factor-alfa inhibition decreases IMT in psoriasis.

METHODS

In 16 patients with severe psoriasis, the Psoriasis Area and Severity Index score was calculated before therapy (etanercept, infliximab, adalimumab) and after 6-month treatment. Simultaneously, carotid and brachial IMT was measured by high-resolution, B-mode ultrasonography. Difference between initial and 6-month IMT values was determined for monitored arteries collectively and separately in carotid and brachial arteries.

RESULTS

All of 16 patients achieved Psoriasis Area and Severity Index 75, and 14 of 16 achieved Psoriasis Area and Severity Index 90 improvement. In the group of patients without initial calcified atherosclerotic plaques (13 of 16) significant IMT decrease was detected when arteries were measured collectively (P = .0002). Initial and follow-up data differed significantly also at individual analysis of carotid (P = .011) and brachial (P = .006) arteries. Eleven of 13 patients had initial carotid IMT exceeding age-adjusted normal values. The other group (3 of 16) with initial manifest plaques showed increasing IMT tendency. Their baseline ultrasonography revealed carotid IMT above the upper limit of healthy adults' age-adjusted values.

LIMITATIONS

Study limitation involves small patient numbers, self-controlled study design, and lack of patients' stratification according to common cardiovascular risk factors.

CONCLUSION

In our pilot study effective tumor necrosis factor-alfa inhibition was found to decrease IMT in psoriatic patients without irreversible atherosclerotic plaques. Further analysis is recommended to confirm and complete our primary observations.

Modulation of cardiometabolic pathways in skin and serum from patients with psoriasis

Background

Moderate-to-severe psoriasis is associated with an increased risk of atherosclerotic cardiovascular disease (ASCVD); however, the link is poorly understood.

Methods

Skin and serum from patients with psoriasis were evaluated to understand if there was evidence of dysregulation in a targeted group of inflammatory and lipid genes related to ASCVD. Microarray analyses of expression of targeted ASCVD genes from skin in 89 patients with moderate-to-severe psoriasis from the ACCEPT trial were compared with non-diseased skin from healthy controls (n = 25). Serum (n = 149) was tested at baseline for monocyte chemoattractant protein-1 (MCP-1), macrophage-derived chemokine (MDC), and apolipoprotein-A1 (Apo-A1) comparing to healthy controls (n=162).

Results

An increase in skin gene expression for MCP-1 (7.98-fold) and MDC (6.66-fold) (p < 0.001 each) was observed in lesional versus healthy skin. Significant decreases in liver X receptor-alpha (LXR-α) (−5.94-fold), a protective lipoprotein metabolism gene, and in peroxisome proliferator-activated receptor-alpha (PPAR-α) (−7.58-fold), a protective anti-inflammatory and lipid modulating gene, were observed in lesional versus healthy skin (p < 0.001 each). Serum analyses revealed that MCP-1 (502 vs. 141 pg/mL) and MDC (1240 vs. 409 pg/mL) levels were significantly elevated in psoriasis compared with healthy controls (p < 0.001 each). Dysregulated lipid metabolism was also evident in the serum, as Apo-A1, a protein product related to PPAR-α activation, was significantly decreased in patients with psoriasis compared with healthy controls (25.2 vs. 38.9 mg/dL; p < 0.001).

Conclusions

Analyses of targeted genes and their products known to be associated with ASCVD revealed dysregulation of inflammatory (MCP-1 and MDC) and lipid metabolism (LXR-α, PPAR-α) genes in psoriasis. These findings provide evidence of a potential shared pathophysiology linking psoriasis to cardiometabolic diseases.

Cardiovascular Comorbidities of Psoriasis and Psoriatic Arthritis: A Report from the GRAPPA 2012 Annual Meeting

At the 2012 annual meeting of the Group for Research and Assessment of Psoriasis and Psoriatic Arthritis (GRAPPA) in Stockholm, Sweden, several GRAPPA members led a panel discussion on cardiovascular (CV) comorbidities of psoriasis and psoriatic arthritis (PsA). The panelists discussed the role of insulin resistance in the pathophysiology of psoriasis, the possible effect of tumor necrosis factor inhibitors on CV comorbidities, and the effect of 12/23 monoclonal antibodies on CV outcomes. The panelists also addressed how lessons from CV comorbidity research could be applied to other areas of comorbidity research in psoriasis and PsA and identified future research directions in this area.

Putting together the psoriasis puzzle: an update on developing targeted therapies

Psoriasis vulgaris is a chronic, debilitating skin disease that affects millions of people worldwide. There is no mouse model that accurately reproduces all facets of the disease, but the accessibility of skin tissue from patients has facilitated the elucidation of many pathways involved in the pathogenesis of psoriasis and highlighted the importance of the immune system in the disease. The pathophysiological relevance of these findings has been supported by genetic studies that identified polymorphisms in genes associated with NFκB activation, IL-23 signaling and T helper 17 (Th17)-cell adaptive immune responses, and in genes associated with the epidermal barrier. Recently developed biologic agents that selectively target specific components of the immune system are highly effective for treating psoriasis. In particular, emerging therapeutics are focused on targeting the IL-23–Th17-cell axis, and several agents that block IL-17 signaling have shown promising results in early-phase clinical trials. This review discusses lessons learned about the pathogenesis of psoriasis from mouse-and patient-based studies, emphasizing how the outcomes of clinical trials with T-cell-targeted and cytokine-blocking therapies have clarified our understanding of the disease.

The IL-23/T17 pathogenic axis in psoriasis is amplified by keratinocyte responses

Psoriasis is a complex inflammatory process resulting from activation of the well-defined interleukin (IL)-23/T17 cytokine axis. We review the role of key cytokines IL-17 and IL-23 in psoriasis, as well as tumor necrosis factor (TNF)α, focusing on therapeutic cytokine interventions and what they reveal about psoriatic inflammation. The potential role of recently described epidermal IL-36RN and CARD14 genetic mutations in psoriasis pathogenesis is also explored, because they augment keratinocyte responses to proinflammatory cytokines. The discovery of these genetic mutations in familial and pustular psoriasis suggests new links between cytokine-induced gene products and IL-1 family members from keratinocytes, which may regulate features of the disease, including epidermal hyperplasia and neutrophil infiltrating responses.

Increased risk of diabetes mellitus and likelihood of receiving diabetes mellitus treatment in patients with psoriasis

OBJECTIVE

To assess the risk of incident diabetes mellitus (DM) in patients with psoriasis and to evaluate DM treatment patterns among patients with psoriasis and incident DM.

DESIGN

Population-based cohort study.

SETTING

United Kingdom-based electronic medical records.

PATIENTS

We matched 108 132 patients with psoriasis aged 18 to 90 years with 430 716 unexposed patients based on practice and time of visit. For our nested study, only patients who developed incident DM during our study time were included.

MAIN OUTCOME MEASURES

Incident DM and adjusted risk of pharmacotherapy among those with incident DM.

RESULTS

The fully adjusted hazard ratios (95% CIs) for incident DM were 1.14 (95% CI, 1.10-1.18), 1.11 (95% CI, 1.07-1.15), and 1.46 (95% CI, 1.30-1.65) in the overall, mild, and severe psoriasis groups, respectively. Among those with incident DM and severe psoriasis, the adjusted risk for receiving DM pharmacotherapy was 1.55 (95% CI, 1.15-2.10).

CONCLUSIONS

Our results suggest that psoriasis is an independent risk factor for the development of type 2 DM in a dose-dependent manner, and that patients with severe psoriasis who develop DM are more likely to receive systemic diabetic therapies in comparison with patients with DM but without psoriasis.

Exploring priority research areas in psoriasis and psoriatic arthritis from dermatologists' perspective: a report from the GRAPPA 2011 annual meeting

At the 2011 annual meeting of the Group for Research and Assessment of Psoriasis and Psoriatic Arthritis (GRAPPA) in Naples, Italy, the GRAPPA dermatology members led discussions on priority research areas in psoriasis and psoriatic arthritis (PsA). These discussions centered on 3 primary areas: evaluation of PsA screening tools, updates on psoriasis comorbidities, and new developments in genetics and comparative effectiveness research. Introductory presentations were followed by engaging panel discussions and audience interaction. The members agreed that screening tools are highly valuable in early detection of PsA among dermatology patients and that efforts are necessary to develop tools suitable for adoption in clinical practice. Members also agreed that a collaborative investigation to evaluate the effect of psoriasis treatments on cardiovascular comorbidities would be highly informative. Finally, the members supported continued efforts to explore the genetic basis of psoriasis and more studies focused on comparative effectiveness of existing treatments.

Aortic vascular inflammation in psoriasis is associated with HDL particle size and concentration: a pilot study

Psoriasis is a model Th1-mediated inflammatory disease associated with increased incidence of stroke and cardiovascular disease (CVD). The mechanism behind these associations is unknown, however abnormal HDL particle composition measured by nuclear magnetic resonance (NMR) spectroscopy has been shown to be associated with CVD. Using [18F]-fluorodeoxyglucose (FDG) positron emission tomography-computed tomography (PET/CT), a validated surrogate marker of CVD, we assessed whether HDL particle size and concentration were associated with vascular inflammation in patients with psoriasis. Patients with psoriasis were prospectively enrolled (439 aortic samples from 10 patients). Lipoprotein profiles using NMR spectroscopy were obtained and the relationship between vascular inflammation within the thoracic aorta by FDG-PET/CT was analyzed for association with lipoprotein particle characteristics. The plasma total cholesterol (206 mg/dL (IQR 154-229)), LDL (105 (90-161)), and triglyceride levels were within normal range (151 (94-191)) while HDL levels were low (28.9 (27.2-31.3)); however, the NMR profile demonstrated an atherogenic profile with increased small LDL and HDL particles. Total HDL particle concentration (p<0.001) and HDL particle size (p<0.001) were associated with decreased aortic inflammation, while concentration of small HDL particles was associated with increased inflammation (p<0.001). The association of total HDL particle concentration (β -0.0113, p=0.002) and small HDL particle concentration (β 0.026, p<0.001) with aortic inflammation persisted following adjustment for CVD risk factors. Total HDL particle concentration and small HDL particle concentration were associated with vascular inflammation within the thoracic aorta in psoriasis. These findings suggest that HDL particle characteristics may play an important role in psoriatic vascular inflammation and CVD.

Metabolic syndrome in patients with psoriatic disease

Psoriasis is a common Th-1 and Th-17-mediated chronic inflammatory disease that has been associated with metabolic syndrome, a constellation of cardiovascular risk factors including obesity, hypertension, dyslipidemia, and insulin resistance. Overlapping inflammatory pathways and genetic susceptibility may be potential biologic links underlying this association. Multiple epidemiologic studies have consistently demonstrated higher prevalence of metabolic syndrome in patients with psoriasis. Dose-response relationships between more severe psoriasis and higher prevalence of metabolic syndrome components were recently established. This association has important clinical implications for the comprehensive management of psoriasis: Patients with psoriasis should be routinely screened for metabolic syndrome and treated accordingly to manage cardiometabolic risk, while clinicians should monitor potential effects on treatment efficacy and safety in patients with comorbid psoriasis and metabolic syndrome. Further research will be necessary to establish the directionality of this association and to explore the effect of treatment on these comorbid diseases.

Chronic skin-specific inflammation promotes vascular inflammation and thrombosis

Patients with psoriasis have systemic and vascular inflammation and are at increased risk for myocardial infarction, stroke, and cardiovascular death. However, the underlying mechanism(s) mediating the link between psoriasis and vascular disease is incompletely defined. This study sought to determine whether chronic skin-specific inflammation has the capacity to promote vascular inflammation and thrombosis. Using the KC-Tie2 doxycycline-repressible (Dox-off) murine model of psoriasiform skin disease, spontaneous aortic root inflammation was observed in 33% of KC-Tie2 compared with 0% of control mice by 12 months of age (P=0.04) and was characterized by the accumulation of macrophages, T lymphocytes, and B lymphocytes, as well as by reduced collagen content and increased elastin breaks. Importantly, aortic inflammation was preceded by increases in serum tumor necrosis factor-α, IL-17A, vascular endothelial growth factor, IL-12, monocyte chemotactic protein-1, and S100A8/A9, as well as splenic and circulating CD11b(+)Ly-6C(hi) pro-inflammatory monocytes. Doxycycline treatment of old mice with severe skin disease eliminated skin inflammation and the presence of aortic root lesion in 1-year-old KC-Tie2 animals. Given the bidirectional link between inflammation and thrombosis, arterial thrombosis was assessed in KC-Tie2 and control mice; mean time to occlusive thrombus formation was shortened by 64% (P=0.002) in KC-Tie2 animals; and doxycycline treatment returned thrombosis clotting times to that of control mice (P=0.69). These findings demonstrate that sustained skin-specific inflammation promotes aortic root inflammation and thrombosis and suggest that aggressive treatment of skin inflammation may attenuate pro-inflammatory and pro-thrombotic pathways that produce cardiovascular disease in psoriasis patients.

Abnormal lipoprotein particles and cholesterol efflux capacity in patients with psoriasis

OBJECTIVES

Psoriasis is a Th-1/17 mediated inflammatory disease associated with increased risk of cardiovascular disease (CVD). Inflammation may modulate lipoprotein particle number and directly impair HDL functions, in particular reverse cholesterol transport (RCT). We sought to study how chronic in vivo inflammation modulates lipoprotein particle composition using nuclear magnetic resonance spectroscopy (NMR) and HDL efflux in psoriasis.

METHODS AND RESULTS

We prospectively enrolled a consecutive sample of patients with psoriasis (n = 122) and compared lipoprotein and metabolic risk factors to patients without psoriasis (n = 134). Fasting lipids, insulin, glucose were measured by standard assays, and lipoprotein concentration and size were measured by NMR. In a random subset (n = 100 each group), HDL efflux capacity was quantified using a validated ex vivo system involving the incubation of macrophages with apolipoprotein B-depleted serum from patients. Traditional lipid concentrations were similar in both groups except for HDL concentration which was lower in psoriasis (43 mg/dl (36-58) vs 50 (42-62), p < 0.01). However, NMR showed an atherogenic profile in psoriasis similar to that observed in diabetes, with significant increase in LDL particle concentration [1210.5 (1002-1498) vs 1115 (935-1291), p = 0.02] with decrease in LDL size [20.6 (20.3-21.1) vs 21.3 (20.6-21.1), p < 0.001] beyond CV risk factors and HOMA-IR (p = 0.001). Finally, HDL efflux capacity was lower in psoriasis compared to controls in fully adjusted models (beta -0.14, p = 0.001).

CONCLUSIONS

These data support a more atherogenic lipoprotein profile by NMR and decreased HDL efflux capacity in psoriasis patients compared to controls beyond CVD risk factors. The abnormal lipoprotein particle composition and HDL efflux capacity in psoriasis may provide a link between psoriasis and CVD.

A Patient with Psoriatic Arthritis Imaged with FDG-PET/CT Demonstrated an Unusual Imaging Pattern with Muscle and Fascia Involvement: A Case Report

We describe the case of a patient with known history of psoriasis that presented with 1 year of unexplained fever, muscle weakness and marked weight loss, suspicious for B symptoms of a malignant origin. [(18)F]-Fluorodeoxyglucose positron emission tomography-computed tomography (FDG-PET/CT) scans demonstrated an unusual serpiginous pattern of uptake in the fascia and muscles as well as lymph node activity. Multiple histological samples, including a final PET-probe guided lymph node surgical resection, excluded malignancy and confirmed the diagnosis of reactive inflammatory changes, with a plausible diagnosis of autoimmune lymphoproliferative syndrome with associated lymphadenitis, fasciitis and myositis, possibly mediated by tumor necrosis factor (TNF) inhibitor. To our knowledge, there is no evidence of a previously reported FDG uptake pattern of fascia and muscle involvement in psoriatic arthritis.

Quantification of atherosclerotic plaque activity and vascular inflammation using [18-F] fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT)

Conventional non-invasive imaging modalities of atherosclerosis such as coronary artery calcium (CAC) and carotid intimal medial thickness (C-IMT) provide information about the burden of disease. However, despite multiple validation studies of CAC, and C-IMT, these modalities do not accurately assess plaque characteristics, and the composition and inflammatory state of the plaque determine its stability and, therefore, the risk of clinical events. [(18)F]-2-fluoro-2-deoxy-D-glucose (FDG) imaging using positron-emission tomography (PET)/computed tomography (CT) has been extensively studied in oncologic metabolism. Studies using animal models and immunohistochemistry in humans show that FDG-PET/CT is exquisitely sensitive for detecting macrophage activity, an important source of cellular inflammation in vessel walls. More recently, we and others have shown that FDG-PET/CT enables highly precise, novel measurements of inflammatory activity of activity of atherosclerotic plaques in large and medium-sized arteries. FDG-PET/CT studies have many advantages over other imaging modalities: 1) high contrast resolution; 2) quantification of plaque volume and metabolic activity allowing for multi-modal atherosclerotic plaque quantification; 3) dynamic, real-time, in vivo imaging; 4) minimal operator dependence. Finally, vascular inflammation detected by FDG-PET/CT has been shown to predict cardiovascular (CV) events independent of traditional risk factors and is also highly associated with overall burden of atherosclerosis. Plaque activity by FDG-PET/CT is modulated by known beneficial CV interventions such as short term (12 week) statin therapy as well as longer term therapeutic lifestyle changes (16 months). The current methodology for quantification of FDG uptake in atherosclerotic plaque involves measurement of the standardized uptake value (SUV) of an artery of interest and of the venous blood pool in order to calculate a target to background ratio (TBR), which is calculated by dividing the arterial SUV by the venous blood pool SUV. This method has shown to represent a stable, reproducible phenotype over time, has a high sensitivity for detection of vascular inflammation, and also has high inter-and intra-reader reliability. Here we present our methodology for patient preparation, image acquisition, and quantification of atherosclerotic plaque activity and vascular inflammation using SUV, TBR, and a global parameter called the metabolic volumetric product (MVP). These approaches may be applied to assess vascular inflammation in various study samples of interest in a consistent fashion as we have shown in several prior publications.

[Psoriatric arthritis - a permanent challenge for rheumatologists and patients: part 2: imaging diagnostics, classification and therapy]

In recent years a considerable number of imaging techniques have been used to demonstrate the onset and progression of arthritis-related changes in psoriatric arthritis (PsA). Moreover the identification of new immunological pathways has resulted in a substantial improvement of available therapies for PsA increasing the chance for the individual to receive effective treatment. Although an all-embracing disease activity score is still lacking, there is a variety of symptom-related tools to adequately reflect the course of disease and to evaluate the corresponding treatment success. This manuscript aims to give an overview of the latest corresponding knowledge with respect to PsA.