Inflammatory plasma signature of chronic hand eczema: Associations with aetiological and clinical subtypes.

BACKGROUND: Chronic hand eczema (CHE) is a highly prevalent, heterogeneous, skin disease that encompasses different aetiological and clinical subtypes. Severe CHE without atopic dermatitis has been associated with systemic inflammation; yet it remains unknown if specific CHE subtypes leave distinct, systemic, molecular signatures. OBJECTIVES: To characterize the inflammatory plasma signature of different aetiological and clinical CHE subtypes. METHODS: We assessed expression levels of 266 inflammatory and cardiovascular disease risk plasma proteins as well as filaggrin gene mutation status in 51 well-characterized CHE patients without concomitant atopic dermatitis and 40 healthy controls. Plasma protein expression was compared between aetiological and clinical CHE subgroups and controls both overall and according to clinical CHE severity. Correlation analyses for biomarkers, clinical and self-reported variables were performed. RESULTS: Very severe, chronic allergic contact dermatitis (ACD) on the hands was associated with a mixed Type 1/Type 2 systemic immune activation as compared with controls. Circulating levels of Type 1/Type 2 inflammatory biomarkers correlated positively with clinical disease severity among CHE patients with ACD. No biomarkers were found, that could discriminate between aetiological subtypes, for example, between ACD and irritant contact dermatitis. Hyperkeratotic CHE showed a distinct, non-atopic dermatitis-like, systemic footprint with upregulation of markers associated with Type 1 inflammation and tumour necrosis factor alpha, but not Type 2 inflammation. Increased levels of CCL19 and CXCL9/10 could discriminate hyperkeratotic CHE from both vesicular and chronic fissured CHE, whereas no difference was found between the latter two subtypes. CONCLUSION: Profiling of systemic biomarkers showed potential for identifying certain CHE subtypes. Peripheral blood levels of inflammatory biomarkers were associated and correlated with the clinical disease severity of chronic ACD on the hands, underlining that this is a systemic disease. We question whether hyperkeratotic CHE should be classified as eczema.

Circulating biomarkers are associated with disease severity of chronic hand eczema and atopic dermatitis.

BACKGROUND: Although chronic hand eczema (CHE) is a highly prevalent and disabling skin disease, it is currently unknown if CHE is associated with systemic inflammation. OBJECTIVES: To characterize the plasma inflammatory signature of CHE. METHODS: Using Proximity Extension Assay technology, we assessed 266 inflammatory and cardiovascular disease risk proteins in the plasma of 40 healthy controls, 57 patients with atopic dermatitis (AD) with active lesions, 11 with CHE and a history of AD (CHEPREVIOUS_AD), and 40 with CHE and no history of AD (CHENO_AD). Filaggrin gene mutation status was also assessed. Protein expression was compared between groups and according to disease severity. Correlation analyses for biomarkers, and clinical- and self-reported variables, were performed. RESULTS: Very severe CHENO_AD was associated with systemic inflammation when compared with controls. Levels of T helper (Th)2- and Th1-, general inflammation and eosinophil activation markers increased with severity of CHENO_AD, primarily being significantly increased in very severe disease. Significant, positive correlations were found between markers from these pathways and severity of CHENO_AD. Moderate-to-severe but not mild AD displayed systemic inflammation. The Th2 markers C-C motif chemokine (CCL)17 and CCL13 (also known as monocyte chemotactic protein 4) were the top differentially expressed proteins in both very severe CHENO_AD and moderate-to-severe AD, showing a higher fold change and significance in AD. CCL17 and CCL13 levels further correlated positively with disease severity in both CHENO_AD and AD. CONCLUSIONS: Systemic Th2-driven inflammation is shared between very severe CHE with no history of AD, and moderate-to-severe AD, suggesting that Th2 cell targeting could be effective in several CHE subtypes.

IL-17 Pathway Members as Potential Biomarkers of Effective Systemic Treatment and Cardiovascular Disease in Patients with Moderate-to-Severe Psoriasis.

Psoriasis is a chronic inflammatory condition associated with atherosclerotic cardiovascular disease (CVD). Systemic anti-psoriatic treatments mainly include methotrexate and biological therapies targeting TNF, IL-12/23 and IL-17A. We profiled plasma proteins from patients with moderate-to-severe psoriasis to explore potential biomarkers of effective systemic treatment and their relationship to CVD. We found that systemically well-treated patients (PASI < 3.0, n = 36) had lower circulating levels of IL-17 pathway proteins compared to untreated patients (PASI > 10, n = 23). Notably, IL-17C and PI3 were decreased with all four examined systemic treatment types. Furthermore, in patients without CVD, we observed strong correlations among IL-17C/PI3/PASI (r ≥ 0.82, p ≤ 1.5 × 10-12) pairs or between IL-17A/PASI (r = 0.72, p = 9.3 × 10-8). In patients with CVD, the IL-17A/PASI correlation was abolished (r = 0.2, p = 0.24) and the other correlations were decreased, e.g., IL-17C/PI3 (r = 0.61, p = 4.5 × 10-5). Patients with moderate-to-severe psoriasis and CVD had lower levels of IL-17A compared to those without CVD (normalized protein expression [NPX] 2.02 vs. 2.55, p = 0.013), and lower IL-17A levels (NPX < 2.3) were associated with higher incidence of CVD (OR = 24.5, p = 0.0028, 95% CI 2.1-1425.1). As a result, in patients with moderate-to-severe psoriasis, we propose circulating IL-17C and PI3 as potential biomarkers of effective systemic anti-psoriatic treatment, and IL-17A as potential marker of CVD.

Biomarkers of subclinical atherosclerosis in patients with psoriasis.

Psoriasis is linked with increased risk of cardiovascular disease (CVD) that is underestimated by traditional risk stratification. We conducted a large-scale plasma proteomic analysis by use of a proximity extension assay in 85 patients with a history of moderate-to-severe psoriasis with or without established atherosclerotic CVD. Differentially expressed proteins associated with CVD were correlated with subclinical atherosclerotic markers including vascular inflammation determined by 18F-fluorodeoxyglucose positron emission tomography/computed tomography, carotid intima-media thickness (CIMT), carotid artery plaques, and coronary artery calcium score (CCS) in the patients without CVD and statin treatment. We also examined the association between the neutrophil-to-lymphocyte ratio (NLR) and subclinical atherosclerosis. In unadjusted analyses, growth differentiation factor-15 (GDF-15) levels and NLR were increased, while tumor necrosis factor (TNF)-related activation-inducing ligand (TRANCE) and TNF-related apoptosis-induced ligand (TRAIL) levels were decreased in patients with established CVD compared to those without CVD. Among patients with psoriasis without CVD and statin treatment, GDF-15 levels were negatively associated with vascular inflammation in the ascending aorta and entire aorta, and positively associated with CIMT and CCS. NLR was positively associated with vascular inflammation in the carotid arteries. Our data suggest that circulating GDF-15 levels and NLR might serve as biomarkers of subclinical atherosclerosis in patients with psoriasis.

Neutrophil Pathways of Inflammation Characterize the Blood Transcriptomic Signature of Patients with Psoriasis and Cardiovascular Disease.

BACKGROUND: Patients with psoriasis have an increased risk of atherosclerotic cardiovascular disease (CVD). The molecular mechanisms behind this connection are not fully understood, but the involvement of neutrophils have drawn attention as a shared inflammatory factor. METHODS: RNA sequencing using the Illumina platform was performed on blood from 38 patients with moderate to severe psoriasis; approximately half had prior CVD. The neutrophil to lymphocyte ratio (NLR) was obtained from blood samples. Subclinical atherosclerosis was assessed by 18F-fluorodeoxyglucose positron emission tomography/computed tomography and ultrasound imaging. Transcriptomic analysis for differential expression and functional enrichment were performed, followed by correlation analyses of differentially expressed genes (DEGs), NLR and subclinical measurers of CVD. RESULTS: 291 genes were differentially expressed between patients with psoriasis with and without CVD. These included 208 upregulated and 83 downregulated DEGs. Neutrophil degranulation was identified as the most significant process related to the upregulated DEGs. Genes for the neutrophil-associated markers MPO, MMP9, LCN2, CEACAM1, CEACAM6 and CEACAM8 were identified as being of special interest and their mRNA levels correlated with NLR, high-sensitive C-reactive protein and markers of subclinical CVD. CONCLUSIONS: Patients with psoriasis and CVD had an increased expression of genes related to neutrophil degranulation in their blood transcriptome compared with patients with psoriasis without CVD. NLR may be a potential biomarker of subclinical CVD in psoriasis.

Multiscale Biology of Cardiovascular Risk in Psoriasis: Protocol for a Case-Control Study.

BACKGROUND: Patients with psoriasis have increased risk of cardiovascular disease (CVD) independent of traditional risk factors. The molecular mechanisms underlying the psoriasis-CVD connection are not fully understood. Advances in high-throughput molecular profiling technologies and computational analysis techniques offer new opportunities to improve the understanding of disease connections. OBJECTIVE: We aim to characterize the complexity of cardiovascular risk in patients with psoriasis by integrating deep phenotypic data with systems biology techniques to perform comprehensive multiomic analyses and construct network models of the two interacting diseases. METHODS: The study aims to include 120 adult patients with psoriasis (60 with prior atherosclerotic CVD and 60 without CVD). Half of the patients are already receiving systemic antipsoriatic treatment. All patients complete a questionnaire, and a medical interview is conducted to collect medical history and information on, for example, socioeconomics, mental health, diet, and physical exercise. Participants are examined clinically with assessment of the Psoriasis Area and Severity Index and undergo imaging by transthoracic echocardiography, 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG-PET/CT), and carotid artery ultrasonography. Skin swabs are collected for analysis of microbiome metagenomics; skin biopsies and blood samples are collected for transcriptomic profiling by RNA sequencing; skin biopsies are collected for immunohistochemistry; plasma samples are collected for analyses of proteomics, lipidomics, and metabolomics; blood samples are collected for high-dimensional mass cytometry; and feces samples are collected for gut microbiome metagenomics. Bioinformatics and systems biology techniques are utilized to analyze the multiomic data and to integrate data into a network model of CVD in patients with psoriasis. RESULTS: Recruitment was completed in September 2020. Preliminary results of 18F-FDG-PET/CT data have recently been published, where vascular inflammation was reduced in the ascending aorta (P=.046) and aortic arch (P=.04) in patients treated with statins and was positively associated with inflammation in the visceral adipose tissue (P<.001), subcutaneous adipose tissue (P=.007), pericardial adipose tissue (P<.001), spleen (P=.001), and bone marrow (P<.001). CONCLUSIONS: This systems biology approach with integration of multiomics and clinical data in patients with psoriasis with or without CVD is likely to provide novel insights into the biological mechanisms underlying these diseases and their interplay that can impact future treatment. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/28669.