Molecular dissection of psoriasis: integrating genetics and biology

A BET inhibitor, NHWD-870, can downregulate dendritic cells maturation via the IRF7-mediated signaling pathway to ameliorate imiquimod-induced psoriasis-like murine skin inflammation

Psoriasis is a chronic, recurrent, inflammatory dermatosis accompanied by excessive activation of dendritic cells (DCs), which are primarily responsible for initiating an immune response. The bromodomain and extraterminal domain (BET) family plays a pivotal role in the transcriptional regulation of inflammation and its inhibitors can downregulate DCs maturation and activation. Here we investigated the effect of NHWD-870, a potent BET inhibitor, on inflammation in an imiquimod (IMQ)-induced psoriasis-like mouse model and murine bone marrow-derived dendritic cells (BMDCs) stimulated by lipopolysaccharide (LPS) and IMQ. Application of NHWD-870 significantly ameliorated IMQ-triggered skin inflammation in mice, and markers associated with DC maturation (CD40, CD80 and CD86) were decreased in skin lesions, spleen and lymph nodes. Additionally, NHWD-870 reduced LPS or IMQ induced DCs maturation and activation in vitro, with lower expression of inflammatory cytokines [interleukin (IL)-12, IL-23, tumor necrosis factor-α, IL-6, IL-1β, chemokine (C-X-C motif) ligand (CXCL)9 and CXCL10]. In addition, we found that interferon regulatory factor 7 (IRF7) significantly increased during DCs maturation, and inhibition of IRF7 could impair BMDCs maturation and activation. What's more, IRF7 was highly expressed in both psoriatic patients and IMQ-induced psoriasis-like mice. Single-cell RNA sequencing of normal and psoriatic skin demonstrated that IRF7 expression was increased in DCs of psoriatic skin. While NHWD-870 could inhibit IRF7 and phosphorylated-IRF7 expression in vivo and in vitro. These results indicate that NHWD-870 suppresses the maturation and activation of DCs by decreasing IRF7 proteins which finally alleviates psoriasis-like skin lesions, and NHWD-870 may be a potent therapeutic drug for psoriasis.

Gentiopicrin-Loaded Chitosan Nanoparticles as a Topical Agent for the Treatment of Psoriasis

Psoriasis, a chronic inflammatory skin disease induced by various factors, including genetic factors, immune factors, environmental factors, and psychological factors, is characterized by thickening of the epidermis, excessive proliferation of keratinocytes, abnormal differentiation, and an excessive inflammatory response. Traditional treatments for psoriasis still face challenges because of limited curative effects, notable side effects, and a tendency for recurrence. In contrast, topical therapy provides a favorable option for psoriasis treatment because of its noninvasive and self-administered method. In this study, gentiopicrin (Gen) is encapsulated in the liposomes to form a nanodrug, and then chitosan is covered on the nanodrug to assemble the nanodrug delivery system (CS@Gen), which is used as a topical agent for treating psoriasis. Then M5 (a mixture of five pro-inflammatory cytokines, i.e., IL-17A, IL-22, IL-1α, oncostatin M, and TNF-α)-induced HacaT cells and imiquimod-induced psoriasis mouse models are established, whose results show that CS@Gen induces apoptosis and inhibits the proliferation and cell migration of psoriasis keratinocytes. Additionally, the application of CS@Gen cream can significantly reduce epidermal thickness, diminish skin scaling, and improve other related mechanisms in mice affected by psoriasis. Meanwhile, the prepared CS@Gen can significantly reduce the expression levels of IL-17a, Cxcl2, S100a, Mki67, and other related inflammatory factors, resulting in indirectly inhibiting the inflammation of keratinocytes. In summary, the present study provides an ideal loading for an anti-inflammatory and immunomodulatory drug delivery system for the treatment of psoriasis.

High-dimensional profiling of regulatory T cells in psoriasis reveals an impaired skin-trafficking property

BACKGROUND

Psoriasis is a chronic inflammatory skin disease with a Th17-skewed immune phenotype. Although it has been generally accepted that regulatory T cells (Tregs) in lesional psoriatic skin have functional impairment due to the local inflammatory microenvironment, the molecular properties of skin-homing psoriatic Tregs have not been well explored.

METHODS

We designed an extensive 39 marker mass cytometry (CyTOF) panel to deeply profile the immune landscape of skin-homing Tregs from 31 people with psoriasis stratified by psoriasis area severity index score as mild (n = 15) to moderate-severe (n = 16) and 32 healthy controls. We further validated the findings with an in-vitro chemokine-mediated Treg migration assay, immunofluorescent imaging of normal and psoriatic lesional skin and analysed public single-cell RNA-sequencing datasets to expand upon our findings into the local tissue microenvironments.

FINDINGS

We discovered an overall decrease in CLAhi Tregs and specifically, CLAhiCCR5+ Tregs in psoriasis. Functional markers CD39 and FoxP3 were elevated in psoriatic Tregs. However, CCR7 expression was significantly increased while CCR4 and CLA expression was reduced in psoriatic Tregs and CLAhi Tregs, which was associated with disease severity. Moreover, psoriatic Tregs revealed increased migratory capacity towards CCR7's ligands, CCL19/CCL21. Interrogation of public single-cell RNA sequencing data confirmed reduced expression of skin-trafficking markers in lesional-skin Tregs compared to non-lesioned skin, further substantiated by immunofluorescent staining.

INTERPRETATION

Psoriatic circulating Tregs showed an impaired skin-trafficking phenotype thus leading to insufficient suppression of ongoing inflammation in the lesional skin, expanding upon our current understanding of the impairment of Treg-mediated immunosuppression in psoriasis.

FUNDING

This research was supported by the Basic Science Research Program through the National Research Foundation of Korea funded by the Ministry of Science and Information and Communications Technology (2020R1C1C1014513, 2021R1A4A5032185, 2020R1F1A1073692); and the new faculty research seed money grant of Yonsei University College of Medicine for 2021 (2021-32-0033).

Development of an Effective Psoriasis Treatment by Combining Tacrolimus-Encapsulated Liposomes and Iontophoresis

Psoriasis is a chronic T-cell-mediated autoimmune skin disease. Tacrolimus (FK506) is commonly used treatment for psoriasis. However, since the molecular weight of FK506 is more than 500 Da, its skin penetration is limited, so that there is a need to improve the penetrability of FK506 to allow for more effective treatment. To this end, we employed iontophoresis (ItP), which is a physical, intradermal drug delivery technology that relies on the use of weak electric current. Previous findings suggest that activation of cell signaling by the weak electric current applied during ItP may affect the expression of inflammatory cytokines, leading to aggravation of psoriasis. In this study, we analyzed the effect of ItP on the expression of various inflammatory cytokines in the skin, and subsequently examined the therapeutic effect of ItP using negatively-charged liposomes encapsulating FK506 (FK-Lipo) in a rat psoriasis model induced by imiquimod. We found that ItP (0.34 mA/cm2, 1 h) did not affect mRNA levels of inflammatory cytokines or epidermis thickness, indicating that ItP is a safe technology for psoriasis treatment. ItP of FK-Lipo suppressed the expression of inflammatory cytokines induced by imiquimod treatment to a greater extent than skin treated with FK506 ointment for 1 h. Furthermore, epidermis thickening was significantly suppressed only by ItP of FK-Lipo. Taken together, results of this study demonstrate the successful development of an efficient treatment for psoriasis by combining FK-Lipo and ItP, without disease aggravation associated with the weak electric current.

Exploring Psoriasis Inflammatory Microenvironment by NanoString Technologies

Psoriasis is a chronic inflammatory skin disease whose molecular mechanisms and microenvironment are poorly understood. We performed gene expression analysis through the nCounter® PanCancer Immune Profiling Panel (NanoString Technologies, Seattle, WA, USA) on 22 FFPE punch biopsies from 19 psoriasis-affected patients. A subset of five cases was analyzed before (T0) and after 6 months (T6) of treatment with dimethyl fumarate (DMF) to address immune microenvironment changes. Molecular comparisons according to biopsy site and age of onset showed a different distribution of innate immune cells (mast cells, macrophages, NK cells, and DC cells) and pathways (complement regulation and transporter functions). The analysis according to PASI (Psoriasis Area and Severity Index) led to non-significant results, suggesting no link between molecular expression profile and clinical amount of skin disease. In DMF-treated patients, we observed a strong immunomodulatory effect after treatment: A subversion of exhausted CD8 T cells, NK CD56dim cells, Tregs, neutrophils, CD45+ cells, T cells, B cells, and macrophages was reported between the two analyzed time-points, as well as the reduction in pro-inflammatory pathways and molecules, including cytotoxicity, pathogen defense, antigen processing, adhesion, cell cycle, chemokines, cytokines, and interleukins. The inflammatory psoriatic microenvironment can be modulated using DMF with encouraging results, achieving an immune-tolerant and non-inflammatory condition through the regulation of both innate and adaptive immunity.

Effect of the age of onset on epidemiology, clinical features, and comorbidity of geriatric psoriasis

Psoriasis is an immune-mediated chronic, relapsing, inflammatory, systemic disease induced by a combination of genetics and environment. Currently, there are limited reports on the epidemiological and clinical characteristics of geriatric psoriatic patients in mainland China. This study analyzed the epidemiological characteristics, clinical features, and comorbidity rates of geriatric patients with psoriasis and evaluated the influence of age of onset on disease characteristics. This retrospective study enrolled 1259 geriatric patients with psoriasis in hospitals affiliated with the National Standardized Psoriasis Diagnosis and Treatment Center in China from September 2011 to July 2020 to analyze the epidemiological characteristics, clinical features, and prevalence of comorbidity in geriatric psoriasis. The cases were classified according to the age of onset into two groups to compare differences: early-onset psoriasis (EOP) and late-onset psoriasis (LOP). The mean age of geriatric patients with psoriasis was 67, with a 1.8:1 male-to-female ratio and 10.7% positive family history. The clinical manifestations of plaque psoriasis accounted for a high proportion (82.0%) and 85.1% of patients had moderate to severe disease. Overweight (27.8%), hypertension (18.0%), joint involvement (15.8%), diabetes (13.7%), and coronary heart disease (4.0%) were the first five common comorbidities. The LOP group had significantly more patients (79.9%) than the EOP group (20.1%). Positive family history was significantly associated with the EOP group (21.7%) than the LOP group (7.9%). The scalp (60.2%) was the most affected area, followed by the nails (25.3%), palmoplantar region (25.0%), and genitals (12.7%). This study analyzed the epidemiological and clinical characteristics of geriatric psoriasis in China and found that age of onset had no effect on disease characteristics or other comorbidities, except for toenail involvement, diabetes, and joint damage.

PARP2 promotes inflammation in psoriasis by modulating estradiol biosynthesis in keratinocytes

Poly(ADP-ribose) polymerase 2 (PARP2) alongside PARP1 are responsible for the bulk of cellular PARP activity, and they were first described as DNA repair factors. However, research in past decades implicated PARPs in biological functions as diverse as the regulation of cellular energetics, lipid homeostasis, cell death, and inflammation. PARP activation was described in Th2-mediated inflammatory processes, but studies focused on the role of PARP1, while we have little information on PARP2 in inflammatory regulation. In this study, we assessed the role of PARP2 in a Th17-mediated inflammatory skin condition, psoriasis. We found that PARP2 mRNA expression is increased in human psoriatic lesions. Therefore, we studied the functional consequence of decreased PARP2 expression in murine and cellular human models of psoriasis. We observed that the deletion of PARP2 attenuated the imiquimod-induced psoriasis-like dermatitis in mice. Silencing of PARP2 in human keratinocytes prevented their hyperproliferation, maintained their terminal differentiation, and reduced their production of inflammatory mediators after treatment with psoriasis-mimicking cytokines IL17A and TNFα. Underlying these observations, we found that aromatase was induced in the epidermis of PARP2 knock-out mice and in PARP2-deficient human keratinocytes, and the resulting higher estradiol production suppressed NF-κB activation, and hence, inflammation in keratinocytes. Steroidogenic alterations have previously been described in psoriasis, and we extend these observations by showing that aromatase expression is reduced in psoriatic lesions. Collectively, our data identify PARP2 as a modulator of estrogen biosynthesis by epidermal keratinocytes that may be relevant in Th17 type inflammation. KEY MESSAGES : PARP2 mRNA expression is increased in lesional skin of psoriasis patients. PARP2 deletion in mice attenuated IMQ-induced psoriasis-like dermatitis. NF-κB activation is suppressed in PARP2-deficient human keratinocytes. Higher estradiol in PARP2-deficient keratinocytes conveys anti-inflammatory effect.

The Genetic Susceptibility to Psoriasis and the Relationship of Linked Genes to Our Treatment Options

Understanding the factors creating genetic susceptibility in psoriasis may provide a basis for improving targeted treatment strategies. In this review, we discuss the genes linked to the pathogenesis of psoriasis and their relationship to the available treatment options. To identify the relevant genetic markers and treatments, we searched PubMed, Google Scholar, MEDLINE, and Web of Science with keywords, including genetic susceptibility to psoriasis, genetics and psoriasis, psoriasis treatments, and biologics treatments in psoriasis. The articles in English from database inception to 1/1/23 were included. Case reports and series were excluded. Gene variant forms commonly implicated in the pathogenesis of psoriasis include those encoding for interleukins, interferons, and other mediators involved in inflammatory pathways, such as JAK/STAT, and NF-κB. Several of the treatments for psoriasis (for example IL23 and TYK2 inhibitors) target the products of genes linked to psoriasis. Multiple genes are linked to the pathogenesis of psoriasis. This understanding may provide an avenue for the development of new psoriasis treatment strategies and for more effective, safer treatment outcomes.

Single cell and spatial sequencing define processes by which keratinocytes and fibroblasts amplify inflammatory responses in psoriasis

The immunopathogenesis of psoriasis, a common chronic inflammatory disease of the skin, is incompletely understood. Here we demonstrate, using a combination of single cell and spatial RNA sequencing, IL-36 dependent amplification of IL-17A and TNF inflammatory responses in the absence of neutrophil proteases, which primarily occur within the supraspinous layer of the psoriatic epidermis. We further show that a subset of SFRP2+ fibroblasts in psoriasis contribute to amplification of the immune network through transition to a pro-inflammatory state. The SFRP2+ fibroblast communication network involves production of CCL13, CCL19 and CXCL12, connected by ligand-receptor interactions to other spatially proximate cell types: CCR2+ myeloid cells, CCR7+ LAMP3+ dendritic cells, and CXCR4 expressed on both CD8+ Tc17 cells and keratinocytes, respectively. The SFRP2+ fibroblasts also express cathepsin S, further amplifying inflammatory responses by activating IL-36G in keratinocytes. These data provide an in-depth view of psoriasis pathogenesis, which expands our understanding of the critical cellular participants to include inflammatory fibroblasts and their cellular interactions.

Pan-cancer investigation of psoriasis-related BUB1B gene: genetical alteration and oncogenic immunology

Unknown factors contribute to psoriasis' hyperproliferative, chronic, inflammatory, and arthritic features. Psoriasis patients have been linked to an increased risk of cancer, though the underlying genetics remain unknown. Since our prior research indicated that BUB1B contributes to the development of psoriasis, we designed and carried out this investigation using bioinformatics analysis. Using the TCGA database, we investigated the oncogenic function of BUB1B in 33 tumor types. To sum up, our work sheds light on BUB1B's function in pan-cancer from various perspectives, including its pertinent signaling pathways, mutation locations, and connection to immune cell infiltration. BUB1B was shown to have a non-negligible role in pan-cancer, which is connected to immunology, cancer stemness, and genetic alterations in a variety of cancer types. BUB1B is highly expressed in a variety of cancers and may serve as a prognostic marker. This study is anticipated to offer molecular details on the elevated cancer risk that psoriasis sufferers experience.

Subclinical high-resolution chest CT scan features in psoriasis

BACKGROUND

Although psoriasis is considered a systemic disease, no clear association has been established between psoriasis and lung diseases. This study aims to detect and describe subclinical pulmonary involvement in psoriasis patients with various degrees of cutaneous manifestations.

METHODS

Adult psoriasis patients with no known active pulmonary disease or respiratory symptoms were screened for subclinical pulmonary manifestations and possible parenchymal changes using high-resolution computed tomography (HRCT) scan of the chest. Patients were classified according to the severity of skin manifestations. The clinical characteristics and radiographic findings of these patients were evaluated.

RESULTS

Fifty-nine patients with psoriasis were included, among which 47 (79.7%) had abnormal HRCT scan features. Micronodules were the most common detected lung lesions (66.1%), followed by nonspecific interstitial changes (32.2%), including pleuro-parenchymal band/atelectasis, scarring, and focal ground-glass opacities. Other HRCT findings included emphysematous changes and calcified granulomas. Abnormal HRCT findings correlated with older age and duration of psoriasis but not with the severity of skin manifestations.

CONCLUSIONS

Micronodules and minor focal nonspecific interstitial changes were the most detected lung alterations in patients with psoriasis. These findings of the pilot study highlight a possible pulmonary involvement in patients with psoriasis. Larger multicenter studies are needed to clarify these findings further.

LIMITATIONS

A major limitation of the study, is the lack of a control group with similar radiologic findings of different conditions done in the same geographical region.

Secukinumab for the Treatment of Psoriasis in Pediatrics: Patient Selection and Acceptability

Psoriasis (PsO) is a chronic, systemic, immune-mediated inflammatory skin disease affecting 1% to 5% population worldwide. In one-third of patients, the first symptoms of PsO manifest in childhood, with a mean age of nine years. Psoriasis in children under 16 years of age constitutes 4% of dermatological problems in this age group. Chronic inflammation of the skin observed in PsO is associated with a development of potentially serious comorbidities, including psoriatic arthritis, hypertension, metabolic syndrome, cardiovascular diseases, inflammatory bowel disease, depression and anxiety. It is reported that among children with psoriasis between 5 and 16 years of age health-related quality of life is reduced by 30.5%. Early diagnosis and effective treatment are crucial in pediatric psoriatic patients to avoid future complications and stigmatization. Treatment for psoriasis consists of a range of topical medications, phototherapy and non-biologic and biologic systemic therapies. Approved biologics for PsO in pediatric patients include etanercept, adalimumab, ustekinumab, ixekizumab and secukinumab. Secukinumab, a recombinant, fully human monoclonal antibody targeting IL-17A, was approved by the EMA (2020) and FDA (2021) in pediatric patients above 6 years of age for the treatment of moderate to severe plaque psoriasis who are candidates for systemic therapy. This review discusses the selection and acceptability of secukinumab in children with psoriasis.

Five Rutaceae family ethanol extracts alleviate H2O2 and LPS-induced inflammation via NF-κB and JAK-STAT3 pathway in HaCaT cells

This study was designed to investigate the effects of five Rutaceae family ethanol extracts (FRFEE): Citrus medica Linn (CML), Citrus aurantium L. Cv. Daidai (CAD), Citrus medica Linn. var. sarcodactylis (Noot.) Swingle (CMS),Citrus sinensis L. Osbeck (CSO) and Zanthoxylum bungeanum Maxim (ZBM) on retarding the progression of H₂O₂ and LPS-induced HaCaT cells. Cell inflammatory injury model was established by H₂O₂ and LPS. The alleviative effects of FRFEE were evaluated by detecting the activity of superoxide dismutase (SOD), glutathione (GSH) and the generation of reactive oxygen species (ROS). The inflammatory signaling pathways of NF-κB and JAK-STAT3 were detected by Western blotting, the mRNA expression levels of inflammatory factors and skin barrier factors were detected by RT-PCR. 50% ethanol extracts of five medicinal and food homologous herbs of Rutaceae family showed different levels of anti-oxidant and anti-inflammatory activities. The FRFEE effectively improved SOD and GSH content and decreased ROS levels. Meanwhile, FRFEE strongly suppressed two inflammatory signaling pathways NF-κB and JAK-STAT3. The RT-PCR examination of inflammatory factors and skin barrier factor revealed significant anti-inflammatory effects of FRFEE. It was worth noting that among the five extracts, Zanthoxylum bungeanum Maxim extract had the best anti-inflammatory and anti-oxidation effects. In addition, it could strongly inhibit the expression of psoriasis factor CCL20. In summary, these results suggested that Zanthoxylum bungeanum Maxim extract could be used as an anti-psoriatic agent in the treatment of psoriasis among FRFEE.

Treatment Patterns and Pharmacoutilization in Patients Affected by Psoriasis: An Observational Study in an Italian Real-World Setting

BACKGROUND

Real-world data can inform the use of biologics for psoriasis (PSO).

OBJECTIVE

The aim was to evaluate treatment patterns and analyze pharmacoutilization in PSO patients in a real-world Italian setting, with a focus on the biologics most recently introduced.

METHODS

An observational study based on administrative databases was conducted. Patients were included based on PSO diagnosis identified by either discharge diagnosis or exemption code or prescription of anti-psoriatic topical drugs (proxy of diagnosis). To describe patient characteristics and treatment patterns using the most up-to-date data, two different approaches were used: a cross-sectional study performed during 2016-2018, and a longitudinal study conducted with patients who received their first biological/targeted synthetic drugs (naïve patients) in 2014 and 2017 (the inclusion periods).

RESULTS

During 2016-2018, the number of prevalent patients diagnosed with PSO was 194,054 (2016), 210,830 (2017), and 225,171 (2018). The percentage of patients receiving biologics or targeted synthetic agents ranged from 1.5 to 2.1%. Among them, naïve patients receiving interleukin (IL) inhibitors increased from 37.5% (2016) to 69.4% (2018), while those receiving anti-tumor necrosis factor (anti-TNF) decreased from 62.5% (2016) to 30.6% (2018). The longitudinal analysis included 894 and 1218 naïve patients in 2014 and 2017, respectively, of whom 7.2% (2014) and 6.9% (2017) switched therapy after a mean of 7.1 (2014) and 6.9 (2017) months. Overall, 259 patients were prescribed ixekizumab starting in 2017, of whom 73% were naïve. Ixekizumab was prescribed as monotherapy to 52.5%.

CONCLUSIONS

The proportion of patients receiving biologics appeared constant over the years, with an increasing number of naïve patients being prescribed IL-17 inhibitors. Ixekizumab patients were mostly naïve.

Systemic pharmacological treatments for chronic plaque psoriasis: a network meta-analysis

BACKGROUND

Psoriasis is an immune-mediated disease with either skin or joints manifestations, or both, and it has a major impact on quality of life. Although there is currently no cure for psoriasis, various treatment strategies allow sustained control of disease signs and symptoms. The relative benefit of these treatments remains unclear due to the limited number of trials comparing them directly head-to-head, which is why we chose to conduct a network meta-analysis.

OBJECTIVES

To compare the efficacy and safety of non-biological systemic agents, small molecules, and biologics for people with moderate-to-severe psoriasis using a network meta-analysis, and to provide a ranking of these treatments according to their efficacy and safety.

SEARCH METHODS

For this update of the living systematic review, we updated our searches of the following databases monthly to October 2021: the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, and Embase.

SELECTION CRITERIA

Randomised controlled trials (RCTs) of systemic treatments in adults over 18 years with moderate-to-severe plaque psoriasis, at any stage of treatment, compared to placebo or another active agent. The primary outcomes were: proportion of participants who achieved clear or almost clear skin, that is, at least Psoriasis Area and Severity Index (PASI) 90; proportion of participants with serious adverse events (SAEs) at induction phase (8 to 24 weeks after randomisation).

DATA COLLECTION AND ANALYSIS

We conducted duplicate study selection, data extraction, risk of bias assessment and analyses. We synthesised data using pairwise and network meta-analysis (NMA) to compare treatments and rank them according to effectiveness (PASI 90 score) and acceptability (inverse of SAEs). We assessed the certainty of NMA evidence for the two primary outcomes and all comparisons using CINeMA, as very low, low, moderate, or high. We contacted study authors when data were unclear or missing. We used the surface under the cumulative ranking curve (SUCRA) to infer treatment hierarchy, from 0% (worst for effectiveness or safety) to 100% (best for effectiveness or safety).

MAIN RESULTS

This update includes an additional 19 studies, taking the total number of included studies to 167, and randomised participants to 58,912, 67.2% men, mainly recruited from hospitals. Average age was 44.5 years, mean PASI score at baseline was 20.4 (range: 9.5 to 39). Most studies were placebo-controlled (57%). We assessed a total of 20 treatments. Most (140) trials were multicentric (two to 231 centres). One-third of the studies (57/167) had high risk of bias; 23 unclear risk, and most (87) low risk. Most studies (127/167) declared funding by a pharmaceutical company, and 24 studies did not report a funding source. Network meta-analysis at class level showed that all interventions (non-biological systemic agents, small molecules, and biological treatments) showed a higher proportion of patients reaching PASI 90 than placebo. Anti-IL17 treatment showed a higher proportion of patients reaching PASI 90 compared to all the interventions, except anti-IL23. Biologic treatments anti-IL17, anti-IL12/23, anti-IL23 and anti-TNF alpha showed a higher proportion of patients reaching PASI 90 than the non-biological systemic agents. For reaching PASI 90, the most effective drugs when compared to placebo were (SUCRA rank order, all high-certainty evidence): infliximab (risk ratio (RR) 50.19, 95% CI 20.92 to 120.45), bimekizumab (RR 30.27, 95% CI 25.45 to 36.01), ixekizumab (RR 30.19, 95% CI 25.38 to 35.93), risankizumab (RR 28.75, 95% CI 24.03 to 34.39). Clinical effectiveness of these drugs was similar when compared against each other. Bimekizumab, ixekizumab and risankizumab showed a higher proportion of patients reaching PASI 90 than other anti-IL17 drugs (secukinumab and brodalumab) and guselkumab. Infliximab, anti-IL17 drugs (bimekizumab, ixekizumab, secukinumab and brodalumab) and anti-IL23 drugs (risankizumab and guselkumab) except tildrakizumab showed a higher proportion of patients reaching PASI 90 than ustekinumab and three anti-TNF alpha agents (adalimumab, certolizumab and etanercept). Ustekinumab was superior to certolizumab; adalimumab and ustekinumab were superior to etanercept. No significant difference was shown between apremilast and two non-biological drugs: ciclosporin and methotrexate. We found no significant difference between any of the interventions and the placebo for the risk of SAEs. The risk of SAEs was significantly lower for participants on methotrexate compared with most of the interventions. Nevertheless, the SAE analyses were based on a very low number of events with low- to moderate-certainty for all the comparisons (except methotrexate versus placebo, which was high-certainty). The findings therefore have to be viewed with caution. For other efficacy outcomes (PASI 75 and Physician Global Assessment (PGA) 0/1), the results were similar to the results for PASI 90. Information on quality of life was often poorly reported and was absent for several of the interventions.

AUTHORS' CONCLUSIONS

Our review shows that, compared to placebo, the biologics infliximab, bimekizumab, ixekizumab, and risankizumab were the most effective treatments for achieving PASI 90 in people with moderate-to-severe psoriasis on the basis of high-certainty evidence. This NMA evidence is limited to induction therapy (outcomes measured from 8 to 24 weeks after randomisation), and is not sufficient for evaluating longer-term outcomes in this chronic disease. Moreover, we found low numbers of studies for some of the interventions, and the young age (mean 44.5 years) and high level of disease severity (PASI 20.4 at baseline) may not be typical of patients seen in daily clinical practice. We found no significant difference in the assessed interventions and placebo in terms of SAEs, and the safety evidence for most interventions was low to moderate quality. More randomised trials directly comparing active agents are needed, and these should include systematic subgroup analyses (sex, age, ethnicity, comorbidities, psoriatic arthritis). To provide long-term information on the safety of treatments included in this review, an evaluation of non-randomised studies and postmarketing reports from regulatory agencies is needed. Editorial note: This is a living systematic review. Living systematic reviews offer a new approach to review updating, in which the review is continually updated, incorporating relevant new evidence as it becomes available. Please refer to the Cochrane Database of Systematic Reviews for the current status of this review.

Multiomic Analysis of the Gut Microbiome in Psoriasis Reveals Distinct Host‒Microbe Associations

Psoriasis is a chronic, inflammatory skin disease that affects 2‒3% of the global population. Besides skin manifestations, patients with psoriasis have increased susceptibility to a number of comorbidities, including psoriatic arthritis, cardiovascular disease, and inflammatory bowel disease. To understand the systemic component of psoriasis pathogenesis, we performed a pilot study to examine the fecal metagenome, host colonic transcriptome, and host peripheral blood immune profiles of patients with psoriasis and healthy controls. Our study showed increased functional diversity in the gut microbiome of patients with psoriasis. In addition, we identified microbial species that preferentially associate with patients with psoriasis and which have been previously found to associate with other autoimmune diseases. Intriguingly, our data revealed three psoriasis subgroups that have distinct microbial and host features. Integrating these features revealed host‒microbe associations that are specific to psoriasis or particular psoriasis subgroups. Our findings provide insight into the factors that may affect the development of comorbidities in patients with psoriasis and may hold diagnostic potential for early identification of patients with psoriasis at risk for these comorbidities.

Improvement of Psoriasis Using Oral Probiotic Streptococcus salivarius K-12: a Case-Control 24-Month Longitudinal Study

Psoriasis is a common chronic skin disease, associated with an important physical and physiological involvement for any age. There is a strong link between psoriasis and streptococcal infection, particularly that of the tonsils. There are many therapies to treat psoriasis including topical, systemic, and biologic agents but these treatments are not free from side effects. Streptococcus salivarius K-12 is an oral probiotic product useful for the prophylaxis and treatment of tonsillar infections in children and adults, now tested here for the first time for control of psoriasis. Our retrospective analysis was conducted on 198 patients affected by mild to moderate psoriasis: 100 patients were first treated for 90 days with Streptococcus salivarius K-12, while 98 did not receive any probiotics and were the control group. The patients treated with S. salivarius K-12 exhibited a significant improvement of their psoriasis from the baseline condition: 83.7% patients treated achieved a 100% improvement of the PASI score at 24 weeks and efficacy continued to improve with longer treatment, maintaining same result also during follow-up observation. In all patients, the treatment was well tolerated, and no adverse events have been observed. Our data show that oral preparations containing Streptococcus salivarius may provide a beneficial option for the prevention and cure of pediatric and adult psoriasis.

Gut and Cutaneous Microbiome Featuring Abundance of Lactobacillus reuteri Protected Against Psoriasis-Like Inflammation in Mice

Background

Psoriasis is a chronic autoinflammatory skin disease, and its aetiology remains incompletely understood. Recently, gut microbial dysbiosis is found to be tightly associated with psoriasis.

Objective

We sought to reveal the causal role of gut microbiota dysbiosis in psoriasis pathogenesis and investigate the protective effect of healthy commensal bacteria against imiquimod -induced psoriasis-like skin response.

Methods

By using fecal microbial transplantation (FMT), 16S rRNA gene-based taxonomic profiling and Lactobacillus supplement, we have assessed the effect of FMT from healthy individuals on psoriasis-like skin inflammation and associated immune disorders in imiquimod-induced psoriasis mice.

Results

Here, by using psoriasis mice humanized with the stools from healthy donors and psoriasis patients, the imiquimod-induced psoriasis in mice with psoriasis patient stool was found to be significantly aggravated as compared to the mice with healthy donor stools. Further analysis showed fecal microbiota of healthy individuals protected against Treg/Th17 imbalance in psoriasis. Moreover, we found the gut and skin microbiome in mice receipted with gut microbiota of healthy individuals (HD) differed from those of mice receipted with gut microbiota of psoriasis patients (PSD). 16S rRNA sequencing revealed that Lactobacillus reuteri was greatly enriched in fecal and cutaneous microbiome of HD mice as compared to PSD mice. Intriguingly, supplement with Lactobacillus reuteri was sufficient to increase the expression of anti-inflammatory gene IL-10, reduce Th17 cells counts and confer resistance to imiquimod-induced inflammation on the mice with gut microbiota dysbiosis.

Conclusion

Our results suggested that the gut microbiota dysbiosis is the potential causal factor for psoriasis and the gut microbiota may serve as promising therapy target for psoriasis patients.

Genetic variants in IL-17A rs10484879 and serum levels of IL-17A are associated with psoriasis risk

Psoriasis is an inflammatory skin disease characterized by keratinocyte hyperproliferation with effective environmental and genetic factors. Recent studies showing that the IL-23/IL-17 axis plays a central role in the pathogenesis of the disease. Experimental and clinical studies suggest that IL-17A, an important regulatory effector cytokine in this pathway and triggers changes mainly in affected tissues. Based on the central role of IL-17A in the pathogenesis of psoriasis, we thought that variations in this gene could affect the susceptibility and severity of this disease. Therefore, in this study, we aimed to analyze whether IL-17A rs10484879 variant has an effect on psoriasis pathogenesis in Turkish population. In this case-control study, the study group consisting of 564 patient (188 psoriasis patients (66 males/122 females)/376 controls (132 males/244 females) and they were genotyped in terms of IL-17A (rs10484879) polymorphism with TaqMan 5 'Allelic Discrimination Test. IL-17A serum levels were measured with the Enzyme-linked immunosorbent assay (ELISA). The genotype distributions of the IL-17A rs10484879 polymorphism between the patient and control groups were statistically different in the TT genotype and it was observed more commonly in the patient group compared to the controls (p < 0.001). Similarly, the T allele was observed with a higher prevalence in the patient group compared to the controls (p = 0.007). IL-17A serum levels were associated with increased serum concentration, respectively, TT > GT > GG in all study groups (p < 0.05). We would like to report that IL-17A rs10484879 TT genotype and T allele are associated with increased risk of psoriasis in the Turkish population.

Contribution of Dysregulated DNA Methylation to Autoimmunity

Epigenetic mechanisms, such as DNA methylation, histone modifications, and non-coding RNAs are known regulators of gene expression and genomic stability in cell growth, development, and differentiation. Because epigenetic mechanisms can regulate several immune system elements, epigenetic alterations have been found in several autoimmune diseases. The purpose of this review is to discuss the epigenetic modifications, mainly DNA methylation, involved in autoimmune diseases in which T cells play a significant role. For example, Rheumatoid Arthritis and Systemic Lupus Erythematosus display differential gene methylation, mostly hypomethylated 5′-C-phosphate-G-3′ (CpG) sites that may associate with disease activity. However, a clear association between DNA methylation, gene expression, and disease pathogenesis must be demonstrated. A better understanding of the impact of epigenetic modifications on the onset of autoimmunity will contribute to the design of novel therapeutic approaches for these diseases.

Cutaneous and Systemic Psoriasis: Classifications and Classification for the Distinction

Psoriasis is a chronic multisystem inflammatory disease that affects ~0.1–1.5% of the world population. The classic cutaneous manifestation of psoriasis is scaly erythematous plaques, limited or widely distributed. Moreover, psoriasis could be associated with comorbidities like psoriatic arthritis, metabolic syndrome, diabetes, cardiovascular disease, nephropathy, bowel disease, and brain diseases. In this review, we suggest that psoriasis should be classified as cutaneous psoriasis or systemic psoriasis and propose the classification for distinction. This would help to better understand and manage psoriasis.

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

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

Is there a relationship between psoriasis and hepatitis C? A meta-analysis and bioinformatics investigation

Background

The relationship between psoriasis and hepatitis C was previously controversial, so our purpose is to investigate this connection.

Methods

We conducted a systematic review of the case–control, cross-sectional and cohort studies examining the association between psoriasis and hepatitis C in PubMed, EMBASE and Cochrane library databases and investigated the overlapping genes between psoriasis targets and hepatitis C targets using bioinformatics analysis. Based on overlapping genes and hub nodes, we also constructed the protein–protein interaction (PPI) network and module respectively, followed by the pathway enrichment analysis.

Results

We included 11 publications that reported a total of 11 studies (8 cross-sectional and 3 case–control). The case–control and cross-sectional studies included 25,047 psoriasis patients and 4,091,631 controls in total. Psoriasis was associated with a significant increase of prevalent hepatitis C (OR 1.72; 95% confidence interval [CI] (1.17–2.52)). A total of 389 significant genes were common to both hepatitis C and psoriasis, which mainly involved IL6, TNF, IL10, ALB, STAT3 and CXCL8. The module and pathway enrichment analyses showed that the common genes had the potential to influence varieties of biological pathways, including the inflammatory response, cytokine activity, cytokine–cytokine receptor interaction, Toll-like receptor signaling pathway, which play an important role in the pathogenesis of hepatitis C and psoriasis.

Conclusion

Patients with psoriasis display increased prevalence of hepatitis C and the basic related mechanisms between hepatitis C and psoriasis had been preliminarily clarified.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12985-021-01606-z.

STAT3/SH3PXD2A-AS1/miR-125b/STAT3 positive feedback loop affects psoriasis pathogenesis via regulating human keratinocyte proliferation

Psoriasis is a chronic immune-mediated inflammatory dermatosis. STAT3 has been considered a critical regulator of psoriasis pathogenesis due to its role in inflammation and immune responses. Furthermore, alongside non-coding RNAs, including long non-coding RNAs (lncRNAs) and miRNAs, STAT3 also plays a critical role in psoriasis pathogenesis. Two sets of online microarray profiles (GSE50790 and GSE13355) were subsequently downloaded and analyzed to search for lncRNAs upregulated in psoriasis lesion tissues. The expression of lncRNA SH3PXD2A-AS1 could be remarkably upregulated in psoriasis specimens. SH3PXD2A-AS1 silence was found to suppress HaCaT cell proliferation and promote HaCaT cell apoptosis significantly. Meanwhile, SH3PXD2A-AS1 silence significantly increased cleaved-caspase-3 protein levels and inhibited S100A7, TNF-α, IL-6, p-STAT3, STAT3, CyclinD1, and survivin protein levels. Moreover, the expression of miR-125b could be substantially decreased within psoriasis lesion tissue samples, while miR-125b could negatively regulate the SH3PXD2A-AS1 and STAT3 expression. As predicted by an online tool and validated by luciferase reporter and RIP assays, miR-125b was found to bind to SH3PXD2A-AS1 and STAT3 3'UTR directly; SH3PXD2A-AS1 competed with 3'UTR of STAT3 for miR-125b binding to counteract miR-125b-mediated suppression of STAT3. STAT3 is known to activate the transcription of SH3PXD2A-AS1 through the targeting of its promoter region. It consequentially forms a regulatory feedback loop promoting SH3PXD2A-AS1 expression affecting HaCat cell proliferation and apoptosis. A novel STAT3 related mechanism whereby STAT 3/ SH3PXD2A-AS1/ miR-125b/STAT3 positive feedback loop which could potentially affect the pathogenesis of Psoriasis has been established.

Desmoglein-4 Deficiency Exacerbates Psoriasiform Dermatitis in Rats While Psoriasis Patients Displayed a Decreased Gene Expression of DSG4

Desmogleins are involved in cell adhesion conferring structural skin integrity. However, their role in inflammation has been barely studied, and whether desmoglein-4 modulates psoriasis lesions is completely unknown. In this study, we assessed the impact of desmoglein-4 deficiency on the severity of imiquimod (IMQ)-induced skin inflammation and psoriasiform lesions. To this end, desmoglein-4-/- Oncins France Colony A (OFA) with Sprague-Dawley (SD) genetic background were used. Additionally, human RNA-Seq datasets from psoriasis (PSO), atopic dermatitis (AD), and a healthy cohort were analyzed to obtain a desmosome gene expression overview. OFA rats displayed an intense skin inflammation while SD showed only mild inflammatory changes after IMQ treatment. We found that IMQ treatment increased CD3+ T cells in skin from both OFA and SD, being higher in desmoglein-4-deficient rats. In-depth transcriptomic analysis determined that PSO displayed twofold less DSG4 expression than healthy samples while both, PSO and AD showed more than three-fold change expression of DSG3 and DSC2 genes. Although underlying mechanisms are still unknown, these results suggest that the lack of desmoglein-4 may contribute to immune-mediated skin disease progression, promoting leukocyte recruitment to skin. Although further research is needed, targeting desmoglein-4 could have a potential impact on designing new biomarkers for skin diseases.

Systemic pharmacological treatments for chronic plaque psoriasis: a network meta-analysis

BACKGROUND

Psoriasis is an immune-mediated disease for which some people have a genetic predisposition. The condition manifests in inflammatory effects on either the skin or joints, or both, and it has a major impact on quality of life. Although there is currently no cure for psoriasis, various treatment strategies allow sustained control of disease signs and symptoms. Several randomised controlled trials (RCTs) have compared the efficacy of the different systemic treatments in psoriasis against placebo. However, the relative benefit of these treatments remains unclear due to the limited number of trials comparing them directly head-to-head, which is why we chose to conduct a network meta-analysis.

OBJECTIVES

To compare the efficacy and safety of non-biological systemic agents, small molecules, and biologics for people with moderate-to-severe psoriasis using a network meta-analysis, and to provide a ranking of these treatments according to their efficacy and safety.

SEARCH METHODS

For this living systematic review we updated our searches of the following databases monthly to September 2020: the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, and Embase. We searched two trials registers to the same date. We checked the reference lists of included studies and relevant systematic reviews for further references to eligible RCTs.

SELECTION CRITERIA

Randomised controlled trials (RCTs) of systemic treatments in adults (over 18 years of age) with moderate-to-severe plaque psoriasis or psoriatic arthritis whose skin had been clinically diagnosed with moderate-to-severe psoriasis, at any stage of treatment, in comparison to placebo or another active agent. The primary outcomes of this review were: the proportion of participants who achieved clear or almost clear skin, that is, at least Psoriasis Area and Severity Index (PASI) 90 at induction phase (from 8 to 24 weeks after the randomisation), and the proportion of participants with serious adverse events (SAEs) at induction phase. We did not evaluate differences in specific adverse events.

DATA COLLECTION AND ANALYSIS

Several groups of two review authors independently undertook study selection, data extraction, 'Risk of bias' assessment, and analyses. We synthesised the data using pair-wise and network meta-analysis (NMA) to compare the treatments of interest and rank them according to their effectiveness (as measured by the PASI 90 score) and acceptability (the inverse of serious adverse events). We assessed the certainty of the body of evidence from the NMA for the two primary outcomes and all comparisons, according to CINeMA, as either very low, low, moderate, or high. We contacted study authors when data were unclear or missing. We used the surface under the cumulative ranking curve (SUCRA) to infer on treatment hierarchy: 0% (treatment is the worst for effectiveness or safety) to 100% (treatment is the best for effectiveness or safety).

MAIN RESULTS

We included 158 studies (18 new studies for the update) in our review (57,831 randomised participants, 67.2% men, mainly recruited from hospitals). The overall average age was 45 years; the overall mean PASI score at baseline was 20 (range: 9.5 to 39). Most of these studies were placebo-controlled (58%), 30% were head-to-head studies, and 11% were multi-armed studies with both an active comparator and a placebo. We have assessed a total of 20 treatments. In all, 133 trials were multicentric (two to 231 centres). All but two of the outcomes included in this review were limited to the induction phase (assessment from 8 to 24 weeks after randomisation). We assessed many studies (53/158) as being at high risk of bias; 25 were at an unclear risk, and 80 at low risk. Most studies (123/158) declared funding by a pharmaceutical company, and 22 studies did not report their source of funding. Network meta-analysis at class level showed that all of the interventions (non-biological systemic agents, small molecules, and biological treatments) were significantly more effective than placebo in reaching PASI 90. At class level, in reaching PASI 90, the biologic treatments anti-IL17, anti-IL12/23, anti-IL23, and anti-TNF alpha were significantly more effective than the small molecules and the non-biological systemic agents. At drug level, infliximab, ixekizumab, secukinumab, brodalumab, risankizumab and guselkumab were significantly more effective in reaching PASI 90 than ustekinumab and three anti-TNF alpha agents: adalimumab, certolizumab, and etanercept. Ustekinumab and adalimumab were significantly more effective in reaching PASI 90 than etanercept; ustekinumab was more effective than certolizumab, and the clinical effectiveness of ustekinumab and adalimumab was similar. There was no significant difference between tofacitinib or apremilast and three non-biological drugs: fumaric acid esters (FAEs), ciclosporin and methotrexate. Network meta-analysis also showed that infliximab, ixekizumab, risankizumab, bimekizumab, secukinumab, guselkumab, and brodalumab outperformed other drugs when compared to placebo in reaching PASI 90. The clinical effectiveness of these drugs was similar, except for ixekizumab which had a better chance of reaching PASI 90 compared with secukinumab, guselkumab and brodalumab. The clinical effectiveness of these seven drugs was: infliximab (versus placebo): risk ratio (RR) 50.29, 95% confidence interval (CI) 20.96 to 120.67, SUCRA = 93.6; high-certainty evidence; ixekizumab (versus placebo): RR 32.48, 95% CI 27.13 to 38.87; SUCRA = 90.5; high-certainty evidence; risankizumab (versus placebo): RR 28.76, 95% CI 23.96 to 34.54; SUCRA = 84.6; high-certainty evidence; bimekizumab (versus placebo): RR 58.64, 95% CI 3.72 to 923.86; SUCRA = 81.4; high-certainty evidence; secukinumab (versus placebo): RR 25.79, 95% CI 21.61 to 30.78; SUCRA = 76.2; high-certainty evidence; guselkumab (versus placebo): RR 25.52, 95% CI 21.25 to 30.64; SUCRA = 75; high-certainty evidence; and brodalumab (versus placebo): RR 23.55, 95% CI 19.48 to 28.48; SUCRA = 68.4; moderate-certainty evidence. Conservative interpretation is warranted for the results for bimekizumab (as well as mirikizumab, tyrosine kinase 2 inhibitor, acitretin, ciclosporin, fumaric acid esters, and methotrexate), as these drugs, in the NMA, have been evaluated in few trials. We found no significant difference between any of the interventions and the placebo for the risk of SAEs. Nevertheless, the SAE analyses were based on a very low number of events with low to moderate certainty for all the comparisons. Thus, the results have to be viewed with caution and we cannot be sure of the ranking. For other efficacy outcomes (PASI 75 and Physician Global Assessment (PGA) 0/1) the results were similar to the results for PASI 90. Information on quality of life was often poorly reported and was absent for several of the interventions.

AUTHORS' CONCLUSIONS

Our review shows that compared to placebo, the biologics infliximab, ixekizumab, risankizumab, bimekizumab, secukinumab, guselkumab and brodalumab were the most effective treatments for achieving PASI 90 in people with moderate-to-severe psoriasis on the basis of moderate- to high-certainty evidence. This NMA evidence is limited to induction therapy (outcomes were measured from 8 to 24 weeks after randomisation) and is not sufficient for evaluation of longer-term outcomes in this chronic disease. Moreover, we found low numbers of studies for some of the interventions, and the young age (mean age of 45 years) and high level of disease severity (PASI 20 at baseline) may not be typical of patients seen in daily clinical practice. Another major concern is that short-term trials provide scanty and sometimes poorly-reported safety data and thus do not provide useful evidence to create a reliable risk profile of treatments. We found no significant difference in the assessed interventions and placebo in terms of SAEs, and the evidence for all the interventions was of low to moderate quality. In order to provide long-term information on the safety of the treatments included in this review, it will also be necessary to evaluate non-randomised studies and postmarketing reports released from regulatory agencies. In terms of future research, randomised trials directly comparing active agents are necessary once high-quality evidence of benefit against placebo is established, including head-to-head trials amongst and between non-biological systemic agents and small molecules, and between biological agents (anti-IL17 versus anti-IL23, anti-IL23 versus anti-IL12/23, anti-TNF alpha versus anti-IL12/23). Future trials should also undertake systematic subgroup analyses (e.g. assessing biological-naïve participants, baseline psoriasis severity, presence of psoriatic arthritis, etc.). Finally, outcome measure harmonisation is needed in psoriasis trials, and researchers should look at the medium- and long-term benefit and safety of the interventions and the comparative safety of different agents. Editorial note: This is a living systematic review. Living systematic reviews offer a new approach to review updating, in which the review is continually updated, incorporating relevant new evidence as it becomes available. Please refer to the Cochrane Database of Systematic Reviews for the current status of this review.

Number needed to treat for interleukin inhibitors approved for the treatment of moderate-to-severe plaque psoriasis in Italy

Background

Interleukin (IL) inhibitors achieve greater levels of efficacy than older systemic therapies. We calculated the number needed to treat (NNT) of ixekizumab compared with other IL inhibitors approved in Italy for the treatment of moderate-to-severe plaque psoriasis.

Methods

The clinical efficacy was evaluated in terms of NNT, based on the results of a recent network meta--analysis (NMA) by the Cochrane Database of Systematic Reviews. The NMA investigated many systemic and biological treatments, but this analysis compared only the efficacy of the following IL inhibitors - brodalumab, guselkumab, ixekizumab, risankizumab, secukinumab, tildrakizumab and ustekinumab - for patients with moderate-to-severe plaque psoriasis. Drugs were compared and ranked according to effectiveness considering the PASI (Psoriasis Area and Severity Index) 90 score.

Results

One-hundred and forty trials (51,749 patients) were included in the NMA. Considering the proportion of patients who achieve PASI90, ixekizumab showed the lowest NNT among all comparators (ixekizumab 2.01 [2.46-3.00]; risankizumab 2.05 [2.50-3-05]; guselkumab 2.16 [2.68-3.36]; secukinumab 2.40 [2.90-3.51]; brodalumab 2.61 [3.18-3.88]; ustekinumab 3.44 [4.12-4.95]; tildrakizumab 3.10 [4.15-5.59].

Conclusion

The findings show that ixekizumab is the most effective option (NNT) for the treatment of moderate-to-severe plaque psoriasis.

Psoriasis

Psoriasis is a common, chronic papulosquamous skin disease occurring worldwide, presenting at any age, and leading to a substantial burden for individuals and society. It is associated with several important medical conditions, including depression, psoriatic arthritis, and cardiometabolic syndrome. Its most common form, chronic plaque or psoriasis vulgaris, is a consequence of genetic susceptibility, particularly in the presence of the HLA-C*06:02 risk allele, and of environmental triggers such as streptococcal infection, stress, smoking, obesity, and alcohol consumption. There are several phenotypes and research has separated pustular from chronic plaque forms. Immunological and genetic studies have identified IL-17 and IL-23 as key drivers of psoriasis pathogenesis. Immune targeting of these cytokines and of TNFα by biological therapies has revolutionised the care of severe chronic plaque disease. Psoriasis cannot currently be cured, but management should aim to minimise physical and psychological harm by treating patients early in the disease process, identifying and preventing associated multimorbidity, instilling lifestyle modifications, and employing a personalised approach to treatment.

Proteomic analysis of psoriatic skin lesions in a Chinese population

Psoriasis is a chronic skin disorder with undefined pathogenesis. Several biomarkers for this disease have been identified by proteomic analysis. We explored the whole-proteomic changes in 45 pairs of psoriatic and adjacent noninvolved skin tissues in a Chinese population. A total of 3686 proteins were identified, of which 3008 were quantified. A total of 102 and 124 proteins were upregulated and downregulated in lesional skin, respectively. SART1 (P = 3.55 × 10^-5) and GLTP (P = 1.54 × 10^-3) were the most significantly down- and upregulated proteins. Nearly 90% of these differentially regulated proteins exhibited the same expression trends as those in an online RNA sequencing dataset for psoriasis; 19 differentially regulated proteins exhibited a negative relationship with DNA methylation data for psoriatic lesions. The differentially expressed proteins were enriched in ribosomes, antigen processing and presentation, immune response, and IL-17 signalling pathways. This study identified multiple differentially regulated proteins in psoriatic lesions, which suggested that changes in the proteome play important regulatory roles in psoriasis-associated processes. SIGNIFICANCE: Proteomic analysis was performed in 45 pairs of psoriatic and adjacent noninvolved skin tissues in a Chinese population. More than 3000 proteins were quantified, of which 226 were differentially expressed in psoriatic skin tissues. These proteins were mainly enriched in the immune response, antigen processing and presentation and IL-17 signalling pathways, which have been reported to be associated with the pathogenesis of psoriasis.

Polymers in topical delivery of anti-psoriatic medications and other topical agents in overcoming the barriers of conventional treatment strategies

In recent decades, topical treatments to dermal disorders have shown ineffectiveness in delivering the medication at a particular location without a suitable drug carrier. Psoriasis treatment is hindered because of the ineffective delivery and efficacy of conventional pharmaceutical treatment. In conventional medication formulation approach, it is difficult to breach the transdermal layer of a skin membrane for topical drugs, i.e. cyclosporine, methotrexate. This problem is further complicated by extreme disease-associated conditions such as hyperkeratosis and irritation. Intending to assure better drug delivery carriers, this review emphasizes the therapeutic efficacy of polymers and their potential to deliver the drug into the deeper layer of the skin membrane. The polymers are essential in structural and physiochemical perspectives as it works as a carrier for the medication. A vast variety of delivery carriers is available nowadays but their applicability in such dermal cases like psoriasis is still lacking due to less knowledge on an appropriate polymer. The current investigation of suitable polymer would assist in brushing our expertise to optimize the advantages of a wide spectrum of polymers to fulfill the topical targeting of psoriasis.

Amelioration of imiquimod-induced psoriasis-like dermatitis in mice by DSW therapy inspired hydrogel

Psoriasis is a long-lasting and recurrent autoimmune disease which is incurable so far. Dead Sea water (DSW) therapy is an effective approach to help control the symptoms of psoriasis due to the abundant mineral ions in DSW, which inspired the material formulation in this study. Rubidium-Sodium alginate/Polyacrylamide hydrogels (Rb-SA/PAAm gels) composed of sodium alginate and polyacrylamide interpenetrating network structure with different concentrations of rubidium and certain magnesium and zinc content were prepared for the treatment of psoriasis. The obtained results suggest the good mechanical properties of the Rb-SA/PAAm gels including toughness and swelling performance. In terms of in vitro tests, the Rb-SA/PAAm gels not only show nontoxicity to human keratinocyte cell line (Hacats) but also inhibits the activity against inflammatory NF-κβ signaling pathway. Meanwhile, they can release Rb+ which enable the Rb-SA/PAAm gels have better antibacterial ability to Streptococcus and Escherichia coli. The results obtained from in vivo tests indicate that these hydrogels could alleviate the symptoms of psoriasis caused by Imiquimod (IMQ) in mice by reducing the inflammatory factor in STAT3 pathway and therefore reduce the immune stimulation of the spleen. In conclusion, the 100Rb-SA/PAAm gel has demonstrated great potential to be a topical wettable dressing for psoriasis treatment.

Circ_0061012 contributes to IL-22-induced proliferation, migration and invasion in keratinocytes through miR-194-5p/GAB1 axis in psoriasis

Psoriasis is a chronic inflammation-associated skin disorder featured by excessive proliferation and abnormal differentiation of keratinocytes. Here, we intended to investigate the role of circular RNA 0061012 (circ_0061012) in psoriasis progression. The expression of circ_0061012, SLMO2-ATP5E readthrough (SLMO2-ATP5E) messenger RNA (mRNA), microRNA-194-5p (miR-194-5p) and GRB2 associated binding protein 1 (GAB1) mRNA was determined by quantitative real-time polymerase chain reaction (qRT-PCR). Cell proliferation and metastasis were analyzed by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and transwell assays. Western blot assay was used to measure the protein levels of Ki67, matrix metallopeptidase 9 (MMP9) and GAB1. Dual-luciferase reporter assay and RNA immune co-precipitation (RIP) assay were used to verify the interaction between miR-194-5p and circ_0061012 or GAB1. Circ_0061012 abundance was significantly enhanced in lesional skin samples from psoriasis patients than that in normal skin specimens from healthy volunteers. Interleukin-22 (IL-22) treatment increased the expression of circ_0061012 in a dose-dependent manner. Circ_0061012 silencing alleviated IL-22-induced promoting effects in the proliferation, migration and invasion of HaCaT cells. Circ_0061012 interacted with miR-194-5p, and miR-194-5p knockdown counteracted circ_0061012 silencing-mediated influences in IL-22-induced HaCaT cells. GAB1 was a target of miR-194-5p in HaCaT cells, and miR-194-5p hampered proliferation and metastasis which were induced by IL-22 partly through targeting GAB1. Circ_0061012 elevated the expression of GAB1 through sponging miR-194-5p in HaCaT cells. Circ_0061012 accelerated IL-22-induced proliferation and metastasis in HaCaT cells through enhancing GAB1 expression via sponging miR-194-5p in psoriasis.

The Effect of Antioxidant and Anti-Inflammatory Capacity of Diet on Psoriasis and Psoriatic Arthritis Phenotype: Nutrition as Therapeutic Tool?

Chronic inflammation and increased oxidative stress are contributing factors to many non-communicable diseases. A growing body of evidence indicates that dietary nutrients can activate the immune system and may lead to the overproduction of pro-inflammatory cytokines. Fatty acids as macronutrients are key players for immunomodulation, with n-3 polyunsaturated fatty acids having the most beneficial effect, while polyphenols and carotenoids seem to be the most promising antioxidants. Psoriasis is a chronic, immune-mediated inflammatory disease with multifactorial etiology. Obesity is a major risk factor for psoriasis, which leads to worse clinical outcomes. Weight loss interventions and, generally, dietary regimens such as gluten-free and Mediterranean diet or supplement use may potentially improve psoriasis’ natural course and response to therapy. However, data about more sophisticated nutritional patterns, such as ketogenic, very low-carb or specific macro- and micro-nutrient substitution, are scarce. This review aims to present the effect of strictly structured dietary nutrients, that are known to affect glucose/lipid metabolism and insulin responses, on chronic inflammation and immunity, and to discuss the utility of nutritional regimens as possible therapeutic tools for psoriasis and psoriatic arthritis.

Weighted gene coexpression network and experimental analyses identify lncRNA SPRR2C as a regulator of the IL-22-stimulated HaCaT cell phenotype through the miR-330/STAT1/S100A7 axis

Psoriasis is a chronic inflammatory disease of the skin with highly complex pathogenesis. In this study, we identified lncRNA SPRR2C (small proline-rich protein 2C) as a hub gene with a critical effect on the pathogenesis of psoriasis and response to treatment using both weighted gene coexpression network analysis (WGCNA) and differential expression analysis. SPRR2C expression was significantly upregulated in both psoriatic lesion samples and HaCaT cell lines in response to IL-22 treatment. After SPRR2C knockdown, IL-22-induced suppression of HaCaT proliferation, changes in the KRT5/14/1/10 protein levels, and suppression of the IL-1β, IL-6, and TNF-α mRNA levels were dramatically reversed. In the coexpression network with SPRR2C based on GSE114286, miR-330 was significantly negatively correlated with SPRR2C, while STAT1 and S100A7 were positively correlated with SPRR2C. By binding to miR-330, SPRR2C competed with STAT1 and S100A7 to counteract miR-330-mediated suppression of STAT1 and S100A7. MiR-330 overexpression also reversed the IL-22-induced changes in HaCaT cell lines; in response to IL-22 treatment, miR-330 inhibition significantly attenuated the effects of SPRR2C knockdown. STAT1 and S100A7 expression was significantly upregulated in psoriatic lesion samples. The expression of miR-330 had a negative correlation with the expression of SPRR2C, while the expression of SPRR2C had a positive correlation with the expression of STAT1 and S100A7. Thus, SPRR2C modulates the IL-22-stimulated HaCaT cell phenotype through the miR-330/STAT1/S100A7 axis. WGCNA might uncover additional biological pathways that are crucial in the pathogenesis and response to the treatment of psoriasis.

Psoriasis Exacerbates the State of Insulin Resistance in Patients with Type 2 Diabetes

PURPOSE

Although psoriasis (PsO) is highly associated with insulin resistance (IR), the role of PsO on activity of insulin secretion or its action in diabetic patients has not been explored.

MATERIALS AND METHODS

In-patient data on type 2 diabetes (T2D) with or without PsO from 2016-2019 in our hospital were analyzed. Data for 42 diabetic patients with PsO were compared with that of the control group (T2D only). Blood examinations with reference to the levels of fasting blood glucose, C-peptide, insulin, HbA1c, plasma lipids, lipoproteins, and kidney function were explored. HOMA-IR and HOMA-β models were established to explore IR and pancreatic β-cell function.

RESULTS

HOMA-IR level was significantly higher (P=0.0003<0.05) in patients with PsO compared with the controls. Although the durations of diabetes in patients with PsO were significantly shorter compared with that of patients with diabetes only (P=0.012<0.05), analysis of mean BMI, eGFR, plasma lipids, and lipoprotein showed no significant differences. Analysis of the level of fasting glucose and HOMA-β showed no statistical differences between the two groups. On the other hand, the levels of C-peptide of PsO group were significantly high in both fasting state (P=0.0182<0.05) and after glucose challenge (P=0.0011<0.01).

CONCLUSION

The findings of this study show that under the same fasting conditions, patients with PsO may have relatively preserved pancreatic β-cell function, and PsO significantly increases IR.

Deciphering the Association Between Psoriasis and Obesity: Current Evidence and Treatment Considerations

PURPOSE OF REVIEW

Obesity and psoriasis represent chronic inflammatory states that are interconnected in a vicious cycle, sharing also a degree of synergy. In this review, we aim to decipher the various lines of evidence supporting the bidirectional association between psoriasis and obesity highlighting their pathophysiologic connections as well as we attempt to strategize a therapeutic holistic approach for obese psoriatic patients.

RECENT FINDINGS

Recent meta-analyses have shown that (1) genetically higher BMI increased the odds of psoriasis occurrence; (2) obesity is associated with higher incidence and prevalence of psoriasis as well as psoriasis severity; (3) obesity is associated with lower efficacy to anti-TNF agents and may predict biologic treatment discontinuation; and (4) weight loss through diet and physical exercise may improve pre-existing psoriasis and prevent from de novo psoriasis. Methotrexate, acitretin, and cyclosporine could worsen hypertension, liver steatosis, and dyslipidemia. Since infliximab and ustekinumab are weight adjusted, they may be ideal drugs to treat obese psoriatic patients. IL-17 inhibitors are very effective independently from body weight; however, they tend to present better clearance rates in normal weight patients. There is a paucity on weight data regarding the efficacious IL-23 inhibitors. Apremilast may induce weight loss as an adverse effect presenting also some beneficial metabolic actions. Finally, simvastatin and some antidiabetic drugs could decrease psoriasis severity. More mechanistic, observational studies and well-conducted RCTs are necessary to decipher the enigmatic link between psoriasis and obesity, and to provide evidence-based specific guidelines for the screening and management of obese psoriatic patients.

Albendazole negatively regulates keratinocyte proliferation

BACKGROUND

Increased keratinocyte proliferation occurs in the skin of psoriatic patients and is supposed to play a role in the pathogenesis of this disorder. Compounds interfering with keratinocyte proliferation could be useful in the management of psoriatic patients.

AIM

To investigate whether albendazole, an anti-helmintic drug that regulates epithelial cell function in various systems, inhibits keratinocyte proliferation in models of psoriasis.

METHODS

Aldara-treated mice received daily topical application of albendazole. Keratinocyte proliferation and keratin (K) 6 and K16 expression were evaluated by immunohistochemistry and Western blotting and inflammatory cells/mediators were analysed by immunohistochemistry and real-time PCR. In human keratinocytes (HEKa and HaCaT) treated with albendazole, cell cycle and proliferation, keratins and cell cycle-associated factors were evaluated by flow cytometry, colorimetric assay and Western blotting respectively.

RESULTS

Aldara-treated mice given albendazole exhibited reduced epidermal thickness, decreased number of proliferating keratinocytes and K6/K16 expression. Reduction of CD3- and Ly6G-positive cells in the skin of albendazole-treated mice associated with inhibition of IL-6, TNF-α, IL-1β, IL-17A, IL-36, CCL17, CXCL1, CXCL2 and CXCL5 expression. Treatment of keratinocytes with albendazole reduced K6/K16 expression and reversibly inhibited cell growth by promoting accumulation of cells in S-phase. This phenomenon was accompanied by down-regulation of CDC25A, a phosphatase regulating progression of cell cycle through S-phase, and PKR-dependent hyper-phosphorylation of eIF2α, an inhibitor of CDC25 translation. In Aldara-treated mice, albendazole activated PKR, enhanced eIF2α phosphorylation and reduced CDC25A expression.

CONCLUSIONS

Data show that albendazole inhibits keratinocyte proliferation and exerts therapeutic effect in a murine model of psoriasis.

The miR-155/GATA3/IL37 axis modulates the production of proinflammatory cytokines upon TNF-α stimulation to affect psoriasis development

Psoriasis is a recrudescent chronic immune-mediated inflammatory dermatosis; the production and release of proinflammatory cytokines/chemokines such as TNF-α has been regarded as critical issues during psoriasis pathogenesis. Based on online microarray profiles, the expression of the transcription factor GATA3 was downregulated in psoriasis lesion tissues. In the present study, we searched for miRNAs that might be related to TNF-α and GATA3 to investigate an in-depth understanding of psoriasis pathogenesis. Herein, higher TNF-α and GATA3 protein levels were observed in psoriasis lesion tissues and that GATA3 overexpression significantly reverses TNF-α-induced increases within the production of IL-6 and CXCL8 in keratinocytes. TNF-α stimulation increases miR-155 expression dose-independently, and the miR-155 inhibitor significantly reverses TNF-α-induced suppression of GATA3 protein levels and increases IL-6 and CXCL8 production. miR-155 could suppress the expression of GATA3 by targeting its 3'UTR, while GATA3 could activate the transcription of IL37 by targeting its promoter region. miR-155 overexpression reduces IL37 protein and increases CXCL8 production; GATA3 overexpression might significantly attenuate the effects of miR-155 overexpression. In contrast to GATA3, miR-155 expression is significantly upregulated in psoriasis lesion tissue and is negatively correlated with GATA3 and IL37. In summary, the miR-155/GATA3/IL37 axis modulates the production of IL-6 and CXCL8 upon TNF-α stimulation to affect psoriasis development. Thus, miR-155/GATA3/IL37 may be potent targets for psoriasis treatment, which needs further in vivo and clinical investigation.

Exacerbated Imiquimod-Induced Psoriasis-Like Skin Inflammation in IRF5-Deficient Mice

Interferon regulatory factors (IRFs) play diverse roles in the regulation of the innate and adaptive immune responses in various diseases. In psoriasis, IRF2 is known to be involved in pathogenesis, while studies on other IRFs are limited. In this study, we investigated the role of IRF5 in psoriasis using imiquimod-induced psoriasis-like dermatitis. Although IRF5 is known to play a critical role in the induction of proinflammatory cytokines by immune cells, such as dendritic cells (DCs), macrophages, and monocytes, IRF5 deficiency unexpectedly exacerbated psoriasiform skin inflammation. The interferon-α and tumor necrosis factor-α mRNA expression levels were decreased, while levels of Th17 cytokines including IL-17, IL-22, and IL-23 were increased in IRF5-deficient mice. Furthermore, IL-23 expression in DCs from IRF5-deficient mice was upregulated both in steady state and after toll-like receptor 7/8 agonist stimulation. Importantly, the expression of IRF4, which is also important for the IL-23 production in DCs, was augmented in DCs from IRF5-deficient mice. Taken together, our results suggest that IRF5 deficiency induces the upregulation of IRF4 in DCs followed by augmented IL-23 production, resulting in the amplification of Th17 responses and the exacerbation of imiquimod-induced psoriasis-like skin inflammation. The regulation of IRF4 or IRF5 expression may be a novel therapeutic approach to psoriasis.

Keratinocytes Derived from Patient-Specific Induced Pluripotent Stem Cells Recapitulate the Genetic Signature of Psoriasis Disease

Psoriasis is characterized by hyperproliferation and defective differentiation of keratinocytes (KCs). Patients with psoriasis are at a high risk of developing diabetes and cardiovascular diseases. The debate on the genetic origin of psoriasis pathogenesis remains unresolved due to lack of suitable in vitro human models mimicking the disease phenotypes. In this study, we provide the first human induced pluripotent stem cell (iPSC) model for psoriasis carrying the genetic signature of the patients. iPSCs were generated from patients with psoriasis (PsO-iPSCs) and healthy donors (Ctr-iPSCs) and were efficiently differentiated into mature KCs. RNA sequencing of KCs derived from Ctr-iPSCs and PsO-iPSCs identified 361 commonly upregulated and 412 commonly downregulated genes. KCs derived from PsO-iPSCs showed dysregulated transcripts associated with psoriasis and KC differentiation, such as HLA-C, KLF4, chemokines, type I interferon-inducible genes, solute carrier family, IVL, DSG1, and HLA-DQA1, as well as transcripts associated with insulin resistance, such as IRS2, GDF15, GLUT10, and GLUT14. Our data suggest that the KC abnormalities are the main driver triggering psoriasis pathology and highlights the substantial contribution of genetic predisposition in the development of psoriasis and insulin resistance.

Interleukin-17A suppresses granular layer formation in a 3-D human epidermis model through regulation of terminal differentiation genes

Immunotherapies targeting interleukin (IL)-17 greatly improve plaque psoriasis. Most previous studies on IL-17 focused on the T-helper (Th)17 immune response, but investigation of the effects of IL-17A on psoriatic epidermal structure are limited. Using an in vitro 3-D human epidermis model, we investigated the effects of IL-17A and IL-17C on morphological changes and gene expression. IL-17A directly suppressed the formation of the granular layer, whereas IL-17C did not. IL-17A significantly downregulated the gene expression of profilaggrin (FLG), which is a major component of keratohyalin granules in the granular layer. Global gene expression analysis of this 3-D epidermis model showed that both IL-17A and IL-17C upregulated S100A7A and type 1 interferon-related genes including MX1, IFI44L, XAF1 and IFIT1. However, only IL-17A directly downregulated keratinocyte differentiation-related and cornified envelope-related genes including FLG, LOR, C1ORF68, LCE1E, LCE1B, KRT10, CST6 and RPTN. In conclusion, IL-17A, a systemic inflammatory cytokine, affected keratinization in our 3-D epidermis model. In contrast, IL-17C, a locally produced cytokine, did not have strong effects on keratinization. Targeting IL-17A does not only reduce inflammation but it may also directly affect epidermal differentiation in psoriasis.

Super Critical Fluid Extracted Fatty Acids from Withania somnifera Seeds Repair Psoriasis-Like Skin Lesions and Attenuate Pro-Inflammatory Cytokines (TNF-α and IL-6) Release

(1) Background: Withania somnifera Dunal (Ashwagandha) is a widely used medicinal herb in traditional medicinal systems with extensive research on various plant parts. Surprisingly, seeds of W. somnifera have never been investigated for their therapeutic potential. (2) Methods: W. somnifera seeds were extracted for fatty acids (WSSO) using super critical fluid extraction, and was analyzed by gas chromatography. Its therapeutic potential in psoriasis-like skin etiologies was investigated using a 12-O tetradecanoyl phorbol 13-acetate (TPA)-induced psoriatic mouse model. Psoriatic inflammation along with psoriatic lesions and histopathological scores were recorded. WSSO was also tested on murine macrophage (RAW264.7), human epidermoid (A431), and monocytic (THP-1) cells, stimulated with TPA or lipo poly-saccharide (LPS) to induce pro-inflammatory cytokine (IL-6 and TNF-α) release. NFκB promoter activity was also measured by luciferase reporter assay. (3) Results: Topical application of WSSO with concurrent oral doses significantly reduced inflammation-induced edema, and repaired psoriatic lesions and associated histopathological scores. Inhibition of pro-inflammatory cytokines release was observed in WSSO-treated A431 and THP-1 cells, along with reduced NFκB expression. WSSO also inhibited reactive nitrogen species (RNS) in LPS-stimulated RAW264.7 cells. (4) Conclusion: Here we show that the fatty acids from W. somnifera seeds have strong anti-inflammatory properties, along with remarkable therapeutic potential on psoriasis-like skin etiologies.

Systemic pharmacological treatments for chronic plaque psoriasis: a network meta-analysis

BACKGROUND

Psoriasis is an immune-mediated disease for which some people have a genetic predisposition. The condition manifests in inflammatory effects on either the skin or joints, or both, and it has a major impact on quality of life. Although there is currently no cure for psoriasis, various treatment strategies allow sustained control of disease signs and symptoms. Several randomised controlled trials (RCTs) have compared the efficacy of the different systemic treatments in psoriasis against placebo. However, the relative benefit of these treatments remains unclear due to the limited number of trials comparing them directly head-to-head, which is why we chose to conduct a network meta-analysis. This is the baseline update of a Cochrane Review first published in 2017, in preparation for this Cochrane Review becoming a living systematic review.

OBJECTIVES

To compare the efficacy and safety of conventional systemic agents, small molecules, and biologics for people with moderate-to-severe psoriasis, and to provide a ranking of these treatments according to their efficacy and safety.

SEARCH METHODS

We updated our research using the following databases to January 2019: the Cochrane Skin Specialised Register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, LILACS and the conference proceedings of a number of dermatology meetings. We also searched five trials registers and the US Food and Drug Administration (FDA) and European Medicines Agency (EMA) reports (until June 2019). We checked the reference lists of included and excluded studies for further references to relevant RCTs.

SELECTION CRITERIA

Randomised controlled trials (RCTs) of systemic treatments in adults (over 18 years of age) with moderate-to-severe plaque psoriasis or psoriatic arthritis whose skin had been clinically diagnosed with moderate-to-severe psoriasis, at any stage of treatment, in comparison to placebo or another active agent. The primary outcomes of this review were: the proportion of participants who achieved clear or almost clear skin, that is, at least Psoriasis Area and Severity Index (PASI) 90 at induction phase (from 8 to 24 weeks after the randomisation), and the proportion of participants with serious adverse effects (SAEs) at induction phase. We did not evaluate differences in specific adverse effects.

DATA COLLECTION AND ANALYSIS

Several groups of two review authors independently undertook study selection, data extraction, 'Risk of bias' assessment, and analyses. We synthesised the data using pair-wise and network meta-analysis (NMA) to compare the treatments of interest and rank them according to their effectiveness (as measured by the PASI 90 score) and acceptability (the inverse of serious adverse effects). We assessed the certainty of the body of evidence from the NMA for the two primary outcomes, according to GRADE, as either very low, low, moderate, or high. We contacted study authors when data were unclear or missing.

MAIN RESULTS

We included 140 studies (31 new studies for the update) in our review (51,749 randomised participants, 68% men, mainly recruited from hospitals). The overall average age was 45 years; the overall mean PASI score at baseline was 20 (range: 9.5 to 39). Most of these studies were placebo-controlled (59%), 30% were head-to-head studies, and 11% were multi-armed studies with both an active comparator and a placebo. We have assessed a total of 19 treatments. In all, 117 trials were multicentric (two to 231 centres). All but two of the outcomes included in this review were limited to the induction phase (assessment from 8 to 24 weeks after randomisation). We assessed many studies (57/140) as being at high risk of bias; 42 were at an unclear risk, and 41 at low risk. Most studies (107/140) declared funding by a pharmaceutical company, and 22 studies did not report the source of funding. Network meta-analysis at class level showed that all of the interventions (conventional systemic agents, small molecules, and biological treatments) were significantly more effective than placebo in terms of reaching PASI 90. At class level, in terms of reaching PASI 90, the biologic treatments anti-IL17, anti-IL12/23, anti-IL23, and anti-TNF alpha were significantly more effective than the small molecules and the conventional systemic agents. At drug level, in terms of reaching PASI 90, infliximab, all of the anti-IL17 drugs (ixekizumab, secukinumab, bimekizumab and brodalumab) and the anti-IL23 drugs (risankizumab and guselkumab, but not tildrakizumab) were significantly more effective in reaching PASI 90 than ustekinumab and 3 anti-TNF alpha agents: adalimumab, certolizumab and etanercept. Adalimumab and ustekinumab were significantly more effective in reaching PASI 90 than certolizumab and etanercept. There was no significant difference between tofacitinib or apremilast and between two conventional drugs: ciclosporin and methotrexate. Network meta-analysis also showed that infliximab, ixekizumab, risankizumab, bimekizumab, guselkumab, secukinumab and brodalumab outperformed other drugs when compared to placebo in reaching PASI 90. The clinical effectiveness for these seven drugs was similar: infliximab (versus placebo): risk ratio (RR) 29.52, 95% confidence interval (CI) 19.94 to 43.70, Surface Under the Cumulative Ranking (SUCRA) = 88.5; moderate-certainty evidence; ixekizumab (versus placebo): RR 28.12, 95% CI 23.17 to 34.12, SUCRA = 88.3, moderate-certainty evidence; risankizumab (versus placebo): RR 27.67, 95% CI 22.86 to 33.49, SUCRA = 87.5, high-certainty evidence; bimekizumab (versus placebo): RR 58.64, 95% CI 3.72 to 923.86, SUCRA = 83.5, low-certainty evidence; guselkumab (versus placebo): RR 25.84, 95% CI 20.90 to 31.95; SUCRA = 81; moderate-certainty evidence; secukinumab (versus placebo): RR 23.97, 95% CI 20.03 to 28.70, SUCRA = 75.4; high-certainty evidence; and brodalumab (versus placebo): RR 21.96, 95% CI 18.17 to 26.53, SUCRA = 68.7; moderate-certainty evidence. Conservative interpretation is warranted for the results for bimekizumab (as well as tyrosine kinase 2 inhibitor, acitretin, ciclosporin, fumaric acid esters, and methotrexate), as these drugs, in the NMA, have been evaluated in few trials. We found no significant difference between any of the interventions and the placebo for the risk of SAEs. Nevertheless, the SAE analyses were based on a very low number of events with low to very low certainty for just under half of the treatment estimates in total, and moderate for the others. Thus, the results have to be viewed with caution and we cannot be sure of the ranking. For other efficacy outcomes (PASI 75 and Physician Global Assessment (PGA) 0/1) the results were very similar to the results for PASI 90. Information on quality of life was often poorly reported and was absent for several of the interventions.

AUTHORS' CONCLUSIONS

Our review shows that compared to placebo, the biologics infliximab, ixekizumab, risankizumab, bimekizumab, guselkumab, secukinumab and brodalumab were the best choices for achieving PASI 90 in people with moderate-to-severe psoriasis on the basis of moderate- to high-certainty evidence (low-certainty evidence for bimekizumab). This NMA evidence is limited to induction therapy (outcomes were measured from 8 to 24 weeks after randomisation) and is not sufficient for evaluation of longer-term outcomes in this chronic disease. Moreover, we found low numbers of studies for some of the interventions, and the young age (mean age of 45 years) and high level of disease severity (PASI 20 at baseline) may not be typical of patients seen in daily clinical practice. Another major concern is that short-term trials provide scanty and sometimes poorly-reported safety data and thus do not provide useful evidence to create a reliable risk profile of treatments. Indeed, we found no significant difference in the assessed interventions and placebo in terms of SAEs, but the evidence for all the interventions was of very low to moderate quality. In order to provide long-term information on the safety of the treatments included in this review, it will also be necessary to evaluate non-randomised studies and postmarketing reports released from regulatory agencies. In terms of future research, randomised trials comparing directly active agents are necessary once high-quality evidence of benefit against placebo is established, including head-to-head trials amongst and between conventional systemic and small molecules, and between biological agents (anti-IL17 versus anti-IL23, anti-IL23 versus anti-IL12/23, anti-TNF alpha versus anti-IL12/23). Future trials should also undertake systematic subgroup analyses (e.g. assessing biological-naïve participants, baseline psoriasis severity, presence of psoriatic arthritis, etc.). Finally, outcome measure harmonisation is needed in psoriasis trials, and researchers should look at the medium- and long-term benefit and safety of the interventions and the comparative safety of different agents. Editorial note: This is a living systematic review. Living systematic reviews offer a new approach to review updating, in which the review is continually updated, incorporating relevant new evidence as it becomes available. Please refer to the Cochrane Database of Systematic Reviews for the current status of this review.

Association between psoriasis and celiac disease: A systematic review and meta-analysis

BACKGROUND

Multiple studies have examined the association between psoriasis and celiac disease (CD). However, these studies have shown conflicting results.

OBJECTIVE

To analyze the association between psoriasis and CD.

METHODS

We conducted a systematic review of the case-control, cross-sectional, and cohort studies examining the association between psoriasis and CD in the PubMed, Scopus, and Cochrane databases. The adjusted effect sizes or crude data were extracted for quantitative analysis.

RESULTS

Of 754 citations initially identified, 18 studies were included. Random effects meta-analysis found significant odds ratios of 2.16 (95% confidence interval, 1.74-2.69; 9 studies) for CD in patients with psoriasis and 1.8 (95% confidence interval, 1.36-2.38; 8 studies) for psoriasis in patients with CD. We also found a significantly increased risk of new-onset psoriasis in CD (hazard ratio, 1.75; 95% confidence interval, 1.58-1.93). Subgroup analyses according to disease severity and geographic region could not be performed due to limited data.

CONCLUSION

This 2-way meta-analysis found a significant association between psoriasis and CD. Clinicians should be aware of this association. Patients with psoriasis with bowel complaints might benefit from screening for CD through questionnaires or interviews with subsequent gastroenterology consultation.

Mesenchymal Stromal Cells from the Epidermis and Dermis of Psoriasis Patients: Morphology, Immunophenotype, Differentiation Patterns, and Regulation of T Cell Proliferation

Psoriasis is a skin disease characterized by hyperproliferation of keratinocytes and chronic inflammation. Mesenchymal stem/stromal cells (MSCs) exhibit an immunoregulatory function that can be altered in the skin of these patients. However, to date, the presence and functional capacity of MSCs in the dermis and epidermis of patients with psoriasis have not been fully established. In the present study, we evaluated the presence of MSCs in the skin of patients by obtaining adherent cells from the dermis and epidermis of lesional and nonlesional areas and characterizing them in a comparative manner with corresponding cells obtained from the dermis (HD-MSCs) and epidermis (HE-MSCs) of healthy donors. We determined whether the adherent cells had immunophenotypic profiles and differentiation potentials that were characteristic of MSCs. In addition, we analyzed their immunosuppression function by evaluating their capacity to decrease T cell proliferation. Our results indicate the presence of MSCs in the dermis and epidermis of healthy donors and patients with psoriasis; adherent cells from all skin sources exhibited MSC characteristics, such as expression of CD73, CD90, and CD105 markers and a lack of hematopoietic and endothelial marker expression. However, the cell populations obtained showed differences in differentiation potential toward adipogenic, osteogenic, and chondrogenic lineages. In addition, we observed a low MSC obtention frequency in nonlesional epidermal samples (NLE-MSCs), which also showed alterations in morphology and proliferation rate. Interestingly, MSCs from both the nonlesional dermis (NLD-MSCs) and lesional dermis (LD-MSCs) showed higher HLA class I antigen (HLA-I) expression than HD-MSCs. Moreover, NLD-MSCs showed a low T cell proliferation suppression capacity. In summary, this study demonstrates the presence of MSCs in the epidermis and dermis of patients with psoriasis and suggests that such cells may favor the inflammatory process and thus psoriatic lesion development through high HLA-I expression and low immunosuppression capacity.