The role of IL-23 in the immunopathogenesis of psoriasis

Orchestrated Cytokines Mediated by Biologics in Psoriasis and Its Mechanisms of Action

Psoriasis is an autoimmune disease mediated by disturbed T cells and other immune cells, and is defined by deep-red, well-demarcated skin lesions. Due to its varied etiologies and indefinite standard pathogenesis, it is challenging to consider the right treatment exclusively for each psoriasis patient; thus, researchers yearn to seek even more precise treatments other than topical treatment and systemic therapy. Using biologics to target specific immune components, such as upregulated cytokines secreted by activated immune cells, is the most advanced therapy for psoriasis to date. By inhibiting the appropriate pro-inflammatory cytokines, cellular signaling can be altered and, thus, can inhibit further downstream inflammatory pathways. Herein, the roles of cytokines with their mechanisms of action in progressing psoriasis and how the usage of biologics alleviates cellular inflammation are discussed. In addition, other potential pro-inflammatory cytokines, with their mechanism of action, are presented herein. The authors hope that this gathered information may benefit future research in expanding the discovery of targeted psoriasis therapy.

Long-Term, Durable, Absolute Psoriasis Area and Severity Index and Health-Related Quality of Life Improvements with Risankizumab Treatment: A Post-Hoc Integrated Analysis of Patients with Moderate-to-Severe Plaque Psoriasis

Background

Risankizumab has demonstrated durable, high rates of efficacy in patients with moderate‐to‐severe plaque psoriasis as assessed by the achievement of relative Psoriasis Area and Severity Index (PASI) improvement and Dermatology Life Quality Index (DLQI) 0/1.

Objectives

The aim of this post hoc analysis is to assess the achievement of absolute PASI thresholds and related improvements in health‐related quality of life (HRQoL) in patients with moderate‐to‐severe plaque psoriasis treated with (i) risankizumab compared with ustekinumab, and (ii) long‐term (>52 weeks to 172 weeks) risankizumab.

Methods

Data from patients randomised to 150 mg risankizumab or 45 or 90 mg ustekinumab in replicate randomised controlled trials UltIMMa‐1 and UltIMMa‐2 were analysed for the achievement of absolute PASI thresholds PASI ≤ 3, PASI ≤ 1, and PASI = 0, time to achieve these thresholds, and combined PASI and DLQI endpoints. Data from pat ients initially randomised to risankizumab who continued on risankizumab in the open‐label extension study LIMMitless were analysed for the achievement of absolute PASI levels, mean DLQI scores, and DLQI 0/1.

Results

Significantly greater proportions of patients treated with risankizumab compared with ustekinumab achieved PASI ≤ 3, PASI ≤ 1, and PASI = 0, as well as combined endpoints for absolute PASI and DLQI [(PASI ≤ 3 and DLQI ≤ 5) or (PASI ≤ 1 and DLQI 0/1)]. The median time to first achieve PASI ≤ 3, PASI ≤ 1, and PASI = 0 was significantly lower for risankizumab‐treated patients compared with ustekinumab‐treated patients. Among patients treated with long‐term risankizumab, more than 90% achieved PASI ≤ 3 though week 172 and more than 80% achieved DLQI 0/1. Low absolute PASI scores corresponded with low mean absolute DLQI scores through week 172 of continuous risankizumab treatment.

Conclusions

Risankizumab treatment demonstrated high rates of rapid and durable efficacy as measured by absolute PASI thresholds and improvements in patient HRQoL.

Antihypertensive drug use and psoriasis: A systematic review, meta- and network meta-analysis

AIMS

Diverse genetic and/or external factors may induce psoriasis. Drug exposure is 1 such prominent external factor; antihypertensive drugs are reportedly associated with psoriasis, but study results have been inconsistent. In this context, we investigated the associations between antihypertensive drugs and incidence if psoriasis via a systematic literature review and meta-analysis.

METHODS

Literature search in databases such as PubMed, Embase and Web of Science was conducted on 8 January 2021, and obtained data were pooled for meta- and network meta-analysis. Fixed- or random effect models were used to calculate odds ratios (ORs) and 95% confidence intervals (CIs) for evaluating the strength of the associations between antihypertensive drugs and psoriasis incidence. In addition to meta-analysis, Bayesian network meta-analysis was performed. ResultsThirteen eligible studies were included for meta-analysis with 6 378 116 individuals and 8 studies for network meta-analysis with 5 615 918 individuals. All antihypertensive drugs were significantly associated with psoriasis incidence. In a meta-analysis, the pooled ORs were 1.67 (95% CI: 1.31-2.13) for angiotensin-converting enzyme (ACE) inhibitors, 1.40 (95% CI: 1.20-1.63) for β-blockers, 1.53 (95% CI: 1.23-1.89) for calcium-channel blockers (CCBs), and 1.70 (95% CI: 1.40-2.06) for thiazide diuretics. For the comparative risks of psoriasis among antihypertensive drugs in the network meta-analysis, ORs were 2.09 (95% CI: 1.39-3.18) for ACE inhibitors, 1.35 (95% CI: 0.99-1.91) for BBs, 1.53 (95% CI: 1.07-2.24) for CCBs and 1.80 (95% CI: 1.23-2.66) for thiazide diuretics.

CONCLUSION

This study confirmed the associations between antihypertensive drugs and psoriasis; ACE inhibitors, BBs, CCBs and thiazide diuretics increased the risk of psoriasis. Therefore, antihypertensive drug users should be carefully monitored for psoriasis.

IL-23 blockade with guselkumab potentially modifies psoriasis pathogenesis: rationale and study protocol of a phase 3b, randomised, double-blind, multicentre study in participants with moderate-to-severe plaque-type psoriasis (GUIDE)

BACKGROUND

Guselkumab is an interleukin (IL)-23 pathway blocker with proven efficacy in patients with moderate-to-severe plaque psoriasis. Early intervention with guselkumab may result in changes to the clinical disease course versus later intervention.

METHODS AND ANALYSIS

Here we present the rationale and design of a phase 3b, randomised, double-blind, multicentre study (GUIDE), comparing treatment effects of guselkumab in patients with short (≤2 years) or longer (>2 years) duration of plaque-type psoriasis, measured from first appearance of psoriatic plaques. Participants achieving skin clearance (Psoriasis Area and Severity Index (PASI)=0) by week 20 and maintaining complete clearance at week 28 visit ('super-responders' (SRe)) will be randomised to continue approved maintenance dosing every 8 weeks (q8w) versus an investigational maintenance dosing interval of 16 weeks (q16w) until week 68. Primary endpoint: proportion of participants in the q8w vs q16w arms with absolute PASI <3 at week 68. Participants with PASI <3 at week 68 will be withdrawn from guselkumab treatment for up to 48 weeks. Participants not achieving SRe criteria (non-SRe) will remain in the study with q8w guselkumab dosing through week 68. Additional to serum samples obtained from all patients, skin biopsies and whole-blood samples will be taken from SRe and non-SRe participants at various time points in optional substudies. Analyses include: genetics; immunophenotyping (fluorescence-activated cell sorting); gene and protein expression profiling; immunohistology. By merging clinical endpoints with mechanistic findings, this study aims to elucidate how IL-23 blockade with guselkumab can modify the disease course by altering molecular and cellular drivers that cause relapse after treatment withdrawal, particularly among SRe.

ETHICS AND DISSEMINATION

Approval obtained from ethics committee Medical Council Hamburg, Germany (PVN5925). GUIDE is compliant with the Declaration of Helsinki.

TRIAL REGISTRATION NUMBER

Registered at ClinicalTrials.gov (NCT03818035). All primary endpoint results (prespecified analyses) will be submitted to peer-reviewed, international journals within 18 months after primary completion date.

A Review of the Efficacy and Safety for Biologic Agents Targeting IL-23 in Treating Psoriasis With the Focus on Tildrakizumab

Psoriasis is a chronic and debilitating inflammatory immune-mediated skin disorder. Several cytokines including interleukin (IL)-23 were demonstrated to play a central role in the pathogenesis of this disease. Treatment options for psoriasis range from topical to systemic modalities, depending on the extent, anatomical locations involved and functional impairment level. Targeting cytokines or their cognate receptors that are involved in disease pathogenesis such as IL-12/23 (i.e., targeting the IL-12p40 subunit shared by these cytokines), IL-17A, IL-17F, IL-17RA, and TNF-α using biologic agents emerged in recent years as a highly effective therapeutic option for patients with moderate-to-severe disease. This review provides an overview of the important role of IL-23 signaling in the pathogenesis of psoriasis. We describe in detail the available IL-23 inhibitors for chronic plaque psoriasis. The efficacy, pharmacokinetic properties, and the safety profile of one of the most recent IL-23 biologic agents (tildrakizumab) are evaluated and reviewed in depth.

Therapeutic wavelengths of ultraviolet B radiation activate apoptotic, circadian rhythm, redox signalling and key canonical pathways in psoriatic epidermis

Ultraviolet B radiation (UVB) exerts pleiotropic effects on human skin. DNA damage response and repair pathways are activated by UVB; if damage cannot be repaired, apoptosis ensues. Although cumulative UVB exposure predisposes to skin cancer, UVB phototherapy is widely used as an effective treatment for psoriasis. Previous studies defined the therapeutic action spectrum of UVB and showed that psoriasis is resistant to apoptosis. This study aimed to investigate early molecular responses within psoriasis plaques following irradiation with single equi-erythemogenic doses of clinically-effective (311 nm, narrow-band) compared to clinically-ineffective (290 nm) UVB. Forty-eight micro-dissected epidermal samples from 20 psoriatic patients were analyzed using microarrays. Our bioinformatic analysis compared gene expression between 311 nm irradiated, 290 nm irradiated and control psoriasis epidermis to specifically identify 311 nm UVB differentially expressed genes (DEGs) and their upstream regulatory pathways. Key DEGs and pathways were validated by immunohistochemical analysis. There was a dynamic induction and repression of 311 nm UVB DEGs between 6 h and 18 h, only a limited number of DEGs maintained their designated expression status between time-points. Key disease and function pathways included apoptosis, cell death, cell migration and leucocyte chemotaxis. DNA damage response pathways, NRF2-mediated oxidative stress response and P53 signalling were key nodes, interconnecting apoptosis and cell cycle arrest. Interferon signalling, dendritic cell maturation, granulocyte adhesion and atherosclerotic pathways were also differentially regulated. Consistent with these findings, top transcriptional regulators of 311 nm UVB DEGs related to: a) apoptosis, DNA damage response and cell cycle control; b) innate/acquired immune regulation and inflammation; c) hypoxia/redox response and angiogenesis; d) circadian rhythmicity; f) EGR/AP1 signalling and keratinocyte differentiation; and g) mitochondrial biogenesis. This research provides important insights into the molecular targets of 311 nm UVB, underscoring key roles for apoptosis and cell death. These and the other key pathways delineated may be central to the therapeutic effects of 311 nm in psoriasis.

Efficacy and Safety of Continuous Risankizumab Therapy vs Treatment Withdrawal in Patients With Moderate to Severe Plaque Psoriasis: A Phase 3 Randomized Clinical Trial

Question

Is continuous risankizumab treatment efficacious and safe in adults with moderate to severe plaque psoriasis?

Findings

In this 2-part, phase 3 randomized clinical trial in 507 patients, a significantly greater proportion of patients treated with risankizumab vs placebo achieved a treatment response at week 16 and with long-term continuous risankizumab compared with withdrawal to placebo at 52 and 104 weeks. Rates of treatment-emergent adverse events were similar to those with placebo and remained stable over time.

Meaning

These findings support the use of 12-week risankizumab dosing as an efficacious and well-tolerated regimen for maintenance of clinical efficacy in patients with moderate to severe plaque psoriasis.

Importance

Risankizumab selectively inhibits interleukin 23, a cytokine that contributes to psoriatic inflammation.

Objective

To evaluate the efficacy and safety of risankizumab vs placebo and continuous treatment vs withdrawal in adults with moderate to severe plaque psoriasis.

Design, Setting, and Participants

Multinational, phase 3, randomized, double-blind, placebo-controlled trial conducted from March 6, 2016, to July 26, 2018. A total of 507 eligible patients had stable moderate to severe chronic plaque psoriasis for 6 months or longer, body surface area involvement greater than or equal to 10%, Psoriasis Area and Severity Index (PASI) greater than or equal to 12, and a static Physician’s Global Assessment (sPGA) score greater than or equal to 3. Intention-to-treat analysis was conducted.

Interventions

Patients were randomized (4:1, interactive response technology) to risankizumab, 150 mg, subcutaneously, or placebo at weeks 0 and 4 (part A1). All patients received risankizumab at week 16. At week 28, patients randomized to risankizumab who achieved an sPGA score of 0/1 were rerandomized 1:2 to risankizumab or placebo every 12 weeks (part B).

Main Outcomes and Measures

Co-primary end points for the part A1 phase included proportions of patients achieving greater than or equal to 90% improvement in PASI (PASI 90) and sPGA score of 0/1 at week 16. The PASI measures severity of erythema, infiltration, and desquamation weighted by area of skin involvement over the head, trunk, upper extremities, and lower extremities; scores range from 0 (no disease) to 72 (maximal disease activity). The sPGA assesses average thickness, erythema, and scaling of all psoriatic lesions; scores range from 0 (clear) to 4 (severe), with 0/1 indicating clear or almost clear. Primary and secondary end points in part B included proportion of rerandomized patients achieving an sPGA score of 0/1 at week 52 (primary) and week 104 (secondary).

Results

Of 563 patients screened, 507 were randomized to risankizumab (n = 407) or placebo (n = 100). Most patients were men (356 [70.2%]); median age was 51 years (interquartile range, 38-60 years). At week 16, 298 patients (73.2%) in the treatment group vs 2 patients (2.0%) receiving placebo achieved a PASI 90 response, and 340 patients (83.5%) receiving risankizumab vs 7 patients (7.0%) receiving placebo achieved sPGA 0/1 scores (placebo-adjusted differences: PASI 90: 70.8%; 95% CI, 65.7%-76.0%; sPGA 0/1: 76.5%; 95% CI, 70.4%-82.5%; P < .001 for both). At week 28, 336 responders were rerandomized to risankizumab (n = 111) or treatment withdrawal (n = 225). At week 52, the sPGA 0/1 score was achieved by 97 patients (87.4%) receiving risankizumab vs 138 patients (61.3%) receiving placebo. At week 104, the sPGA 0/1 score was achieved by 90 patients (81.1%) receiving risankizumab vs 16 patients (7.1%) receiving placebo (placebo-adjusted differences: week 52: 25.9%; 95% CI, 17.3%-34.6%; week 104: 73.9%; 95% CI, 66.0%-81.9%; P < .001 for both). Rates of treatment-emergent adverse events were similar between risankizumab (186 [45.7%]) and placebo (49 [49.0%]) in part A1 and remained stable over time.

Conclusions and Relevance

Risankizumab showed superior efficacy compared with placebo through 16 weeks and treatment withdrawal through 2 years. Risankizumab was well tolerated, with no unexpected safety findings during the 2-year trial.

Trial Registration

ClinicalTrials.gov Identifier: NCT02672852

Emerging Therapeutic Options for Chronic Pruritus

Chronic pruritus, defined as an unpleasant sensation resulting in a need to scratch that lasts more than 6 weeks, is a prevalent and bothersome symptom associated with both cutaneous and systemic conditions. Due to complex pathogenesis and profuse contributing factors, chronic pruritus therapy remains challenging. Regardless of the well-established antipruritic properties of classic pharmacotherapy (topical therapy, phototherapy and systemic therapy), these methods often provide insufficient relief for affected individuals. Owing to the growing interest in the field of pruritic research, further experimental and clinical data have emerged, continuously supporting the possibility of instigating novel therapeutic measures. This review covers the most relevant current modalities remaining under investigation that possess promising perspectives of approval in the near future, especially opioidergic drugs (mu-opioid antagonists and kappa-opioid agonists), neurokinin-1 receptor antagonists, biologic drugs, Janus kinase inhibitors, ileal bile acid transporter inhibitors, aryl hydrocarbon receptor agonists and histamine H₄ receptor antagonists.

A Systematic Literature Review and Bucher Indirect Comparison: Tildrakizumab versus Guselkumab

BACKGROUND

Psoriasis is a chronic inflammatory skin condition that impacts quality of life and requires long-term treatment and effective symptom management. Interleukin-23 (IL-23) has emerged as a key player in the pathogenesis of psoriasis and tildrakizumab and guselkumab are both immunomodulatory agents that inhibit the p19 subunit of IL-23. In its pivotal Phase III trial, tildrakizumab demonstrated greater efficacy than etanercept in moderate-to-severe psoriasis. However, there are no head-to-head trials comparing tildrakizumab with guselkumab.

METHODS

We conducted a systematic literature review and Bucher indirect comparison of tildrakizumab and guselkumab, using placebo as a common comparator. We searched MEDLINE, MEDLINE In-Process, MEDLINE(R) Daily Epub Ahead of Print, and Cochrane Central Register of Controlled Trials for Phase III randomized controlled trials between 1946 and November 2018. Inclusion criteria were adult patients ≥18 years with moderate-to-severe chronic plaque psoriasis, and intervention with tildrakizumab or guselkumab compared to placebo or best supportive care. Outcomes included were severity of psoriasis as defined by the Psoriasis Area and Severity Index (PASI) 75 and PASI 90, frequency of serious adverse events (SAEs), and treatment discontinuations. Outcomes were evaluated at Weeks 12 to 16 and 24 to 28. Analysis was based on the intent-to-treat population and, for all outcomes, the number of events reported were analyzed as a proportion of the number of patients randomized to ensure consistency across trials.

RESULTS

Overall, 154 unique records were identified. Five studies met the eligibility criteria and were included in the analysis; two tildrakizumab trials (reSURFACE 1 and reSURFACE 2) and three guselkumab trials (VOYAGE 1, VOYAGE 2, and a Japanese study). There was no statistically significant difference between guselkumab and tildrakizumab for PASI 75, PASI 90, SAEs, and rate of discontinuations at either timepoint.

CONCLUSION

This study assessed the comparative efficacy of tildrakizumab and guselkumab for the treatment of moderate-to-severe psoriasis. Limitations included the limited number of publications, imputation of placebo arm values for Weeks 24 to 28, and limited relevance of the Japanese study. This indirect comparison does not provide evidence that one treatment is superior to the other.

Interleukin 23p19 inhibitors in chronic plaque psoriasis with focus on mirikizumab: A narrative review

Psoriasis, a T-cell mediated chronic dermatosis, has a complex etiopathogenesis. There has been extensive research into the aberrant immune response, which leads to the formation of clinical lesions, and the need for developing better and safer drugs has been unrelenting. The past two decades of research has opened up new areas of the immune pathway that can be targeted in order to control the disease. Therefore, we have seen the emergence of biologics which either target T-cell receptors or inhibit Tumor Necrosis Factor-alpha (TNF-α) or inhibit interleukins (IL) like IL-12, IL-17, IL-17 receptor, and more recently IL-23. Drugs specifically targeting the p19 subunit of IL-23 have shown promising results in the management of chronic plaque psoriasis. This has given way to the development of a new class of biologics, that is, the IL-23p19 inhibitors that have a better safety profile as compared to its predecessors. In this review, we shall scrutinize the role of IL-23 and Th17 cell signaling in the evolution of the psoriatic lesions and summarize the clinical experience with IL-23p19 inhibitors especially mirikizumab in the treatment of chronic plaque psoriasis.

Mechanisms of Beta-Blocker Induced Psoriasis, and Psoriasis De Novo at the Cellular Level

Beta-blockers are a commonly prescribed medication, but the increase in use goes hand in hand with increasing side effects; one of particular interest lately has been its dermatological reactions. Although rare, beta-blockers can exacerbate pre-existing psoriasis and also cause de novo psoriasis in patients naïve to the disease. The mechanism by which this occurs is still unclear, although numerous articles have been published throughout the years as to how this unusual effect takes place. The most common mechanism suggests that beta-blockers cause intracellular changes in calcium, affecting both keratinocyte proliferation and granulocyte function via decreased cyclic adenosine monophosphate (cAMP) levels. Several inflammatory mediators are known to play a role, as well as reduced expression and desensitization of the beta-adrenergic receptor itself. We discuss these posed pathways in-depth and how each contributes to the worsening or formation of new psoriasis. With this knowledge, future physicians may be more mindful of this side effect should it occur, and why they occur, to better manage our patients on this widely used medication.

Unbalanced Sphingolipid Metabolism and Its Implications for the Pathogenesis of Psoriasis

Sphingolipids (SLs), which have structural and biological responsibilities in the human epidermis, are importantly involved in the maintenance of the skin barrier and regulate cellular processes, such as the proliferation, differentiation and apoptosis of keratinocytes (KCs). As many dermatologic diseases, including psoriasis (PsO), intricately characterized by perturbations in these cellular processes, are associated with altered composition and unbalanced metabolism of epidermal SLs, more education to precisely determine the role of SLs, especially in the pathogenesis of skin disorders, is needed. PsO is caused by a complex interplay between skin barrier disruption, immune dysregulation, host genetics and environmental triggers. The contribution of particular cellular compartments and organelles in SL metabolism, a process related to dysfunction of lysosomes in PsO, seems to have a significant impact on lysosomal signalling linked to a modulation of the immune-mediated inflammation accompanying this dermatosis and is not fully understood. It is also worth noting that a prominent skin disorder, such as PsO, has diminished levels of the main epidermal SL ceramide (Cer), reflecting altered SL metabolism, that may contribute not only to pathogenesis but also to disease severity and/or progression. This review provides a brief synopsis of the implications of SLs in PsO, aims to elucidate the roles of these molecules in complex cellular processes deregulated in diseased skin tissue and highlights the need for increased research in the field. The significance of SLs as structural and signalling molecules and their actions in inflammation, in which these components are factors responsible for vascular endothelium abnormalities in the development of PsO, are discussed.

Genomic alterations driving psoriasis pathogenesis

Psoriasis is an immune mediated inflammatory skin disease with complex etiology involving interplay between environmental and genetic risk factors as disease initiating event. Enhanced understanding on genetic risk factors, differentially expressed genes, deregulated proteins and pathway-targeted therapeutics have established multiple axis of psoriasis pathogenesis. So far, loci in 424 genes are reported to be associated with psoriasis alongside copy number variations and epigenetic alterations. From clinical perspective, presence of specific genetic trigger(s) in individual psoriasis patient could aid in devising a personalized therapeutic strategy. Therefore, the review presents an updates on reported genomic alterations and their subsequent course of cutaneous inflammations that potentially drive to psoriasis.

Biologics for the primary care physician: Review and treatment of psoriasis

Psoriasis is a chronic inflammatory disease that affects approximately 7.5 million people in the United States. The disease results in significant suffering, morbidity, and economic impact. Psoriasis is a multifaceted disease with a strong genetic component. Genetic data has revealed the presence of particular risk alleles in patients with psoriasis. Triggers of the disease have been elucidated and include factors such as trauma, obesity, infection, stress, and medications. At its core, psoriasis is a result of a dysfunctional immune response with T-cells at the center of immunogenesis. Clinically, psoriasis is characterized by discrete, erythematous scaly plaques. These lesions are often found on extensor surfaces, especially the elbows and knees. Although extensor surfaces are the prototypical destination of lesions, psoriasis may affect any area of the skin including the scalp, intertriginous areas, nails, palms, and soles. Location of lesions are important in assessing the impact on quality of life for patients. Diagnosis of psoriasis can typically be made clinically based on characteristic history and physical examination findings. In rare cases, biopsy may be needed to rule out other papulosquamous disease. Histologic findings of psoriasis can be non-specific and include marked epidermal hyperplasia, dilated vessels within the dermal papilla, and elongated rete ridges. Importantly, psoriasis is a systemic disease and organ systems outside of the skin must be considered. Co-morbidities of psoriasis include psoriatic arthritis, type 2 diabetes mellitus, cardiovascular disease, psychiatric disease, inflammatory bowel disease, neoplasms, and ocular disease. Management of psoriasis depends on the severity of the disease. In mild to moderate cases, topical medications are the cornerstone of treatment. Topical corticosteroids are the most commonly used and have limited systemic effects due to the localized application of medication. In moderate to severe cases of psoriasis, topical medications are ineffective and not feasible. Phototherapy and non-biologic systemic medications have been useful treatments; however, phototherapy is time consuming and non-biologic systemics have only modest response rates. In the last decade, biologic medications have become an important component of care for treating moderate to severe psoriasis. These medications target various cytokines responsible for psoriasis manifestations such as tumor necrosis factor (TNF-α), interleukin-12, interleukin-23, and interleukin-17. In the past 15 years, numerous biologic medications have been granted FDA approval, with the majority approved in the past several years. Some of the commonly used biologics include etanercept, adalimumab, infliximab, ixekizumab, secukinumab, brodalumab, guselkumab, ustekinumab, and tildrakizumab. Given the wealth of new biologics, current treatment guidelines have rapidly become outdated. This review provides summarized information of landmark trials that led to the approval of these medications.

Guselkumab, a human interleukin-23 monoclonal antibody in Japanese patients with generalized pustular psoriasis and erythrodermic psoriasis: Efficacy and safety analyses of a 52-week, phase 3, multicenter, open-label study

Generalized pustular psoriasis (GPP) and erythrodermic psoriasis (EP) are the rare and severe subtypes of psoriasis, which are often difficult to treat. The aim of this phase 3, open‐label study was to evaluate efficacy and safety of guselkumab, a human interleukin‐23 monoclonal antibody, in Japanese patients with GPP and EP. Guselkumab 50 mg was administrated to GPP (n = 10) and EP (n = 11) patients at weeks 0, 4 and thereafter every 8 weeks (q8w). Beginning at week 20, patients were escalated to 100 mg q8w if they met the dose escalation criteria. The primary end‐point was the proportion of patients achieving treatment success (Clinical Global Impression score of “very much improved”, “much improved” or “minimally improved”) at week 16. Safety evaluations included assessment of treatment‐emergent adverse events (TEAE) through week 52. At week 16, the proportions of GPP and EP patients achieving treatment success were 77.8% (7/9) and 90.9% (10/11), respectively. Furthermore, guselkumab treatment consistently showed improvement in responses of secondary end‐points such as Psoriasis Area and Severity Index, Investigator's Global Assessment, Japanese Dermatological Association severity index and improvement in body surface area involvement. Improvements in quality of life, as assessed by the Dermatology Life Quality Index, were also observed through week 52. The most commonly reported TEAE was nasopharyngitis (28.6%, 6/21). Safety findings were consistent with those observed previously in other studies. In conclusion, guselkumab treatment demonstrated efficacy and showed no safety concerns in Japanese patients with GPP and EP through week 52.

Epidermal Nbn deletion causes premature hair loss and a phenotype resembling psoriasiform dermatitis

Nijmegen Breakage Syndrome is a disease caused by NBN mutations. Here, we report a novel function of Nbn in skin homeostasis. We found that Nbn deficiency in hair follicle (HF) progenitors promoted increased DNA damage signaling, stimulating p16^Ink4a up-regulation, Trp53 stabilization and cytokines secretion leading to HF-growth arrest and hair loss. At later stages, the basal keratinocytes layer exhibited also enhanced DNA damage response but in contrast to the one in HF progenitor was not associated with pro-inflammatory cytokines expression, but rather increased proliferation, lack of differentiation and immune response resembling psoriasiform dermatitis. Simultaneous Nbn and Trp53 inactivation significantly exacerbated this phenotype, due to the lack of inhibition of pro-inflammatory cytokines secretion by Trp53. Altogether, we demonstrated novel functions of Nbn in HF maintenance and prevention of skin inflammation and we provide a mechanistic explanation that links cell intrinsic DNA maintenance with large scale morphological tissue alterations.

Targeting IL-23 in psoriasis: current perspectives

The recent advances in the understanding of psoriasis pathogenesis have clarified the pivotal role of interleukin (IL)-23. It is a heterodimeric cytokine consisting of two subunits, the unique p19 and the p40, which are shared with IL-12. The basic role of IL-23 in psoriasis is the activation and maintenance of the T-helper 17 pathway. New research findings indicate that IL-23 is more important than IL-12 in the pathogenesis of psoriasis. Based on that background, the selective targeting of the IL-23p19 subunit emerged as an attractive therapeutic option and led to the development of a new category of biologic agents. Three monoclonal antibodies that selectively inhibit the IL-23p19 subunit, guselkumab, tildrakizumab, and risankizumab, are in the pipeline for the treatment of moderate-to-severe psoriasis. In this article, we review the most recent efficacy and safety data regarding these IL-23p19 inhibitors.

Topical use and systemic action of green and roasted coffee oils and ground oils in a cutaneous incision model in rats (Rattus norvegicus albinus)

Introduction

Wounds are a common health problem. Coffee is widely consumed and its oil contains essential fatty acids. We evaluated the local (skin) and systemic effects associated with the topical use of coffee oils in rats.

Methods

Punch skin wounds (6 mm) incisions were generated on the backs of 75 rats. Saline (SS), mineral oil (MO), green coffee oil (GCO), roasted coffee oil (RCO), green coffee ground oil (GCGO) or roasted coffee ground oil (RCGO) were topically applied to the wounds. Healing was evaluated by visual and histological/morphometric optical microscopy examination; second harmonics generation (SHG) microscopy, wound tissue q-PCR (values in fold-change) and blood serum (ELISA, values in pg/mL).

Results

RCO treated animals presented faster wound healing (0.986 vs. 0.422), higher mRNA expression of IGF-1 (2.78 vs. 1.00, p = 0.01), IL-6 (10.72 vs. 1.00, p = 0.001) and IL-23 (4.10 vs. 1.2, p = 0.05) in early stages of wound healing; higher IL-12 (3.32 vs. 1.00, p = 0.05) in the later stages; and lower serum levels of IFN-γ (11.97 vs. 196.45, p = 0.01). GCO treatment led to higher mRNA expression of IL-6 (day 2: 7.94 vs. 1.00, p = 0.001 and day 4: 6.90 vs. 1.00, p = 0.01) and IL-23 (7.93 vs. 1.20, p = 0.001) in the early stages. The RCO treatment also produced higher serum IFN-α levels throughout the experiment (day 2: 52.53 vs. 21.20; day 4: 46.98 vs.21.56; day 10: 83.61 vs. 25.69, p = 0.05) and lower levels of IL-4 (day 4: 0.9 vs.13.36, p = 0.01), adiponectin (day 10: 8,367.47 vs. 16,526.38, p = 0.001) and IFN-γ (day 4: 43.03 vs.196.45, p = 0.05). The SHG analysis showed a higher collagen density in the RCO and GCO treatments (p = 0.05).

Conclusion

Topical treatment with coffee oils led to systemic actions and faster wound healing in rats. Further studies should be performed are necessary to assess the safety of topical vegetal oil use for skin lesions.

IL-23 Blockade for Crohn s disease: next generation of anti-cytokine therapy

INTRODUCTION

Adaptive immunity in intestinal inflammation may play a key role in the pathogenesis of Crohn's disease. In particular, interleukin (IL)-23 may be a key mediator in chronic intestinal inflammation by inducing the differentiation of naïve CD4 + T cells into Th17, with the production of several pro-inflammatory cytokines. Furthermore, IL-23 induces interferon-γ (IFN- γ) production from activated T cells, a critical cytokine in innate and adaptive immunity against infections. Areas covered: We aim to review the available data from literature regarding the role of IL-23, with a more specific focus on the recent progresses in the therapeutic modulation of this cytokine. Expert commentary: Increased knowledge regarding the role of IL-23 has allowed for the development of effective therapeutic progresses by blocking the IL-23 mediated pathways. Primary or secondary loss of response to anti-TNF therapies in Crohn's disease patients during the first year is widely described in literature: the development of new drugs, with alternative mechanisms of action, is thus a key point to consider for the optimal management of these subjects. Drugs blocking the IL-12/23 pathway showed a good efficacy and safety profile in immune-mediated diseases Further studies are necessary regarding the role of the single blockade of IL-23.

Suppressive effect of β,β-dimethylacryloyl alkannin on activated dendritic cells in psoriasis by the TLR7/8 pathway

β,β-dimethylacryloyl alkannin (DMA) is a key component of Lithospermum and possesses good efficacy for treating psoriasis. DMA inhibits activated dendritic cells (DCs), but the mechanism is unknown. Therefore, this study aimed to explore the modulation of the TLR7/8 pathway by DMA in psoriasis-activated DCs. Models of psoriasis-like skin lesions were established using BALB/c mice; 8 mice were treated with DMA (2.5mg/kg). Bone marrow cells were isolated and induced into DCs using R848, a TLR7/8 agonist. Splenic CD11c+ cells were detected by flow cytometry. Skin CD11c+ cells were detected by immunofluorescence. TLR7, TLR8, MYD88, and IRAKM proteins were detected by Western blot. The effects of DMA on surface molecules of DCs were observed by flow cytometry. mRNA expression of inflammatory factors was detected by qRT-PCR. Secreted cytokines were detected by cytometric bead array. Compared with the model group, psoriasis-like skin lesions were alleviated by DMA, the splenic CD11c+ cells were significantly decreased (P<0.01), and CD11c+ cell numbers in skin lesions were decreased (P<0.01). Expression levels of TLR7, MYD88, and IRAKM were significantly decreased (P<0.05). R848-stimulated DCs showed increased expression of I-A/I-E, CD80, and CD86 (P<0.01), increased IL-23 and IL-1β mRNA and secretion (P<0.05), and increased TLR7, TLR8, MYD88, and IRAKM expression (P<0.01); DMA inhibited all of these effects of the TLR7/8 pathway activation by R848 (P<0.05). In conclusion, DMA could inhibit psoriasis-activated DCs via the TLR7/8 pathway.

New and emerging biologic therapies for moderate-to-severe plaque psoriasis: mechanistic rationales and recent clinical data for IL-17 and IL-23 inhibitors

The development of effective and well-tolerated biologic therapies has advanced the management of psoriasis by enabling clinicians to treat underlying disease mechanisms. Biologics approved for the treatment of moderate-to-severe psoriasis include three tumor necrosis factor alpha inhibitors and an interleukin-12/interleukin-23 inhibitor. The establishment of the immunological basis of psoriasis has led to the development of biologic agents targeting specific downstream mediators in the psoriatic cascade. These drugs inhibit cytokines and cytokine signaling/transcription mediators like interleukin-17, which plays an important role in immunopathogenesis. Several interleukin-17 inhibitors are undergoing phase 3 clinical studies. In addition, biologics that selectively inhibit interleukin-23 have been assessed in phase 2 studies. This review describes how the dissection of pathways in the immunopathogenesis of psoriasis has led to the development of therapeutic agents and highlights the latest clinical efficacy, safety and tolerability data on new and emerging biologic therapies that selectively target interleukin-17 or interleukin-23.

The interleukin (IL)-23/IL-17 axis in ankylosing spondylitis: new advances and potentials for treatment

Ankylosing spondylitis (AS), the most common form of spondyloarthropathy, is a chronic, progressive multi-system inflammatory disorder characteristically affecting the sacroiliac joints and axial skeleton. Although the exact mechanisms underlying the pathogenesis of AS remain to be elucidated, the presence of human leucocyte antigen (HLA)-B27 is known to markedly increase its risk of development. Current treatments include non-steroidal anti-inflammatory drugs (NSAIDs) and tumour necrosis factor (TNF) blockers. In recent years, the interleukin (IL)-23/IL-17 pathway has been shown to have significance in the pathogenesis of AS and treatment modalities targeting this pathway have been shown to be beneficial in various other inflammatory conditions. This review provides an overview of the IL-23/IL-17 pathway in the pathogenesis of AS and summarizes new potential treatments for AS and related inflammatory diseases.

Ustekinumab improves psoriasis without suppressing tumor antigen-specific cytotoxic T lymphocytes

BACKGROUND

Ustekinumab is currently used for the treatment of psoriasis with remarkable efficiency. However, worries about the development of malignancies in ustekinumab-treated patients have not been completely resolved because of the major role of IL-12 and IL-23 in tumor immunity. In the present study, we tried to elucidate the effects of ustekinumab on antigen-specific tumor immunity.

METHODS

After approval by the institutional ethical committee, a 56-year-old male volunteer with psoriasis was administered with 20 doses of WT1 peptide. WT1-specific cytotoxic T lymphocytes (CTLs) were evaluated by WT1 tetramer assay after mixed lymphocyte peptide culture.

RESULTS

WT1 tetramer+ T cells with cytotoxic ability appeared in the blood after peptide administration and the frequency of WT1 tetramer+ T cells increased to more than 15 in 10(6) CD8+ T cells. Thirty months after stopping WT1 administration, the patient commenced treatment with ustekinumab for psoriasis at weeks 0 and 4, and every 12 weeks thereafter. Psoriasis plaques were almost cleared up and the response to ustekinumab has so far lasted for 30 months. The frequency of WT1 tetramer+ T cells has not changed since the initiation of ustekinumab treatment. The effects of ustekinumab on the antigen-presenting and CTL-inducing abilities of dendritic cells were explored in vitro, revealing limited effects on both immune functions.

CONCLUSIONS

These in vivo/vitro findings imply that ustekinumab improves psoriasis without suppressing tumor antigen-specific CTLs and support the data of recent clinical trials showing no increased incidence of malignancies with ustekinumab treatment.

Biological products for the treatment of psoriasis: therapeutic targets, pharmacodynamics and disease-drug-drug interaction implications

Psoriasis is a chronic inflammatory skin disease condition that involves altered expression of a broad spectrum of proinflammatory cytokines which are associated with activation of T cells and proliferation of keratinocytes. Currently approved biological products for psoriasis treatment fall into two main classes: cytokine modulators and biologics targeting T cells. In psoriatic patients, elevated levels of proinflammatory cytokines are observed. Elevated proinflammatory cytokines can suppress some cytochrome P450 (CYP) enzymes, and the treatment of psoriasis with biological products can reduce proinflammatory cytokine levels. Therefore, the exposure of CYP substrate drugs is anticipated to be affected by the psoriasis disease resulting in a higher exposure than in healthy state (named disease-drug interaction) as well as by the biological treatments due to disease improvements resulting in a decrease in exposure (named disease-drug-drug interaction, disease-DDI). However, the quantitative impact on CYP substrate exposure due to disease or due to treatment with biological products remains to be evaluated. The objective of the current review is to provide an overview of the therapeutic targets and cytokine-related pharmacodynamic effects of biological products in psoriasis treatment with a particular focus on their implications for disease-DDI. The clinical study design considerations for psoriasis disease-DDI evaluation are also discussed.

The IL-23/IL-17 axis in psoriatic arthritis

Psoriatic arthritis (PsA) is an immune-mediated chronic inflammatory disease, affecting both the skin and joints. Disease progression is associated with aberrant cytokine expression, and TNF blockade is the most successful therapy to date. However, not all patients are responsive to anti-TNF treatment, highlighting the need to better understand the cellular and molecular mechanisms that govern the disease. PsA associations with single nucleotide polymorphisms in IL23R as well as TRAF3IP2 (Act1), a molecule downstream of the IL-17 receptor (IL-17R), have linked the IL-23/IL-17 axis to disease pathology. Although both cytokines are implicated in PsA, a full picture of their cellular targets and pathogenic mechanisms has not yet emerged. In this review, we focus on the IL-23/IL-17 axis-elicited responses mediated by osteoclasts, keratinocytes and neutrophils. Expanding our understanding of the cellular and molecular mechanisms that dictate pathogenicity in PsA will contribute to developing novel treatment strategies to combat disease.

Effect of Narrow Band Ultraviolet B Therapy versus Methotrexate on Serum Levels of Interleukin-17 and Interleukin-23 in Egyptian Patients with Severe Psoriasis

Background. There is raised interest in the involvement of interleukin-(IL-)23/T-helper 17 cells (Th17) axis in the pathogenesis of psoriasis. Objectives. To compare the effect of narrow band ultraviolet B (NB-UVB) and methotrexate (MTX) therapy on serum levels of IL-17 and IL-23 in psoriatic patients. Methods. Thirty patients with severe plaque psoriasis were included: 15 patients received NB-UVB three times weekly (group I) and 15 patients received MTX 0.3 mg/kg per week (group II), both for 8 weeks. Before and after treatment, serum levels of IL-17 and IL-23 were investigated by ELISA technique and psoriasis area and severity index (PASI) was calculated. Results. After treatment, all patients showed a reduction in their PASI score, IL-17 and IL-23 serum levels with a nonsignificant difference between both therapeutic modalities (P value >0.05). A positive correlation was detected between the percent of reduction of IL-17, IL-23 and the percent of reduction of PASI score for patients receiving both treatments. No correlation was found between the percent of reduction of IL-17, IL-23 and duration of disease or age of all patients in this study. Conclusion. Interleukin-17 and IL-23 serum level may serve as a potential biomarker for predicting the prognosis and therapeutic response of NB-UVB or MTX in treating psoriasis.

Specific targeting of interleukin-23p19 as effective treatment for psoriasis

Interleukin (IL)-23 is a heterodimeric cytokine composed of a distinct p19 subunit and a p40 subunit, which it shares with IL-12. The dermatology and rheumatology communities have long surmised that anti-IL-12/23p40 antibodies suppress autoinflammatory disease owing to their effect on IL-12. The aim of this review is to bring to light new data from murine and human studies demonstrating that in fact IL-23 and its resulting Th17 pathway mediate the inflammatory cascade that induces psoriatic plaque formation. Evidence derives from lesional immunohistochemical analyses, genetic studies, and research in other autoimmune diseases. Although current IL-12/23p40 inhibitors have shown good efficacy and safety, data regarding the functional role of IL-12 in immune defense suggest that preserving this cytokine would be beneficial. To date, evidence from mouse models and preliminary data in human beings show that specifically targeting IL-23p19 may be a safer but equally efficacious treatment option.

CXCR4 in epidermal keratinocytes: crosstalk within the skin

In this issue, Takekoshi et al. investigated the role of CXCR4 in IL-23-induced keratinocyte hyperproliferation using an epidermal-specific knockout mouse model and found that CXCR4 limited keratinocyte proliferation. Some reports in the literature support this idea, whereas others contradict it; this disparity may be related to the differential roles of CXCR4 in various cell types or to a recently identified second receptor (CXCR7). Nevertheless, CXCR4 and its ligand SDF-1 have been implicated in skin wound healing, systemic lupus erythematosus, and basal cell carcinoma tumor angiogenesis. Further study is merited.

Serum levels of selected Th17 and Th22 cytokines in psoriatic patients

INTRODUCTION

Psoriasis is a T cell-mediated inflammatory disease in which pathogenesis T helper (Th) lymphocytes (Th1, Th17, and Th22) play an important role. The aim of the study was to assess the serum levels of some cytokines involved in the Th17 and Th22 responses in psoriatic patients.

MATERIAL AND METHODS

The study comprised 60 psoriatic patients and 30 healthy controls. In the serum collected from psoriatic patients and healthy controls, the concentrations of IL-6, IL-12, IL-17, IL-20, IL-22, and IL-23 were examined with ELISA kits. Severity of psoriatic skin lesions was assessed by means of PASI, BSA, and PGA scores.

RESULTS

IL-6, IL-20, and IL-22 concentrations were significantly higher in psoriatic patients in comparison with the control group. The positive correlations between the concentrations of IL-22 and IL-20 and severity of psoriasis assessed with PASI and BSA scores as well as IL-17 and PASI score were found. There was also a positive correlation between IL-23 and IL-17 concentrations.

CONCLUSIONS

Results of the conducted studies suggest that Th22 response may contribute to the skin and systemic inflammatory disease in psoriasis. It seems that early identification of soluble biomarkers and initiation of well-matched treatment may prevent exacerbation and progression of psoriasis.

Sarcoptes scabiei mites modulate gene expression in human skin equivalents

The ectoparasitic mite, Sarcoptes scabiei that burrows in the epidermis of mammalian skin has a long co-evolution with its hosts. Phenotypic studies show that the mites have the ability to modulate cytokine secretion and expression of cell adhesion molecules in cells of the skin and other cells of the innate and adaptive immune systems that may assist the mites to survive in the skin. The purpose of this study was to identify genes in keratinocytes and fibroblasts in human skin equivalents (HSEs) that changed expression in response to the burrowing of live scabies mites. Overall, of the more than 25,800 genes measured, 189 genes were up-regulated >2-fold in response to scabies mite burrowing while 152 genes were down-regulated to the same degree. HSEs differentially expressed large numbers of genes that were related to host protective responses including those involved in immune response, defense response, cytokine activity, taxis, response to other organisms, and cell adhesion. Genes for the expression of interleukin-1α (IL-1α) precursor, IL-1β, granulocyte/macrophage-colony stimulating factor (GM-CSF) precursor, and G-CSF precursor were up-regulated 2.8- to 7.4-fold, paralleling cytokine secretion profiles. A large number of genes involved in epithelium development and keratinization were also differentially expressed in response to live scabies mites. Thus, these skin cells are directly responding as expected in an inflammatory response to products of the mites and the disruption of the skin's protective barrier caused by burrowing. This suggests that in vivo the interplay among these skin cells and other cell types, including Langerhans cells, dendritic cells, lymphocytes and endothelial cells, is responsible for depressing the host's protective response allowing these mites to survive in the skin.

Cytokines and the skin barrier

The skin is the largest organ of the human body and builds a barrier to protect us from the harmful environment and also from unregulated loss of water. Keratinocytes form the skin barrier by undergoing a highly complex differentiation process that involves changing their morphology and structural integrity, a process referred to as cornification. Alterations in the epidermal cornification process affect the formation of the skin barrier. Typically, this results in a disturbed barrier, which allows the entry of substances into the skin that are immunologically reactive. This contributes to and promotes inflammatory processes in the skin but also affects other organs. In many common skin diseases, including atopic dermatitis and psoriasis, a defect in the formation of the skin barrier is observed. In these diseases the cytokine composition within the skin is different compared to normal human skin. This is the result of resident skin cells that produce cytokines, but also because additional immune cells are recruited. Many of the cytokines found in defective skin are able to influence various processes of differentiation and cornification. Here we summarize the current knowledge on cytokines and their functions in healthy skin and their contributions to inflammatory skin diseases.

NK cells and psoriasis

Psoriasis is a chronic condition of the skin characterised by distinctive scaly plaques. The immune system is now thought to play a major role in the development and pathogenesis of psoriasis with immune cells and cytokines influencing keratinocyte function. Keratinocytes in turn, can activate and recruit immune cells leading to a positive feedback loop in disease. Natural Killer (NK) cells are lymphocytes that are best known for killing virally infected and cancer cells. However, evidence is emerging to support a role for NK cells in psoriasis. NK cells are found in the inflammatory infiltrate in psoriatic skin lesions. They can produce a range of inflammatory cytokines, many of which are important in the pathogenesis of psoriasis. Recent genetic studies have identified a range of potential molecules relating to NK cell biology that are known to be important in psoriasis. This paper will discuss the evidence, both cellular and genetic, for NK cell involvement in psoriasis.