Molecular Pathogenesis of Psoriasis and Biomarkers Reflecting Disease Activity

Modulation of the skin and gut microbiome by psoriasis treatment: a comprehensive systematic review

The microbiome is intricately linked to the development of psoriasis, serving as both a potential cause and consequence of the psoriatic process. In recent years, there has been growing interest among psoriasis researchers in exploring how psoriasis treatments affect the skin and gut microbiome. However, a comprehensive evaluation of the impact of modern treatment approaches on the microbiome has yet to be conducted. In this systematic review, we analyze studies investigating alterations in the skin and gut microbiome resulting from psoriasis treatment, aiming to understand how current therapies influence the role of the microbiome in psoriasis development. The systematic review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. PubMed and Scopus databases were searched for eligible studies from the inception dates until July 5, 2023. Study selection, data extraction, and risk of bias assessment were carried out by three overlapping pairs of reviewers, resolving any disagreements through consensus. Our analysis of various treatments, including biologics, conventional medications, phototherapy, and probiotics, reveals significant shifts in microbial diversity and abundance. Importantly, favorable treatment outcomes are associated with microbiota alterations that approach those observed in healthy individuals. While the studies reviewed exhibit varying degrees of bias, underscoring the need for further research, this review supports the potential of microbiome modulation as both a preventive and therapeutic strategy for psoriasis patients. The findings underscore the importance of personalized therapeutic approaches, recognizing the profound impact of treatment on the microbiome. They also highlight the promise of probiotics, prebiotics, and dietary interventions in psoriasis management.

Biomarkers in Psoriasis: The Future of Personalised Treatment

Psoriasis is a chronic and complex immune-mediated papulosquamous disease affecting almost 2% of the world population. The interaction between a genetically predisposed individual and environmental triggers leads to a vicious cycle involving autoreactive T cells, dendritic cells, keratinocytes and dermal cells. Up to 40% of the psoriasis cases develop disabling psoriatic arthritis and an equal number of patients also tend to develop metabolic syndrome as well as cardiovascular comorbidities; hence, this is no more considered to be a disease limited to skin only. Being a systemic disease, there is an urgent need to develop potential biomarkers for the assessment of disease severity, prediction of outcome of the therapeutic intervention and association with various systemic comorbidities. Diverse genetic markers not only function as predictors of diseases pathogenesis, but also help to predict development of psoriasis and psoriatic arthritis. Personalised medicine is customising the therapeutic needs of a psoriasis patient and improving the outcome as per the hints we receive from the various biomarkers. This review deals with the list of potential biomarkers proposed to be useful in psoriasis, though there is limited data validating their routine use in clinical practice and the progress so far made in the field of precision medicine for psoriasis.

Clinical Characteristics of Psoriasis Cases Treated by Biologics With an Extended Administration Interval: A Single-Center, Retrospective Observational Study

Background Psoriasis is a chronic inflammatory skin disease with multiple organ manifestations such as arthritis and cardiovascular diseases. While recent therapeutic advancements in systemic biologics have demonstrated efficacy against psoriasis, a complete cure has not been achieved and patients require lifelong treatment to control symptoms. Objective This study aimed to clarify the clinical characteristics of psoriasis patients treated with biologics at an extended interval. Methods This study included patients with psoriasis who were administered biologic therapy for longer than the standard interval (at least a week) and who objectively maintained favorable conditions (static Physician's Global Assessment ≤ 0 to 1). Clinical characteristics, such as body weight (BW), body mass index (BMI), and body fat percentage, were compared to those of patients who were administered biologic therapy at standard intervals. Results Among 162 Japanese patients with psoriasis, 35 were treated with biologics at extended intervals. In the group with extended treatment intervals, patients treated with interleukin (IL)-17 inhibitors (n = 15) presented statistically lower BMI than those treated with IL-23 inhibitors (n = 17) (P < 0.016). The group treated with IL-17 inhibitors at extended intervals showed significantly lower BMI and body fat percentage than the group at standard intervals (P < 0.05). Conclusion Trends in our hospital suggest that psoriasis patients with low BMI and body fat percentage can maintain good status with extended interleukin (IL)-17 inhibitor dosing intervals (static Physician's Global Assessment ≤ 0 to 1).

Effect of Treatment With Biologic Agents on the Novel Inflammatory Biomarkers Systemic Immune Inflammation Index and Systemic Inflammation Response Index for Psoriasis

INTRODUCTION

Psoriasis is a chronic cutaneous disorder with underlying systemic inflammation. The systemic immune inflammation (SII) and systemic inflammation response indexes (SIRI) are novel biomarkers that indicate systemic inflammation.

OBJECTIVES

We aimed to evaluate the effect of biological agent treatment on SII and SIRI in psoriasis patients.

METHODS

Between April 2019 and October 2022, SII and SIRI were retrospectively evaluated in patients with psoriasis before and three months after the initiation of biological agents.

RESULTS

This study included 220 patients, 101 females and 119 males. SIRI was significantly higher in male patients compared to females (P < 0.001). Although not statistically significant, SII and SIRI were higher in obese patients, patients with severe psoriasis, longer disease duration, nail involvement and patients who received previous biological agent treatment. SII was also higher in patients with hypertension, diabetes, hepatic steatosis, depression and coronary artery disease (P = 0.801, P = 0.752, P = 0.706, P = 0.079, P = 0.861, respectively), whereas SIRI was higher in patients with diabetes and depression (P = 0.263, P = 0.777, respectively). Both SII and SIRI statistically significantly decreased after treatment with adalimumab, infliximab, ixekizumab, secukinumab, ustekinumab and risankizumab.

CONCLUSIONS

SII and SIRI may indicate the severity of psoriasis as well as SII may be associated with psoriatic arthritis, hypertension, hepatic steatosis and coronary artery disease in patients with psoriasis. There is no consensus on the biomarkers that can be used to create an optimized treatment strategy in psoriasis. Therefore, SII and SIRI may be helpful in making the choice of treatment and in the follow-up of patients with psoriasis treated with biological agents.

S100 calcium-binding protein A9 promotes skin regeneration through toll-like receptor 4 during tissue expansion

Background

In plastic surgery, tissue expansion is widely used for repairing skin defects. However, low expansion efficiency and skin rupture caused by thin, expanded skin remain significant challenges in promoting skin regeneration during expansion. S100 calcium-binding protein A9 (S100A9) is essential in promoting wound healing; however, its effects on skin regeneration during tissue expansion remain unclear. The aim of the present study was to explore the role of S100A9 in skin regeneration, particularly collagen production to investigate its importance in skin regeneration during tissue expansion.

Methods

The expression and distribution of S100A9 and its receptors-toll-like receptor 4 (TLR-4) and receptor for advanced glycation end products were studied in expanded skin. These characteristics were investigated in skin samples of rats and patients. Moreover, the expression of S100A9 was investigated in stretched keratinocytes in vitro. The effects of S100A9 on the proliferation and migration of skin fibroblasts were also observed. TAK-242 was used to inhibit the binding of S100A9 to TLR-4; the levels of collagen I (COL I), transforming growth factor beta (TGF-β), TLR-4 and phospho-extracellular signal-related kinase 1/2 (p-ERK1/2) in fibroblasts were determined. Furthermore, fibroblasts were co-cultured with stretched S100A9-knockout keratinocytes by siRNA transfection and the levels of COL I, TGF-β, TLR-4 and p-ERK1/2 in fibroblasts were investigated. Additionally, the area of expanded skin, thickness of the dermis, and synthesis of COL I, TGF-β, TLR-4 and p-ERK1/2 were analysed to determine the effects of S100A9 on expanded skin.

Results

Increased expression of S100A9 and TLR-4 was associated with decreased extracellular matrix (ECM) in the expanded dermis. Furthermore, S100A9 facilitated the proliferation and migration of human skin fibroblasts as well as the expression of COL I and TGF-β in fibroblasts via the TLR-4/ERK1/2 pathway. We found that mechanical stretch-induced S100A9 expression and secretion of keratinocytes stimulated COL I, TGF-β, TLR-4 and p-ERK1/2 expression in skin fibroblasts. Recombined S100A9 protein aided expanded skin regeneration and rescued dermal thinning in rats in vivo as well as increasing ECM deposition during expansion.

Conclusions

These findings demonstrate that mechanical stretch promoted expanded skin regeneration by upregulating S100A9 expression. Our study laid the foundation for clinically improving tissue expansion using S100A9.

Psoriasis Area and Severity Index (PASI) Objectivisation by Flow Cytometry Analysis of Major Lymphocytes Subsets

Background

Psoriasis as an immune-mediated inflammatory skin disease. The basis of the pathogenesis of psoriasis is the dysregulation of immune cell function in genetically predisposed individuals. The characteristic dysfunction of the immune system in patients with psoriasis is manifested as a variation in the cellular phenotypic profile in accordance with the disease status.

Objective

The aim of this study was to evaluate the immunophenotypic profile of lymphocytes obtained by flow cytometry as an auxiliary diagnostic tool in the objectivization of the PASI score.

Methods

The study group included 40 patients with psoriasis, hospitalized and treated at Dermatology Clinic of Clinical center University of Sarajevo and 30 healthy individuals as controls. After venepunction, the blood samples for determining the immune profile were prepared following standard laboratory procedures using conjugated monoclonal antibodies and BD FACSCanto II flow cytometer. T-lymphocytes (CD3, CD4, CD8), B lymphocytes (CD19), Natural killer cells (NK), and activatet T-cells (CD3HLA) were determined for all patients. Based on the PASI score, the severity and area of the disease was assessed for all psoriasis patients by dermatology specialist.

Results

Our data shows no significant difference in any of the lymphocyte subpopulations between psoriasis patients and healthy controls, except CD3HLA. CD3HLA has higher values in patients with psoriasis, p=0.015. Of all the parameters, only NK cells were significantly correlated to the PASI score (rho -0.279; p=0.048). ROC curve analysis revealed a statistically significant difference for the proportion of CD3 lymphocytes (AUC 0.799; p=0.004), CD8 lymphocytes (AUC 0.733; p= 0.023), NK cells (AUC 0.722; p=0.008) and CD3HLA activated T lymphocytes (AUC 0.347; p=0.034).

Conclusion

Profile of major lymphocyte subsets in patients with psoriasis is similar to that of healthy controls. The values of CD3, CD8, NK, CD3HLA were defined as biomarkers capable of distinguishing psoriasis according to the severity of the disease. Immunophenotyping of peripheral blood lymphocytes can play an important role as an auxiliary diagnostic method in differentiating the clinical stages of psoriasis and objectifying the PASI score.

Psoriasis and Its Relationship With Somatosensory Amplification, Health Anxiety, and Depression

Objective The present study investigates the relationship between psoriasis and diseases such as health anxiety, depression, and somatosensory amplification. Methods The participating patients (n=117, including 60 psoriasis patients and 57 controls) filled out the Beck Depression Inventory (BDI), Beck Anxiety Inventory (BAI), Somatosensory Amplification Scale (SSAS), and Health Anxiety Inventory (HAI) questionnaires. Results The mean scores from SSAS, HAI, and BDI were significantly higher in the psoriasis group than in the control group (p<0.05 in all comparisons). When the group medians of BAI were evaluated, the differences were not statistically significant, although BAI medians were higher in the patient group. Furthermore, a moderate correlation was found between the involvement of specific areas (especially the scalp and face) and SSAS scores. Conclusion Patients with psoriasis score highly in depression, health anxiety, and somatosensory amplification, and there was a moderate correlation between specific body area involvement (especially the scalp and face) and SSAS score. The results of this study seem to indicate that psychiatric assessment and treatment approaches should be included in the treatment of such chronic skin diseases as psoriasis that follow a life-long remission and relapse pattern.

Deciphering the Function of New Therapeutic Targets and Prospective Biomarkers in the Management of Psoriasis

Psoriasis is an immune-mediated skin condition affecting people worldwide, presenting at any age, and leading to a substantial burden physically and mentally. The innate and adaptive immune systems interact intricately with the pathomechanisms that underlie disease. T cells can interact with keratinocytes, macrophages, and dendritic cells through the cytokines they secrete. According to recent research, psoriasis flare-ups can cause systemic inflammation and various other co-morbidities, including depression, psoriatic arthritis, and cardio-metabolic syndrome. Additionally, several auto-inflammatory and auto-immune illnesses may be linked to psoriasis. Although psoriasis has no proven treatment, care must strive by treating patients as soon as the disease surfaces, finding and preventing concurrent multimorbidity, recognising and reducing bodily and psychological distress, requiring behavioural modifications, and treating each patient individually. Biomarkers are traits that are assessed at any time along the clinical continuum, from the early stages of a disease through the beginning of treatment (the foundation of precision medicine) to the late stages of treatment (outcomes and endpoints). Systemic therapies that are frequently used to treat psoriasis provide a variety of outcomes. Targeted therapy selection, better patient outcomes, and more cost-effective healthcare would be made possible by biomarkers that reliably predict effectiveness and safety. This review is an attempt to understand the role of Antimicrobial peptides (AMP), Interleukin-38 (IL-38), autophagy 5 (ATG5) protein and squamous cell carcinoma antigen (SCCA) as biomarkers of psoriasis.

The Intriguing Links between Psoriasis and Bullous Pemphigoid

The coexistence of psoriasis with autoimmune bullous diseases (AIBDs), particularly bullous pemphigoid (BP), has been documented in case reports and series, as well as in epidemiological studies. The onset of psoriasis precedes that of BP in the majority of cases. Patients with concomitant BP and psoriasis are generally younger at the onset of BP and present with fewer erosions and blisters as compared with patients suffering from isolated BP. Intriguingly, it has been speculated that some BP cases with comorbid psoriasis can actually correspond to anti-laminin gamma-1 pemphigoid, a rare form that was recently recognized as a distinct entity and which can mimic BP and/or other subepidermal AIBDs. The pathomechanisms underlying the BP-psoriasis association have not yet been identified, although several hypotheses have been proposed. The most credited among such hypotheses involves the so-called "epitope spreading" phenomenon, with tissue injury secondary to a primary inflammatory process (i.e., psoriasis) leading to the exposure of sequestered antigens evoking a secondary autoimmune disease (i.e., bullous pemphigoid). This narrative review aims to give a brief overview of the association between psoriasis and BP, examining epidemiological, clinical, and immunopathological features, the pathomechanisms underlying this association, the treatments for psoriasis incriminated as potential triggers of BP, and the therapeutic management of patients with psoriasis and BP.

Curcumin and Curcuma longa Extract in the Treatment of 10 Types of Autoimmune Diseases: A Systematic Review and Meta-Analysis of 31 Randomized Controlled Trials

Objective

To evaluate the randomized controlled trials (RCTs) of Curcumin and Curcuma longa Extract in the treatment of autoimmune diseases.

Methods

Databases such as Embase, Web of Science, PubMed and The Cochrane Library were searched from the database establishment to February 2022 to collect RCTs of Curcumin and Curcuma longa Extract in the treatment of autoimmune diseases. Then the literature was screened and the data were extracted. Meta-analysis was performed using RevMan 5.3 software.

Results

A total of 34 records were included, involving 31 RCTs and 10 types of autoimmune disease. Among them, ankylosing spondylitis (AS) involves one RCT, Behcet ‘s disease (BD) involves one RCT, Crohn ‘s disease involves two RCTs, multiple sclerosis (MS) involves two RCTs, oral lichen planus involves six RCTs, psoriasis involves two RCTs, rheumatoid arthritis (RA) involves five RCTs, systemic lupus erythematosus (SLE) involves two RCTs, arteritis involves one RCT, ulcerative colitis (UC) involves nine RCTs. Among them, most of the RCTs of ulcerative colitis (UC), oral lichen planus, RA showed that curcumin and curcumin extracts improved clinical or laboratory results. Crohn ‘ s disease, MS, SLE, psoriasis included two RCTs; they all showed improvements (at least one RCT reported improvements in clinical outcomes). AS, BD and arteritis included only one RCT, and the clinical results showed improvement. However, due to the small number of RCTs and the small number of patients involved in each disease, there is still a need for more high-quality RCTs.

Conclusion

Curcumin and Curcuma longa Extract had good clinical efficacy in the treatment of Psoriasis, UC and RA, so Curcumin and Curcuma longa Extract could be used in the treatment of the above diseases in the future. The results of Meta-analysis showed that Curcumin and Curcuma longa Extract did not show efficacy in the treatment of oral lichen planus, while Takayasu arteritis, SLE, MS, AS, BD and CD did not report sufficient clinical data for meta-analysis. Therefore, large-sample, multi-center clinical trials are still needed for revision or validation.

Unmet Medical Needs in Chronic, Non-communicable Inflammatory Skin Diseases

An estimated 20-25% of the population is affected by chronic, non-communicable inflammatory skin diseases. Chronic skin inflammation has many causes. Among the most frequent chronic inflammatory skin diseases are atopic dermatitis, psoriasis, urticaria, lichen planus, and hidradenitis suppurativa, driven by a complex interplay of genetics and environmental factors. Autoimmunity is another important cause of chronic skin inflammation. The autoimmune response may be mainly T cell driven, such as in alopecia areata or vitiligo, or B cell driven in chronic spontaneous urticaria, pemphigus and pemphigoid diseases. Rare causes of chronic skin inflammation are autoinflammatory diseases, or rheumatic diseases, such as cutaneous lupus erythematosus or dermatomyositis. Whilst we have seen a significant improvement in diagnosis and treatment, several challenges remain. Especially for rarer causes of chronic skin inflammation, early diagnosis is often missed because of low awareness and lack of diagnostics. Systemic immunosuppression is the treatment of choice for almost all of these diseases. Adverse events due to immunosuppression, insufficient therapeutic responses and relapses remain a challenge. For atopic dermatitis and psoriasis, a broad spectrum of innovative treatments has been developed. However, treatment responses cannot be predicted so far. Hence, development of (bio)markers allowing selection of specific medications for individual patients is needed. Given the encouraging developments during the past years, we envision that many of these challenges in the diagnosis and treatment of chronic inflammatory skin diseases will be thoroughly addressed in the future.

Generalized pustular psoriasis: the new era of treatment with IL-36 receptor inhibitors

Generalized pustular psoriasis (GPP) is a rare yet severe variant of psoriasis, characterized by the eruption of superficial sterile pustules that appear suddenly and widely distributed, potentially life-threatening. It more commonly presents through recurrent acute flares triggered by stress, corticosteroid withdrawals, pregnancy, or infections. The pathogenesis of this disease is yet to be fully understood. Nevertheless, studies have suggested an important role of an IL-1 subfamily of cytokines, due to an imbalance of the IL-36 axis favoring of pro-inflammatory activity. The therapeutic intervention for this condition is still a challenge as its rarity and scarce available information contribute to the absence of specific treatment. Current options stand on small, open-label trials or follows standard treatment for plaque psoriasis. Spesolimab and imsidolimab are two IL-36 receptor inhibitors which completed phase 1 and 2 trials with a good efficacy and safety profile in the treatment of this disease, including in the fast control of its acute flares. The most common adverse events reported with spesolimab were mild to moderate infections, and imsidolimab was well tolerated. GPP clinical trials remain to have their small sample size as a major limitation, but IL-36 receptor inhibitors are promising therapeutic options currently under investigation.