Pembrolizumab-Induced Rupioid Psoriasis Treated by Apremilast Without Interrupting the Ongoing Antineoplastic Treatment.

We report the case of a 77-year-old man affected by a poorly differentiated metastatic pulmonary adenocarcinoma who, after the first course of therapy with cisplatin-pemetrexed-pembrolizumab treatment, developed rupioid psoriasis. We decided to discontinue pembrolizumab for four weeks until lesions improved and to start therapy with apremilast (an oral small molecule phosphodiesterase (PDE)4 inhibitor) in combination with systemic methylprednisolone 16 mg/day with consequent tapering until discontinuation in a few weeks. After accomplishing three months of treatment with apremilast, the patient gained complete remission of the rupioid lesions. Pembrolizumab therapy was reintroduced, and cycles were carried out without exacerbating the clinical picture. During the fourth month of therapy with apremilast, it was attempted to stop the treatment despite continuing the therapy with pembrolizumab. As a result, there was a relapse of the erythematous scaling plaques. After the subsequent reintroduction of apremilast, a new remission of the clinical picture occurred despite the absence of interruption of pembrolizumab. As far as we know, this is the second case of rupioid psoriasis induced by immunotherapy with pembrolizumab. Still, while the previous case was undergoing therapy with acitretin and methylprednisone, our patient is the first case treated with apremilast with excellent and rapid remission even after discontinuation and re-administration of pembrolizumab without exacerbation of dermatitis. In addition, the appearance of psoriasis during immunotherapy can be properly treated, which does not contraindicate the continuation of the antineoplastic treatment.

Dietary Influences on Skin Health in Common Dermatological Disorders.

The role of diet in the development of skin disorders is well-established, with nutritional deficiency often identified as a risk factor for skin diseases. Imbalances in the skin can be caused by nutritional deficiencies, excessive intake, insufficient nutrients, and hazardous ingredients. Patients frequently inquire about the impact of dietary patterns on skin health when consulting dermatologists in clinical settings. Simultaneously, the popularity of using nutritional supplements containing vitamins, minerals, and nutraceutical blends has been on the rise. It is crucial for dermatologists, primary care physicians, and other healthcare providers to be acquainted with evidence-based dietary interventions, distinguishing them from those that are more market-driven than truly efficacious. This review explores the modification of diet, encompassing both dietary exclusion and supplementation, as a therapeutic approach for conditions such as psoriasis, atopic dermatitis, bullous disease, vitiligo, and alopecia areata. A comprehensive literature search, utilizing the PubMed/Medline, Google Scholar, and Medscape databases, was conducted to investigate the relationship between each nutrient and various inflammatory skin diseases. The findings emphasize the significance of a well-balanced and thoughtfully planned diet in supplying adequate amounts of proteins, vitamins, and minerals to support optimal skin health. Additionally, this comprehensive review navigates through various dietary recommendations, offering insights into their multifaceted impacts on the immune system, gut microbiome, and skin health. The goal is to pave the way for informed and targeted dietary interventions for individuals dealing with food allergies and associated skin conditions.

Geniposide alleviates imiquimod-induced psoriasis-like skin lesions in mice via inhibition of angiogenesis.

In this study, we aimed to evaluate the protective effect of geniposide (GEN) on imiquimod (IMQ)-induced psoriasis-like skin lesions in mice. Firstly, visual changes of psoriatic skin lesions were observed and the severity was recorded using psoriasis area and severity index (PASI) score. Histological changes were assessed by HE staining for epidermal thickness and Masson's staining for collagen fibers. Then, photographs of microvascular inside the skin were taken for macroscopic observation, and microscopic changes associated with angiogenesis were evaluated. Furthermore, expression of angiogenic factors were analyzed by ELISA, immunohistochemistry and immunofluorescence, separately. Lastly, the expression of VEGFR signaling-related proteins was detected by WB. Compared with control, IMQ drove a significant increment of epidermal thicknesses with higher PASI scores and more dermal collagen deposition. IMQ treatment led to abnormal keratinocyte proliferation, increased microvascular inside skin, growing production of angiogenesis-related factors, up-regulated expression of VEGFR1 and VEGFR2, and enhanced phosphorylation of p38. However, GEN significantly ameliorated the psoriatic skin lesions, the epidermal thickness, the formation of collagen fibers, and abnormal keratinocyte proliferation. Importantly, GEN inhibited angiogenesis, the production of angiogenic factors (VEGF-A, Ang-2, TNF-α, and IL-17A), and the proliferation of vascular endothelial cells. Simultaneously, GEN curbed the expression of VEGFR1, VEGFR2, p38, and P-p38 proteins involved in VEGFR signaling. Of note, the suppressive effect of GEN was reversed in the HUVECs with over-expressed VEGFR1 or VEGFR2 related to the cells without transfection. These findings suggest that VEGFR1 and VEGFR2 participate in the anti-angiogenesis of GEN in IMQ-induced psoriasis-like skin lesions in mice.

The skin circadian clock gene F3 as a potential marker for psoriasis severity and its bidirectional relationship with IL-17 signaling in keratinocytes.

OBJECTIVE: Psoriasis is an immune-mediated skin disease where the IL-17 signaling pathway plays a crucial role in its development. Chronic circadian rhythm disorder in psoriasis pathogenesis is gaining more attention. The relationship between IL and 17 signaling pathway and skin clock genes remains poorly understood. METHODS: GSE121212 with psoriatic lesion and healthy controls was used as the exploration cohort for searching analysis. Datasets GSE54456, GSE13355, GSE14905, GSE117239, GSE51440, and GSE137218 were applied to validation analysis. Single-cell RNA sequencing (scRNA-seq) dataset GSE173706 was used to explore the F3 expression and related pathway activities in single-cell levels. Through intersecting with high-expression DEGs, F3 was selected as the signature skin circadian gene in psoriasis for further investigation. Functional analyses, including correlation analyses, prediction of transcription factors, protein-protein interaction, and single gene GSEA to explore the potential roles of F3. ssGSEA algorithm was performed to uncover the immune-related characteristics of psoriasis. We further explored F3 expression in the specific cell population in scRNA-seq dataset, besides this, AUCell analysis was performed to explore the pathway activities and the results were further compared between the specific cell cluster. Immunohistochemistry experiment, RT-qPCR was used to validate the location and expression of F3, small interfering RNA (siRNA) transfection experiment in HaCaT, and transcriptome sequencing analysis were applied to explore the potential function of F3. RESULTS: F3 was significantly down-regulated in psoriasis and interacted with IL-17 signaling pathway. Low expression of F3 could upregulate the receptor of JAK-STAT signaling, thereby promoting keratinocyte inflammation. CONCLUSION: Our research revealed a bidirectional link between the skin circadian gene F3 and the IL-17 signaling pathway in psoriasis, suggesting that F3 may interact with the IL-17 pathway by activating JAK-STAT within keratinocytes and inducing abnormal intracellular inflammation.

Interferon-Alpha Induces Psoriatic Inflammation in Mice by Phosphorylating FOXO3.

Psoriasis is a chronic, immune-mediated inflammatory skin disease characterized by epidermal thickening and inflammatory cell infiltration. Excessive proliferation of keratinocytes and resistance to apoptosis lead to thickening of the epidermis. Plasmacytoid dendritic cells are involved in the occurrence of psoriasis mainly by secreting interferon-alpha (IFN-α). IFN-α is a glycoprotein with antiviral, antitumor, and immunomodulatory effects, but its role in psoriasis remains unclear. In this investigation, a mild psoriatic phenotype was observed in mice upon topical application of IFN-α cream, and the inflammation was exacerbated when combined with imiquimod (IMQ). Immunohistochemical analyses demonstrated that IFN-α induces psoriatic inflammation in mice by stimulating phosphorylation of forkhead box O3, consistent with the involvement of this protein in cell proliferation, apoptosis, and inflammation. Our results suggested that topical IFN-α caused psoriatic inflammation and that the psoriatic inflammation was exacerbated by the combination of IFN-α and IMQ, possibly due to the dysfunction of forkhead box O3.

Causal role of immune cells in psoriasis: a Mendelian randomization analysis.

Background: A growing body of evidence has shown that immune cells are linked to psoriasis. It is, however, still unclear if these associations reflect a relationship of cause and effect. Objective: We employed a two-sample Mendelian randomization (MR)-based study to elucidate the probable causative connection between immune cells and psoriasis. Methods: Summary information for psoriasis (Ncase = 5,427, Ncontrol = 479,171) was obtained from the European Bioinformatics Institute. Summarized statistical information on 731 immune cell features, including morphological parameters (MP; n = 32), relative cell number (n = 192), median fluorescence intensity (MFI) of surface antigens (n = 389), and absolute cell number (n = 118), was obtained from the genome-wide association studies (GWAS) catalog. The research consisted of forward MR analysis, in which immune cell traits were used as the exposure factor, and psoriasis was the outcome, as well as reverse MR analysis, in which psoriasis was used as the exposure factor, and immune cell traits were the outcome. We ran numerous sensitivity analyses to ascertain the study results for robustness, heterogeneity, and potential multiple-biological effects. Result: This research determined a probable causative connection between immune cells and psoriasis. In particular, we identified 36 distinct types of immune cells that are potentially causally linked to psoriasis. Conclusion: Our findings indicate strong causal correlations between 36 immunological phenotypes and psoriasis, thus, directing future clinical trials.

Double-negative T cells ameliorate psoriasis by selectively inhibiting IL-17A-producing γδlow T cells.

BACKGROUND: Psoriasis is a chronic immune-mediated skin condition. Although biologic treatments are effective in controlling psoriasis, some patients do not respond or lose response to these therapies. Thus, new strategies for psoriasis treatment are still urgently needed. Double-negative T cells (DNT) play a significant immunoregulatory role in autoimmune diseases. In this study, we aimed to evaluate the protective effect of DNT in psoriasis and explore the underlying mechanism. METHODS: We conducted a single adoptive transfer of DNT into an imiquimod (IMQ)-induced psoriasis mouse model through tail vein injection. The skin inflammation and IL-17A producing γδ T cells were evaluated. RESULTS: DNT administration significantly reduced the inflammatory response in mouse skin, characterized by decreased skin folds, scales, and red patches. After DNT treatment, the secretion of IL-17A by RORc+ γδlow T cells in the skin was selectively suppressed, resulting in an amelioration of skin inflammation. Transcriptomic data suggested heightened expression of NKG2D ligands in γδlow T cells within the mouse model of psoriasis induced by IMQ. When blocking the NKG2D ligand and NKG2D (expressed by DNT) interaction, the cytotoxic efficacy of DNT against RORc+IL17A+ γδlow T cells was attenuated. Using Ccr5-/- DNT for treatment yielded evidence that DNT migrates into inflamed skin tissue and fails to protect IMQ-induced skin lesions. CONCLUSIONS: DNT could migrate to inflamed skin tissue through CCR5, selectively inhibit IL-17-producing γδlow T cells and finally ameliorate mouse psoriasis. Our study provides feasibility for using immune cell therapy for the prevention and treatment of psoriasis in the clinic.

Unicentric Castleman's disease in the parotid gland associated with psoriasis: a case report.

BACKGROUND: Castleman's disease is a rare lymphoproliferative disorder that is often misdiagnosed because of its untypical clinical or imaging features except for a painless mass. Besides, it is also difficult to cure Castleman's disease due to its unclear pathogenesis. CASE PRESENTATION: We present a Castleman's disease case with diagnostic significance regarding a 54-year-old Chinese male who has a painless mass in his left parotid gland for 18 months with a 30-years history of autoimmune disease psoriasis. Computed tomography scan showed a high-density nodule with clear boundaries in the left parotid and multiple enlarged lymph nodes in the left submandibular and neck region. General checkup, the extremely elevated serum interleukin-6 and lymph node biopsy in the left submandibular region gave us an initial suspicion of Castleman's disease. Then the patient underwent a left superficial parotidectomy. Based on histopathologic analysis, we made a certain diagnosis of Castleman's disease and gave corresponding treatments. In 18 months of follow-up, the patient showed no evidence of recurrence, with the level of serum interleukin-6 decreased. CONCLUSIONS: Clinicians should be aware of the possibility of Castleman's disease when faced with masses or enlarged lymph nodes in the parotid gland to avoid misdiagnosis, especially in patients with autoimmune diseases and elevated serum interleukin-6.

Comparison of dermoscopic characteristics on toenail onychomycosis in psoriatic and non-psoriatic patients: A prospective study.

BACKGROUND: Psoriatic patients may experience the coexistence of onychomycosis (OM). However, the evaluation of OM in psoriatics has been hindered by potential clinical differences from OM in non-psoriatics. OBJECTIVE: To assess and compare dermoscopic features between toenail OM in psoriatic and in non-psoriatic patients. PATIENTS AND METHODS: Between September 2020 and September 2023, dermoscopy was conducted on 183 affected toenails by OM in psoriatics and 232 affected toenails by OM in non-psoriatics in two centres. The dermoscopic characteristics were compared using the Chi-squared test. RESULTS: Among toenail OM cases in psoriatic subjects, the most prevalent dermoscopic features included pitting (147/183, 80.33%) and subungual hyperkeratosis (118/183, 64.48%). Conversely, toenail OM in non-psoriatics was characterized by subungual hyperkeratosis (175/232, 75.43%) and nail spikes (139/232, 59.91%). Comparative analysis revealed a significantly higher occurrence of pitting (80.33% vs. 15.96%, p < .001), periungual telangiectasis (22.40% vs. 4.74%, p < .001), oil patches (12.57% vs. 0.43%,p < .001) and transverse grooves (43.72% vs. 28.45%,p < .01) in toenail OM in psoriatics. Furthermore, toenail OM in psoriatics exhibited a significantly lower frequency of yellow structureless area (13.11% vs. 42.67%, p < .001), nail spikes (43.17% vs. 59.91%, p < .01), ruin appearance of sulphur nugget (8.20% vs. 31.03%, p < .001), dotted/blocky haemorrhage (6.01% vs. 20.69%,p < .001) and partial onycholysis (32.79% vs. 46.98%, p < .01). CONCLUSIONS: Dermoscopic features of toenail OM in psoriatic and non-psoriatic patients exhibit notable differences. OM in psoriatics shows a higher frequency of pitting and periungual telangiectasis, while a lower frequency of yellow structureless areas and nail spikes under dermoscopy.

Adalimumab in the management of psoriasis and psoriatic arthritis: Results from a Delphi investigation.

Background and Objectives: Psoriasis (PsO) and psoriatic arthritis (PsA) are often undertreated and require a multidisciplinary approach. In recent years, patent expiration has allowed the introduction of tumor necrosis factor inhibitor (anti-TNF) biosimilars, which have stimulated a significant increase in the use of biological therapies. This article reports the findings of a multidisciplinary approach to achieve a consensus on the use of adalimumab in patients with PsO or PsA. Methods: A voting panel of 36 Italian dermatologists and rheumatologists were chosen by eight Italian clinicians (the Board), to provide a consensus on the real-world management of PsO and PsA with adalimumab using the Delphi Method, comprising three survey rounds. Twelve statements were defined by the Board and submitted to the panel (rating scale 1-7). Results: Clinicians reached a wide consensus on the effectiveness (score 6-7: 67%) and long-term efficacy (6-7: 100%) of adalimumab in all clinical forms of PsO and PsA, including pediatric patients (6-7: 85%). Considering cost-effectiveness and safety, adalimumab is suggested as a first-line treatment in patients with enthesitis, predominant peripheral arthritis, axial involvement or associated inflammatory bowel disease (IBD) or uveitis. Adalimumab can be also considered after failure of etanercept (6-7: 94%). Conclusion: Results from this Delphi study clearly show an overall consensus on the use of adalimumab in the management of PsO and PsA, particularly as first-choice for specific subpopulations (uveitis, IBD, hidradenitis suppurativa). Considering the cost-effectiveness of biosimilars within Italy, adalimumab may represent an effective and safe first-line treatment for patients with moderate-to-severe PsO or PsA, and a valid choice for switching after failure.

Quality of Life in Psoriasis: A Cross-Sectional Study from North India.

Background: Psoriasis is a chronic inflammatory papulo-squamous disease characterized by multiple remissions and relapses. This study aimed to assess the impact of psoriasis on the quality of life of patients. Materials and Methods: A hospital-based, cross-sectional study was conducted enrolling 198 adult patients of psoriasis. The STROBE (Strengthening the Reporting of Observational Studies in Epidemiology) guidelines for observational studies were followed. Clinical severity of psoriasis was measured using Psoriasis Area Severity Index (PASI), and quality of life was measured by EuroQoL 5D (EQ-5D-5L, EQ-VAS) and Psoriasis Quality-Of-Life-12 (PQOL-12) Questionniares. Results: Of the 198 patients, 71.7% (n = 142/198) were males with a mean age of 41.65 ± 13.19 years. The mean PASI score was 12.46 ± 11.51, and the mean PQOL-12 score was 50.18 ± 23.36. Up to 22.7% (n = 45) cases had 'severe' and 6.1% (n = 12) cases has 'very severe' PQOL-12 scores. Statistically significant correlation (P < 0.05) was observed between PASI scores and almost all domains of EQ-5D-5L and PQOL-12. Conclusion: Psoriasis affects most psycho-social domains of a patient's life. Coping with these QOL issues remains a challenge to the patients in everyday life. The goal of management of psoriasis therefore must include measures to improve quality of life along with long-lasting remittance of physical symptoms.

New-insight UVB Treatment for Psoriasis Vulgaris in Vietnamese Patients.

Background: Narrowband UVB (NBUVB) has recently been used in Vietnam for the treatment of psoriasis. However, there are no data on Vietnamese patients to adopt a uniform national protocol. Objectives: This study aimed to establish an optimal NBUVB therapy for the treatment of psoriasis in Vietnamese patients. Materials and Methods: One hundred and twenty-two patients with psoriasis vulgaris were included. They were randomly allocated to two groups: the percentage dose (group 1, 62 patients) and the fixed dose (group 2, 60 patients). In group 1, the starting dose was 50% of the minimal erythema dose (MED) and the 10% increment dose adjusted in the next sessions. In group 2, the starting dose was based on Fitzpatrick skin types (fixed dose). Psoriasis area and severity index (PASI) was used to evaluate efficacy. Results: More than 68% of the patients get PASI75 at session 36. Group 2 had significantly fewer sessions (20 ± 5 vs 25 ± 7, P- value = 0.0004) and lower cumulative dose than group 1 (14.1 ± 4.3 J/cm2 vs 18.0 ± 8.0 J/cm2, P- value = 0.0075) to achieve PASI75. Adverse effects were more common in group 2 than group 1, including burning sensation/erythema (43.33% vs 14.52%, P- value = 0.0009) and pruritus (75.00% vs 22.58%, P- value <0.0001). Conclusion: NBUVB therapy was safe and effective for Vietnamese psoriasis patients. Fixed doses produced a quicker clinical response with fewer sessions and lower cumulative doses. Adverse effects were mild in both groups and less noted for the MED-based dose. For the recommendation, a fixed dose should be applied for patients who have less concern about side effects, while a MED-based dose can be suitable for patients having conditions related to light sensitivity.

Natural Treatment Options for Nail Disorders.

The growing demand for natural treatments has raised concerns among clinicians due to limited scientific evidence supporting their use. This review article addresses the issue by assisting dermatologists and general practitioners in recommending natural treatments for the following common nail disorders: nail brittleness, onychomycosis, periungual verrucae, paronychia, chloronychia, nail psoriasis, nail lichen planus, onychocryptosis, onycholysis, and congenital malalignment of the great toenail. One limitation is the scarcity of existing reviews on natural treatment options for nail disorders in the literature. Through a comprehensive review of existing literature, this article consolidates the available evidence on natural treatment options for these conditions. Although some natural treatments for nail disorders are supported by scientific evidence, the indiscriminate use of such remedies may lead to severe poisoning and health problems. Given the widespread and increasing use of natural treatments, clinicians play a pivotal role in educating patients about evidence-based remedies and debunking misleading claims. By doing so, clinicians can enhance patient safety and improve treatment outcomes. It is essential for healthcare professionals to be well-informed and equipped with the knowledge to differentiate between effective natural treatments and unverified claims, ensuring that patients receive appropriate care.

Ablative CO2-Assisted Laser for Topical Drug Delivery in Nail Psoriasis: A Systematic Review.

Background: Nail psoriasis poses challenges for effective treatment, and topical drug delivery through the nail plate is limited. A novel approach to address this challenge involves the use of ablative fractional laser as a pretreatment strategy to enhance topical drug delivery for nail psoriasis. Summary: This systematic review, conducted in accordance with PRISMA guidelines, involved an extensive literature search across PubMed/MEDLINE, EMBASE, and the Cochrane Library up to July 2023. The primary focus was on exploring studies that investigated the application of ablative laser technology to augment drug delivery for nail psoriasis. Key Messages: (1) The review included seven randomized controlled trials, all examining the combination of fractional CO2 laser with topical treatments. These trials demonstrated varying degrees of improvement in nail psoriasis. (2) Patients undergoing laser treatment reported experiencing moderate levels of pain, effectively managed through the application of topical anesthesia. (3) Commonly observed side effects included erythema, swelling, and crusting, with the Koebner phenomenon being a rare occurrence. (4) Notably, patient satisfaction levels with the combined approach of laser and topical treatments were consistently high. In conclusion, the utilization of ablative CO2-assisted laser pretreatment, when used in conjunction with topical therapy, appears to be both effective and well-tolerated for the treatment of nail psoriasis. However, the establishment of optimal parameters and treatment intervals for fractional laser therapy remains an area for further research. Standardized studies are imperative to identify the most effective strategy for enhancing topical drug delivery in the context of nail psoriasis treatment.

Improvements in Psoriasis-Related Work Productivity with Tildrakizumab: Results from a Phase 4 Real-World Study in Patients with Moderate-to-Severe Plaque Psoriasis.

INTRODUCTION: Plaque psoriasis is a chronic condition that may impact patients' work productivity. Tildrakizumab, an interleukin-23 p19 inhibitor, is approved for treatment of moderate-to-severe plaque psoriasis in adults. However, the effect of tildrakizumab treatment on work productivity in patients with psoriasis is not well characterized. METHODS: In this multicenter, open-label, uncontrolled phase 4 study (NCT03718299), patients with moderate-to-severe plaque psoriasis received tildrakizumab 100 mg at week 0, week 4, and every 12 weeks thereafter through week 52. Patients completed the Work Productivity and Activity Impairment Questionnaire: Psoriasis (WPAI:PSO) at baseline and every 12 weeks from week 16 through week 64. The following four domains of the WPAI:PSO were examined: absenteeism (percentage of time missed from work due to psoriasis), presenteeism (percentage reduction of productivity while at work due to psoriasis), total activity impairment (percentage impairment in activities other than work due to psoriasis), and total work productivity impairment (total percentage of work impairment from both absenteeism and presenteeism due to psoriasis). Missing data were not imputed. RESULTS: Of the 55 patients enrolled, 31 patients completed all domains of the WPAI:PSO at week 64. From baseline to week 64, respectively, mean ± standard deviation (SD) scores improved for presenteeism (20.5 ± 21.7 to 2.6 ± 5.8; P < 0.001), total activity impairment (29.5 ± 26.6 to 4.4 ± 9.4; P < 0.001), and total work productivity impairment (20.9 ± 22.2 to 2.6 ± 5.8; P < 0.001). The mean ± SD score for absenteeism decreased from 1.1 ± 5.7 at baseline to 0.0 ± 0.0 at week 64, but this change was not statistically significant. CONCLUSION: Tildrakizumab treatment mitigated work productivity loss due to psoriasis as measured by the presenteeism, total activity impairment, and total work productivity impairment domains of the WPAI:PSO. TRIAL REGISTRATION: ClinicalTrials.gov identifier, NCT03718299.

Disruption of Post-thymic tolerance in Skin-Reactive TCR Transgenic Mice through the Interaction of Lymphopenia and Intestinal Microbiota.

Autoimmune diseases often arise from conditions where the immune system is compromised. While lymphopenia-induced proliferation (LIP) is crucial for immune system development and maturation, it is also caused by environmental insult, such as infection and becomes a risk factor for autoimmunity in adults. We used Dsg3H1 TCR Transgenic mice, whose T cells are designed to recognize desmogrein-3, a skin antigen, to explore the impact of lymphopenia on post-thymic tolerance. Dsg3H1 mice are known to delete the most highly autoreactive T cells in thymus, and develop only subtle immune-mediated pathology in a steady state. However, we found that a transient lymphopenia by total body irradiation or cyclophosphamide, results in massive dermatitis in Dsg3H1 mice. The symptoms included expansion and development of self-reactive T cells, their differentiation into CD44 high IL-17 producing helper T cells, and severe neutrophilic inflammation. Repopulation of FOXP3+ T regulatory cells after lymphopenia normally occurred, suggesting escape of skin-reactive conventional T cells from control by regulatory T cell. Furthermore, we found that a depletion of the intestinal microbiota by antibiotics prevents the cyclophosphamide induced dermatitis, indicating roles of commensal intestinal microbiota in LIP and Th17 development in vivo. The current data suggested that post thymic tolerance of Dsg3H1 mice is established on a fragile balance in lymphoreplete immune environment and broken by interplay between lymphopenia and intestinal microbiota. The dynamic phenotypes observed in Dsg3H1 mice prompts a reevaluation of opportunistic lymphopenia together with microbiota as pivotal environmental factors, impacting individuals with genetic predispositions of autoimmune diseases.

Modeling pulsed dye laser treatment of psoriatic plaques by combining numerical methods and image-derived lesion morphologies.

OBJECTIVES: Knowledge of the physical effects of pulsed dye laser (PDL) treatment of psoriatic lesions is essential in unraveling the remedial mechanisms of this treatment and hence also in maximizing in its disease-modifying potential. Therefore, the main objective of this study was to provide estimates of these physical effects (for laser wavelengths of 585 and 595 nm), with the aim of identifying pathogenic processes that may be affected by these conditions. METHODS: We modeled the laser light propagation and subsequent photothermal heating by numerically solving the transient diffusion and heat equations simultaneously. To this end, we used the finite element method in conjunction with an image-derived psoriatic lesion morphology (which was defined by segmenting blood vessels from a confocal microscopy image of a fluorescently labeled section of a 3 mm punch biopsy of a psoriatic lesion). The resulting predictions of the generated temperature field within the lesion were then used to assess the possibility of stalling or arresting some suspected pathogenic processes. RESULTS: According to our results, it is conceivable that perivascular nerves are thermally denatured, as almost all locations that reach 60°C were found to be within 18 µm (at 585 nm) and 11 µm (at 595 nm) of a blood vessel wall. Furthermore, activation of TRPV1 and TRPV2 channels in perivascular neuronal and immune cells is highly likely, since a critical temperature of 43°C is generated at locations within up to 350 µm of a vessel wall (at both wavelengths) and sustained for up to 700 ms (at 585 nm) and 40 ms (at 595 nm), while a critical temperature of 52°C is reached by locations within 80 µm (at 585 nm) and 30 µm (at 595 nm) of a vessel wall and sustained for up to 100 ms (at 585 nm) and 30 ms (at 595 nm). Finally, we found that the blood vessel coagulation-inducing temperature of 70°C is sustained in the vascular epithelium for up to 19 and 5 ms at 585 and 595 nm, respectively, rendering partial or total loss of vascular functionality a distinct possibility. CONCLUSIONS: The presented approach constitutes a useful tool to provide realistic estimates of the photothermal effects of PDL treatment of psoriatic plaques (as well as other selective photothermolysis-based treatments), yielding information that is essential in guiding future experimental studies toward unraveling the remedial mechanisms of these treatments.

The immunological understanding on germinal center B cells in psoriasis.

The development of psoriasis is mainly driven by the dysregulation of T cells within the skin, marking a primary involvement of these cells in the pathogenesis. Although B cells are integral components of the immune system, their role in the initiation and progression of psoriasis is not as pivotal as that of T cells. The paradox of B cell suggests that, while it is crucial for adaptive immunity, B cells may contribute to the exacerbation of psoriasis. Numerous ideas proposed that there are potential relationships between psoriasis and B cells especially within germinal centers (GCs). Recent research projected that B cells might be triggered by autoantigens which then induced molecular mimicry to alter B cells activity within GC and generate autoantibodies and pro-inflammatory cytokines, form ectopic GC, and dysregulate the proliferation of keratinocytes. Hence, in this review, we gathered potential evidence indicating the participation of B cells in psoriasis within the context of GC, aiming to enhance our comprehension and advance treatment strategies for psoriasis thus inviting many new researchers to investigate this issue.