Aetiology and pathogenesis of psoriasis

Protein adducts with lipid peroxidation products in patients with psoriasis

Psoriasis, one of the most frequent immune-mediated skin diseases, is manifested by numerous psoriatic lessons on the skin caused by excessive proliferation and keratinization of epidermal cells. These disorders of keratinocyte metabolism are caused by a pathological interaction with the cells of the immune system, including lymphocytes, which in psoriasis are also responsible for systemic inflammation. This is accompanied by oxidative stress, which promotes the formation of lipid peroxidation products, including reactive aldehydes and isoprostanes, which are additional pro-inflammatory signaling molecules. Therefore, the presented review is focused on highlighting changes that occur during psoriasis development at the level of lipid peroxidation products, including 4-hydroxynonenal, 4-oxononenal, malondialdehyde, and acrolein, and their influence on protein structures. Furthermore, we will examine inducing agents of cellular functioning, as well as intercellular signaling. These lipid peroxidation products can form adducts with a variety of proteins with different functions in the body, including proteins within skin cells and cells of the immune system. This is especially true in autoimmune diseases such as psoriasis. For example, these changes concern proteins involved in maintaining redox homeostasis or pro-inflammatory signaling. Therefore, the formation of such adducts should attract attention, especially during the design of preventive cosmetics or anti-psoriasis therapies.

Single-Cell RNA Sequencing Reveals the Immune Cell Profiling in IMQ Induced Psoriasis-Like Model

PURPOSE

Psoriasis is a chronic systemic inflammatory skin disease with a high recurrence rate. The immune response plays an important role in psoriasis. However, the subsets of immune cells involved in inflammation in psoriatic mice have not been fully studied. This study showed the immune environment characteristics of psoriasis in mice.

METHODS

We used single-cell RNA sequencing (10× Genomics) as an unbiased analytical strategy to investigate the heterogeneity of skin immune cells in imiquimod-induced psoriasis mice systematically.

RESULTS

We identified 10 major clusters and their marker genes among 14,439 cells. The proportions of macrophages, NK/T cells, conventional dendritic cells (cDCs) and plasmacytoid dendritic cells (pDCs) were increased in psoriatic mice. Macrophages were the largest group and were further divided into 7 subgroups, and all macrophage clusters were increased in psoriatic mice. Differentially expressed genes in control versus psoriatic mice skin lesions showed that Fcgr4, Saa3 and Acp5 in macrophages, Acp5, Fcgr4 and Ms4a6d in NK/T cells, Saa3 in cDCs, and Ifitm1 in pDCs were upregulated in psoriasis mice. Kyoto Encyclopedia of Genes and Genomes (KEGG) signaling pathway enrichment analysis emphasized the role of oxidative phosphorylation signals and antigen processing and presentation signals in murine psoriasis-like models.

CONCLUSION

Our study reveals the immune environment characteristics of the commonly used IMQ induced psoriasis-like models and provides a systematic insight into the immune response of mice with psoriasis, which is conducive to comparing the similarities and differences between the mouse model and human psoriasis.

Analytical approaches to assess metabolic changes in psoriasis

Psoriasis is one of the most common human skin diseases, although its development is not limited to one tissue, but is associated with autoimmune reactions throughout the body. Overproduction of pro-inflammatory cytokines and growth factors systemically stimulates the proliferation of skin cells, which manifests as excessive exfoliation of the epidermis, and/or arthritis, as well as other comorbidities such as insulin resistance, metabolic syndrome, hypertension, and depression. Thus, there is a great need for a thorough analysis of the pathophysiology of psoriatic patients, including classical methods, such as spectrophotometry, chromatography, or Western blot, and also novel omics approaches such as lipidomics and proteomics. Moreover, the extensive pathophysiology forces increased research examining biological changes in both skin cells, and systemically. A wide range of techniques involved in lipidomic research based on a combination of mass spectrometry and different types of chromatography (RP-LC-QTOF-MS/MS, HILIC-QTOF-MS/MS or RP-LC-QTRAP-MS/MS), have allowed comprehensive assessment of lipid modification in psoriatic skin and provided new insight into the role of lipids and their mechanism of action in psoriasis. Moreover, proteomic analysis using gel-nanoLC-OrbiTrap-MS/MS, as well as MALDI-TOF/TOF techniques facilitates the description of panels of enzymes involved in lipidome modifications, and the response of the endocannabinoid system to metabolic changes. Psoriasis is known to alter the expression of proteins that are involved in the inflammatory and antioxidant response, as well as protein biosynthesis, degradation, as well as cell proliferation and apoptosis. Knowledge of changes in the lipidomic and proteomic profile will not only allow the understanding of psoriasis pathophysiology, but also facilitate proper and early diagnosis and effective pharmacotherapy.

Anti-psoriatic and anti-inflammatory effects of Kaempferia parviflora in keratinocytes and macrophage cells

Kaempferia parviflora (KP) has been used as folk medicine for curing various conditions, including anti-inflammatory diseases. However, anti-psoriatic effects in an aspect of suppression of NF-κB activation have not been explored. Therefore, our current study aimed to elucidate the anti-inflammation of KP in lipopolysaccharide (LPS)-induced RAW264.7 cells and anti-psoriatic effects of KP in cytokine-induced human keratinocytes, HaCaT cells. We discovered that KP extract significantly suppressed LPS-induced inflammation at both gene expression and protein production. Specifically, dramatic reduction of nitric oxide (NO) was explored by using Griess method. Consistently, data from RT-qPCR, ELISA, and western blot analysis confirmed that crucial inflammatory and psoriatic markers including inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), tumor necrosis factor (TNF)-α, interleukin (IL)-1, IL-6, IL-17, IL-22, and IL-23 were significantly decreased by the action of KP. These events were associated with the results from immunofluorescence study and western blot analysis where the activation of NF-κB upon LPS stimulation was clearly inhibited by KP through its ability to suppress IκB-α degradation resulting in inhibition of NF-κB nuclear translocation. Furthermore, KP extract significantly inhibited LPS-stimulated phosphorylation of ERK1/2, JNK, and p38 in a dose-dependent manner, along with inhibition of ERK1/2 activation in both TNF-α- and EGF-induced HaCaT cells. Interestingly, HaCaT cells exposed to 15 μg/mL of KP also exhibited significant decrease of cell migration and proliferation. Our results revealed that KP extract has a potential to be developed as a promising agent for treating inflammation and psoriasis, in part through targeting the proliferation and the NF-κB pathways.

Serum galectin-3 levels in patients with psoriasis

INTRODUCTION

Galectin-3 is a β-galactoside-binding lectin associated with cellular proliferation, inflammation and angiogenesis, which are the major characteristics of psoriatic skin.

OBJECTIVES

To investigate serum galectin-3 levels in psoriasis patients compared with healthy controls and to study its relationship with disease characteristics.

METHODS

Seventy-eight patients diagnosed with psoriasis and 78 age- and sex-matched healthy volunteers were included in the study. Serum galectin-3, IL-17, IL-6 and TNF-α levels were measured using Enzyme-linked immunosorbent assay (ELISA).

RESULTS

Serum Galectin-3, IL-17, IL-6 and TNF-α levels were significantly higher in psoriasis patients compared with control group (P < .001, P = .003, P < .001 and P < .001, respectively). A cut-off value of 10 ng/mL for galectin-3 was set after receiver operating characteristic analysis. A serum galectin-3 level >10 ng/mL increased the risk of psoriasis by 14.5 times (95% CI: 6.6-32.3, P < .001) and a serum galectin-3 level >10 ng/mL predicted psoriasis with 83.3% sensitivity and 74.3% specificity. No statistically significant association was observed between serum galectin-3 concentrations and disease characteristics including disease severity, presence of psoriatic arthritis, nail involvement and psoriatic comorbidity. No statistically significant correlation was observed between serum galectin-3 level and serum IL-17, IL-6 and TNF-α levels (all three P values > .05).

CONCLUSIONS

Elevated serum galectin-3 levels in psoriasis patients may indicate a possible role of galectin-3 in pathogenesis of psoriasis.

Healthcare utilization and costs among patients with psoriasis and psoriatic arthritis in the USA-a retrospective study of claims data from 2009 to 2020

OBJECTIVES

To compare healthcare resource utilization and costs among patients with psoriasis, psoriatic arthritis (PsA), and a control group of patients without psoriasis and PsA in the USA.

METHODS

The IBM® MarketScan® Commercial Database was used to identify three adult patient groups from 1/1/2009 through 4/30/2020: (1) Psoriasis: ≥ 2 diagnoses ≥ 30 days apart for psoriasis (no PsA diagnoses); (2) PsA: ≥ 2 diagnoses for PsA; (3) Control: no psoriasis or PsA diagnoses in their entire claims records. Patients with comorbid rheumatoid arthritis, ankylosing spondylitis, Crohn's disease, or ulcerative colitis were excluded from the analyses. Controls were matched 1:1 to psoriasis and PsA patients based on age, gender, index year, and number of non-rheumatological comorbidities. Healthcare resource utilization and costs (in 2019 USD) were evaluated descriptively and through mixed models for five years of follow-up.

RESULTS

A total of 142,531 psoriasis and 21,428 PsA patients were matched to the control group (N = 163,959). Annual all-cause healthcare costs per patient were $7,470, $11,062, and $29,742 for the control, psoriasis, and PsA groups, respectively. All-cause healthcare costs increased over time and were significantly greater among PsA vs. psoriasis (p < 0.0001) and the control groups (p < 0.0001). Across all categories of healthcare resources, utilization was greatest among patients with PsA and lowest in the control group.

CONCLUSION

Annual healthcare costs and resource utilization were significantly higher with PsA compared with psoriasis and the control group, confirming the substantial economic burden of PsA. The cost disparity between these patient groups highlights a continued unmet medical need. Key Points • Patients with PsA incurred significantly greater healthcare resource utilization and costs than patients with psoriasis and patients without psoriasis and PsA. • Significantly greater costs and healthcare resource utilization were also observed among patients with psoriasis compared with patients without psoriasis and PsA.

miR-183-3p suppresses proliferation and migration of keratinocyte in psoriasis by inhibiting GAB1

Background

MicroRNAs (miRNAs) target genes involved in the hyperproliferation of keratinocytes or immune dysfunction of psoriasis. This study prospectively determined the involvement of miR-183-3p in the pathogenesis of psoriasis.

Methods

Differentially expressed miR-183-3p between psoriatic lesional and non-lesional skin were determined by quantitative RT-PCR and in situ hybridization (ISH). CCK8 and wound healing assays were performed to assess cell viability and migration of human keratinocyte cell line (HaCaT). The target of miR-183-3p was validated by luciferase activity assay.

Results

Lower miR-183-3p expression was observed in psoriatic lesional skin compared to psoriatic non-lesional skin. MiR-183-3p over-expression inhibited the viability and migration of HaCaT cells, while inhibition of miR-183-3p promoted the viability and migration of HaCaT cells. Moreover, miR-183-3p could bind to the 3′ UTR of GAB1 (growth factor receptor binding 2-associated binding protein 1) and decrease the mRNA and protein expression of GAB1 in HaCaT cells. In addition, higher GAB1 expression was observed in psoriatic lesional skin than psoriatic non-lesional skin.

Conclusion

MiR-183-3p exhibited inhibition property in the proliferation and migration of HaCaT cells via down-regulation of GAB1, suggesting the potential therapeutic strategy for psoriasis.

Management of psoriasis with nutraceuticals: An update

Psoriasis is a chronic skin disorder that speeds up the life cycle of skin cells, typically on the surface of the skin. Additional skin cells form thick scales and red fixes which are awfully itchy and sometimes painful. Although there are many therapeutic systems available to get symptomatic relief, unfortunately replete cure for psoriasis is not yet reported. Moreover, poor treatment outcomes as well as high toxicity profile of drugs makes these therapies more inconvenient to treat psoriasis. In search of alternative and complementary therapy for this disease, the focus has been shifted to nutraceuticals, few of them were reported since ages. It includes vitamins, herbal extracts, phytochemicals and dietary supplements. In this review, the attempt has been made to highlight key nutraceuticals for better management of psoriasis. Supplementation of appropriate nutraceutical may improve the quality of patient's life and have positive impact on overall state of disease.

Risk and predictors of psoriasis in patients with breast cancer: a Swedish population-based cohort study

BACKGROUND

The risk of psoriasis in patients with breast cancer is largely unknown, as available evidence is limited to case findings. We systematically examined the incidence and risk factors of psoriasis in patients with breast cancer.

METHODS

A Swedish nationwide cohort of 56,235 breast cancer patients (2001-2012) was compared to 280,854 matched reference individuals from the general population to estimate the incidence and hazard ratio (HR) of new-onset psoriasis. We also calculated HRs for psoriasis according to treatment, genetic, and lifestyle factors in a regional cohort of 8987 patients.

RESULTS

In the nationwide cohort, 599 patients with breast cancer were diagnosed with psoriasis during a median follow-up of 5.1 years compared to 2795 cases in the matched reference individuals. This corresponded to an incidence rate of 1.9/1000 person-years in breast cancer patients vs. 1.7/1000 person-years in matched reference individuals. Breast cancer patients were at an increased risk of psoriasis (HR = 1.17; 95% confidence interval (CI) = 1.07-1.28), especially its most common subtype (psoriasis vulgaris; HR = 1.33; 95% CI = 1.17-1.52). The risk of psoriasis vulgaris was highest shortly after diagnosis but remained increased up to 12 years. Treatment-specific analyses indicated a higher risk of psoriasis in patients treated with radiotherapy (HR = 2.44; 95% CI = 1.44-4.12) and mastectomy (HR = 1.54, 95% CI = 1.03-2.31). Apart from treatment-specific effects, we identified genetic predisposition, obesity, and smoking as independent risk factors for psoriasis in breast cancer patients.

CONCLUSIONS

The incidence of psoriasis is slightly elevated among patients with breast cancer, with treatment, lifestyle, and genetic factors defining the individual risk profile.

The Role of Interleukin-1 in Inflammatory and Malignant Human Skin Diseases and the Rationale for Targeting Interleukin-1 Alpha

Inflammation plays a major role in the induction and progression of several skin diseases. Overexpression of the major epidermal proinflammatory cytokines interleukin (IL) 1 alpha (IL-1α) and 1 beta (IL-1β) is positively correlated with symptom exacerbation and disease progression in psoriasis, atopic dermatitis, neutrophilic dermatoses, skin phototoxicity, and skin cancer. IL-1β and the interleukin-1 receptor I (IL-1RI) have been used as a therapeutic target for some autoinflammatory skin diseases; yet, their system-wide effects limit their clinical usage. Based on the local effects of extracellular IL-1α and its precursor, pro-IL-1α, we hypothesize that this isoform is a promising drug target for the treatment and prevention of many skin diseases. This review provides an overview on IL-1α and IL-β functions, and their contribution to inflammatory and malignant skin diseases. We also discuss the current treatment regimens, and ongoing clinical trials, demonstrating the potential of targeting IL-1α, and not IL-1β, as a more effective strategy to prevent or treat the onset and progression of various skin diseases.

Management of Psoriasis Vulgaris with Methotrexate 0.25% in a Hydrophilic Gel: A Placebo-Controlled, Double-Blind Study

Background:

Methotrexate has been used as one of the first and systemic therapies for psoriasis. In general, 70% of patients with psoriasis prefer topical therapy as the treatment of choice.

Objective:

The purpose of this placebo-controlled double-blind study was to evaluate the clinical efficacy and tolerability of methotrexate 0.25% incorporated in a hydrophilic gel (hydroxyethylcellulose 1%) to treat patients afflicted with psoriasis vulgaris.

Methods:

Sixty patients (37M/23F) ranging between 18 and 70 years of age, with slight to moderate chronic plaque-type psoriasis and PASI (Psoriasis Area and Severity Index) scores between 5.3 and 17.5 joined the study. The mean duration of the disease at entry was 9.6 years (range 1–24 years). The diagnosis of psoriasis was established by clinical and histopathologic methods. Patients were sequentially randomized into two parallel groups. Each patient was allocated a precoded 100-g tube (active or placebo) with instructions on how to self-administer the trial medication topically (without occlusion) to their lesions two times daily for 5 consecutive days per week. The study lasted for 12 weeks with 4 weeks of active treatment. Patients were examined on a weekly basis and those showing total clearing or remission of lesions were considered effectively treated.

Results:

By the end of the treatment, breaking the code disclosed that methotrexate 0.25% gel had significantly treated more patients than placebo (83.3% vs. 6.7%; p < 0.0001), reduced the PASI score to a mean of 2.2, and cleared more plaques (82.2% vs. 4.3%; p < 0.0001). Laboratory evaluations, including CBC with differential and platelet count, renal function, liver chemistry [SGOT (aspartate transaminase) and SGPT (alanine transaminase)], and serum creatinine, were within the normal limits. The treatment was well-tolerated by all the patients, with no adverse drug-related symptoms and no dropouts. The study was followed up for 12 months from the first day of the treatment; two cured patients had relapsed after 8 months.

Conclusion:

The findings of this study demonstrate that methotrexate 0.25% in a hydrophilic gel is well tolerated and significantly more effective than placebo as a patient-applied topical medication to treat psoriasis vulgaris.

Reactive oxygen species in psoriasis and psoriasis arthritis: relevance to human disease

Psoriasis (Ps) is a chronic, immune-mediated, skin inflammatory disease affecting up to 3% of the population worldwide. Different environmental triggers initiate this complex multifactorial syndrome. Many individuals affected by Ps (6-26%) develop inflammatory disease in other organs, often in the joints as in psoriasis arthritis (PsA). Animal models that reflect the typical Ps syndrome, including both skin and joint pathology as in Ps and PsA, are valuable tools for dissecting disease pathways leading to clinical manifestations. In this context, we developed a new acute Ps and PsA-like disease model that appears after exposure to Saccharomyces cerevisiae mannan in certain mouse strains. The disease was found to be triggered by mannan-activated macrophages, leading to the activation of a pathogenic interleukin-17 pathway involving innate lymphocytes. Interestingly, the production of reactive oxygen species protected the mice from the triggering of this pathway and ameliorated Ps and PsA development.

The IL-20 subfamily of cytokines--from host defence to tissue homeostasis

The interleukin-20 (IL-20) subfamily of cytokines comprises IL-19, IL-20, IL-22, IL-24 and IL-26. These cytokines are all members of the larger IL-10 family, but have been grouped together to form the IL-20 subfamily based on their usage of common receptor subunits and similarities in their target-cell profiles and biological functions. Members of the IL-20 subfamily facilitate the communication between leukocytes and epithelial cells, thereby enhancing innate defence mechanisms and tissue repair processes at epithelial surfaces. In this Review, we describe the cellular sources and targets of the IL-20 subfamily cytokines, and we detail how their expression is regulated. Much of our understanding of the unique biology of this group of cytokines is still based on IL-22, which is the most studied member of the IL-20 subfamily. Nevertheless, we attempt a broader discussion of the emerging functions of IL-20 subfamily cytokines in host defence, inflammatory diseases, cancer and metabolism.

Antipsoriatic activity and cytotoxicity of ethanolic extract of Nigella sativa seeds

Background:

Nigella sativa Linn (Ranunculaceae) is popularly known as black cumin with a wide spectrum of pharmacological activities including anti-inflammatory, antibacterial, antifungal and antihelmenthic. The seeds are externally applied for eruptions of skin. The seeds are used traditionally for psoriasis tropicus with general pain and eruption of patches.

Objective:

The ethanolic extract of Nigella sativa seeds were evaluated for antipsoriatic activity.

Materials and Methods:

The screening of antipsoriatic activity of 95% of ethanolic extract of Nigella sativa seeds by using mouse tail model for psoriasis and in vitro antipsoriatic activity was carried out by SRB Assay using HaCaT human keratinocyte cell lines.

Results:

The ethanolic extract of Nigella sativa seeds extract produced a significant epidermal differentiation, from its degree of orthokeratosis (71.36±2.64) when compared to the negative control (17.30±4.09%). This was equivalent to the effect of the standard positive control, tazarotene (0.1%) gel, which showed a (90.03±2.00%) degree of orthokeratosis. The 95% ethanolic extract of Nigella sativa shown IC50 239 μg/ml, with good antiproliferant activity compared to Asiaticoside as positive control which showed potent activity with IC50 value of 20.13 μg/ml.

Conclusion:

The ethanolic extract of Nigella sativa seeds also showed increase in relative epidermal thickness when compared to control group by confirming its traditional use in psoriasis treatment.

Psoriasis

Psoriasis is a common relapsing and remitting immune-mediated inflammatory disease that affects the skin and joints. This review focuses on current immunogenetic concepts, key cellular players, and axes of cytokines that are thought to contribute to disease pathogenesis. We highlight potential therapeutic targets and give an overview of the currently used immune-targeted therapies.

Evaluation of the antipsoriatic activity of Aloe vera leaf extract using a mouse tail model of psoriasis

Aloe vera gel is used traditionally for the treatment of skin diseases, including psoriasis. An ethanolic extract of the gel was assessed for antipsoriatic activity using a mouse tail model of psoriasis. The extract produced a significant differentiation in the epidermis, as seen from its degree of orthokeratosis (85.07 ± 3.36%) when compared with the negative control (17.30 ± 4.09%). This was equivalent to the effect of the standard positive control, tazarotene (0.1%) gel, which showed a 90.03 ± 2.00% degree of orthokeratosis. The ethanolic extract of Aloe vera leaf gel also produced a significant increase in relative epidermal thickness when compared with the control group, whereas the standard tazarotene showed no change. Taken together, the extract showed an overall antipsoriatic activity of 81.95%, compared with 87.94 for tazarotene, in the mouse tail model for psoriasis.

HLA allele associations and V-beta T-lymphocyte expansions in patients with psoriasis, harboring toxin-producing Staphylococcus aureus

HLA alleles have been associated with psoriasis. Toxin-producing strains of Staphylococcus aureus behave as superantigens, and if present in patients, might play a role in the exacerbation of psoriatic lesions by activating certain V-beta (V beta) T-lymphocyte subsets. Allele frequencies in 22 patients and 22 controls (alleles determined by DNA/SSP typing) were used to calculate a relative risk of $4.7$ ($P < .05$) for HLA-Cw6. S aureus was isolated from the throat of 11 patients. Enterotoxins A and C were detected by agglutination in the culture filtrate of one isolate. The enterotoxin A and/or C genes were detected by PCR in 9 isolates, and transcripts were detected by RT-PCR in 7 of them. None of the isolates from controls harbored enterotoxin genes. V beta expansions were detected by RT-PCR in all 22 patients. Low or no V beta expansions were obtained in controls. The association of HLA-Cw6 with psoriasis in Lebanese concurs with that reported for other ethnic groups. Toxin-producing isolates that colonize patients might play a role in the exacerbation of psoriatic lesions.

Integrated network analysis of transcriptomic and proteomic data in psoriasis

BACKGROUND

Psoriasis is complex inflammatory skin pathology of autoimmune origin. Several cell types are perturbed in this pathology, and underlying signaling events are complex and still poorly understood.

RESULTS

In order to gain insight into molecular machinery underlying the disease, we conducted a comprehensive meta-analysis of proteomics and transcriptomics of psoriatic lesions from independent studies. Network-based analysis revealed similarities in regulation at both proteomics and transcriptomics level. We identified a group of transcription factors responsible for overexpression of psoriasis genes and a number of previously unknown signaling pathways that may play a role in this process. We also evaluated functional synergy between transcriptomics and proteomics results.

CONCLUSIONS

We developed network-based methodology for integrative analysis of high throughput data sets of different types. Investigation of proteomics and transcriptomics data sets on psoriasis revealed versatility in regulatory machinery underlying pathology and showed complementarities between two levels of cellular organization.

Serum lipid profile paraoxonase and arylesterase activities in psoriasis

Psoriasis is a common chronic and recurrent inflammatory skin disease with unknown etiology that has been associated with abnormal plasma lipid metabolism and oxidative stress. There are controversial results in the previous studies investigating oxidant/antioxidant systems in psoriasis.The aim of this work was to evaluate dyslipidemia, oxidative stress, total antioxidant capacity and serum paraoxonase (PON1) and arylesterase (ARE) activities in psoriasis, and to look for a correlation between these parameters and lesion percentage in psoriasis.Thirty psoriatic patients and twenty three sex- and agematched healthy volunteers were included in the study. From blood samples, lipid profile, malondialdehyde (MDA) levels, total antioxidant capacity (TAO), serum PON1 and ARE activities were determined.No significant differences between the patients and controls were found in terms of total cholesterol, triacylglycerol (TAG), HDL-cholesterol, LDL-cholesterol, VLDL-cholesterol, MDA and TAO levels. Serum PON1 and sodium-stimulated PON1 activities (p < 0.05) and ARE activity (p < 0.01) were found significantly higher in the patients than in the controls. There was not any significant correlation between lesion percentage and the parameters studied.

Cancer risk in hospitalised psoriasis patients: a follow-up study in Sweden

We examined overall and specific cancer risks among Swedish subjects who had been hospitalised one or more times for psoriasis. A database was created by identifying such patients from the Swedish Hospital Discharge Register and linking them with the Cancer Registry. Follow-up of patients was carried out from the last hospitalisation through 2004. A total of 15 858 patients were hospitalised for psoriasis during 1965-2004, of whom 1408 developed cancer, giving an overall standardised incidence ratios (SIRs) of 1.33. A significant excess was noted for squamous cell skin cancer, and for cancers of the upper aerodigestive tract, oesophagus, stomach, liver, pancreas, lung, kidney and bladder as well as non-Hodgkin lymphoma. Many of these may reflect the effects of alcohol drinking and tobacco smoking. Patients with multiple hospitalisations showed high risk, particularly for oesophageal (SIR 6.97) and skin (SIR 4.76) cancers.

Impact of Stat3 activation upon skin biology: a dichotomy of its role between homeostasis and diseases

Signal transducer and activator of transcription 3 (Stat3) is a latent cytoplasmic protein that conveys signals to the nucleus upon stimulation with IL-6, EGF, and many other cytokines/growth factors, leading to transcriptional activation of the downstream genes. It has been well defined that Stat3 plays critical roles in biological activities including cell proliferation, migration, survival, and oncogenesis. The in vivo role for Stat3 in the skin was elucidated using keratinocyte-specific Stat3 gene knockout mice, referred to as Stat3-disrutped mice. It was shown that Stat3 activation contributed to skin wound healing, keratinocyte migration, hair follicle growth, and resistance to UV irradiation-induced apoptosis. Furthermore, in the two-stage chemical carcinogenesis protocol, Stat3-disrupted mice did not develop any skin tumors. In contrast, transgenic mice with a constitutive active form of Stat3 (K5.Stat3C mice) developed squamous cell carcinoma (SCC) with a shorter latency and in much greater number compared to control mice. These results suggested a role for Stat3 not only in early stages of skin carcinogenesis but also in driving malignant progression in vivo. Moreover, Stat3 was consistently activated in epidermal keratinocytes in human psoriatic lesions, which has been assumed to recapitulate a condition of persistent wound healing reaction. Accordingly, K5.Stat3C mice were found to be psoriasis-prone. Finally, it was demonstrated that an inhibition of Stat3 activation ameliorated these pathological conditions, i.e., skin carcinogenesis and psoriasis. Here we will review the dichotomous roles for Stat3 in maintaining skin homeostasis and in the development of skin diseases such as psoriasis and skin cancer.

Psoriasis following growth hormone therapy in a child

OBJECTIVE

To report a case of psoriasis that developed following growth hormone treatment.

CASE SUMMARY

An 8-year-old boy was admitted to our pediatric endocrinology department because of short stature (<3rd percentile). A dopamine stimulation test and an insulin tolerance test revealed growth hormone (GH) deficiency with a normal cortisol response. His insulin-like growth factor 1 (IGF-1) level (9 ng/mL; reference range 113-261) was under the limits for his age and sex. Six months after the initiation of treatment with recombinant human GH 0.33 mg/kg/wk, the patient presented with a 10 day history of desquamation and a burning sensation in his right knee and hip. Lesions of erythematous papules consistent with plaques of psoriasis were present. Histologic findings from skin biopsies were consistent with psoriasis. The GH dose was reduced to 0.2 mg/kg/wk and treatment for psoriasis (including hydrocortisone and clemastine) was started. Three months after those interventions, the plaques had resolved.

DISCUSSION

Previous studies proposed that the extent and severity of psoriasis correlate with GH levels, although psoriatic patients, in general, have normal GH and IGF-1 levels. The Naranjo probability scale indicated that the development of psoriasis was probably associated with GH therapy.

CONCLUSIONS

This case suggests that the development of psoriasiform lesions in a previously unaffected individual represents an adverse effect of GH treatment, occurring at higher doses, with higher IGF-1 levels.

Possible relations between the polymorphisms of the cytokines IL-19, IL-20 and IL-24 and plaque-type psoriasis

The aim of present study was to elucidate the role of the interleukin (IL)-24 gene in predicting risk for plaque-type psoriasis and to describe the linkage disequilibrium (LD) pattern emerging from the genes of IL-19, IL-20 and IL-24. Genes encoding IL-19, IL-20 and IL-24 locate in the region q32 of chromosome 1. The association between the single-nucleotide polymorphisms (SNPs) or haplotypes of the IL-24 gene and the susceptibility of psoriasis was not found. However, a significant protective effect of the combined haplotype CAAAC of IL-20 and IL-24 genes against plaque-type psoriasis was established (OR 0.154). Protective effect against psoriasis was also observed with haplotype TGGGT (OR 0.591) and haplotype CGAGT (OR 0.457). Performing a comprehensive analysis using the data regarding SNPs of IL-24 gene together with the previously published data regarding IL-19 and IL-20 SNPs, we identified two haplotype blocks within the region q32 of chromosome 1. The main result of the present study is that while the IL-19/IL-20 extended haplotype CACCGGAA is a significant susceptibility factor for psoriasis (previous study), IL-20/IL-24 haplotypes CAAAC, TGGGT and CGAGT have a significant protective effect. Nevertheless, family-based studies are required to confirm the impact of IL-19, IL-20 and IL-24 genes in the genetic predisposition for psoriasis.

Autoantibodies directed against the protease inhibitor calpastatin in psoriasis

Psoriasis is believed to be a T cell-mediated autoimmune disease, but also exhibits autoantibody production. Calpastatin is an endogenous inhibitor of calpain, a ubiquitous protease that regulates inflammatory processes. Anti-calpastatin autoantibody was first identified as an autoantibody specific to rheumatoid arthritis, but has been also detected in other autoimmune diseases. In this study, we examined the presence and levels of anti-calpastatin antibody in 77 psoriasis patients by enzyme-linked immunosorbent assay. Compared with normal controls, psoriasis patients exhibited significantly elevated IgG anti-calpastatin antibody levels that were similar to those found in rheumatoid arthritis patients. Remarkably, IgG anti-calpastatin autoantibody in sera from psoriasis patients inhibited calpastatin activity. Calpain II expression was up-regulated in psoriasis skin lesions compared with normal skin while calpastatin expression was normal. The results of this study reveal the presence of anti-calpastatin autoantibody in psoriasis.

Stat3 links activated keratinocytes and immunocytes required for development of psoriasis in a novel transgenic mouse model

Here we report that epidermal keratinocytes in psoriatic lesions are characterized by activated Stat3. Transgenic mice with keratinocytes expressing a constitutively active Stat3 (K5.Stat3C mice) develop a skin phenotype either spontaneously, or in response to wounding, that closely resembles psoriasis. Keratinocytes from K5.Stat3C mice show upregulation of several molecules linked to the pathogenesis of psoriasis. In addition, the development of psoriatic lesions in K5.Stat3C mice requires cooperation between Stat3 activation in keratinocytes and activated T cells. Finally, abrogation of Stat3 function by a decoy oligonucleotide inhibits the onset and reverses established psoriatic lesions in K5.Stat3C mice. Thus, targeting Stat3 may be potentially therapeutic in the treatment of psoriasis.

Chemokines and inflammatory skin diseases

Accumulating evidence indicates that chronically relapsing inflammatory skin diseases such as atopic dermatitis and psoriasis are T cell-mediated diseases. Thus, understanding the underlying mechanisms of memory T-cell homing to the skin may provide promising targets for the development of novel therapeutics to interfere with inflammatory processes of the skin. Chemokines, a superfamily of small cytokine-like, chemotactic proteins, have recently been shown to critically regulate leukocyte trafficking. Here we summarize results of recent studies associating chemokines with a psoriatic or atopic dermatitis phenotype and delineating their role in the recruitment of memory T cells to the skin.

Epidermal homeostasis: the role of the growth hormone and insulin-like growth factor systems

GH and IGF-I and -II were first identified by their endocrine activity. Specifically, IGF-I was found to mediate the linear growth-promoting actions of GH. It is now evident that these two growth factor systems also exert widespread activity throughout the body and that their actions are not always interconnected. The literature highlights the importance of the GH and IGF systems in normal skin homeostasis, including dermal/epidermal cross-talk. GH activity, sometimes mediated via IGF-I, is primarily evident in the dermis, particularly affecting collagen synthesis. In contrast, IGF action is an important feature of the dermal and epidermal compartments, predominantly enhancing cell proliferation, survival, and migration. The locally expressed IGF binding proteins play significant and complex roles, primarily via modulation of IGF actions. Disturbances in GH and IGF signaling pathways are implicated in the pathophysiology of several skin perturbations, particularly those exhibiting epidermal hyperplasia (e.g., psoriasis, carcinomas). Additionally, many studies emphasize the potential use of both growth factors in the treatment of skin wounds; for example, burn patients. This overview concerns the role and mechanisms of action of the GH and IGF systems in skin and maintenance of epidermal integrity in both health and disease.

Allelic variants of drug metabolizing enzymes as risk factors in psoriasis

The onset or exacerbation of psoriasis, a T-cell-dependent skin disease with autoimmune features, can be triggered by drugs such as antimalarials and beta-blockers. Xenobiotics may also play a role in idiopathic psoriasis. It has been hypothesized that different metabolic efficiencies caused by variant alleles of xenobiotic metabolizing enzymes could lead to the accumulation of xenobiotics or their reactive metabolites in target organs. Subsequently, neoantigens or cryptic peptides could be presented and initiate an aggressive T cell response. In this context, we analyzed a broad array of xenobiotic metabolizing enzymes in up to 327 Caucasian psoriasis patients and compared them to 235 control persons. Alleles tested include four phase I and three phase II enzymes. Significantly more carriers of the variant alleles of CYP1A1 (alleles *2A and *2C) were found in healthy controls than in patients, suggesting a protective role for these alleles. No significant difference between patients and controls could be found, however, for the other phase I alleles 1B1*1 and 1B1 *3, 2C19*1A and 2C19*2A, and 2E1*1A and 2E1*5B. Of the variant alleles coding for phase II enzymes only GSTM1, but not GSTT1 or NQOR, correlated with a risk to contract psoriasis. Some combinations of phase I and phase II enzymes suggested protective or risk-associated effects. Interestingly, heterozygosity for CYP2C19 alleles *1A and *2A was associated with increased risk for "late onset" psoriasis, whereas this genotype was protective for psoriatic arthritis. This is the first large-scale study on these enzymes and the results obtained support the concept that different activities of metabolizing enzymes can contribute to disease etiology and progression.

[Trigger factors for psoriasis]

Psoriasis is often defined as a disease in which there is a genetic predisposition but environmental stimuli ("trigger factors") are also necessary for clinical expression. Various endogenous and exogenous factors can either induce or exacerbate the clinical features. Knowledge of these factors is of primary importance in clinical practice. This review focuses on the most common environmental trigger factors (infection/superantigens, injury/Köbner phenomenon, stress/neuropeptides, smoking and alcohol) and evaluates the clinical and experimental concepts to explain "environmentally" triggered psoriasis.

Oligoclonal expansion of intraepidermal T cells in psoriasis skin lesions

CD8(+) T cell infiltration into the epidermis is thought to be a key event in the pathogenesis of psoriasis. A quantitative competitive polymerase chain reaction method was developed to examine the expression of T cell receptor beta chain variable region 2, 3, 6.1-3, 8, and 13.1 genes in the epidermis of psoriatic lesions. Paired epidermal samples and peripheral blood samples from five psoriasis patients were studied. The results demonstrated the expansion of T cell receptor beta chain variable region 3 (two patients), 8 (two patients), and/or 2 (one patient). Contrary to previous reports, neither beta chain variable region 6.1-3 nor beta chain variable region 13.1 subgroups were expanded in any of the lesions. DNA sequence analysis revealed dominant T cell clones observed in all expanded beta chain variable region families and heterogeneous populations and/or small clones observed in non-expanded beta chain variable region families. Using CDR3 length analysis to examine the complete beta chain repertoire of the infiltrating T cells in the lesional epidermis, we found that approximately 50% of the T cell receptor beta chain variable region families in each patient's lesion demonstrated abnormal CDR3 DNA length distribution, indicating the presence of monoclonal or oligoclonal T cell expansion. Together, the results show that among different patients, T cell oligoclonality is not restricted to a limited number of T cell receptor beta chain variable region families. In an attempt to identify the pathogenic T cells among the many expanded T cell clones in the lesions, we compared T cell receptor expansion in the lesional epidermis with non-lesional epidermis. Particular T cell receptor were found to be preferentially expanded in lesional epidermis and these lesion-specific T cell clones may be most important in the pathogenesis and development of psoriatic lesions.

Efficacy and safety of infliximab monotherapy for plaque-type psoriasis: a randomised trial

BACKGROUND

Currently available treatments for moderate to severe psoriasis are either incompletely effective in some patients, or are associated with toxic effects. Since tumour necrosis factor alpha (TNF-alpha) is thought to have a role in the pathogenesis of psoriasis, we did a double-blind, randomised trial to assess the clinical benefit and safety of infliximab-a monoclonal antibody against TNF-alpha.

METHODS

33 patients with moderate to severe plaque psoriasis were randomly assigned intravenous placebo (n=11), infliximab 5 mg/kg (n=11), or infliximab 10 mg/kg (n=11) at weeks 0, 2, and 6. Patients were assessed at week 10 for the primary endpoint (score on the physician's global assessment [PGA]). Analysis was by intention to treat.

FINDINGS

Of the 33 patients enrolled, three dropped out. Nine of 11 (82%) patients in the infliximab 5 mg/kg group were responders (good, excellent, or clear rating on PGA), compared with two of 11 (18%) in the placebo group (difference 64% [95% CI 20-89], p=0.0089), and ten of 11 (91%) patients in the infliximab 10 mg/kg group were responders (difference from placebo 73% [30-94], p=0.0019). The median time to response was 4 weeks for patients in both infliximab groups. There were no serious adverse events, and infliximab was well tolerated.

INTERPRETATION

In this controlled trial, patients receiving the anti-TNF-alpha agent infliximab as monotherapy experienced a high degree of clinical benefit and rapid time to response in the treatment of moderate to severe plaque psoriasis compared with patients who received placebo. These findings suggest that TNF-alpha has a pivotal role in the pathogenesis of psoriasis.

Psoriatic eruption in Kawasaki disease

We describe 10 patients who developed a psoriatic skin eruption during either the acute or convalescent phase of Kawasaki disease. The skin eruption was pustular in 3 patients, but more typical psoriasiform skin lesions were seen in the remaining 7 patients. No patient has yet developed chronic psoriasis.

Psoriasis: current perspectives with an emphasis on treatment

An individualized treatment regimen is necessary for each patient with psoriasis because of the diverse nature of the disease. The manifestation of psoriasis, the severity and extent of the lesions, and the medical history and lifestyle of the patient are important factors that determine the selection of treatment, but in general therapies with the fewest side effects are preferred. First-line topical treatments are corticosteroids, calcipotriene, and tazarotene. If topical treatments are unsuccessful, phototherapy with ultraviolet B or photochemotherapy with psoralens plus ultraviolet A (PUVA) are the next choices. If psoriasis fails to respond to an adequate trial of topical therapy or phototherapy, systemic therapies including methotrexate, acitretin, or cyclosporin should be initiated. Because the regimens involved in systemic and phototherapy are complex and require frequent dose adjustments and specialized equipment, the patient should be referred to a dermatologist when topical therapy is not effective.

Overexpression of monocyte-derived cytokines in active psoriasis: a relation to coexistent arthropathy

An overexpression of inflammatory cytokines has been found in the lesional skin as well as peripheral blood in patients with psoriasis, although its etiological significance is not yet understood. In order to evaluate the cell type responsible for the elevated cytokines in the peripheral blood, we investigated cytokine profiles of the fractionated peripheral blood mononuclear cells (PBMCs) in 30 patients with psoriasis and 27 healthy controls. Without stimulation, higher levels of interleukin (IL)-1beta, IL-6, and IL-8 were produced by freshly isolated PBMCs from the patients than those from the controls. In the fractionated PBMCs, the monocyte-rich fractions were mainly responsible for the production of these cytokines and mRNA. The elevated levels of monocyte-derived cytokine mRNAs decreased following successful treatment with cyclosporin A. Although no correlation was found between the cytokine levels and the psoriasis area and severity index (PASI) scores, patients with arthropathy showed significantly high production levels of IL-1beta, IL-6, and IL-8. These findings suggest that monocytes are the major cell source producing inflammatory cytokines in the peripheral blood of psoriasis, and the increased cytokine levels are related to the coexistent arthropathy rather than the severity of cutaneous lesions.

Vitamin D receptor polymorphism is associated with psoriasis

Vitamin D receptor is a trans-acting transcriptional factor that mediates 1alpha,25-dihydroxyvitamin D3 action in the regulation of target gene expression. Recent studies have shown that clinical response of psoriasis to 1alpha,25-dihydroxyvitamin D3 is correlated with the vitamin D receptor mRNA expression level, which may be influenced by the genotype of the vitamin D receptor. In this study, we have explored a possible association between psoriasis and the polymorphism in the gene encoding the vitamin D receptor. We examined the allelic frequencies of the vitamin D receptor in psoriasis patients (n = 104) and in healthy controls (n = 104) by analyzing the restriction pattern of the polymerase chain reaction products. A significant increase in the frequency of the A allele (absence of the restriction site at intron 8) by ApaI restriction fragment length polymorphism was observed in psoriasis patients compared with that of the control group, and the tendency was more accentuated in early onset psoriasis. Odds ratios (95% confidence interval) for psoriasis of AA and Aa genotypes were 5.0 (1.3-19.1) and 2.4 (1.3-4.3), and odds ratios for early onset of AA and Aa genotypes were 6.4 (1.6-25.0) and 3.1 (1.7-5.9), respectively. Allele frequencies for A and a alleles were 0.317 and 0.683 in the psoriasis group and 0.168 and 0.832 in the control group (p = 0.001). A significant association between vitamin D receptor genotypes and the mean age at onset was observed (p < 0.05). Our findings suggest that allelic variance in the vitamin D receptor gene itself or other genes in linkage disequilibrium with this gene, could predispose to the development of psoriasis.

Adult skin disease in the pediatric patient

The incidence of many skin diseases peak in adulthood, and these disorders may be difficult to recognize when they do present in childhood. Their clinical features may be distinct in pediatric patients, and they may be managed differently in children as compared to adults. Therefore, it is important that dermatologists are able to identify "adult" skin disease in the pediatric patient, and know how to appropriately manage these problems in young patients. The epidemiology, clinical features, differential diagnosis, and management of the following "adult" skin diseases in children are reviewed: psoriasis, lichen planus, rosacea, Sweet's syndrome, and mucosis fungoides. Distinctive features of lichen sclerosus and immunobullous diseases in childhood will also be briefly discussed.

Down-regulation of transforming growth factor-beta receptors I and II is seen in lesional but not non-lesional psoriatic epidermis

Transforming growth factor-beta s (TGF-beta s) are a family of growth factors with inhibitory effects on epithelial cell proliferation. Their effects are mediated by two interacting receptors, of which type I (T beta R-I) mediates signal transduction after interaction with type II (T beta R-II) carrying the TGF-beta ligand. We have studied the expression of T beta R-I and T beta R-II in psoriatic and normal human skin by using polyclonal rabbit antisera and immunohistochemistry. Immunohistochemical analysis revealed an intense immunoreactivity for both receptors in the basal and often also suprabasal layer of normal and non-lesional psoriatic epidermis. In contrast, all psoriatic lesions studied lacked detectable immunoreactivity of either receptor in the epidermis. The results suggest that lack of TGF-beta-mediated growth inhibition by down-regulation of TGF-beta receptor expression may play an important part in the pathogenesis of psoriasis.