Elevated rate of Thelper1 (T(H)1) lymphocytes and serum IFN-gamma levels in psoriatic patients

Dysbiosis of pro-inflammatory and anti-inflammatory salivary cytokines during psoriasis providing a therapeutic window and a valuable diagnostic aid in future

The objective of this article is to evaluate the salivary levels of tumor necrosis factor-alpha (TNF-α), interferon-gamma (IFN-γ), interleukin-2 (IL-2), and IL-10 in patients with active psoriasis and compare them with those in healthy control subjects. This study included 60 subjects who were clinically diagnosed cases with active psoriasis (categorized further into 33 mild to moderate and 27 severe cases based on the Psoriasis Area Severity Index score) and 60 age- and gender-matched healthy control subjects. Levels of TNF-α, IFN-γ, IL-2, and IL-10 in the unstimulated saliva of subjects were determined via enzyme-linked immunosorbent assay (BT Lab). The salivary levels of TNF-α, IFN-γ, and IL-2 were significantly higher, whereas IL-10 concentration was significantly reduced in psoriatic patients in comparison to controls, and the difference increased with the progressing severity of the disease. Assessment of cytokine profiles in psoriasis patients is significant for diagnostic validation and monitoring the disease severity. Saliva offers an alternate, noninvasive, and readily available biological sample for evaluating cytokine levels. Extensive research in this field has been recommended for better scientifically proven conclusions.

A glimpse on the role of IL-21 in psoriatic arthritis pathogenesis

Psoriatic arthritis (PsA) is a chronic inflammatory arthropathy affecting the skin, entheses, and joints. Over the past decade, experimental evidence has revealed the activation of several immune cells and signaling cascades in modulating the pathophysiology of PsA. Recently, targeted therapies have been developed to combat the severity of disease. However, with diverse etiologies, flareups, and relapses, there has been an increased prevalence and mortality associated with PsA in recent years. Therefore, it is imperative to investigate new potential mediators and combination therapies to manage PsA pathogenesis. IL-21, an immunomodulatory cytokine, has pleiotropic effects on immune cells and the protein cascades involved in PsA pathogenesis. Recently, emerging evidence of increased IL-21 levels in patients with PsA has engendered much enthusiasm for its potential as a therapeutic target. Here, we unmasked IL-21 as a significant modulator of PsA pathogenesis and reviewed the comorbidities associated with the disease, further cataloging future therapeutic modalities to ameliorate PsA progression.

Circulating inflammatory cell profiling and periodontitis: A systematic review and meta-analysis

Inflammation is a key driver of common noncommunicable diseases. Among common triggers of inflammation, chronic gingival inflammation (periodontitis) triggers a consistent humoral host inflammatory response, but little is known on its impact on circulating inflammatory cell profiles. We aimed to systematically appraise all the evidence linking periodontitis and its treatment to circulating inflammatory cell profiles. From 6 databases, 157 studies were eligible for qualitative synthesis and 29 studies for meta-analysis. Our meta-analysis showed that participants with periodontitis exhibited a significant mean increase in circulating CD4⁺ , CD4⁺ CD45RO⁺ , IFNγ-expressing CD4⁺ and CD8⁺ T cells, CD19⁺ CD27⁺ and CD5⁺ B cells, CD14⁺ CD16⁺ monocytes, and CD16⁺ neutrophils but decrease in CD8⁺ T and CD14⁺⁺ CD16^- monocytes. Our qualitative synthesis revealed that peripheral blood neutrophils of patients with periodontitis consistently showed elevated production of reactive oxygen species (ROS) when compared with those of healthy controls. Some evidence suggested that the treatment of periodontitis reversed the exaggerated ROS production, but limited and inconclusive data were found on several circulating inflammatory cell profiling. We conclude that periodontitis and its treatment are associated with minor but consistent alterations in circulating inflammatory cell profiles. These changes could represent key mechanisms explaining the association of periodontitis with other comorbidities such as cardiovascular disease, diabetes, and rheumatoid arthritis.

Evaluation of cytokine gene expression in psoriasis

Introduction

Psoriasis is a chronic inflammatory disease affecting the skin with an unclear etiological significance.

Aim

In this study, we determined the mRNA expression and circulating levels of T helper (Th)/T regulatory (Treg) cytokines in psoriasis and analyzed their association with disease severity and treatment response.

Material and methods

189 psoriasis patients and 189 controls were recruited. Circulating Th/Treg cytokines (IL-12, IFN-γ, IL-17, IL-23, TGF-β and IL-4) were measured at baseline and at follow-up after 12 weeks of methotrexate treatment by ELISA and their relative mRNA expression at baseline was estimated by quantitative PCR.

Results

We observed increased levels of Th1/Th17 cytokines (IFN-γ, IL-17, IL-12 and IL-23) and a decrease in levels of Th2/Treg cytokines (IL-4 and TGF-β) in psoriasis patients at baseline, as compared to controls. Further, we observed that there was a significant decrease in Th1/Th17 cytokines, whilst Th2/Treg cytokine levels were significantly increased on follow-up after treatment with systemic metho trexate, as compared to pre-treatment levels. Our results were further confirmed by the significantly higher mRNA expression of Th1/Th17 cytokine genes and significantly lower mRNA expression of Th2/Treg cytokine genes in patients with psoriasis, as compared to controls. A significant positive correlation of Th1/Th17 cytokines was observed with disease severity in cases, whilst Th2/Treg cytokines correlated negatively with disease severity.

Conclusions

Our results show that increased Th1/Th17 cytokines and decreased Th2/Treg cytokines, both at the circulatory and gene expression level, play an important role in the immunopathogenesis and severity of psoriasis.

Cross-sectional study reveals thatHLA-C*07:02 is a potential biomarker of early onset/lesion severityof psoriasis

Psoriasis is a common chronic autoimmune skin disease, with T cells playing a predominant role in its pathogenesis.Here, we aimed to investigate the relation of T cell repertoires (TCR) and major histocompatibility complex (MHC) in psoriatic patients to further understand mechanisms in disease pathogenesis.We conducted a cross-sectional study involving 9 pairs of monozygotic twins with inconsistent psoriasis and examined the TCR diversity and MHC haplotype ofthe individuals using multiple-PCR and high-throughput sequencing. Additionally, 665 psoriatic patients were applied to validate the relation of human leukocyte antigen (HLA)-class I allele HLA-C*07:02 and early onset or lesion severity of psoriasis.The immune diversity was lower in psoriatic patients compared with unaffected individuals within the twin pairs, although the difference was not significant.The clonotypes of TCR significantly decreased in psoriatic patients with high PASI score and early onset. HLA-C*07:02, a haplotype associated with psoriasis, was positively correlated with the diversity of the TCRV gene. Moreover, HLA-C*07:02 clustered in patients with high PASI and early onset. In the replication stage, we found that the PASI and onset age in psoriasis with HLA-C*07:02 were significantly different from those without HLA-C*07:02 and without HLA-C*06:02. Our observations indicate that HLA-C*07:02 is positively correlated with the diversity of TCRV gene in psoriasis, and maybe a potential biomarker of early onset/severe lesions of psoriasis.

Review-Current Concepts in Inflammatory Skin Diseases Evolved by Transcriptome Analysis: In-Depth Analysis of Atopic Dermatitis and Psoriasis

During the last decades, high-throughput assessment of gene expression in patient tissues using microarray technology or RNA-Seq took center stage in clinical research. Insights into the diversity and frequency of transcripts in healthy and diseased conditions provide valuable information on the cellular status in the respective tissues. Growing with the technique, the bioinformatic analysis toolkit reveals biologically relevant pathways which assist in understanding basic pathophysiological mechanisms. Conventional classification systems of inflammatory skin diseases rely on descriptive assessments by pathologists. In contrast to this, molecular profiling may uncover previously unknown disease classifying features. Thereby, treatments and prognostics of patients may be improved. Furthermore, disease models in basic research in comparison to the human disease can be directly validated. The aim of this article is not only to provide the reader with information on the opportunities of these techniques, but to outline potential pitfalls and technical limitations as well. Major published findings are briefly discussed to provide a broad overview on the current findings in transcriptomics in inflammatory skin diseases.

Serum levels of adipokines and cytokines in psoriasis patients: a systematic review and meta-analysis

Purpose

To evaluate the association of serum levels of adipokines and cytokines with psoriasis.

Materials and Methods

A comprehensive literature search was performed in PubMed, ScienceDirect and Web of Science for the available relevant studies published before December 1, 2016. Differences in serum marker levels between patients and controls were pooled as standardized mean differences (SMDs) with 95% confidence interval to combine the effect estimations. We also conducted stratified analysis, meta-regression analysis and sensitivity analysis.

Results

Sixty-three studies containing 2876 psoriasis patients and 2237 healthy controls were included in this meta-analysis. The pooled serum levels of TNF-α, IFN-γ, IL-2, IL-6, IL-8, IL-18, IL-22, chemerin, lipocalin-2, resistin, sE-selectin, fibrinogen and C3 were higher in psoriasis patients compared with healthy controls (all P < 0.05). In contrast, adiponectin levels were lower. Serum levels of IL-1β, IL-4, IL-10, IL-12, IL-17, IL-21, IL-23, visfatin and omentin were not significantly different between psoriasis patients and controls (all P > 0.05). However, increased serum levels of IL-17 correlated with psoriasis in men. For other biomarkers, age, gender and psoriasis area and severity index did not explain the differences in effect size between the studies.

Conclusions

Serum levels of TNF-α, IFN-γ, IL-2, IL-6, IL-8, IL-18, IL-22, chemerin, lipocalin-2, resistin, sE-selectin, fibrinogen, complement 3, and adiponectin correlate with psoriasis and can be used as potential biomarkers for psoriasis and response to the treatment. Future studies are needed to identify additional players involved in the pathogenesis of psoriasis and to fully decipher the underlying mechanism.

Natural killer cells from psoriasis vulgaris patients have reduced levels of cytotoxicity associated degranulation and cytokine production

Psoriasis vulgaris is a chronic inflammatory disease of the skin with a strong genetic component and immune system involvement. Although some evidence suggests that Natural Killer (NK) cells may play a part in psoriasis, their role is relatively unstudied and results are controversial. In this current study, NK cells from psoriasis patients exhibited reduced degranulation and produced lower levels of the pro-inflammatory cytokines IFN-γ and TNF-α. Further investigation found that NK cells from psoriasis patients and healthy controls expressed similar levels of activation markers, NK cell receptors and apoptosis-inducing molecules. In addition, comparable levels of several cytokines important in NK cell biology were found in the serum of psoriasis patients and healthy controls. Genotyping analysis revealed that HLA-C2, which provides a ligand for killer-cell immunoglobulin-like receptors (KIR) expressed by NK cells, was strongly associated with psoriasis susceptibility. However, no link between the KIR genes themselves and disease was found.

Psoriasis and the risk of pneumonia: a population-based study

BACKGROUND

Psoriasis is a prevalent autoimmune disorder. Various studies have reported on the relationship between psoriasis and chronic diseases but very few have explored the association between psoriasis and subsequent acute infection. This retrospective cohort study aimed to compare the risk of pneumonia between subjects with and those without psoriasis.

METHODS

The medical records of 14,022 patients with psoriasis and 14,022 without psoriasis were obtained from the Taiwan Longitudinal Health Insurance Database 2000. Each patient was followed-up for a three-year period. Cox proportional hazard regressions were performed to compare difference of subsequent pneumonia incidence between subjects with and those without psoriasis.

RESULTS

There were 206 (1.47%) subjects with psoriasis and 138 (0.98%) without psoriasis hospitalized for pneumonia. By Cox proportional hazard regressions analysis, the HR (hazard ratio) of pneumonia requiring hospitalization for patients with psoriasis was 1.50 (95% confidence interval [CI]: 1.21-1.86) compared to patients without psoriasis. The adjusted HR was 1.40 (95% CI: 1.12-1.73). The adjusted HR of pneumonia hospitalization for subjects with mild and severe psoriasis was 1.36 (95% CI: 1.09-1.70) and 1.68 (95% CI: 1.12-2.52), respectively, compared to those without psoriasis.

CONCLUSIONS

Patients with psoriasis have significantly higher incidence of pneumonia compared to those without psoriasis.

The 3'UTR 1188A/C polymorphism of IL-12p40 is not associated with susceptibility for developing plaque psoriasis in Mestizo population from western Mexico

Psoriasis is a chronic autoimmune inflammatory disease that affects the skin and the joints. Psoriasis is characterized by the keratinocyte proliferation, which is induced by cytokines Th1 and Th17. Patients with plaque psoriasis present a chronic inflammatory response with high levels of interleukin (IL)-12 and IL-23. Various single-nucleotide polymorphisms (SNP) have been identified in the IL12B gene, such as SNP 3' UTR 1188 A/C (SNP rs3212227), which has been associated with susceptibility to developing plaque psoriasis and with the production of IL-12 and IL-23 in individuals of different ethnic groups. In this study, we determined whether there is an association of SNP rs3212227 with the susceptibility of developing plaque psoriasis and with serum levels of IL-12 and IL-23 in Mestizo population in western Mexico. We included 112 patients with psoriasis and 112 clinical healthy individuals in the study. The frequencies of genotypes A/A, A/C, and C/C in patients with plaque psoriasis were 41, 53, and 6%, respectively, while in the control group, these were 37, 53, and 10%, respectively, without finding statistically significant differences between both groups (p>0.05). Although IL-12 and IL-23 serum levels were higher in patients than in controls, we found no significant differences. The group of patients with genotype CC presented the highest levels of IL-23 (p<0.05). These data suggest that the SNP rs3212227 phenotype is not associated with the risk of developing plaque psoriasis or with IL-12 and IL-23 levels in Mestizo population in western Mexico.

Macrophage migration inhibitory factor triggers chemotaxis of CD74+CXCR2+ NKT cells in chemically induced IFN-γ-mediated skin inflammation

IFN-γ mediates chemically induced skin inflammation; however, the mechanism by which IFN-γ-producing cells are recruited to the sites of inflammation remains undefined. Secretion of macrophage migration inhibitory factor (MIF), a proinflammatory cytokine, from damaged cells may promote immune cell recruitment. We hypothesized that MIF triggers an initial step in the chemotaxis of IFN-γ-producing cells in chemically induced skin inflammation. Using acute and chronic models of 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced skin inflammation in mouse ears, MIF expression was examined, and its role in this process was investigated pharmacologically. The cell populations targeted by MIF, their receptor expression patterns, and the effects of MIF on cell migration were examined. TPA directly caused cytotoxicity accompanied by MIF release in mouse ear epidermal keratinocytes, as well as in human keratinocytic HaCaT cells. Treatment with the MIF antagonist (S,R)-3-(4-hydroxyphenyl)-4,5-dihydro-5-isoxazole acetic acid methyl ester considerably attenuated TPA-induced ear swelling, leukocyte infiltration, epidermal cell proliferation, and dermal angiogenesis. Inhibition of MIF greatly diminished the dermal infiltration of IFN-γ(+) NKT cells, whereas the addition of exogenous TPA and MIF to NKT cells promoted their IFN-γ production and migration, respectively. MIF specifically triggered the chemotaxis of NKT cells via CD74 and CXCR2, and the resulting depletion of NKT cells abolished TPA-induced skin inflammation. In TPA-induced skin inflammation, MIF is released from damaged keratinocytes and then triggers the chemotaxis of CD74(+)CXCR2(+) NKT cells for IFN-γ production.

Analysis of Th1/Th2 response pattern for erythrodermic psoriasis

As one of the most serious types of psoriasis, pathogenesis of erythrodermic psoriasis (EP) is unclear so far. In this study, we aimed to detect the levels of Th1/Th2 cytokine-associated transcription factors and T-lymphocyte clone in peripheral blood mononuclear cells (PBMCs) derived from EP patients, and gene expression level of T-bet/GATA-3 in skin lesion. The potential role of Th1/Th2 reaction pattern played in the pathogenesis of EP was also discussed. Serum levels of IFN-γ, IL-2, IL-4 and IL-10 were quantified by ELISA among 16 EP patients, 20 psoriasis vulgaris (PV) patients and 15 healthy controls. The expression levels of T-bet/GATA-3 in the skin lesion and PBMCs were examined by real-time qPCR. The ratio of Th1/Th2 was measured by flow cytometry. The levels of IFN-γ, IL-2, IL-4 and IL-10 were higher in EP patients than in the healthy controls. The levels of IL-4 and IL-10 were 69.44±11.45 and 12.62±4.57 pg/mL, respectively, in EP patients, significantly higher than those in PV patients and healthy controls (P<0.05). Flow cytometry revealed the levels of both Th1 and Th2 in PBMCs from EP patients were higher than those in healthy controls, and the Th1/Th2 ratio was dramatically lower than in PV patients (P<0.01). The ratios of IFN-γ/IL-4 and T-bet/GATA-3 in EP patients were both less than 1.0, suggesting a reversal when compared with the other two groups. Our study indicated that the EP patients exerted a Th1/Th2 bidirectional response pattern, and the balance of Th cell subsets inclines to Th2, which might be one of the important mechanisms of EP pathogenesis.

Brodalumab: an evidence-based review of its potential in the treatment of moderate-to-severe psoriasis

Advances in knowledge regarding the pathogenesis of psoriasis have allowed the development of a new class of agents known as biologic drugs. Data confirm that T helper (Th)17 and interleukin (IL)-17 signaling has a crucial role in the pathogenesis of the disease. High levels of IL-17 and Th17-related cytokines have been reported in psoriasis, leading to the suggestion of agents targeting IL-17 as a potential therapeutic strategy in psoriasis. Brodalumab is a human monoclonal antibody that targets IL-17 receptor A, blocking the effects of IL-17A, IL-17F, and IL-17E. Data from Phase I and Phase II clinical trials indicate that brodalumab has a favorable safety and tolerability profile, with strong clinical activity, suggesting that it is a potential tool for use in the treatment of moderate-to-severe psoriasis.

[Psychological and biological background of the correlation between psoriasis and stress]

Stress is considered as a major contributor to the development and exacerbation of psoriasis by a significant proportion of patients and dermatologists. As both stressor and its effects are subject-dependent, thus extremely difficult to measure, our understanding of the exact role of stress in disease development was limited for a long time. In the past decade several new studies were carried out which expanded our knowledge on the pathophysiologic processes linking stress to psoriasis via with their objective measurements and the applied new techniques. The authors review the current literature of both psychological (alexithymia, personality, affect) and biological (cortisol, epinephrine, neurogenic inflammation) factors influencing stress perception and response in psoriasis. Results of recent investigations support previous reports about the interaction between stress and psoriasis with objective evidence. Knowing how effective stress-reducing psychopharmacologic and psychotherapeutic interventions are in the treatment of psoriasis the authors hope that this review contributes to a wider acceptance of the psychosomatic attitude in everyday dermatologic practice.

Differentially-expressed genes identified by suppression subtractive hybridization in the bone marrow hematopoietic stem cells of patients with psoriasis

Psoriasis is a T cell-mediated, chronic, relapsing and inflammatory cutaneous disorder. The dysfunctional activity of T cells in patients with psoriasis is attributed to bone marrow hematopoietic stem cells (BMHSCs). To understand the pathogenic roles of BMHSCs in psoriasis, a differential gene expression analysis was performed using suppression subtractive hybridization of the BMHSCs from a patient with psoriasis and a healthy control. Using a cDNA array dot blot screening to screen 600 genes from forward- and reverse-subtracted cDNA libraries, 17 differentially-expressed sequence tags (ESTs) were identified. The genes within the ESTs were observed to be the homologs of genes that are involved in various cellular processes, including hormone signaling, RNA catabolism, protein ADP DNA base melting, transcriptional regulation, cell cycle regulation and metabolism. CD45, which was overexpressed in the psoriatic BMHSCs, was further analyzed using relative quantitative polymerase chain reaction. In addition, the levels of CD45 in the peripheral blood cells (PBCs) of the patients with psoriasis were markedly increased and closely associated with disease severity. An abnormality of hematopoietic progenitor cells, e.g., CD45 overexpression, may be transferred to PBCs via hematopoiesis, and may account for the psoriasis-inducing properties of activated T cells.

Immunological and histological evaluation of clinical samples from psoriasis patients treated with anti-CD6 itolizumab

Psoriasis is a chronic inflammatory disease with a prevalence of approximately 2-3% in the general population. The majority of diagnosed patients have plaque psoriasis, and about 20% have moderate-to-severe disease. Itolizumab, a new monoclonal antibody specific for the CD6 molecule mainly expressed on T lymphocytes, has demonstrated to inhibit in vitro ligand-induced proliferation and pro-inflammatory cytokine production. We assessed the immunological and histopathological effect of the antibody using clinical samples taken from 26 patients with moderate-to-severe psoriasis included in a clinical trial. The precursor frequency of lymphocytes activated with anti-CD2/CD3/CD28 beads, as well as the number of interferon (IFN)-γ-secreting T cells after stimulation, were measured at different time points of the study. Serum cytokine levels and anti-idiotypic antibody response to itolizumab were also evaluated. Additionally, lymphocyte infiltration and epidermis hyperplasia were studied in five patients. A significant reduction in T cell proliferation capacity and number of IFN-γ-producing T cells was found in treated patients. Serum levels of interleukin-6, tumor necrosis factor and IFN-γ showed an overall trend toward reduction. No anti-idiotypic antibody response was detected. A significant reduction in the epidermis hyperplasia was observed in analyzed patients. These results support the relevance of the CD6 molecule as a therapeutic target for the treatment of this disease.

Markers of systemic inflammation in psoriasis: a systematic review and meta-analysis

Studies investigating systemic inflammation in psoriasis use different serum markers and report discrepant results. We set out to determine whether systemic inflammation is elevated in patients with psoriasis compared with healthy controls, and to measure the extent of this elevation, by summarizing available data on serum inflammatory markers. PubMed, Embase and Web of Science were searched from inception to March 2011. We included studies comparing the serum inflammatory markers interleukin (IL)-1β, IL-6, IL-10, C-reactive protein (CRP), intracellular adhesion molecule (ICAM)-1, E-selectin and tumour necrosis factor (TNF)-α in patients with psoriasis and healthy controls. Differences in serum marker levels between patients and controls were pooled as standardized mean differences (SMDs; Cohen's d) using a random-effects model. Seventy-eight studies were eligible. Of the 7852 individuals included, 3085 had (severe plaque) psoriasis. The pooled SMDs were higher in patients with psoriasis than in healthy controls for IL-6 [d = 1·32, 95% confidence interval (CI) 0·83-1·81], CRP (d = 1·83, 95% CI 0·76-2·90), TNF-α (d = 1·32, 95% CI 0·86-1·79), E-selectin (d = 1·78, 95% CI 1·32-2·25) and ICAM-1 (d = 1·77, 95% CI 1·15-2·39). The SMD between cases and controls for IL-1β and IL-10 was not significant. Age had a significant effect on the SMD for IL-6 and TNF-α. For IL-6 the effect size was higher for plaque psoriasis studies (d = 1·98). The effect size was not influenced by the Psoriasis Area and Severity Index, measurement method or quality assessment. The pooled analyses suggest modest but significantly elevated levels of the proinflammatory cytokines in the serum of patients with psoriasis with predominantly severe disease. To what extent this modest increment is clinically relevant could be investigated in a synthesis of all studies measuring inflammation before and after antipsoriatic therapy.

Study on Certain Biomarkers of Inflammation in Psoriasis Through "OMICS" Platforms

Background:

In recent years, research on psoriasis has focused on the identification of biomarkers for the diagnosis, pathogenesis, prognosis, or therapeutic response of the disease. These studies could provide insights into the susceptibility and natural history of psoriasis. The identification of biomarkers related to comorbidities in psoriasis, such as arthritis, cardiovascular disease, and the metabolic syndrome, is of special clinical interest.

Materials and Methods:

We performed an extensive review on psoriasis biomarkers, including cytokine and growth factors, in the literature published between 1997 and 2013, including cross-references of any retrieved articles. We also included some data from our own studies.

Results:

This review presents current knowledge of soluble biomarkers in psoriasis, including cytokines, chemokines, proangiogenic mediators, growth factors, antimicrobial proteins, neuropeptides, and oxidative stress markers.

Conclusion:

In conclusion, a number of studies have been conducted with the aim of establishing soluble biomarkers for psoriasis. Most of the biomarkers that have been studied do not meet the criteria for a clinically useful biomarker. Further work is needed to establish a role for soluble biomarkers in the diagnosis and treatment of psoriasis, with a special focus on biomarkers for psoriasis comorbidities, such as arthritis, cardiovascular disease, and the metabolic syndrome.

Involvement of P2Y₁₁ receptor in IFN-γ-induced IL-6 production in human keratinocytes

Extracellular ATP and P2 receptors are reported to be involved in interleukin-6 (IL-6) production by human keratinocytes, but the role of extracellular ATP in cytokine-induced IL-6 production remains unclear. In this study, we investigated the involvement of various P2 receptors in IL-6 production induced by the Th1 cytokine interferon-gamma (IFN-γ) in a human keratinocyte cell line, HaCaT. IFN-γ increased IL-6 production in HaCaT cells. A non-selective antagonist of P2Y receptors (suramin), a selective P2Y11 receptor antagonist (NF157), ecto-nucleotidase (apyrase), and a soluble adenylate cyclase inhibitor (KH7) all inhibited IL-6 production. It was further confirmed that ATP was released from HaCaT cells stimulated with IFN-γ. These results suggest that extracellular ATP and P2Y11 receptor are involved in IFN-γ-induced IL-6 production. Knockdown of P2Y11 receptor suppressed IL-6 production, strongly supporting this idea. In conclusion, these data demonstrate that P2Y11 receptor mediates IFN-γ-induced IL-6 production in human keratinocytes, and suggest the importance of purinergic signaling in IFN-γ-induced skin inflammatory conditions, such as psoriasis.

IL-27 activates Th1-mediated responses in imiquimod-induced psoriasis-like skin lesions

IL-27, a member of the IL-12 cytokine family, primes Th1 cell differentiation, whereas it suppresses Th17 cell development. We have previously reported that serum IL-27 levels are elevated in psoriatic patients and that IL-27 greatly induces in vitro production of Th1-type chemokines through STAT1 activation. In this study, to further investigate the in vivo role of IL-27 in the pathogenesis of psoriasis, we induced psoriasis-like inflammation on mouse back skin with topical application of imiquimod (IMQ), and continuously injected IL-27 or PBS subcutaneously. IMQ-treated skin showed an increase of IL-27 mRNA levels and the infiltration of IL-27-producing cells in the papillary dermis. The injection of IL-27 to the IMQ-treated skin exacerbated the disease compared with PBS injection. The IL-27 injection further augmented mRNA levels of IFN-γ, CXCL9, CXCL10, CXCL11, and TNF-α, without altering those of IL-17A, IL-17F, IL-22, and CCL20. Finally, IL-27 antagonism attenuated the upregulation of IFN-γ, CXCL9, CXCL10, CXCL11, and TNF-α mRNA levels, and induced clinical and histological improvement in the IMQ-treated skin. These results indicate that IL-27 would act in a proinflammatory manner, and thereby exacerbate the psoriasis-like skin inflammation induced by IMQ.

Keratinocytes under Fire of Proinflammatory Cytokines: Bona Fide Innate Immune Cells Involved in the Physiopathology of Chronic Atopic Dermatitis and Psoriasis

Cutaneous homeostasis and defenses are maintained by permanent cross-talk among particular epidermal keratinocytes and immune cells residing or recruited in the skin, through the production of cytokines. If required, a coordinated inflammatory response is triggered, relayed by specific cytokines. Due to numerous reasons, troubles in the resolution of this phenomenon could generate a cytokine-mediated vicious circle, promoting skin chronic inflammation, the most common being atopic dermatitis and psoriasis. In this paper, we discuss the biological effects of cytokine on keratinocytes, more particularly on specific or shared cytokines involved in atopic dermatitis or psoriasis. We report and discuss monolayer or 3D in vitro models of keratinocytes stimulated by specific sets of cytokines to mimic atopic dermatitis or psoriasis. IL-22, TNFa, IL-4, and IL-13 combination is able to mimic an “atopic dermatitis like” state. In psoriasis lesions, over expression of IL-17 is observed whereas IL-4 and IL-13 were not detected; the replacement of IL-4 and IL-13 by IL-17 from this mix is able to mimic in vitro a “psoriasis like” status on keratinocytes. We conclude that specific cytokine environment deregulation plays a central role on skin morphology and innate immunity, moving towards specific pathologies and opening the way to new therapeutic strategies.

Analysis of genetic variants of class II cytokine and their receptor genes in psoriasis patients of two ethnic groups from the Volga-Ural region of Russia

BACKGROUND

The molecular basis of pathogenesis of psoriasis remains unclear, but one unifying hypothesis of disease aetiology is the cytokine network model. The class II cytokines (CF2) and their receptors (CRF2) are all involved in the inflammatory processes and single nucleotide polymorphisms (SNPs) in respective genes have been associated with psoriasis in a previous study of the Estonian population.

OBJECTIVE

We performed a replication study of 47 SNPs in CF2 and CRF2 genes in independent cohorts of psoriasis patients of two ethnic groups (Russians and Bashkirs) from the Volga-Ural region of Russia.

METHODS

DNA was obtained from 395 psoriasis patients of two ethnic groups from the Volga-Ural region of Russia and 476 ethnically matched controls. 47 SNPs in the loci of the genes encoding Class II cytokines and their receptors were selected by SNPbrowser version 3.5. Genotyping was performed using the SNPlex™ (Applied Biosystems) platform.

RESULTS

The genetic variant rs30461 previously associated in original case-control study in Estonians, was also associated in Russians (corrected P-value (Pc=0.008, OR=0.44), but did not reach statistical significance in the Bashkir population. Additionally, the haplotype analysis provided that CC haplotype formed by the SNPs rs30461 and rs955155 had a protective effect in Russians (Pc=0.0024, OR=0.44), supporting the involvement of this locus in the protection against psoriasis. Combined meta-analysis of three populations, including 943 psoriasis patients and 812 healthy controls, showed that the IL29 rs30461 C-allele was not associated with decreased risk of psoriasis (P=0.165, OR=0.68). Moreover, stratification of studies by ethnicity revealed a significant association in the European cohort (P=9.506E-006, OR=0.53).

CONCLUSION

Therefore, there is no overall evidence of association between psoriasis and SNP rs30461 of the IL29 gene, but there is some evidence to suggest that an association exists in Europeans. However, this current concept should be considered as preliminary and the results need to be confirmed in future independent studies.

Inhibiting glycogen synthase kinase-3 decreases 12-O-tetradecanoylphorbol-13-acetate-induced interferon-γ-mediated skin inflammation

Glycogen synthase kinase-3 (GSK-3) facilitates interferon (IFN)-γ signaling. Because IFN-γ is involved in inflammatory skin diseases, such as psoriasis, the aim of this study was to investigate the pathogenic role of GSK-3 in 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced IFN-γ-mediated ear skin inflammation. TPA (3 μg per ear) induced acute skin inflammation in the ears of C57BL/6 mice, including edema, infiltration of granulocytes but not T cells, and IFN-γ receptor 1-mediated deregulation of intercellular adhesion molecule 1 (CD54). TPA/IFN-γ induced GSK-3 activation, which in turn activated signal transducer and activator of transcription 1. Inhibiting GSK-3 pharmacologically, by administering 6-bromoindirubin-3'-oxime (1.5 μg per ear), and genetically, with lentiviral-based short-hairpin RNA, reduced TPA-induced acute skin inflammation but not T-cell infiltration. It is noteworthy that inhibiting GSK-3 decreased TPA-induced IFN-γ production and the nuclear translocation of T-box transcription factor Tbx21, a transcription factor of IFN-γ, in CD3-positive T cells. In chronic TPA-induced skin inflammation, inhibiting GSK-3 attenuated epidermis hyperproliferation and dermis angiogenesis. These results demonstrate the dual role of GSK-3 in TPA-induced skin inflammation that is not only to facilitate IFN-γ signaling but also to regulate IFN-γ production. Inhibiting GSK-3 may be a potential treatment strategy for preventing such effects.

Psoriasis and physical activity: a review

Psoriasis is a common, chronic inflammatory skin disease that can cause significant discomfort and impairment to quality of life. Recent research indicates that individuals with moderate-to-severe psoriasis are likely at greater risk for chronic cardiometabolic co-morbidities such as cardiovascular disease, type 2 diabetes, obesity and metabolic syndrome. Physical activity can be an effective primary and adjunctive treatment for these maladies in other populations. Unfortunately, only a limited number of studies have examined physical activity in psoriasis, which are limited by poor design and lack of validated physical activity assessment methodologies. A variety of data suggest shared physiologic pathways between physical activity, psoriasis, and psoriasis cardiometabolic co-morbidities. Increased adiposity, inflammation, oxidative stress, adhesion molecules and lipids are physiologically linked to psoriasis, the risk of psoriasis cardiometabolic co-morbidities, and low levels of physical activity. In addition, epigenetic pathways are involved in psoriasis and could be influenced by physical activity. The physical and psychosocial impairments common in psoriasis may make it difficult to participate in regular physical activity, and future studies should aim to determine if physical activity interventions improve functioning and reduce co-morbidities in psoriasis.

Xiaoyin recipe ( ) for psoriasis induces a Th1/Th2 balance drift toward Th2 in peripheral blood mononuclear cells of experimental autoimmune thyroiditis rats

OBJECTIVE

To explore the regulatory mechanism of Xiaoyin Recipe () on the T helper 1/T helper 2 (Th1/Th2) immune balance.

METHODS

Thirty-six experimental animals were divided into three groups, 12 rats in each group: blank control group (B group), negative control group (N group), and Xiaoyin Recipe treatment group (T group). The latter two groups received immunization of experimental autoimmune thyroiditis (EAT), and T group were treated with Xiaoyin Recipe for a month. Then, the expression of Th1-Th2-related genes in peripheral blood mononuclear cells (PBMCs) were screened with Oligo GEArray Rat Th1-Th2-Th3 Microarray. The expressions of tumor necrosis factor-α (TNF-α), interleukin-10 (IL-10), T-box expressed in T-cells (T-bet), and GATA-binding protein-3 (GATA-3) were detected by real-time polymerase chain reaction (RT-PCR).

RESULTS

Gene array screening showed that compared to N group, in T group after Xiaoyin Recipe treatment, 3 genes were upregulated in EAT rats, including interleukin-27 receptor alpha (IL-27rα), glomulin (Glmn), and GATA-3, while 38 genes were downregulated, such as CD28, IL-18, signal transducer, and activator of transcription 1 (STAT1), T-bet, TNF receptor superfamily member 4 (TNFRSF4), TNF ligand superfamily member 5 (TNFSF5), and TNF receptor superfamily member 5 (TNFRSF5). While RT-PCR showed that there was an increased level of TNF-α mRNA (P<0.01), an elevated ratio of T-bet/GATA-3, and a decreased level of IL-10 mRNA in PBMC of N and T group compared to B group (P <0.01); and after treatment with Xiaoyin Recipe, IL-10 mRNA level increased (P <0.01), while TNF-α mRNA level and T-bet/GATA-3 ratio decreased in T group compared to N group (P <0.01).

CONCLUSION

Xiaoyin Recipe for psoriasis could induce a Th1/Th2 balance drift toward Th2 in PBMC of EAT rats and thus improve the conditions.

Tuberculosis infection versus anti-tumor necrosis factor therapy: screening challenges in psoriatic patients

OBJECTIVES

The aim of this study was to analyze the performance of the tuberculin skin test (TST) for screening and monitoring patients treated with anti-tumor necrosis factor agents, in a high-incidence area.

METHODS

A 3-year retrospective study was carried out on 268 subjects. The study included 68 patients with moderate-to-severe psoriasis, screened for latent tuberculosis infection (LTBI) and subjects without psoriasis (100 adults and 100 children) with close contact with infected individuals.

RESULTS

Positive tuberculin skin test (TST) results (induration >5 mm) were observed in 70.5% (48/68) of patients with psoriasis, higher than those observed in subjects with suspicion of tuberculosis or with close contact with infected individuals: 51% (51/100) in the adult group and 30% (30/100) in the children group.

CONCLUSIONS

These results show that the prevalence of LTBI evaluated with the TST in the psoriatic group is higher than in subjects without psoriasis.

LIMITATION

The positive reactions were not confirmed by other verification methods.

Upregulation and nuclear localization of TNF-like cytokine 1A (TL1A) and its receptors DR3 and DcR3 in psoriatic skin lesions

TNF is critically involved in the pathogenesis of psoriasis. TL1A is a TNF-like cytokine, which, after binding to death domain receptor DR3, provides costimulatory signals to lymphocytes, amplifies Th1- and Th17-mediated immune responses and induces apoptotic cell death. These functions are inhibited when TL1A associates to decoy receptor DcR3. In the present study, we investigated the expression profiles for TL1A, DR3 and DcR3 in the normal skin and in psoriatic skin lesions. By use of immunohistochemistry, we were able to demonstrate constitutive cutaneous expression of DR3 and DcR3 but not of TL1A in healthy skin. On the other hand, in patients with active psoriasis, we observed abundant immunostaining for TL1A and significant upregulation of its receptors (P < 0.05 in comparison to healthy skin). TL1A, DR3 and DcR3 proteins, as well as mRNA transcripts reflecting in situ production of TL1A and DcR3, were also specifically increased in lesional as compared to non-lesional skin from patients with psoriasis (P < 0.05). These proteins were upregulated in cell populations that are critically involved in the pathogenesis of chronic skin inflammation, such as keratinocytes, macrophages in deep dermis and cells at the perivascular/endothelial area. Finally, we provide evidence for the existence of nuclear localization of TL1A in inflammatory cells from psoriatic lesions. This was also observed in inflamed synovia from patients with rheumatoid arthritis, but not in neoplastic TL1A-expressing cell lines. We conclude that interactions between TL1A and its two receptors may be involved in the pathogenesis of chronic skin inflammation that takes place in psoriasis.

Serum cytokines and growth factor levels in Japanese patients with psoriasis

BACKGROUND

Although the precise pathomechanism of psoriasis is still unknown, various cytokines and growth factors derived from T cells, dendritic cells or keratinocytes, are critically involved in this disease. There have been several studies determining the serum levels of cytokines in patients with psoriasis, but with conflicting results. The levels of various cytokines and growth factors were measured in the sera of patients with psoriasis and compared with those of healthy controls. The correlation with disease severity was also determined.

METHODS

Sera were collected from 122 patients with psoriasis and 78 healthy controls for ELISA analysis to evaluate the levels of cytokines and growth factors. The severity of psoriasis was determined by the Psoriasis Area and Severity Index (PASI).

RESULTS

Serum levels of tumour necrosis factor (TNF)-alpha, interferon (IFN)-gamma, interleukin (IL)-2, IL-6, IL-7, IL-8, IL-12, IL-17, IL-18 and vascular endothelial growth factor (VEGF) were significantly increased in patients with psoriasis compared with those of healthy controls. The serum levels of IL-2, soluble intercellular adhesion molecule-1, epidermal growth factor, hepatocyte growth factor and amphiregulin were not significantly different from those of healthy controls. Increased serum levels of TNF-alpha, IFN-gamma, IL-12, IL-17, IL-18 and VEGF correlated with PASI. Furthermore, these cytokine levels were decreased after psoriasis treatment. In contrast, serum levels of IL-10 were decreased in psoriasis and negatively correlated with PASI.

DISCUSSION

Serum levels of TNF-alpha, IFN-gamma, IL2, IL-6, IL-7, IL-8, IL-12, IL-17, IL-18 and VEGF were positively correlated and that of IL-10 was negatively correlated with PASI in Japanese patients with psoriasis. These parameters might be useful for determining the disease activity of psoriasis.

Osteopontin: a new emerging role in psoriasis

Osteopontin (OPN) is a phosphorylated acidic glycoprotein produced by cells of the immune system, epithelial tissue, smooth muscle cells, osteoblasts, and tumor cells. OPN interacts with integrins and CD44 to enhance Th1 and inhibit Th2 cytokine expression. The involvement of this molecule in the onset of psoriasis has not previously been studied. Here, we demonstrate that OPN is expressed in peripheral blood mononuclear cells and in skin biopsies of psoriatic patients. The study was conducted on 30 patients affected with plaque psoriasis, and on 11 healthy donors. Two blood samples and two skin samples from patients affected with atopic dermatitis were used as control for Th2 typical inflammatory skin disease. The analysis of IL-1beta, IFN-gamma, TauNuF-alpha, IL-8, and ICAM-1 showed the characteristic Th1 pattern in all the psoriatic blood and skin samples analyzed. This study offers an opportunity for understanding inflammation in psoriasis and supports the hypothesis that OPN could represent a potential target for therapeutic intervention in psoriatic patients.

T helper 1 to T helper 2 shift in cytokine expression: an autoregulatory process in superantigen-associated psoriasis progression?

Psoriasis is an inflammatory skin disorder characterized by increased activation of CD4+ T lymphocytes, and systemic and local overexpression of pro-inflammatory cytokines such as interleukin 2 (IL-2), gamma interferon (IFN-γ), IL-6 and tumour necrosis factor alpha, indicating that immunopathogenesis of the disease is T helper 1 (Th1) mediated. Several studies suggest a pivotal role of bacterial superantigens in the initiation and/or exacerbation of this illness. This study was conducted to assess the systemic Th1/Th2 imbalance in Indian psoriasis patients presenting with variable duration of disease by studying systemic superantigen-stimulated peripheral blood mononuclear cell (PBMC) cytokine expression. PBMCs were isolated and stimulated in vitro with superantigens (streptococcal pyrogenic exotoxin A and staphylococcal enterotoxin B), and the cytokines released (IFN-γ for a Th1 response, and IL-4 and IL-10 for a Th2 response) were assayed. In contrast to controls, psoriasis patients in the early course of disease were characterized by significantly increased expression of the pro-inflammatory cytokine IFN-γ, whilst a shift towards IL-10 secretion (Th2 response) was observed in those presenting with increased duration of disease. These observations suggest a possible shift from a Th1 to a Th2 cytokine response with superantigen-associated progression for the duration of psoriasis, perhaps as an adaptive process by the immune system in an attempt to downregulate abnormal inflammatory Th1 immune responses.

Induction of IL-17+ T cell trafficking and development by IFN-gamma: mechanism and pathological relevance in psoriasis

Th1 and Th17 T cells are often colocalized in pathological environments, yet Th1-derived IFN-gamma inhibits Th17 cell development in vitro. We explored the physiologic basis of this paradox in humans. In this study, we demonstrate increased the number of CD4(+) and CD8(+) IL-17(+) T cells in skin lesions of psoriasis. Furthermore, we show that myeloid APCs potently support induction of IL-17(+) T cells, and that this activity is greatly increased in psoriasis. We tested stimuli that might account for this activity. Th1 cells and IFN-gamma are increased in psoriatic blood and lesional skin. We show that IFN-gamma programs myeloid APCs to induce human IL-17(+) T cells via IL-1 and IL-23. IFN-gamma also stimulates APC production of CCL20, supporting migration of IL-17(+) T cells, and synergizes with IL-17 in the production of human beta-defensin 2, an antimicrobial and chemotactic protein highly overexpressed by psoriatic keratinocytes. This study reveals a novel mechanistic interaction between Th1 and IL-17(+) T cells, challenges the view that Th1 cells suppress Th17 development through IFN-gamma, and suggests that Th1 and IL-17(+) T cells may collaboratively contribute to human autoimmune diseases.

Serum levels of the pro-inflammatory cytokine interleukin-12 and the anti-inflammatory cytokine interleukin-10 in patients with psoriasis treated by the Goeckerman regimen

BACKGROUND

The Goeckerman regimen (GR) involves the dermal application of a crude coal tar (polycyclic aromatic hydrocarbon, PAH) and exposure to ultraviolet (UV) radiation. Both PAH and UV radiation exhibit immunosuppressive activity. This study describes the changes in the serum levels of the pro-inflammatory cytokine interleukin-12 (IL-12) and the anti-inflammatory cytokine IL-10 in patients with psoriasis (n = 55) treated with GR.

METHODS

The serum levels of IL-12 and IL-10 were compared before and after GR. In addition, the IL-12 and IL-10 levels in psoriatic patients were compared with those in a control group of healthy blood donors (n = 47). The Psoriasis Area and Severity Index (PASI) was used to evaluate the efficacy of GR.

RESULTS

When compared with the control group, both IL-12 and IL-10 were significantly higher in psoriatic patients in all cases (P < 0.001). When compared before and after GR, the IL-12 and IL-10 levels (P < 0.01) and PASI value (P < 0.001) were significantly lower after GR. The decrease in the serum level of IL-12 and IL-10 after GR was related to the entry value before GR (IL-12, r = 0.60, P < 0.001; IL-10, r = 0.36, P < 0.01). There was a significant correlation between the IL-10 level before GR and the PASI value after GR (r = -0.39; P < 0.01).

CONCLUSIONS

The results indicate a strong pro-inflammatory effect of IL-12 in the immunopathogenesis of psoriasis, and confirm the immunosuppressive and anti-inflammatory effect of GR. IL-10 seems to be a promising individual marker for a positive effect of GR therapy.

Inflammation in atherosclerosis and psoriasis: common pathogenic mechanisms and the potential for an integrated treatment approach

Inflammation plays a key role in the pathogenesis of a number of chronic inflammatory systemic diseases (CISDs), including psoriasis, rheumatoid arthritis, systemic lupus erythematosus and Crohn's disease, and also in the pathogenesis of atherosclerosis. CISDs and cardiovascular diseases, such as atherosclerosis, share common pathogenic features, and cardiovascular disease is an important cause of morbidity and mortality in patients with CISDs. Activated inflammatory cells and pro-inflammatory cytokines contribute to the development of psoriatic lesions and play an important role in the breakdown of atherosclerotic plaques. Psoriasis and atherosclerosis also have similar histological characteristics involving T cells, macrophages and monocytes. In particular, the extravasation of T cells through the epithelium is characteristic of both psoriatic and atherosclerotic plaques. Cardiovascular disease is an important cause of morbidity and mortality in patients with psoriasis, which is associated with an increased cardiovascular risk profile compared with the general population. Patients with psoriasis are at increased risk of arterial hypertension, coronary heart disease, hyperlipidaemia, obesity and type II diabetes, which are more prevalent than in control patients. This increased risk could be due to the effects of chronic inflammatory changes, particularly the infiltration of T cells and subsequent secretion of pro-inflammatory cytokines. Some drugs used in the treatment of cardiovascular disease, such as 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (statins) and angiotensin-converting enzyme inhibitors have anti-inflammatory activity. In addition, systemic treatments for psoriasis may, by decreasing inflammation, reduce the risk of cardiovascular disease. It is suggested, therefore, that an integrated approach to the treatment of the inflammatory processes underlying both psoriasis and atherosclerosis may be beneficial in reducing cardiovascular risk in patients with psoriasis. The newer targeted biological therapies, such as efalizumab and infliximab, which offer the potential for long-term disease control in psoriasis, may be of particular use in this setting.

Blockade of CD11a by efalizumab in psoriasis patients induces a unique state of T-cell hyporesponsiveness

Efalizumab (anti-CD11a) interferes with LFA-1/ICAM-1 binding and inhibits several key steps in psoriasis pathogenesis. This study characterizes the effects of efalizumab on T-cell activation responses and expression of surface markers on human circulating psoriatic T cells during a therapeutic trial. Our data suggest that efalizumab may induce a unique type of T-cell hyporesponsiveness, directly induced by LFA-1 binding, which is distinct from conventional anergy described in animal models. Direct activation of T cells through different activating receptors (CD2, CD3, CD3/28) is reduced, despite T cells being fully viable. This hyporesponsiveness was spontaneously reversible after withdrawal of the drug, and by IL-2 in vitro. In contrast to the state of anergy, Ca(+2) release is intact during efalizumab binding. Furthermore, lymphocyte function-associated antigen-1 (LFA-1) blockade resulted in an unexpected downregulation of a broad range of surface molecules, including the T-cell receptor complex, co-stimulatory molecules, and integrins unrelated to LFA-1, both in the peripheral circulation and in diseased skin tissue. These observations provide evidence for the mechanism of action of efalizumab. The nature of this T-cell hyporesponsiveness suggests that T-cell responses may be reduced during efalizumab therapy, but are reversible after ceasing efalizumab treatment.

Psoriasis: evolution of pathogenic concepts and new therapies through phases of translational research

Psoriasis is perhaps unique for a disease studied through translational science in that there is not an accepted animal model, yet many rounds of bidirectional translation have taken place that have helped to define disease pathogenesis and to advance therapy. In this review, we illustrate the evolution of new pathogenic concepts and the testing of new therapeutic agents through translational research in humans. We present a current view of disease pathogenesis that stems from research in patients and animal models, but with the perspectives (i) that disease models can advance or hinder the overall translational enterprise and (ii) that the research process must be firmly grounded in the pathophysiology of the actual human condition.

Heart disease in psoriasis

Psoriasis has been traditionally viewed as an inflammatory skin disorder of unknown origin. Recent advances in the immunopathogenesis and genetics of psoriasis have broadened our understanding of psoriasis. Psoriasis is now considered a systemic inflammatory condition analogous to other inflammatory immune disorders. Patients with other immune disorders, such as systemic lupus erythematosus or rheumatoid arthritis, are known to be at increased risk of heart disease. Similarly, patients with psoriasis may carry an excess risk of heart disease, which would represent an important previously unrecognized cause of morbidity and mortality. This review summarizes the current evidence for an increased cardiovascular risk in patients with psoriasis and outlines deficits in our knowledge in this area.

Blood serum interferon-gamma bioactivity is low in weanling mice subjected to acute deficits of energy or both protein and energy

The main objective of the present study was to determine the influence of acute deficits of protein and energy on the blood serum level of interferon-gamma, a signature type 1 polarising inflammatory cytokine. In two 14 d experiments, male and female C57BL/6J mice, initial age 19 d, consumed a complete purified diet ad libitum or in restricted daily quantities, or had free access to an isoenergetic purified low-protein diet. A zero-time control group (age 19 d) was included in the second experiment. Serum interferon-gamma was assessed in both experiments by sandwich ELISA and, in the second experiment, also by a bioassay based on inhibition of proliferation by WEHI-279 B lymphoma cells. The immunoassay detected interferon-gamma inconsistently in all groups (range 0-14 pg/ml; detection limits 1 x 5 and 0 x 7 pg/ml in experiments 1 and 2, respectively). By contrast, interferon-gamma bioactivity was found in all animals of each group (means 339, 499, 124 and 200 pg/ml in zero-time controls, age-matched controls, low-protein and restricted intake groups, respectively; detection limit, 12 pg/ml), and the mean serum bioactivity of each malnourished group was low compared with the age-matched control (P <or=0 x 05). The present study defines the physiological serum interferon-gamma bioactivity of the adolescent mouse. Moreover, to the extent achievable by way of the blood, the results reflect the influence of metabolically diverse forms of acute malnutrition on the polarising type 1 cytokine profile within lymphoid microenvironments wherein immune responses arise. Therefore, the results suggest a mechanism underlying the cell-mediated inflammatory incompetence that characterises acute, prepubescent malnutrition.

Cytokine gene polymorphisms in Chinese patients with psoriasis

BACKGROUND

Previous studies have shown that cytokine gene polymorphisms may confer susceptibility to psoriasis.

OBJECTIVES

To determine whether genetic polymorphisms of the cytokine genes might influence the development of psoriasis in Chinese patients in Taiwan.

METHODS

DNA samples were obtained from 170 patients with psoriasis vulgaris (PV), 102 patients with psoriatic arthritis (PsA) and 210 control subjects. Using direct sequencing and microsatellite genotyping, we examined 28 polymorphisms in 11 cytokine genes including the interleukin (IL)-1alpha, IL-1beta, IL-1 receptor antagonist, IL-4, IL-8, IL-10, IL-12B, IL-13, tumour necrosis factor (TNF)-alpha, TNF-beta and interferon-gamma genes. Genotypes of HLA-Cw*0602, killer cell immunoglobulin-like receptor (KIR) genes and major histocompatibility complex class I chain-related gene A (MICA) were also determined in patients with PsA.

RESULTS

The patients with PV were more likely to carry the +4496G allele of the IL-12B gene (59.4% vs. 49.3%, P = 0.0067, P(c) = 0.033). However, no significantly different allelic and genotypic distributions of the other analysed genes including IL-1beta, TNF-alpha, TNF-beta, KIR genes and MICA were found between the PV/PsA patients and controls. Moreover, no association was observed with disease onset, gender, peripheral arthritis or joint erosion. With regards to HLA-Cw*0602, its allele frequency was significantly increased in patients with early-onset PV (25.3% vs. 4.8%, P < 10(-7)), but not in patients with PsA.

CONCLUSIONS

The IL-12B gene polymorphism conferred a risk for PV in our Chinese population, although the effect was more minor than that of HLA-Cw*0602. Cw*0602, KIR2DS1/S2 and MICA-A9 were unlikely to be risk alleles in our patients with PsA. The other analysed genetic polymorphisms of cytokine genes do not appear to be associated with susceptibility to PV and PsA in Chinese patients in Taiwan.

Altered distribution of leukocyte subsets and cytokine production in response to acute psychosocial stress in patients with psoriasis vulgaris

Psoriasis (PSO) is a mainly T helper-type 1 (TH(1)) cell mediated chronic inflammatory skin disease characterized by epidermal hyperproliferation and psoriatic plaques. There is ample evidence that stress may trigger psoriatic eruption, however, the underlying mechanisms of stress-induced exacerbation of PSO are poorly understood. The specific goal of the present study was to investigate the impact of acute stress on pathologically relevant immune functions in PSO patients. PSO patients (n=23) and healthy controls (n=25) were exposed to a standardized laboratory stressor ("Trier Social Stress Test", TSST) including a free speech and mental arithmetics in front of an audience. Blood samples were collected 10min before and 1, 10, 20, and 60min after the TSST as well as 24h after the experiment at identical time points under resting conditions. Analyses of leukocyte subsets indicated a significantly increased number of leukocyte subpopulations (lymphocytes, granulocytes, CD3(+), CD8(+), CD16(+)/CD56(+), and CD3(+)/HLA-DR(+)) after the TSST (all p<.01) with no significant between-group differences. However, monocyte number (F(3,120)=2.7; p<.01) and number of CD4(+)cells (F(3,120)=3.09; p<.05) were found to be significantly higher in PSO sufferers than in controls. Moreover, a significant decrease of CD3(+)/CD25(+)cells was observed in the PSO, but not in the control group (F(3,120)=3.46; p<.05). After exposure to the TSST, stimulation of peripheral blood mononuclear cells (PBMCs) with phytohemagglutinin (PHA) resulted in elevated production of IFN-gamma (F(3,126)=6.9; p<.001) and IL-2 (F(3,123)=6.6; p<.001), and moreover, a decreased production of IL-10 (F(3,132)=5.22; p<.01) and IL-4 (F(3,129)=3.9; p<.01). No difference in stress-induced changes of cytokine production to PHA could be identified between the two experimental groups (all p>.05). The present findings suggest that acute psychosocial stress is associated with changes of immune functions known to be involved in PSO which may be one potential explanation of how stress may trigger psoriatic eruption.

Serum levels of TNF-alpha, IFN-gamma, IL-6, IL-8, IL-12, IL-17, and IL-18 in patients with active psoriasis and correlation with disease severity

Recent progress in the understanding of psoriasis has shown that the regulation of local and systemic cytokines plays an important role in its pathogenesis. The most often used psoriasis score is the psoriasis area and severity index (PASI). A simple laboratory test from a blood sample would be an attractive, patient-independent, and observer-independent marker of disease severity. To this end, we evaluated the association of serum levels of some proinflammatory cytokines in vivo and their correlation with severity of psoriasis. The serum levels of cytokines levels were determined with the use of the ELISA method. All mean values except IL-17 levels of patients were significantly higher than those of controls. There was a significant correlation between serum levels of IFN-γ, IL-12, IL-17, and IL-18, and severity of the disease. Psoriasis can be described as a T-cell-mediated disease, with a complex role for a variety of cytokines, which has led to the development of new immunomodulatory therapies. In this study, serum TNF-α, IFN-γ, IL-6, IL-8, IL-12, and IL-18 levels were significantly higher in active psoriatic patients than in controls. Furthermore, high levels of IFN-γ, IL-12, and IL-18 correlated with the clinical severity and activity of psoriasis, and those measurements of serum levels of these cytokines may be objective parameters for the disease severity.

The high prevalence of infections and allergic symptoms in patients with ankylosing spondylitis is associated with clinical symptoms

Ankylosing spondylitis (AS) is strongly associated with the major histocompatibility complex (MHC) class I antigen HLA-B27. This may have influence on the physiologic immune response. Whether it leads to an increased prevalence of infections and/or allergy in AS patients is unclear. This study aims to determine the prevalence of infections and allergic symptoms in patients with AS and to detect a possible association with clinical symptoms. Data on 1,080 AS patients and on 102 disc prolapse patients were collected by questionnaire. The proportion of patients with a symptomatic infection in the last year was 65.5% in AS patients in comparison with 25.5% in disc prolapse patients (p=0.0001). AS patients reported more gastrointestinal (GI) [odds ratio (OR) 5.07, 95% confidence interval (CI) 2.20-11.71], urinary tract (OR 2.81, 95%CI 1.41-5.72), and respiratory (OR 5.83, 95%CI 3.38-10.08) infections than did disc prolapse patients. Multiple infections were more common in AS patients across all infection types. Allergic symptoms were reported by AS patients more frequently than by disc prolapse patients (OR 5.13, 95%CI 3.49-8.80). Patients reporting concurrent inflammatory bowel disease were more likely to report GI (OR 3.0, 95%CI 1.9-4.8) and urinary tract (OR 1.7, 95%CI 1-2.8) infection than primary AS patients. In AS patients, infection was independently associated with female gender (OR 1.96, 95%CI 1.47-2.56), a history of significant peripheral joint inflammation (OR 1.55, 95%CI 1.18-2.05), and increasing pain duration (p=0.05). A high prevalence of common infections and allergic symptoms is seen in patients with AS, most of which are HLA-B27-positive. This may have implications both for underlying mechanisms of disease and for therapeutic options.