The genetic basis of psoriasis

The Current Advancement in Psoriasis

The study on psoriasis disease helps improve the condition and treatment options day by day in dermatology. In the current scenario, research is ongoing to make the best interventions possible for managing the disease. Psoriasis is one of the most common dermatological conditions wherein chronic inflammation of the skin occurs, characterized by the formation of a rash with scaly, itchy patches over the body surface. The condition is mainly related to the immune system wherein epidermal hyperplasia occurs with infiltration of immune cells. Many factors can trigger psoriasis. Environmental, emotional, hereditary, and personal habits are responsible for the conditions. The current research helps to gain a complete understanding, and the basic knowledge of the state with recent advancements in treatment strategies and characteristic features can also be studied. The main aim is to know the disease's primary root cause and management. It involves the main sites of the body. The most commonly affected parts are the scalp, trunks, knees, elbow, and ankle. It is a chronic long-term disease. Sometimes it may be painful. Itching, bleeding, and disturbed sleep patterns are common symptoms. Most commonly involves the upper epidermal surface. The prevalence of the condition has been increased as it is associated with other comorbidities. The main focus of the treatment is to restrict skin cell multiplication and remove scaly surfaces. This review discusses the advancement in the treatment, its initiation, progression, current symptoms, and disease development. The study also includes basic knowledge about the types of psoriatic disease with its specific features and mechanisms.

Insights into interplay of immunopathophysiological events and molecular mechanistic cascades in psoriasis and its associated comorbidities

Psoriasis is an inflammatory skin disease with complex pathogenesis and multiple etiological factors. Besides the essential role of autoreactive T cells and constellation of cytokines, the discovery of IL-23/Th17 axis as a central signaling pathway has unraveled the mechanism of accelerated inflammation in psoriasis. This has provided insights into psoriasis pathogenesis and revolutionized the development of effective biological therapies. Moreover, genome-wide association studies have identified several candidate genes and susceptibility loci associated with this disease. Although involvement of cellular innate and adaptive immune responses and dysregulation of immune cells have been implicated in psoriasis initiation and maintenance, there is still a lack of unifying mechanism for understanding the pathogenesis of this disease. Emerging evidence suggests that psoriasis is a high-mortality disease with additional burden of comorbidities, which adversely affects the treatment response and overall quality of life of patients. Furthermore, changing trends of psoriasis-associated comorbidities and shared patterns of genetic susceptibility, risk factors and pathophysiological mechanisms manifest psoriasis as a multifactorial systemic disease. This review highlights the recent progress in understanding the crucial role of different immune cells, proinflammatory cytokines and microRNAs in psoriasis pathogenesis. In addition, we comprehensively discuss the involvement of various complex signaling pathways and their interplay with immune cell markers to comprehend the underlying pathophysiological mechanism, which may lead to exploration of new therapeutic targets and development of novel treatment strategies to reduce the disastrous nature of psoriasis and associated comorbidities.

IL-23/IL-17 Axis in Inflammatory Rheumatic Diseases

In inflammatory rheumatic disorders, the immune system attacks and damages the connective tissues and invariably internal organs. During the past decade, remarkable advances having been made towards our understanding on the cellular and molecular mechanisms involved in rheumatic diseases. The discovery of IL-23/IL-17 axis and the delineation of its important role in the inflammation led to the introduction of many needed new therapeutic tools. We will present an overview of the rationale for targeting therapeutically the IL-23/IL-17 axis in rheumatic diseases and the clinical benefit which has been realized so far. Finally, we will discuss the complex interrelationship between IL-23 and IL-17 and the possible uncoupling in certain disease settings.

Baccharis dracunculifolia (Asteraceae) essential oil displays anti-inflammatory activity in models of skin inflammation

ETHNOPHARMACOLOGICAL RELEVANCE

Baccharis dracunculifolia (Asteraceae) is a commonly used plant in traditional medicine known as "alecrim-do-campo". Popularly it has been used as an immunostimulant, antibiotic, anti-inflammatory among other applications. So far, only a few studies have investigated the B. dracunculifolia anti-inflammatory effect and none has investigated the effectiveness of essential oil on skin diseases.

AIM OF THE STUDY

The study aimed at evaluating the topical anti-inflammatory activity of B. dracunculifolia essential oil (BdEO) in mice models of acute and chronic skin inflammation.

MATERIALS AND METHODS

BdEO was obtained from leaves and it was analyzed with Gas Chromatograph. Topical anti-inflammatory activity of BdEO (0.1, 0.3 and 1.0 mg/ear) was evaluated in Arachidonic Acid or TPA-induced acute and chronic skin inflammation in mice. Parameters such edema, cell migration and keratinocytes proliferation were evaluated. In addition, safety and a possible mechanism of action for BdEO essential oil were also investigated.

RESULTS

Our results indicate that mainly terpenoids compounds compose BdEO. In addition, topical treatment with BdEO inhibited inflammatory parameters in both acute and chronic models of skin inflammation. This protective effect was associated with reduced edema formation, smaller cellular influx into the inflamed tissue and reduction of keratinocytes hyperproliferation. Although BdEO appears to exert its anti-inflammatory effect through a corticosteroid pathway, no local or systemic side effects were observed.

CONCLUSION

Taken together, the present results showed that the essential oil obtained by hydrodistillation from B. dracunculifolia leaf samples exhibit remarkable topical anti-inflammatory properties. Therefore, our study demonstrated evidence for BdEO topical anti-inflammatory efficacy and safety, suggesting that it could be considered for developing of a new phytotherapeutic formulation as treatment for skin diseases.

Pediatric psoriasis: Evolving perspectives

BACKGROUND/OBJECTIVES

Childhood-onset psoriasis is a common skin disorder that has recently received increasing attention, particularly because of its significant medical, social, financial, and psychological burdens and its associated comorbidities. With limited data available and lack of standardized management guidelines for pediatric psoriasis, an expert panel desired to provide an updated critical overview and practical guidance for management of the affected population.

METHODS

A panel of pediatric dermatologists with extensive experience in pediatric psoriasis defined and prioritized a core set of topics, performed an English-language literature review, prepared critical evaluations and presentations of topic areas, and carried out a consensus meeting and follow-up consensus manuscript.

RESULTS

The summation of evolving perspectives in pediatric psoriasis includes epidemiology and natural history of the disease, precipitating factors and comorbidities, quality of life and burden of disease, clinical features and disease presentation, differential diagnosis, pathogenesis and treatment, including topical, photo, and systemic therapies.

CONCLUSION

Pediatric psoriasis is an important immune-mediated inflammatory skin disease with potential for significant impact on affected individuals and their caregivers. Current state-of-the-art care is based primarily on experience and expert consensus, but pediatric data are accumulating and therapeutic options are rapidly evolving.

Psoriasis in those planning a family, pregnant or breast-feeding. The Australasian Psoriasis Collaboration

The Australasian Psoriasis Collaboration has reviewed the evidence for managing moderate to severe psoriasis in those who are pregnant or are breast-feeding, or planning a family. The severity of the psoriasis, associated comorbidities and specific anti-psoriasis treatment, along with other exposures, can have a deleterious effect on pregnancy outcomes. Psoriasis itself increases the risk of preterm and low birthweight babies, along with spontaneous and induced abortions, but no specific birth defects have been otherwise demonstrated. The baseline risk for a live born baby to have a major birth defect is 3%, and significant neuro-developmental problem is 5%. In Australia, pregnant women with psoriasis are more likely to be overweight or obese, depressed, or smoke in their first trimester, and are also less likely to take prenatal vitamins or supplements. Preconception counselling to improve maternal, pregnancy and baby health is therefore strongly encouraged. The topical and systemic therapies commonly used in psoriasis are each discussed separately, with regards to pregnancy exposure, breast-feeding and effects on male fertility and mutagenicity. The systemic therapies included are acitretin, adalimumab, apremilast, certolizumab, ciclosporin, etanercept, infliximab, ixekizumab, methotrexate, NBUVB, prednisone, PUVA, secukinumab and ustekinumab. The topical therapies include dithranol (anthralin), calcipotriol, coal tar, corticosteroids (weak, potent and super-potent), moisturisers, salicylic acid, tacrolimus, and tazarotene. As a general recommendation, effective drugs that have been widely used for years are preferable to newer alternatives with less foetal safety data. It is equally important to evaluate the risks of not treating, as severe untreated disease may negatively impact both mother and the foetus.

HLA-Cw6 homozygosity in plaque psoriasis is associated with streptococcal throat infections and pronounced improvement after tonsillectomy: A prospective case series

BACKGROUND

Carriage of the HLA-Cw*0602 allele is associated with a particular set of clinical features and treatment responses in psoriasis. Tonsillectomy can improve psoriasis.

OBJECTIVES

We sought to evaluate whether HLA-Cw*0602 predicts a favorable outcome after tonsillectomy of patients with psoriasis.

METHODS

This prospective case series followed up 28 tonsillectomized patients with plaque psoriasis for 24 months. The Psoriasis Area and Severity Index, Psoriasis Disability Index, and Psoriasis Life Stress Inventory were used for assessment. Tonsils were swabbed for bacteria and patients genotyped for HLA-Cw*0602.

RESULTS

After tonsillectomy, HLA-Cw*0602 homozygotes showed significantly more improvement, compared with heterozygous and HLA-Cw*0602-negative patients. Thus, Psoriasis Area and Severity Index score was reduced by 82% in the homozygous patients compared with 42% and 31%, respectively (P < .001), Psoriasis Disability Index score improved by 87% compared with 38% and 41%, respectively (P < .001), and Psoriasis Life Stress Inventory score was 82% reduced compared with 60% and 54%, respectively (P < .001). The homozygotes more often had psoriasis onset associated with a throat infection (P = .007) and an increased frequency of streptococcal throat infections per lifetime (P = .038).

LIMITATIONS

Few patients were included and some data were retrospective.

CONCLUSIONS

Homozygous HLA-Cw*0602 carriage in plaque psoriasis may predict a favorable outcome after tonsillectomy.

A multileveled approach in psoriasis assessment and follow-up: A proposal for a tailored guide for the dermatological practice

BACKGROUND

Psoriasis is a complex and heterogeneous disease resulting from interactions between genetic, immunological, and environmental factors. To make the most optimal treatment decision, the dermatologist must therefore have a detailed overview of the patient's history and lifestyle.

OBJECTIVES

We sought to offer an overview of the various relevant aspects in clinical dermatological assessment of psoriasis patients, emphasizing the importance of a multidisciplinary and integrated clinical approach.

METHODS

We gathered information on psoriasis management and developed a tailored checklist covering all health-related aspects associated with psoriasis.

RESULTS

Demographics, personal and family history were elaborately described as well as drug history to discuss how they affect psoriasis management. Relevant patient information such as the vaccination status or cardiovascular profile were included in the checklist as well and treatment recommendations were adapted and updated in accordance with evidence-based literature. This checklist also emphasizes the importance of drug surveillance, proper follow-up and specialist referral, and why the dermatologist needs to address these health-related aspects when assessing psoriasis patients, going beyond optimal skin care.

CONCLUSIONS

Our comprehensive overview can be used as a consultation checklist for good clinical practice in psoriasis patient management and aid in treatment decision.

HLA-C and TNF gene polymorphisms are associated with psoriasis in Brazilian patients

BACKGROUND

Polymorphisms at the human leukocyte antigens (HLA-C) and tumor necrosis factor (TNF) genes have been associated with susceptibility to psoriasis in several worldwide populations. In this study, HLA-C and TNF (-238/-308) polymorphisms were performed in 125 Brazilian patients and 202 healthy controls.

METHODS

HLA-C and TNF promoter region alleles were typed by polymerase chain reaction using sequence-specific primer-polymerase chain reaction.

RESULTS

The presence of HLA-C*06 was associated with psoriasis onset, particularly in younger patients, being more frequent for patients with disease onset before the age of 20 years (P = 0.03), 25 years (P = 0.01), or 30 years (P = 0.03). No association between HLA-C*06 and psoriasis was observed for patients older than 35 years. Susceptibility to psoriatic arthritis was associated with the TNF -238 G/A genotype (P = 0.02). The TNF -308A allele was overrepresented in patients (P = 0.0061), and the TNF -308 G/A genotype was increased in generalized forms (erythrodermic and generalized pustular psoriasis) compared to plaque psoriasis (P < 0.001). The TNF -238A/HLA-C*06 haplotype was overrepresented in patients (P = 0.025), while the TNF -238G/HLA-C*15 haplotype was increased in controls (P = 0.037).

CONCLUSIONS

The strong association of HLA-C*06 allele with disease susceptibility, particularly in early onset psoriasis, indicates that younger ages could be considered to stratify psoriasis into early and late types. TNF -308 polymorphisms can be associated with psoriasis susceptibility and severity. Potential genetic markers of psoriasis in populations with a complex mixture of ethnicities should be investigated.

A single nucleotide polymorphism -35 kb T>C (rs9264942) is strongly associated with psoriasis vulgaris depending on HLA-Cw(∗)06

HLA class I molecules play a role both in viral infection control and in autoimmune diseases development. rs9264942T>C polymorphism in HLA-C gene was found to impact on HLA-C surface expression level and to be associated with HIV-1 control. It was found that these HLA alleles which protect against AIDS are associated with autoimmune disease e.g. psoriasis vulgaris (PsV). Whether rs9264942 SNP is associated with PsV was investigated here. rs9264942T>C was genotyped in 292 PsV patients, and 254 controls using TaqMan Genotyping Assay. PsV patients differed from controls in frequencies of rs9264942T>C alleles (p=3.62 × 10(-16)) and genotypes (5.67 × 10(-15)). However, rs9264942C allele was predisposing to PsV 3-fold weaker than HLA-Cw(∗)06 (OR=5.04 vs. OR=15.61, respectively). In addition, this SNP was described earlier to be in strong linkage disequilibrium (LD) with another SNP, rs67384697 ins/del, which by affecting a microRNA binding is responsible for regulating HLA-C expression. However, typing for is cheaper and simpler than that for rs67384697, therefore we think it may substitute for it to some extent.

Genetic Epidemiology of Psoriasis

Psoriasis is a chronic, inflammatory, immune-mediated skin condition with a prevalence of 0-11.8% across the world. It is associated with a number of cardiovascular, metabolic, and autoimmune disease co-morbidities. Psoriasis is a multifactorial disorder, influenced by both genetic and environmental factors. Its genetic basis has long been established through twin studies and familial clustering. The association of psoriasis with the HLA-Cw6 allele has been shown in many studies. Recent genome-wide association studies have identified a large number of other genes associated with psoriasis. Many of these genes regulate the innate and adaptive immune system. These findings indicate that a dysregulated immune system may play a major role in the pathogenesis of psoriasis. In this article, we review the clinical and genetic epidemiology of psoriasis with a brief description of the pathogenesis of disease.

Treatment of childhood psoriasis with phototherapy and photochemotherapy

Phototherapy and photochemotherapy are well-described treatment modalities for psoriasis in adults. Like many other treatments, the experience and long-term safety of their use in children is limited. We conducted a literature search and identified publications reporting the use of phototherapy and photochemotherapy in pediatric populations. This article summarizes the existing literature on this topic. Although many studies report good improvement with these treatment modalities, long-term safety data on their use is lacking for pediatric patients.

The HLA-Cw*06 allele and -1149 G/T polymorphism of extrapituitary promoter of PRL gene as a possible common genetic predisposing factors to psoriasis vulgaris and psoriatic arthritis in Czech population

Psoriatic arthritis (PsA) affects approximately 30 % of patients suffering from psoriasis vulgaris (PsV), but the risk factors for its development have not been well elucidated yet. The HLA-Cw*06 allele was described as a predisposing factor to PsV. Prolactin is known as an immune response modulator, and its elevated levels present risk for PsV development. It is possible that these factors interact and together emphasize the predisposition to both diseases. We tested on an association of HLA-Cw alleles and functional polymorphism -1149 G/T in PRL gene extrapituitary promoter with PsV and PsA in Czech population. We found a statistically significant association between HLA-Cw*06 allele and PsV (P corrected = 0.0013) that was most prominent in early onset disease subtype (P corrected = 0.0013). The association between HLA-Cw*06 and PsA was low (P corrected = 0.0585) and restricted to PsA patients with early PsV onset (P corrected = 0.0195). We found no association of -1149 G/T PRL gene polymorphism with either PsV or PsA.

New insights of T cells in the pathogenesis of psoriasis

Psoriasis is one of the most common immune-mediated chronic, inflammatory skin diseases characterized by hyperproliferative keratinocytes and infiltration of T cells, dendritic cells, macrophages and neutrophils. Although the pathogenesis of psoriasis is not fully understood, there is ample evidence suggesting that the dysregulation of immune cells in the skin, particularly T cells, plays a critical role in psoriasis development. In this review, we mainly focus on the pathogenic T cells and discuss how these T cells are activated and involved in the disease pathogenesis. Newly identified 'professional' IL-17-producing dermal γδ T cells and their potential role in psoriasis will also be included. Finally, we will briefly summarize the recent progress on the T cell and its related cytokine-targeted therapy for psoriasis treatment.

[Study of genetic polymorphisms in the tumor necrosis factor α promoter region in Spanish patients with psoriasis]

BACKGROUND

Several studies have reported an association between tumor necrosis factor α (TNF-α) polymorphisms and inflammatory diseases such as psoriasis vulgaris and psoriatic arthritis, although the results vary according to the population studied. No studies have been performed in the Spanish population.

OBJECTIVE

To analyze the polymorphisms of the promoter region of the TNF-α gene in patients with moderate to severe psorasis and to identify potential differences in genotype compared to a group of healthy volunteers.

MATERIAL AND METHODS

Eighty-nine patients with moderate to severe psoriasis and 76 healthy controls with no personal or family history of psoriasis were selected. Polymorphisms of the TNF-α promoter region of both groups were genotyped.

RESULTS

We observed a higher prevalence of the genotype with both wild-type alleles at positions -238 (GG genotype, 86.5% vs 70.4%, respectively) and -1031 (TT genotype, 80.2% vs 45.8%, respectively) in patients compared to the healthy control group. The differences at positions -308 and -857 were not significant.

CONCLUSION

There are differences in polymorphisms at positions -238 and -1031 in patients with moderate to severe psoriasis compared to healthy volunteers. This observation provides further support for the importance of the part that TNF-α plays in the pathophysiology of this disease.

Biological drugs targeting the immune response in the therapy of psoriasis

Chronic plaque psoriasis affects more than 2% of world population, has a chronic recurrent behavior, gives a heavy burden to the patients’ quality of life, and hence remains a huge medical and social problem. The clinical results of conventional therapies of psoriasis are not satisfactory. According to the current knowledge of the molecular and cellular basis of psoriasis, it is defined as an immune-mediated chronic inflammatory and hyperproliferative skin disease. A new generation of biological drugs, targeting molecules and cells involved into perturbed pro-inflammatory immune response in the psoriatic skin and joints, has been recently designed and applied clinically. These biological agents are bioengineered proteins such as chimeric and humanized antibodies and fusion proteins. In particular, they comprise the antitumor necrosis factor-α agents etanercept, infliximab, and adalimumab, with clinical efficacy in both moderate-severe psoriasis and psoriatic arthritis, and the anti-CD11a efalizumab with selective therapeutic action exclusively in the skin. Here, we overview recent findings on the molecular pathways relevant to the inflammatory response in psoriasis and present our clinical experience with the drugs currently employed in the dermatologic manifestations, namely etanercept, infliximab, and efalizumab. The growing body of clinical data on the efficacy and safety of antipsoriasis biological drugs is reviewed as well. Particular focus is given to long-term safety concerns and feasibility of combined therapeutic protocols to ameliorate clinical results.

Multiple loci are associated with white blood cell phenotypes

White blood cell (WBC) count is a common clinical measure from complete blood count assays, and it varies widely among healthy individuals. Total WBC count and its constituent subtypes have been shown to be moderately heritable, with the heritability estimates varying across cell types. We studied 19,509 subjects from seven cohorts in a discovery analysis, and 11,823 subjects from ten cohorts for replication analyses, to determine genetic factors influencing variability within the normal hematological range for total WBC count and five WBC subtype measures. Cohort specific data was supplied by the CHARGE, HeamGen, and INGI consortia, as well as independent collaborative studies. We identified and replicated ten associations with total WBC count and five WBC subtypes at seven different genomic loci (total WBC count-6p21 in the HLA region, 17q21 near ORMDL3, and CSF3; neutrophil count-17q21; basophil count- 3p21 near RPN1 and C3orf27; lymphocyte count-6p21, 19p13 at EPS15L1; monocyte count-2q31 at ITGA4, 3q21, 8q24 an intergenic region, 9q31 near EDG2), including three previously reported associations and seven novel associations. To investigate functional relationships among variants contributing to variability in the six WBC traits, we utilized gene expression- and pathways-based analyses. We implemented gene-clustering algorithms to evaluate functional connectivity among implicated loci and showed functional relationships across cell types. Gene expression data from whole blood was utilized to show that significant biological consequences can be extracted from our genome-wide analyses, with effect estimates for significant loci from the meta-analyses being highly corellated with the proximal gene expression. In addition, collaborative efforts between the groups contributing to this study and related studies conducted by the COGENT and RIKEN groups allowed for the examination of effect homogeneity for genome-wide significant associations across populations of diverse ancestral backgrounds.

A CD40 and an NCOA5 gene polymorphism confer susceptibility to psoriasis in a Southern European population: a case-control study

Recent genome-wide association studies of many complex diseases have successfully identified novel susceptibility loci, with many of them shared by multiple disease-associated pathways. The genes CD40 and nuclear receptor coactivator 5 (NCOA5), located in a 400-kb region surrounding CD40, have been reported to be associated with increased risk for rheumatoid arthritis and other autoimmune diseases. We hypothesized that those genes may also have a role in psoriasis (PS), an autoimmune, chronic inflammatory skin disease. In a case-control study, 198 patients with PS and 400 controls were genotyped for 2 single nucleotide polymorphisms (SNPs) of the CD40 and NCOA5 genes located on chromosome 20q.12-q13.12. Here, we demonstrate for the first time the association of both SNPs with susceptibility to PS, thus suggesting a putative key role of both genes in multiple autoimmune diseases. Alleles G and C of the CD40 rs4810485 and NCOA5 rs2903908 SNPs, respectively, were more common in individuals with PS than in controls (p = 0.03, odds ratio [OR] = 1.42, 95% confidence interval [95% CI] 1.05-1.95 and p = 0.000 003, OR = 1.93, 95% CI 1.47-2.55, respectively). The identification of shared genetic susceptibility loci may provide insight into our understanding of the pathophysiology of autoimmune diseases.

Psoriasis in children: an insight

Onset of psoriasis in childhood is quite common. Chronicity, inflammation and hyperproliferation are the cardinal features by which the condition establishes its uniqueness. Clearance of disease may be farfetched in most patients and relapse is frequent. Early recognition and management of psoriasis in children and adolescents is vital in therapy in children.

Current status and new developments in the treatment of psoriasis and psoriatic arthritis with biological agents

Psoriasis is a chronic inflammatory disease affecting 1-3% of the general population. Among psoriatic patients, 5-40% are affected by psoriatic arthritis. Due to the chronic nature of the disease, patients suffer from substantial psychological and financial burdens, thus adding to a significantly impaired quality of life. Traditional systemic therapies for psoriasis, such as methotrexate, cyclosporin A, retinoids or PUVA therapy, have a potential for long-term toxicity and may not always provide sufficient improvement of the disease. The development of novel therapies targeting key steps in the pathogenesis of psoriasis and psoriatic arthritis now provide new and efficient treatment options. Biological therapies for the treatment of psoriasis and/or psoriatic arthritis are defined by their mode of action and can be classified into three categories: the T-cell modulating agents (alefacept and efalizumab), the inhibitors of tumour necrosis factor-alpha (TNFalpha blockers, e.g. adalimumab, certolizumab, etanercept, golimumab and infliximab) and the inhibitors of interleukin (IL) 12 and IL-23 (e.g. ustekinumab and briakinumab). This article provides a brief overview of the currently approved biological agents in the European Union and of some newer agents, such as briakinumab, certolizumab and golimumab.

Psoriasis--as an autoimmune disease caused by molecular mimicry

Psoriasis is strongly associated with streptococcal throat infection, and patients have increased occurrence of such infections. Psoriatic lesional T cells are oligoclonal, and T cells recognizing determinants common to streptococcal M-protein and keratin have been detected in patients' blood. We propose that CD8(+) T cells in psoriatic epidermis respond mainly to such determinants, whereas CD4(+) T cells in the dermis preferentially recognize determinants on the streptococcal peptidoglycan that might itself act as an adjuvant. The streptococcal association might reflect the concurrence of superantigen production promoting skin-homing of tonsil T cells, M-protein mimicking keratin determinants, and adjuvant effects of the peptidoglycan. Accordingly, improvement of psoriasis after tonsillectomy should be associated with fewer T cells that recognize keratin and streptococcal determinants.

Common polymorphisms in the interleukin-22 gene are not associated with chronic plaque psoriasis

BACKGROUND

Psoriasis is a chronic inflammatory skin disease. Among other cytokines, interleukin 22 (IL-22) has been implicated in the pathogenesis of chronic plaque psoriasis. The purpose of this study was to investigate a hypothesized association between common IL-22 gene polymorphisms and chronic plaque psoriasis.

METHODS

Genotypes of 10 common polymorphisms of the IL-22 gene were determined by fluorogenic 5' exonuclease assays (TaqMan) in 475 patients with chronic plaque psoriasis and 252 controls.

RESULTS

Two blocks of high linkage disequilibrium, formed by eight polymorphisms upstream of exon 5 (rs2227485, rs2227491, rs2046068, rs1179251, rs1012356, rs2227501, rs2227503, rs976748) and two polymorphisms in the 3' near gene region (rs1182844, rs1179246), were observed within the IL-22 gene. Neither single polymorphisms nor haplotypes were significantly associated with the presence or clinical features of chronic plaque psoriasis (P > 0.05).

CONCLUSIONS

Our data suggest that the investigated IL-22 gene polymorphisms are unlikely major risk factors for chronic plaque psoriasis.

STAT4 gene polymorphism is associated with psoriasis in the genetically homogeneous population of Crete, Greece

Recent genome-wide association studies (GWAS) of many complex diseases have successfully identified novel susceptibility loci, with many of them being associated with more than one condition. Taking into consideration that different autoimmune diseases may share some common pathogenetic pathways, we hypothesized that STAT4, a susceptibility gene found to be associated with increased risk for systemic lupus erythematosus, rheumatoid arthritis, type 1 diabetes, Sjögren's syndrome, Wegener's granulomatosis, Crohn's disease, and ulcerative colitis may also have a role in psoriasis. Psoriasis is an autoimmune, chronic inflammatory skin disease. Here we performed a case-control study in the population of island of Crete and demonstrated for the first time the association of a STAT4 single nucleotide polymorphism (SNP) with susceptibility to psoriasis, thus suggesting a putative key role of STAT4 in multiple autoimmune diseases. We found that mutated allele T of the STAT4 rs7574865 SNP, which previously was implicated in the predisposition to many autoimmune diseases, were more common in individuals with psoriasis than in controls (p = 0.045, odds ratio = 1.42, 95% confidence interval 1.01-2.00), thus concluding that the polymorphism examined is associated with the development of psoriasis in our population.

Emerging drugs for psoriasis

BACKGROUND

Psoriasis is a relatively common, chronic and disabling skin disease, due to a disturbed proliferation and differentiation of keratinocytes, accompanied by vascular alterations and infiltration of inflammatory cells with a local T(H)1-type cytokine immune response. There is no cure, but several treatment options are available.

OBJECTIVE

The treatment of psoriasis is far from being satisfactory, due to the impractical modalities of topical treatment and the suboptimal safety profile of the systemic treatments available. In the last few years, parallel to an improved understanding of the disease pathogenesis, there has been a boosting of research in new agents for the treatment of psoriasis. These new agents are the focus of this paper.

METHODS

After a short review of the treatment options already available (mainly based on the available systematic reviews), we focused on agents that are still in clinical development (Phase I - III) and have not yet entered the market. For the purpose of this study, we systematically searched the main registries of ongoing trials up to August 2008.

RESULTS/CONCLUSION

The field is very dynamic, with both immunopharmacology of recombinant DNA techniques and more traditional small-molecule pharmacology actively delivering new agents. With the increasing number of new options, there is a need for research systems that enable to effectively collect long-term safety data on treated patients.

Psoríase na infância e na adolescência

A psoríase é doença inflamatória crônica, imunologicamente mediada, recorrente e de caráter universal. Aproximadamente um terço dos adultos acometidos refere início da doença antes dos 16 anos de idade. Quanto mais precoce, mais grave tende a ser a evolução do quadro. Em crianças, as lesões podem ser fisicamente desfigurantes, causando prejuízos psicológicos e evidente comprometimento da qualidade de vida. As medicações sistêmicas utilizadas na psoríase, bem como a fototerapia, têm indicação limitada na infância, devido aos efeitos cumulativos das drogas, à baixa aceitação e ao risco de teratogenicidade. Nesta seção, discutiremos as principais manifestações clínicas da psoríase na infância e na adolescência, bem como os diagnósticos diferenciais, opções terapêuticas e prognóstico.

New insights and therapies for teenage psoriasis

PURPOSE OF REVIEW

Psoriasis is an important disorder in the adolescent population and has a tremendous physical and psychological impact on patients. It is important to understand the genetics, various clinical presentations, comorbidities, and treatment options associated with psoriasis.

RECENT FINDINGS

The human leukocyte antigen-C gene likely contains a susceptibility locus for psoriasis. Cytokines interleukin-12 and interleukin-23 have been implicated in the pathogenesis of psoriasis as well. Psoriasis is likely associated with an increased risk of myocardial infarction, metabolic syndrome, Crohn's disease, and depression; it is difficult to assess the implications in the adolescent population.

SUMMARY

Psoriasis is not rare in the adolescent population. It is important for physicians to be aware of the different clinical presentations as well as the spectrum of treatment options that are available.

Obesity in psoriasis: leptin and resistin as mediators of cutaneous inflammation

BACKGROUND

Obesity is a significant risk factor for psoriasis and body mass index (BMI) correlates with disease severity. Objectives To investigate the relationship between obesity and psoriasis, focusing on the role of adipokines such as leptin and resistin.

PATIENTS/METHODS

Patients with psoriasis (n = 30) were recruited and their BMI, waist circumference and disease severity [Psoriasis Area and Severity Index (PASI)] were recorded. Fasting serum samples were obtained on enrolment and after a course of ultraviolet (UV) B treatment. Age-, sex- and BMI-matched healthy controls were also recruited.

RESULTS

On enrolment, serum leptin and soluble leptin receptor levels were not raised compared with the controls. However, resistin, interleukin (IL)-1beta, IL-6, and chemokines CCL2, CXCL8 and CXCL9 were all significantly elevated in the patient group and serum resistin correlated with disease severity (r = 0.372, P = 0.043). Improvement after UVB treatment was accompanied by decreased serum CXCL8. In vitro, both leptin and resistin could induce CXCL8 and tumour necrosis factor-alpha production by blood monocytes, and leptin could additionally induce IL-1beta and IL-1 receptor antagonist production. Leptin also dose dependently increased secretion of the growth factor amphiregulin by ex vivo-cultured lesional psoriasis skin.

CONCLUSIONS

These data support the view that leptin and resistin may be involved in the pathogenesis of psoriasis in overweight individuals, possibly by augmenting the cytokine expression by the inflammatory infiltrate.

Update on the natural history and systemic treatment of psoriasis

The onset of psoriatic disease and its associated comorbidities involves the interplay among a myriad of genetic and environmental risk factors. As we gain further insight into the immunopathogenesis of psoriasis, we hope it will provide the basis for the development of safer, more efficacious, and more durable therapeutics in the future. Given its enormous toll on patient health and quality of life, steps should be taken to prevent or decrease the risk for psoriasis-associated comorbidities through behavior modification and use of preventative health screenings and treatments. Future studies will need to be performed to determine if successful treatment of psoriasis will lead to a decreased risk for developing psoriasis-associated comorbidities over time.