Genetic susceptibility to psoriasis and psoriatic arthritis: implications for therapy

Prevention of Psoriatic Arthritis: The Need for Prospective Studies

Psoriatic arthritis (PsA) is a systemic chronic inflammatory disease that develops in up to 30% of patients with psoriasis. Mixed data variably support the potential ability to "prevent" and/or delay PsA through use of systemic therapies in psoriasis patients. Though intriguing, almost all of these studies are retrospective in nature, and hold substantial limitations and potential biases that challenge the ability to meaningfully interpretation their results. Thus, the authors believe prospective observational and interventional studies are crucial to understanding our ability to truly modify the transition from psoriasis to psoriatic arthritis and delay or prevent PsA onset.

Can Essential Oils/Botanical Agents Smart-Nanoformulations Be the Winning Cards against Psoriasis?

Although psoriasis remains one of the most devastating inflammatory disorders due to its huge negative impact on patients’ quality of life, new “green” treatment approaches still need to be fully explored. The purpose of this review article is to focus on the utilization of different essential oils and active constituents of herbal botanical origin for the treatment of psoriasis that proved efficacious via both in vitro and in vivo models. The applications of nanotechnology-based formulations which displayed great potential in augmenting the permeation and delivery of these agents is also addressed. Numerous studies have been found which assessed the potential activity of natural botanical agents to overcome psoriasis. Nano-architecture delivery is applied in order to maximize the benefits of their activity, improve properties, and increase patient compliance. This field of natural innovative formulations can be a promising tool to optimize remediation of psoriasis while minimizing adverse effects.

Tildrakizumab in the treatment of psoriasis: latest evidence and place in therapy

Psoriasis is a chronic inflammatory disorder that is clinically characterized by scaly cutaneous plaques. New evidence suggests that dysregulation of interleukin (IL)-23, a key cytokine in the T-helper-17 pathway, plays a vital role in the development of psoriatic systemic inflammation. The novel biologic medication tildrakizumab is among the first drugs with specific action against IL-23 that has recently been approved by the United States Food and Drug Administration and the European Medicines Agency for moderate-to-severe psoriasis. Tildrakizumab has been shown in large randomized controlled trials to be effective in improving skin manifestations as well as enhancing quality of life outcomes in patients with psoriasis. Its simple dosing, prolonged duration of action, and mild adverse event profile make it a practical option for patients; however, only a small number of trials have investigated the clinical effectiveness of tildrakizumab, and long-term data regarding the drug's efficacy and safety are currently limited. Hence, further research is needed to better understand the risks and benefits of tildrakizumab. This review summarizes and analyzes phase I, phase II, and phase III clinical trials that investigate the mechanism, pharmacokinetics, efficacy, and safety of tildrakizumab. It also identifies areas in which additional studies are warranted to further elucidate the advantages of tildrakizumab over other biologic therapies.

Polymorphisms in IL36G gene are associated with plaque psoriasis

Background

Plaque psoriasis is a non-contagious skin disease in which characteristic red and flaky lesions result from a dysregulation involving both innate and adaptive immune mechanisms. Several cytokines have been implicated in these processes and lately interleukin (IL)-36 family members have become more recognised among them. Thus far, genetic studies have only investigated IL36RN gene of this family in relation to pustular psoriasis. Since IL36G has previously demonstrated markedly increased levels in plaque psoriasis patients and is linked to IL-23/IL-17 axis critical in psoriasis pathology, it was chosen to be the focus of current report.

Methods

Eleven SNPs from IL36G region were genotyped in 728 plaque psoriasis patients and 320 healthy control individuals. Allele and haplotype frequencies between patients and controls were assessed by respective association tests. For more specific analyses, the patients were assigned into subgroups according to sex, age of disease onset, occurrence of psoriasis among relatives, seasonal aggravation, arthritis symptoms, body surface area (BSA) scores, and Psoriasis Area and Severity Index (PASI) scores.

Results

The most significant results were obtained with SNPs rs28947206, rs28947207 and rs28947211 that were associated in entire plaque psoriasis analysis (multiple testing adjusted p value (p_adj) = 0.0054, p_adj = 0.0017 and p_adj = 0.0001) and also several subgroups. The first two of those SNPs were included in the same haplotype block with rs28947205 and rs12328178, and two of the respective haplotypes, CAGC and TGTT, provided similarly significant associations (p_adj = 0.0462 and p_adj = 0.0047).

Conclusions

The associated SNPs of this study or those in linkage disequilibrium with them could potentially affect the functionality of IL-36γ cytokine, which in turn may impact plaque psoriasis pathology. For instance, these variants could influence IL-36γ expression or 3D structure, thereby altering its ability to induce chemokine production in keratinocytes and various immune cells. The precise mechanisms of these actions are currently unknown and out of the scope of this study. To conclude, the present genetic association results confirm the proposed role of IL-36γ in plaque psoriasis development, with corresponding causal effects to be determined in forthcoming research.

Cancer risk in 892 089 patients with psoriasis in Korea: A nationwide population-based cohort study

The relationship between psoriasis and cancer has not yet been established. The aim of this study was to evaluate the association of psoriasis with certain cancers using national statistics. All patients with psoriasis (n = 892 089; 51.7% male) and age- and sex-matched control subjects (n = 4 460 445) at a 5:1 ratio were enrolled using data from the National Health Insurance Service between 2007 and 2014 in Korea. In psoriatic subjects, overall cancer risk was higher than for subjects without psoriasis after adjusting for income level, diabetes, hypertension, dyslipidemia and place of residence (hazard ratio, 1.065; 95% CI, 1.049-1.081). The risk of cancer increased in the following order: prostate, thyroid, liver, ovarian, lung, leukemia, skin, multiple myeloma, lymphoma and testicular. The severity and sex of psoriatic patients also had different cancer risks. In psoriatic patients, a slightly increased risk for specific malignant neoplasms was shown. Therefore, periodic screening for cancer risk is recommended in patients with psoriasis.

Synergistic antiproliferative and differentiating effect of 2,4-monofurfurylidene-tetra-O-methylsorbitol and 4,6-dimethyl-2-(3,4,5-trimethoxyphenylamino)pyrimidine on primary and immortalized keratinocytes

Psoriasis is one of the most common chronic autoinflammatory skin disease, associated with hyperproliferation and abnormal differentiation of keratinocytes, inflammation, and angiogenesis. The available treatments for psoriasis are not curative and may have numerous side effects, and topical administration is preferred over systemic therapy due to the reduced systemic burden of the drug. Thus, novel and more efficacious formulations of anti-inflammatory and/or differentiating compounds for topical application could be very useful for the disease management and for improving the quality of life of the patients. Here we evaluated the potential as anti-psoriatic of an equimolar mixture of two compounds, 2,4-Monofurfurylidene-tetra-O-methylsorbitol (Compound A) and 4,6-dimethyl-2-(3,4,5-trimethoxyphenylamino)pyrimidine (Compound B), that, used individually, are known to possess immunomodulating properties (Compound A) and keratolitic and anti-inflammatory activity (Compound B). Human immortalized keratinocyte cell line (HaCaT cells) and primary human keratinocyte cells from adult donor (HEKa) were used as in vitro experimental models. We show that the mix A + B exhibits antiproliferative activity and induces terminal differentiation more efficiently than compounds A and B used individually. We confirm that the compound B is the active ingredient of the mixture and the mainly responsible for anti-psoriatic activity, but the mix A + B is more effective and possesses lower cytotoxicity than the compound B alone. This could be ascribable to the association with compound A, that is known to possess, in addition to the immunomodulating ability, antioxidant and antiradical action. Our results indicate that mix A + B could be a suitable candidate for a new cosmeceutical formulation for topical treatment of psoriasis.

Current treatment options for psoriatic arthritis: spotlight on abatacept

Psoriatic arthritis (PsA) is a chronic inflammatory disease of joints, tendon sheaths, and entheses affecting patients with established skin psoriasis, or, less frequently, patients without a personal history of psoriasis with a positive familial history. Many treatment options are now available to deal with the different aspects of the disease, including traditional and biological disease-modifying antirheumatic drugs and the recently released targeted synthetic disease-modifying antirheumatic drugs. However, ~40% of patients still fail to achieve a meaningful clinical response to first-line biologic therapy advocating the development of novel medications. It is now well accepted that T-cells participate in the immunopathogenesis of several autoimmune diseases. For this reason, the potential intervention on T-cells represented an attractive therapeutic target for a long time, becoming a clinical reality with the development of abatacept. Abatacept is a biologic agent selectively targeting the T-cell costimulatory signal delivered through the CD80/86-CD28 pathway and was approved in December 2005 by the US Food and Drug Administration and in May 2007 by European Medicines Agency for the treatment of patients with rheumatoid arthritis in combination with methotrexate. Based on the relevant role of T-cells in PsA pathogenesis and following the positive results obtained in a phase III clinical trial, abatacept recently received approval for treatment of patients with PsA. In this review, we will focus on the current knowledge about the emerging role of abatacept in treatment of PsA.

HLA-C*06:02 Does Not Predispose to Clinical Response Following Long-Term Adalimumab Treatment in Psoriatic Patients: A Retrospective Cohort Study

BACKGROUND

The genetic basis of predisposition to psoriasis is recognised; however, the response to psoriasis treatment in patients with different genetic predisposition is poorly understood.

OBJECTIVE

To analyse the presence of the HLA-C*06:02 polymorphism in psoriatic patients treated with adalimumab.

METHODS

Genomic DNA was extracted from whole blood of 122 patients with moderate-to-severe psoriasis treated with adalimumab for 3 years. Genotyping was performed using PCR. Disease severity was assessed by the Psoriasis Area and Severity Index (PASI) at day 0 and after 1, 3, 6, 12, 24 and 36 months. Logistic regression was used to evaluate the association between dependent variables (including HLA-C*06:02 status) and achievement of PASI 50, 75 and 90.

RESULTS

No difference was observed after adalimumab treatment between C*06:02 positive (HLA-C*06:02-POS) patients (n = 46) and C*06:02 negative (HLA-C*06:02-NEG) patients (n = 76) over the 3-year follow-up period in terms of PASI response or time-course when PASI response was achieved. However, a small, but non-statistically significant difference was noted between genotypes for PASI 50 at 1 month (HLA-C*06:02-NEG: 44.7% vs. HLA-C*06:02-POS: 56.5%) and at 3 months (HLA-C*06:02-NEG: 71.1% vs. HLA-C*06:02-POS: 80.4%). Simple logistic regression analysis did not reveal an association between independent variables (including C*06:02 status) and PASI response; however, multivariate regression revealed that gender (females better than males) was associated with achievement of PASI 50 at month 1 (OR 0.34, 95% CI 0.16-0.72, p = 0.005) and of PASI 75 at 3 months (OR 0.36, 95% CI 0.16-0.8, p = 0.012).

CONCLUSION

Adalimumab reduced long-term severity in patients with moderate-severe psoriasis, independent of their HLA-C*06:02 status.

Tacrolimus for the management of psoriasis: clinical utility and place in therapy

Psoriasis affects 1%-3% of the population in the United Kingdom and can convey significant detriment to the physical and mental health of sufferers. Plaques of psoriasis typically affect the extensor skin surfaces and scalp. Less frequently inverse psoriasis can affect more sensitive skin such as the face, genitals, and intertriginous areas. Psoriasis is incurable, but there are a range of treatment modalities that can be used to manage the condition. Treatment options include topical preparations, phototherapy, systemic therapy, and biological agents. Tacrolimus is a macrolide calcineurin inhibitor licensed for immunosuppression in transplant patients and topical administration in atopic dermatitis. Tacrolimus administered orally and in topical form has been shown to produce successful outcomes in patients with psoriasis. Topical tacrolimus is particularly effective for inverse psoriasis, which is likely to be due to the reduced level of induration seen in these psoriatic lesions, which allows greater skin penetrance, compared with hyperkeratotic plaques of psoriasis on the body. It is also notable that the areas affected by inverse psoriasis are more susceptible to adverse effects of topical corticosteroid therapy, and thus a topical preparation without the risk of skin atrophy, telangiectasia, and striae could be a valuable addition to current topical treatment options. Oral tacrolimus has shown efficacy in the treatment of severe, refractory psoriasis. Compared to ciclosporin, systemic tacrolimus may be more suited to a patient population with increased cardiovascular risk. This review will draw together the current literature on topical and oral tacrolimus for the treatment of psoriasis. Efficacy and safety have been evaluated by case reports and randomized controlled trials and comparisons have been made between tacrolimus therapy and standard treatment.

Psoriasis, psoriatic arthritis, and rheumatoid arthritis: Is all inflammation the same?

OBJECTIVES

To review the pathophysiology, co-morbidities, and therapeutic options for psoriasis, psoriatic arthritis and rheumatoid arthritis in order to further understand the similarities and differences in treatment paradigms in the management of each disease. New targets for individualized therapeutic decisions are also identified with the aim of improving therapeutic outcome and reducing toxicity.

SEARCH STRATEGY

Using the PubMed database, we searched literature published from 2000 to 2015 using combinations of the key words "psoriasis," "psoriatic arthritis," "rheumatoid arthritis," "pathogenesis," "immunomodulation," and "treatment."

INCLUSION AND EXCLUSION CRITERIA

This was a non-systematic review and there were no formal inclusion and exclusion criteria.

DATA EXTRACTION

Abstracts identified in the search were screened for relevance and articles considered appropriate evaluated further. References within these selected articles were also screened. Information was extracted from 198 articles for inclusion in this report.

DATA SYNTHESIS

There was no formal data synthesis. Articles were reviewed and summarized according to disease area (psoriasis, psoriatic arthritis, and rheumatoid arthritis).

HEADLINE RESULTS

The pathophysiology of psoriasis, psoriatic arthritis, and rheumatoid arthritis involves chronic inflammation mediated by pro-inflammatory cytokines. Dysfunction in integrated signaling pathways affecting different constituents of the immune system result in varying clinical features in the three diseases. Co-morbidities, including cardiovascular disease, malignancies, and non-alcoholic fatty liver disease are increased. Increased understanding of the immunopathogenesis allowed development of targeted treatments; however, despite a variety of potentially predictive genetic, protein and cellular biomarkers, there is still significant unmet need in these three inflammatory disorders.

Targeted therapies: what they teach us about the pathogenesis of psoriasis and psoriatic arthritis

INTRODUCTION

Biologic therapy has revolutionized treatment pathways in psoriatic joint and skin disease. It has also provided a useful tool with which pathological pathways of this condition may be explored. Areas covered: This review presents data on the clinical and biological effects of targeted therapy in psoriatic arthritis and psoriasis. Therapeutic agents covered include inhibitors of TNFα, inhibitors of the IL-23/IL-17 axis and inhibitors of intracellular small molecules involved in the transduction of the inflammatory signal. Trial data on clinical and imaging efficacy is reviewed in parallel with studies on biological effects at tissue level. Pathological insights gained from the use of these treatments are explored. Expert commentary: A close relationship exists between specific pathological types and clinical manifestations of psoriatic disease, including responses to treatment. Studying these relationships is likely to improve understanding of disease and enable rational selection of specific treatments for patients with specific pathotypes.

Urine metabolome profiling of immune-mediated inflammatory diseases

BACKGROUND

Immune-mediated inflammatory diseases (IMIDs) are a group of complex and prevalent diseases where disease diagnostic and activity monitoring is highly challenging. The determination of the metabolite profiles of biological samples is becoming a powerful approach to identify new biomarkers of clinical utility. In order to identify new metabolite biomarkers of diagnosis and disease activity, we have performed the first large-scale profiling of the urine metabolome of the six most prevalent IMIDs: rheumatoid arthritis, psoriatic arthritis, psoriasis, systemic lupus erythematosus, Crohn's disease, and ulcerative colitis.

METHODS

Using nuclear magnetic resonance, we analyzed the urine metabolome in a discovery cohort of 1210 patients and 100 controls. Within each IMID, two patient subgroups were recruited representing extreme disease activity (very high vs. very low). Metabolite association analysis with disease diagnosis and disease activity was performed using multivariate linear regression in order to control for the effects of clinical, epidemiological, or technical variability. After multiple test correction, the most significant metabolite biomarkers were validated in an independent cohort of 1200 patients and 200 controls.

RESULTS

In the discovery cohort, we identified 28 significant associations between urine metabolite levels and disease diagnosis and three significant metabolite associations with disease activity (P FDR < 0.05). Using the validation cohort, we validated 26 of the diagnostic associations and all three metabolite associations with disease activity (P FDR < 0.05). Combining all diagnostic biomarkers using multivariate classifiers we obtained a good disease prediction accuracy in all IMIDs and particularly high in inflammatory bowel diseases. Several of the associated metabolites were found to be commonly altered in multiple IMIDs, some of which can be considered as hub biomarkers. The analysis of the metabolic reactions connecting the IMID-associated metabolites showed an over-representation of citric acid cycle, phenylalanine, and glycine-serine metabolism pathways.

CONCLUSIONS

This study shows that urine is a source of biomarkers of clinical utility in IMIDs. We have found that IMIDs show similar metabolic changes, particularly between clinically similar diseases and we have found, for the first time, the presence of hub metabolites. These findings represent an important step in the development of more efficient and less invasive diagnostic and disease monitoring methods in IMIDs.

Pharmacogenomics of multifactorial diseases: a focus on psoriatic arthritis

This review will outline the current pharmacogenomics knowledge about psoriatic arthritis with a special attention to the perspectives and the challenges for its implementation in the clinical practice. To date, different drugs have been developed to contrast the symptoms and the progression of psoriatic arthritis. However, patients have shown high variability of drug response in relation to their genetic makeup. In this context, the advances made in the knowledge and the potentialities of genome-drugs associations paved the path for the development of a precision medicine. In fact, these associations may be successfully combined with the environment information to provide new strategies able to prevent and improve the disease management as well as to enhance the patients quality of life.

Psoriasis

Psoriasis is an immune-mediated, genetic disease manifesting in the skin or joints or both. A diverse team of clinicians with a range of expertise is often needed to treat the disease. Psoriasis provides many challenges including high prevalence, chronicity, disfiguration, disability, and associated comorbidity. Understanding the role of immune function in psoriasis and the interplay between the innate and adaptive immune system has helped to manage this complex disease, which affects patients far beyond the skin. In this Seminar, we highlight the clinical diversity of psoriasis and associated comorbid diseases. We describe recent developments in psoriasis epidemiology, pathogenesis, and genetics to better understand present trends in psoriasis management. Our key objective is to raise awareness of the complexity of this multifaceted disease, the potential of state-of-the-art therapeutic approaches, and the need for early diagnosis and comprehensive management of patients with psoriasis.

Biomarkers of An Autoimmune Skin Disease--Psoriasis

Psoriasis is one of the most prevalent autoimmune skin diseases. However, its etiology and pathogenesis are still unclear. Over the last decade, omics-based technologies have been extensively utilized for biomarker discovery. As a result, some promising markers for psoriasis have been identified at the genome, transcriptome, proteome, and metabolome level. These discoveries have provided new insights into the underlying molecular mechanisms and signaling pathways in psoriasis pathogenesis. More importantly, some of these markers may prove useful in the diagnosis of psoriasis and in the prediction of disease progression once they have been validated. In this review, we summarize the most recent findings in psoriasis biomarker discovery. In addition, we will discuss several emerging technologies and their potential for novel biomarker discovery and diagnostics for psoriasis.

Enthesopathies and enthesitis. Part 1. Etiopathogenesis

The pathologies of tendon and ligament attachments are called enthesopathies. One of its types is enthesitis which is a characteristic sign of peripheral spondyloarthropathy. Clinical diagnosis of enthesitis is based on rather non-specific clinical signs and results of laboratory tests. Imaging examinations are highly promising. Numerous publications prove that enthesitis can be differentiated from other enthesopathic processes in an ultrasound examination or magnetic resonance imaging. However, some reports indicate the lack of histological criteria, specific immunological changes and features in imaging examinations that would allow the clinical diagnosis of enthesitis to be confirmed. The first part of the publication presents theories on the etiopathogenesis of enthesopathies: inflammatory, mechanical, autoimmune, genetic and associated with the synovio-entheseal complex, as well as theories on the formation of enthesophytes: inflammatory, molecular and mechanical. The second part of the paper is a review of the state-of-the-art on the ability of imaging examinations to diagnose enthesitis. It indicates that none of the criteria of inflammation used in imaging medicine is specific for this pathology. As enthesitis may be the only symptom of early spondyloarthropathy (particularly in patients with absent HLA-B27 receptor), the lack of its unambiguous picture in ultrasound and magnetic resonance scans prompts the search for other signs characteristic of this disease and more specific markers in imaging in order to establish diagnosis as early as possible.

Identification of loci associated with late-onset psoriasis using dense genotyping of immune-related regions

BACKGROUND

Chronic plaque psoriasis can be subdivided into two groups according to the age of onset: type 1 (early onset, before 40 years) and type 2 (late onset, at or beyond 40 years). So far, 36 genetic loci have been associated with early-onset psoriasis in genome-wide association studies of white populations, while few studies have investigated genetic susceptibility to late-onset psoriasis.

OBJECTIVES

To characterize the genetics underpinning late-onset psoriasis.

METHODS

We genotyped 543 cases of late-onset psoriasis and 4373 healthy controls using the Immunochip array, a dense genotyping chip containing single-nucleotide polymorphisms previously associated with autoimmune diseases. Imputation using SNP2HLA and stepwise logistic regression analysis was performed for markers spanning the human leucocyte antigen gene region.

RESULTS

Two loci (HLA-C and IL12B) previously associated with early-onset psoriasis showed significant association at a genome-wide threshold in the current study (P < 5 × 10(-8)). Six more loci (TRAF3IP2, IL23R, RNF114, IFIH1, IL23A and HLA-A) showed study-wide significant association (P < 2·3 × 10(-5); calculated using Genetic type 1 error calculator). Additionally, we identified an association at IL1R1 on chromosome 2q13, which is not associated with early-onset disease.

CONCLUSIONS

This is the largest study to date of genetic loci in late-onset psoriasis, and demonstrates the overlap that exists with early-onset psoriasis. It also suggests that some loci are associated exclusively with late-onset psoriasis.

Efficacy and safety of emerging immunotherapies in psoriasis

Psoriasis is a common chronic inflammatory disease of the skin. Current biologic therapies are highly effective in the treatment of psoriasis, transforming the lives of patients with this significantly disabling disease. Advances in the understanding of the immunological pathogenesis of psoriasis have led to the development of new biologic therapies, targeting specific inflammatory cytokines upregulated in psoriasis. These include the IL-17 antagonists, secukinumab, brodalumab and ixekizumab; the IL-23 antagonists, guselkumab and tildrakizumab; and the oral small molecule therapies, tofacitinib and apremilast. Here, we review evidence for the efficacy and safety of these novel psoriasis therapies, providing clinicians with an overview of the next era in immunotherapy for psoriasis.

Genetic and epigenetic basis of psoriasis pathogenesis

Psoriasis is a chronic inflammatory skin disease whose prevalence varies among different populations worldwide. It is a complex multi-factorial disease and the exact etiology is largely unknown. Family based studies have indicated a genetic predisposition; however they cannot fully explain the disease pathogenesis. In addition to genetic susceptibility, environmental as well as gender and age related factors were also been found to be associated. Recently, imbalances in epigenetic networks are indicated to be causative elements in psoriasis. The present knowledge of epigenetic involvement, mainly the DNA methylation, chromatin modifications and miRNA deregulation is surveyed here. An integrated approach considering genetic and epigenetic anomalies in the light of immunological network may explore the pathogenesis of psoriasis.

Lack of association of ALOX12 and ALOX15B polymorphisms with psoriasis despite altered urinary excretion of 12(S)-hydroxyeicosatetraenoic acid

BACKGROUND

Pro- and anti-inflammatory metabolites of arachidonic acid - eicosanoids - participate in skin homeostasis, affecting the growth and differentiation of keratinocytes. Alterations of 12-lipoxygenase (LOX) and 15-LOX and their metabolites have been described in the epidermis of patients with psoriasis, but systemic production of 12-LOX and 15-LOX eicosanoids has not been studied in the disease.

OBJECTIVES

To ascertain the frequencies of the genetic variants ALOX12 rs1126667 and ALOX15 rs11568070 in cases and controls, and to compare urinary metabolites of 12(S)-hydroxyeicosatetraenoic acid (HETE) between patients with psoriasis and healthy controls.

METHODS

Patients with psoriasis (n = 200) were stratified depending on the severity of their dermal lesions. Genotyping was performed using a 5'-nuclease real-time assay. The concentrations of 12(S)-HETE, its metabolites and 15(S)-HETE were determined in urine samples using high-performance liquid chromatography-tandem mass spectrometry.

RESULTS

Tetranor-12(S)-HETE metabolite excretion was significantly higher in urine of patients with psoriasis, while excretion of 12(S)-HETE was decreased. Neither 12(S)-HETE nor tetranor-12(S)-HETE correlated with the type of disease or severity score. No difference in urinary 15(S)-HETE was found between the study groups. Genotype distribution of the ALOX12 rs1126667 or ALOX15 rs11568070 polymorphisms did not discriminate for the disease or its severity.

CONCLUSIONS

Systemic metabolism of 12(S)-HETE is accelerated in psoriasis because excretion of the tetranor-12(S)-HETE inactivation product is elevated. No correlation with the severity or extent of psoriasis is detectable. We propose that in patients with psoriasis, 12(S)-HETE to tetranor-12(S)-HETE conversion could be at least a marker for this disease, in which inflammation of the skin can induce microsomal beta-oxidation of this eicosanoid.

Human leucocyte antigen-Cw6 as a predictor for clinical response to ustekinumab, an interleukin-12/23 blocker, in Chinese patients with psoriasis: a retrospective analysis

BACKGROUND

Ustekinumab, an interleukin-12/23 inhibitor, is effective in the treatment of psoriasis. A recent Italian study showed more favourable response to ustekinumab in patients with positive human leucocyte antigen (HLA)-Cw6. Nonetheless, there are differences in genetic susceptibility to psoriasis between races, and no studies have specifically assessed the candidate genetic markers in predicting therapy outcome in Chinese patients with psoriasis treated with ustekinumab.

OBJECTIVES

To determine whether HLA gene polymorphisms can predict the response to ustekinumab in Chinese patients with psoriasis.

METHODS

Sixty-six patients with psoriasis treated with ustekinumab were included in the study, and the effectiveness of ustekinumab therapy was evaluated at weeks 0, 16 and 28 by Psoriasis Area and Severity Index (PASI).

RESULTS

More HLA-Cw6-positive patients achieved a PASI 75 response at week 4 compared with HLA-Cw6-negative patients (38% vs. 9%, P = 0·019). Similarly, at week 16, patients carrying the HLA-Cw6 allele showed a higher likelihood of achieving PASI 50, 75 and 90 than Cw6-negative patients, although this was not statistically significant. At week 28, a significantly higher percentage of HLA-Cw6-positive patients maintained PASI 90 response compared with Cw6-negative patients (63% vs. 26%, P = 0·035). Further analysis of other HLA allele polymorphisms did not show significant associations with therapeutic response to ustekinumab.

CONCLUSIONS

This pharmacogenetic study provides preliminary data indicating that positive HLA-Cw6 is associated with a good response to ustekinumab treatment in Chinese patients with psoriasis.

Ustekinumab for the treatment of psoriatic arthritis: an update

Psoriatic arthritis occurs in 30% of psoriasis patients, and the treatment can be challenging in some patients. Recently, the US Food and Drug Administration approved ustekinumab, a fully human monoclonal antibody, for the management of psoriatic arthritis. In this article, we review large-scale randomized clinical trials addressing the efficacy and safety profile of ustekinumab for the treatment of psoriatic arthritis.

Familial aggregation of moderate to severe plaque psoriasis

BACKGROUND

Psoriasis is a highly heritable disease. It has been suggested that psoriasis is preferentially transmitted from fathers.

AIM

To evaluate the degree of familial aggregation of psoriasis; to determine the recurrence risk ratio (λR ) of psoriasis in first, second and third degree relatives of patients with psoriasis; and to investigate the transmission patterns of the disease and their relationships with the clinical profiles of patients.

METHODS

A cross-sectional study on 640 consecutive, unrelated adult patients with chronic plaque psoriasis was performed. The prevalence of psoriasis in first, second and third degree relatives of the patients was determined, and the λR was calculated under the assumption of a population prevalence of 2%. Age of onset and presence of facial, hand and foot psoriasis were evaluated in probands with paternal vs. maternal transmission.

RESULTS

A positive familial history of psoriasis was found in 380 patients (59.37%). Of these, 174 (27.18%) had at least one parent with psoriasis, with a λR of 13.59, while 106 patients (16.56%) had at least one second degree relative with psoriasis, and 34 patients (5.31%) had one third degree relative with psoriasis. No parent-of-origin effect in transmission of psoriasis from affected parent to offspring was observed, and there were no significant differences in the clinical profiles of the disease between patients grouped by transmission pattern of psoriasis.

CONCLUSIONS

These results show a high familial recurrence risk of psoriasis, and suggest a balanced parental transmission of the disease.

Psoriasis

Psoriasis is a common chronic inflammatory skin disease with a spectrum of clinical phenotypes and results from the interplay of genetic, environmental, and immunological factors. Four decades of clinical and basic research on psoriasis have elucidated many of the pathogenic mechanisms underlying disease and paved the way to effective targeted therapies. Here, we review this progress and identify future directions of study that are supported by a more integrative research approach and aim at further improving the patients' life.

Factors affecting response to biologic treatment in psoriasis

Psoriasis is a chronic, immune-mediated inflammatory skin disease, affecting approximately 2-4% of the population in western countries. Patients with a more severe form of the disease are typically considered for systemic therapy, including biologics. In spite of the overall superiority of biologic agents, the treatment response may differ substantially among individual patients. As with other medical conditions, a range of factors contribute to response heterogeneity observed in psoriasis. Proper identification of these factors can significantly improve the therapeutic decisions. This review focuses on potential genetic and nongenetic factors that may affect the treatment response and outcomes in patients with psoriasis.

Pharmacogenetics of topical and systemic treatment of psoriasis

Psoriasis is a chronic inflammatory skin disease. The cause of psoriasis is unknown, although genetics may play a key role in its development. Treatment of the disease varies with severity. Topical drugs, such as corticosteroids, coal tar, retinoids and vitamin D analogs, are commonly used to treat mild psoriasis. Phototherapy and systemic drugs, such as calcineurin inhibitors, methotrexate, acitretin and biological drugs, are usually used to treat moderate-to-severe psoriasis. Not all patients respond well to treatment, and some can develop severe adverse effects. Interindividual differences in several genes may explain this variation in response to treatment. Pharmacogenetics and pharmacogenomics can facilitate more personalized medicine and prevent the adverse effects associated with treatment.

Pharmacogenetics of psoriasis: HLA-Cw6 but not LCE3B/3C deletion nor TNFAIP3 polymorphism predisposes to clinical response to interleukin 12/23 blocker ustekinumab

BACKGROUND

Our understanding of the genetic basis of predisposition to psoriasis is increasing exponentially due to the progress of genetic studies. However, so far little is known about genetic predisposition in relation to the response to psoriasis treatments. Recent data identified genetic predictors for the clinical outcome of conventional treatments such as methotrexate, acitretin and vitamin D derivatives, but few studies are available on genetic predictors of response to biologics. We hypothesized that genetic variations associated with increased risk of developing psoriasis may also act as predictors for the outcome of biologic therapy.

OBJECTIVES

The aim of our study was to analyse the presence of three different psoriasis susceptibility genetic variations (HLA-Cw6; TNFAIP3 rs610604 polymorphism; LCE3B/3C gene deletions) in a cohort of patients affected by moderate to severe psoriasis under ustekinumab treatment. Our primary endpoint was to evaluate the association between Psoriasis Area and Severity Index (PASI) 75 response at week 12 and HLA-Cw6 status.

METHODS

Fifty-one patients were genotyped by standard methods and psoriasis severity (PASI score) was evaluated at day 0 and after 4, 12, 24 and 40 weeks of treatment.

RESULTS

We observed increased response to ustekinumab in Cw6-positive (Cw6POS) patients [PASI 75 at week 12: 96·4% in Cw6POS vs. 65·2% in Cw6-negative (Cw6NEG) patients; P = 0·008]. In addition, we show that HLA-Cw6POS patients responded faster to ustekinumab, 89·3% of them reaching PASI 50 at week 4, after a single injection (vs. 60·9% of HLA-Cw6NEG patients). The superior response of HLA-Cw6POS patients was maintained throughout the study period, reaching the highest statistical significance for PASI 75 at week 28 (96·35% Cw6POS vs. 72·7% Cw6NEG; odds ratio 9·8). Analysis of TNFAIP3 rs610604 polymorphism and LCE3B/3C gene deletions did not show any significant association with response to ustekinumab.

CONCLUSIONS

Our observations underline the role of HLA-Cw6 not only as a psoriasis susceptibility gene, but also as a pharmacogenetic marker of response to ustekinumab in psoriasis.

Therapeutic strategies in psoriasis patients with psoriatic arthritis: focus on new agents

Psoriatic arthritis affects approximately 6-42 % of patients with psoriasis. It is useful for physicians or dermatologists managing psoriasis patients to be aware of how to concurrently manage the joint manifestations, as it is preferable and convenient to use a single agent in such patients. However, only certain therapies are effective for both. Systemic agents, which can be used for both skin and joint manifestations, include methotrexate and ciclosporin. For the group of biologic agents, the tumor necrosis factor inhibitors such as adalimumab, etanercept, infliximab, golimumab and certolizumab are effective. Ustekinumab is a more recently developed agent belonging to the group of anti-IL-12p40 antibodies and has been shown to be efficacious. Newer drugs in the treatment armamentarium that have shown efficacy for both psoriasis and psoriatic arthritis consist of the anti-IL-17 agent, secukinumab, and a phosphodiesterase-4 inhibitor, apremilast. The other anti-IL-17 agents, ixekizumab and brodalumab, as well as the oral Jak inhibitor, tofacitinib, have very limited but promising data. This review paper provides a good overview of the agents that can be used for the concurrent management of skin and joint psoriasis.

Predictors of biologic treatment of psoriasis: a non-interventional study

Background

Biologic therapies represent a significant advance in the treatment of psoriasis. However, no studies have examined the patient characteristics predictive of biologic treatment of psoriasis. The purpose of this study was to ascertain the frequency and predictors of treatment of psoriasis with biologics in three European countries, ie, France, Spain, and the UK.

Methods

This was a cross-sectional analysis of physician-recorded demographic and clinical data on patients receiving either conventional or biologic treatments for psoriasis. Data were drawn from the Adelphi 2007 Psoriasis Disease Specific Program (DSP®), a multinational, real-world survey of patients with psoriasis consulting practicing dermatologists. The numbers of patients treated with biologic and nonbiologic agents were recorded. Data were subjected to bivariate analysis according to treatment regimen (biologic versus nonbiologic). Predictors of treatment with biologics were identified by logistic regression analysis.

Results

A total of 2,509 psoriasis patients were included in this study (1,374 from France, 561 from Spain, and 574 from the UK). Biologic use was most prevalent in Spain (19.4% of patients), followed by the UK (9.1%), and France (8.4%). In the logistic regression analysis, psoriatic arthritis was a statistically significant predictor of increased biologic use in France (odds ratio [OR] 5.38, 95% confidence interval [CI] 3.32–8.77), Spain (OR 2.71, 95% CI 1.16–6.33), and the UK (OR 8.70, 95% CI 3.65–20.83). Physician-assessed moderate-to-severe disease was also a statistically significant predictor of increased biologic use in France (OR 5.08, 95% CI 2.01–12.82), Spain (OR 11.11, 95% CI 4.33–28.57), and the UK (OR 8.55, 95% CI 1.11–66.67).

Conclusion

In this study, an average of about one tenth of psoriasis patients enrolled in Spain, France, and the UK were treated with biologics in 2007. Physician-assessed moderate-to-severe disease and presence of psoriatic arthritis were significantly associated with biologic use in all three countries.

Association of TNF-α polymorphism with prediction of response to TNF blockers in spondyloarthritis and inflammatory bowel disease: a meta-analysis

Aim: To explore whether TNF-α promoter -308 A/G and -857 C/T polymorphisms have an association with responsiveness to TNF blockers in spondyloarthritis and inflammatory bowel disease. Methods: A meta-analysis was performed. Pooled odds ratios (ORs) and 95% CIs were calculated. Results: Six relevant studies with a total of 211 spondyloarthritis patients and 392 inflammatory bowel disease patients were included. The results showed that the common allele (G and C, respectively) showed a better responsiveness than the minor allele (A and T, respectively). The -308 G/G genotype (OR: 2.31; 95% CI: 1.36–3.91; p = 0.002) and -857 C/C genotype (OR: 3.66; 95% CI: 1.35–9.92; p = 0.01) responded better to therapy, which was different from the results of some studies included. Conclusion: Individuals with the TNF-α-308 G allele and -857 C allele showed better anti-TNF-α treatment responses than those with the TNF-α-308 A allele and -857 T allele. The -308 G/G genotype and -857 C/C genotype are predictors of good response.

Original submitted 30 May 2013; Revised submitted 25 July 2013

Genetics of psoriasis and pharmacogenetics of biological drugs

Psoriasis is a chronic inflammatory disease of the skin. The causes of psoriasis are unknown, although family and twin studies have shown genetic factors to play a key role in its development. The many genes associated with psoriasis and the immune response include TNFα, IL23, and IL12. Advances in knowledge of the pathogenesis of psoriasis have enabled the development of new drugs that target cytokines (e.g., etanercept, adalimumab, and infliximab, which target TNFα, and ustekinumab, which targets the p40 subunit of IL23 and IL12). These drugs have improved the safety and efficacy of treatment in comparison with previous therapies. However, not all patients respond equally to treatment, possibly owing to interindividual genetic variability. In this review, we describe the genes associated with psoriasis and the immune response, the biological drugs used to treat chronic severe plaque psoriasis, new drugs in phase II and III trials, and current knowledge on the implications of pharmacogenomics in predicting response to these treatments.

Clinical profile, morbidity, and outcome of adult-onset generalized pustular psoriasis: analysis of 102 cases seen in a tertiary hospital in Johor, Malaysia

BACKGROUND

Generalized pustular psoriasis (GPP) is a severe but rare variant of psoriasis. Our objective is to review the clinical profile, comorbidities, and outcome of patients with GPP.

MATERIALS AND METHODS

A retrospective note review of all patients with adult-onset GPP.

RESULTS

A total of 102 patients with adult-onset GPP were diagnosed between 1989 and November 2011, with a female to male ratio of 2 : 1. The mean age at onset of GPP was 40.9 years (range: 21-81 years). Acute GPP was the most common variant seen (95 cases), followed by four localized variants of GPP and three with annular pustular psoriasis. Fever and painful skin were present in 89% of patients, arthritis in 34.7%, and leukocytosis in 78.4%. Common triggers were systemic steroids (45 cases), pregnancy (17 cases), and upper respiratory tract infections (16 cases). A positive family history of psoriasis and GPP was present in 29% and 11%, respectively. Comorbidities included obesity (42.9%), hypertension (25.7%), hyperlipidemia (25.7%), and diabetes mellitus (23.7%). The mean duration of admission and pustular flare for acute GPP was 10.3 days (range: 3-44 days) and 16 days (range: 7-60 days), respectively. Fifty-four patients responded to systemic retinoid, 21 to methotrexate, eight to cyclosporine, and one to adalimumab, but recurrences were common.

CONCLUSIONS

Our study confirms the poor response of GPP to currently available anti-psoriatic agents, with frequent flare-ups. There is a need for a more effective targeted therapy for this condition.

Induction and exacerbation of psoriasis with Interferon-alpha therapy for hepatitis C: a review and analysis of 36 cases

BACKGROUND

Interferon-alpha (IFN-α) therapy is used to treat hepatitis C infection. The exacerbation and occurrence of psoriasis in hepatitis C patients treated with IFN-α is increasingly recognized, but the distinct associated features, aetiology and management have not been reviewed.

OBJECTIVE

To review all published cases of hepatitis C patients who developed psoriasis while receiving IFN-α therapy.

METHODS

The review was conducted by searching the PubMed database using the keywords 'hepatitis C' AND 'psoriasis.' In addition, references to additional publications not indexed for PubMed were followed to obtain a complete record of published data.

RESULTS

We identified 32 publications describing 36 subjects who developed a psoriatic eruption while receiving IFN-α therapy for hepatitis C. Topical therapies were a commonly employed treatment modality, but led to resolution in only 30% of cases in which they were employed solely. Cessation of IFN-α therapy led to resolution in 93% of cases. Hundred per cent of those who developed psoriasis while on IFN-α therapy responded to systemic therapy and were able to continue the drug.

CONCLUSION

Further studies and analysis of IFN-α-induced lesions are necessary to clarify the role of IFN-α and the hepatitis C virus in the development of psoriatic lesions.

An investigation of rheumatoid arthritis loci in patients with early-onset psoriasis validates association of the REL gene

BACKGROUND

Phenotypically diverse autoimmune conditions share common genetic susceptibility loci and underlying molecular pathways.

OBJECTIVES

By systematically searching for single nucleotide polymorphisms (SNPs) associated with another autoimmune disease, rheumatoid arthritis (RA), we aimed to elucidate novel genetic markers of psoriasis.

METHODS

We investigated 18 SNPs, previously confirmed as being associated with RA, in a U.K. cohort of 623 patients with early-onset psoriasis (presenting before age 40 years), comparing them with 2662 control subjects.

RESULTS

Our findings confirm the association of early-onset psoriasis with REL (rs13031237, P=0·0027). The minor allele of REL had opposing effects upon susceptibility to disease in patients with psoriasis and RA.

CONCLUSION

Similar exploration of additional autoimmune loci and fine mapping of such regions may provide further insight into the genetics and molecular pathophysiology of psoriasis.

Steps in the management of psoriatic arthritis: a guide for clinicians

Psoriatic arthritis is a common systemic inflammatory disorder, which in addition to skin and nail involvement may be associated with peripheral and axial joint involvement, enthesitis, dactylitis, and important comorbidities - especially cardiovascular morbidity. Better insights into the involved pathogenic mechanisms have resulted in an improved therapeutic armamentarium, which targets key pathways in its pathogenesis. This has resulted in significant clinical responses to newer therapeutic agents, especially those directed at inhibition of tumor necrosis factor α. Biological therapy leads to significant levels of remission, improved quality of life, and retards or improves structural radiological damage.