Psoriasis genomics: analysis of proinflammatory (type 1) gene expression in large plaque (Western) and small plaque (Asian) psoriasis vulgaris

Cytokines in psoriasis: From pathogenesis to targeted therapy

Psoriasis is a multifactorial disease that affects 0.84% of the global population and it can be associated with disabling comorbidities. As patients present with thick scaly lesions, psoriasis was long believed to be a disorder of keratinocytes. Psoriasis is now understood to be the outcome of the interaction between immunological and environmental factors in individuals with genetic predisposition. While it was initially thought to be solely mediated by cytokines of type-1 immunity, namely interferon-γ, interleukin-2, and interleukin-12 because it responds very well to cyclosporine, a reversible IL-2 inhibitor; the discovery of Th-17 cells advanced the understanding of the disease and helped the development of biological therapy. This article aims to provide a comprehensive review of the role of cytokines in psoriasis, highlighting areas of controversy and identifying the connection between cytokine imbalance and disease manifestations. It also presents the approved targeted treatments for psoriasis and those currently under investigation.

Effectiveness of calcipotriol/betamethasone dipropionate aerosol foam in patients with small versus large plaque psoriasis in routine practice in South Korea

Small plaque psoriasis is the typical form of chronic plaque psoriasis affecting adults in South Korea. The effectiveness of calcipotriol/betamethasone dipropionate (Cal/BD) aerosol foam for large and small psoriasis plaques has not previously been examined. We performed a post hoc analysis of a recent, 4-week observational study of Cal/BD aerosol foam use in routine clinical practice in South Korea. Investigator Global Assessment response ([IGA] 0/1 at week 4), Patient Global Assessment response ([PaGA] 0/1 at week 4), change in Psoriasis Area and Severity Index (PASI), changes in psoriasis symptom scores, change in the Dermatology Life Quality Index (DLQI), and the proportion of patients achieving DLQI ≤5 were analyzed for patients with small (≤5 cm; n = 131) or large (>5 cm; n = 35) baseline plaque size. IGA response rates were similar for patients with small and large plaques (59.5% and 51.4% respectively). Similarly, there was no significant difference between the small and large groups in mean change in PASI (-2.20 vs -3.34), the proportions of patients with DLQI ≤5 (62.3% vs 54.3%) or PaGA 0/1 (29.2% vs 40.0%). Mean improvements in DLQI (-4.04 vs -6.20) and in psoriasis symptoms including itching (-1.50 vs -2.83), sleep loss (-0.67 vs -1.89), dryness (-1.57 vs -2.97), scaling (-1.21 vs -3.57), and redness (-1.17 vs -3.11) were greater in patients with large plaques than those with small plaques. Itching and DLQI differences were not statistically significant after adjustment for baseline characteristics. Stratification by body surface area affected eliminated statistically significant differences between the groups for most outcomes. In conclusion, this analysis suggests that Cal/BD aerosol foam is an effective, well-accepted treatment for adult patients with the small plaques typical of chronic plaque psoriasis in South Korea, as well as for those with large plaques.

TNF-α promotes CXCL-1/8 production in keratinocytes by downregulating galectin-3 through NF-κB and hsa-miR-27a-3p pathway to contribute psoriasis development

OBJECTIVE

Treatment with TNF-α inhibitors improve psoriasis with minimize/minor neutrophils infiltration and CXCL-1/8 expression in psoriatic lesions. However, the fine mechanism of TNF-α initiating psoriatic inflammation by tuning keratinocytes is unclear. Our previous research identified the deficiency of intracellular galectin-3 was sufficient to promote psoriasis inflammation characterized by neutrophil accumulation. This study aims to investigate whether TNF-α participated in psoriasis development through dysregulating galectin-3 expression.

METHODS

mRNA levels were assessed through quantitative real-time PCR. Flow cytometry was used to detect cell cycle/apoptosis. Western blot was used to evaluate the activation of the NF-κB signaling pathway. HE staining and immunochemistry were used to detect epidermal thickness and MPO expression, respectively. Specific small interfering RNA (siRNA) was used to knock down hsa-miR-27a-3p while plasmids transfection was used to overexpress galectin-3. Further, the multiMiR R package was utilized to predict microRNA-target interaction.

RESULTS AND DISCUSSION

We found that TNF-α stimulation altered cell proliferation and differentiation and promoted the production of psoriasis-related inflammatory mediators along with the inhibition of galectin-3 expression in keratinocytes. Supplement of galectin-3 could counteract the rise of CXCL-1/8 but not the other phenotypes of keratinocytes induced by TNF-α. Mechanistically, inhibition of the NF-κB signaling pathway could counteract the decrease of galectin-3 and the increase of hsa-miR-27a-3p expression whereas silence of hsa-miR-27a-3p could counteract the decrease of galectin-3 expression induced by TNF-α treatment in keratinocytes. Intradermal injection of murine anti-CXCL-2 antibody greatly alleviated imiquimod-induced psoriasis-like dermatitis.

CONCLUSION

TNF-α initiates psoriatic inflammation by increasing CXCL-1/8 in keratinocytes mediated by the axis of NF-κB-hsa-miR-27a-3p-galectin-3 pathway.

Variations in genetics, biology, and phenotype of cutaneous disorders in skin of color. Part II: Differences in clinical presentation and disparities in cutaneous disorders in skin of color

Skin of color (SOC) patients are projected to comprise the majority of the population by 2044, yet knowledge gaps in the clinical presentation and treatment of both common and uncommon dermatologic conditions in skin of color persist. Improved awareness of disparities that disproportionately impact SOC patients is necessary to address health inequity in the field of dermatology. The first part of this CME discussed structural, genetic, and immunophenotypic differences in SOC in common inflammatory disorders as well as cutaneous malignancies. The second part of this CME highlights clinical differences in the phenotypic presentation of the inflammatory disorders of atopic dermatitis, psoriasis, and hidradenitis suppurativa as well as the cutaneous malignancies of melanoma, basal cell carcinoma, and cutaneous T-cell lymphoma. Health disparities associated with each of these conditions are also discussed.

Variations in genetics, biology, and phenotype of cutaneous disorders in skin of color - Part I: Genetic, biologic, and structural differences in skin of color

Skin of color (SOC) populations include those who identify as Black/African, Hispanic/Latinx, Asian/Pacific Islander, American Indian/Native Alaskan, Indigenous Australian, Middle Eastern, biracial/multiracial, or non-White; this list is far from exhaustive and may vary between and within cultures. Recent genetic and immunological studies have suggested that cutaneous inflammatory disorders (atopic dermatitis, psoriasis, and hidradenitis suppurativa) and malignancies (melanoma, basal cell carcinoma, and cutaneous T-cell lymphoma) may have variations in their immunophenotype among SOC. Additionally, there is growing recognition of the substantial role social determinants of health play in driving health inequalities in SOC communities. It is critically important to understand that social determinants of health often play a larger role than biologic or genetic factors attributed to "race" in health care outcomes. Herein, we describe the structural, genetic, and immunological variations and the potential implications of these variations in populations with SOC. This article underscores the importance of increasing the number of large, robust genetic studies of cutaneous disorders in SOC to create more targeted, effective therapies for this often underserved and understudied population. Part II of this CME will highlight the clinical differences in the phenotypic presentation of and the health disparities associated with the aforementioned cutaneous disorders in SOC.

Differences in Clinical Features and Comorbid Burden between HLA-C∗06:02 Carrier Groups in >9,000 People with Psoriasis

The identification of robust endotypes-disease subgroups of clinical relevance-is fundamental to stratified medicine. We hypothesized that HLA-C∗06:02 status, the major genetic determinant of psoriasis, defines a psoriasis endotype of clinical relevance. Using two United Kingdom-based cross-sectional datasets-an observational severe-psoriasis study (Biomarkers of Systemic Treatment Outcomes in Psoriasis; n = 3,767) and a large population-based bioresource (UK Biobank, including n = 5,519 individuals with psoriasis)-we compared demographic, environmental, and clinical variables of interest in HLA-C∗06:02-positive (one or two copies of the HLA-C∗06:02 allele) with those in HLA-C∗06:02‒negative (no copies) individuals of European ancestry. We used multivariable regression analyses to account for mediation effects established a priori. We confirm previous observations that HLA-C∗06:02-positive status is associated with earlier age of psoriasis onset and extend findings to reveal an association with disease expressivity in females (Biomarkers of Systemic Treatment Outcomes in Psoriasis: P = 2.7 × 10-14, UK Biobank: P = 1.0 × 10-8). We also show HLA-C∗06:02-negative status to be associated with characteristic clinical features (large plaque disease, OR for HLA-C∗06:02 = 0.73, P = 7.4 × 10-4; nail involvement, OR = 0.70, P = 2.4 × 10-6); higher central adiposity (Biomarkers of Systemic Treatment Outcomes in Psoriasis: waist circumference difference of 2.0 cm, P = 8.4 × 10-4; UK Biobank: waist circumference difference of 1.4 cm, P = 1.5 × 10-4), especially in women; and a higher prevalence of other cardiometabolic comorbidities. These findings extend the clinical phenotype delineated by HLA-C∗06:02 and highlight its potential as an important biomarker to consider in future multimarker stratified medicine approaches.

Comparison of Efficacy of Anti-interleukin-17 in the Treatment of Psoriasis Between Caucasians and Asians: A Systematic Review and Meta-Analysis

Background

Interleukin-17 (IL-17) monoclonal antibody drugs have been increasingly significant in the treatment of psoriasis, but it is not clear whether the efficacy is equivalent across ethnicities.

Objective

To explore the differences of short-term efficacy of IL-17 inhibitors between Caucasians and Asians.

Methods

The pooled log risk ratio (logRR) between the groups was estimated. The meta-regression analysis on the logRR was performed, with the proportion of Caucasian patients as the covariate. The subgroup analysis was performed by specific IL-17 inhibitors.

Results

Of the 1,569 potentially relevant studies, sixteen randomized controlled trials (RCTs) were included. For the Psoriasis Area and Severity Index 75 (PASI 75) response at week 12, the pooled logRR of the Asian group and the Caucasian group was 2.81 (95% CI: 2.27–3.35, p < 0.001) and 2.93 (95% CI: 2.71–3.16, p < 0.001), respectively, indicating no significant difference of efficacy between Asians and Caucasians. The meta-regression analysis did not show an association of the proportion of Caucasians with the effect size (β = 0.3203, p = 0.334). In the subgroup analysis, the comparison results of secukinumab were consistent with the main analysis.

Limitations

Only the short-term efficacy was explored. The data from Asian countries were limited.

Conclusions

The short-term efficacy of IL-17 inhibitors in the treatment of psoriasis has no significant difference between Caucasians and Asians.

Systematic Review Registration

PROSPERO, identifier CRD42020201994, https://www.crd.york.ac.uk/prospero/.

Small plaque psoriasis re-visited: A type of psoriasis mediated by a type-I interferon pathway

TNFα-inhibitor-induced psoriasis is mediated by the type-I interferon pathway, of which IFNα, LL37 and IL-36γ are major players. A subset of patients treated with TNFα inhibitors develop small plaque psoriatic lesions. Small plaque psoriasis is similarly observed in patients on immune checkpoint inhibitors (ICI), and with concurrent systemic lupus erythematosus (SLE) or positive antinuclear antibody (ANA). Small plaque psoriasis is also the predominant phenotype in Asian populations. The association between small plaque psoriasis morphology in various clinical scenarios and the type-I interferon pathway has not been previously studied. A cross-sectional study was conducted of patients who developed small plaque psoriasis and had a biopsy for diagnostic clarification between 2009 and 2017. We obtained skin specimens from 14 adults with small plaque psoriasis: four patients taking anti-TNFα treatment, four patients with antecedent SLE, three patients with concurrent ANA positivity and three patients taking ICI. Controls included three patients with chronic plaque psoriasis. Histology confirmed psoriasiform epidermal hyperplasia with focal lichenoid and spongiotic features. Immunohistochemical analysis revealed higher expression of IFNα-induced MXA, LL37 and IL-36γ in all clinical scenarios of small plaque psoriasis compared to chronic plaque psoriasis. There was decreased CD8 T-cell migration to the epidermis and variability in the number of LAMP3+ cytoplasmic dendritic cells in the dermis of small plaque psoriasis. The findings suggest that small plaque psoriasis is a unique type of psoriasis with a distinct morphology and immune-phenotype, primarily mediated by the type-I interferon pathway. Associating morphology and disease pathogenesis may help identify therapeutic targets for better disease control.

Evaluation of short-term (16-week) effectiveness and safety of guselkumab in patients with psoriasis: A prospective real-life study on the Chinese population

Real-life data on guselkumab in psoriasis are limited and not available in China hitherto. This study aimed to evaluate the short-term effectiveness and safety of guselkumab in patients with psoriasis under Chinese real-life conditions and to explore the effect of guselkumab on CD4⁺ CD25⁺ Foxp3⁺ regulatory T cells (Tregs). A Chinese prospective and real-life study involving patients with psoriasis in Dermatology Hospital of Southern Medical University, Guangzhou, China from April to September 2020 was conducted. A total of 45 patients with psoriasis were finally enrolled in the study. Psoriasis Area Severity Index (PASI) 90 and 100 responses at week 16 were achieved by 88.6% and 45.5% of patients, respectively. The analysis of PASI response in different subgroups showed no statistically significant difference. Univariate logistic regression analysis revealed that at week 16, none of the variables were associated with decreasing PASI 90 response, whereas age at onset of disease was a predictor of PASI 100 response. Dynamic detection of CD4⁺ CD25⁺ Foxp3⁺ Tregs frequency from peripheral blood suggested a stable maintained trend in terms of guselkumab treatment duration. No severe adverse events occurred during the follow-up period. This study confirmed the short-term effectiveness and safety of guselkumab, as well as its good tolerance against psoriasis, in the Chinese population. Guselkumab treatment maintains levels of Tregs in patients with psoriasis.

Clinical outcomes in adult patients with plaque psoriasis treated with ustekinumab under real-world practice in Korea: A prospective, observational, multi-center, postmarketing surveillance study

Postmarketing surveillance is conducted to establish drug safety and effectiveness under real-world practice. We aimed to validate the effectiveness and safety of ustekinumab in the treatment of adult Korean patients with plaque psoriasis under real-world practice. This was a prospective, observational, and multi-center study. Subjects aged 18 years or older who were treated with ustekinumab for plaque psoriasis were enrolled. We enrolled 977 patients; 654 (66.9%) were men, with mean body surface area (BSA, ± standard deviation) of 27.0 ± 18.3% and mean psoriasis area severity index (PASI) score of 18.1 ± 9.7. The effectiveness analysis was performed in 581 patients who had at least one follow-up assessment and met treatment criteria per local label and reimbursement guidelines. Of these patients, 287 had effectiveness data for visit 6 at 53.7 ± 2.1 weeks. At visit 6, 91.6% (263/287), 51.2% (147/287), and 9.4% (27/287) patients achieved PASI 75, 90, and 100 responses, respectively. Adverse events (AEs) occurred in 112 of the 977 (11.5%) patients with an incidence rate of 21.5 per 100 patient-years (PYs). Serious AEs occurred in eight (0.8%) patients with an incidence rate of 1.2 per 100 PYs. The estimated 1-year drug survival rate was 87.7%. The multiple logistic regression analysis showed that higher baseline PASI score and no prior biologic exposure were significant predictors for PASI 90 response at visit 6. Ustekinumab was effective and safe, and displayed a high survival rate in the treatment of adult Korean patients with plaque psoriasis in real-world practice.

Efficacy and safety of brodalumab in the Korean population for the treatment of moderate to severe plaque psoriasis: A randomized, phase III, double-blind, placebo-controlled study

Psoriasis, a chronic inflammatory skin disease, negatively impacts patients’ quality of life (QoL). This randomized, phase III, double‐blind, placebo‐controlled, multicenter study evaluated the efficacy and safety of brodalumab, a human anti‐interleukin‐17 receptor A monoclonal antibody, in Korean patients with moderate to severe plaque psoriasis. Coprimary end‐points were the percentage of patients with 75% or more improvement in Psoriasis Area and Severity Index (PASI 75) and static Physician’s Global Assessment (sPGA) success (score 0/1) at week 12. Secondary end‐points included the percentage improvement from baseline in PASI score and proportion of patients with PASI 50/75/90/100 responses. QoL was assessed with the Dermatology Life Quality Index (DLQI). Eligible patients were randomized to receive brodalumab 210 mg (N = 40) or placebo (N = 22) every 2 weeks (Q2W) at a 2:1 ratio for 12 weeks. Subsequently, all patients entered an open‐label extension phase and received brodalumab 210 mg Q2W until week 62. At week 12, the proportion of patients who achieved the coprimary end‐points, PASI 75 and sPGA success, was significantly higher in the brodalumab 210 mg Q2W group compared with the placebo group (92.5% vs 0%). At week 12, the mean ± SD percentage improvement in the PASI score was 96.87 ± 6.01% in the brodalumab 210 mg Q2W group, which was maintained until study end (week 64). PASI 50/75/90 responses were achieved by 100% of patients receiving brodalumab 210 mg Q2W at weeks 6, 13, and 24, respectively; PASI 100 was achieved by 82.8% of patients at week 64. Brodalumab treatment rapidly improved DLQI scores. The most common treatment‐emergent adverse events were nasopharyngitis, upper respiratory tract infections, tinea pedis, and urticaria. Overall, treatment with brodalumab 210 mg Q2W resulted in a rapid and significant clinical benefit and was well tolerated in patients with moderate to severe plaque psoriasis in Korea.

Topical nanoparticles interfering with the DNA-LL37 complex to alleviate psoriatic inflammation in mice and monkeys

Cell-free DNA (cfDNA) released from damaged or dead cells combines with LL37 and is converted into an immune response activator to exacerbate psoriasis. Here, we show that cationic nanoparticles (cNPs) efficiently compete for DNA from the DNA-LL37 immunocomplex and inhibit DNA-LL37-induced cell activation. Using phenotypical images, psoriasis area and severity index scoring, histology, and immunohistochemical analysis, we demonstrate that topical application of cNPs on psoriasiform skin of a mouse model relieves psoriatic symptoms. It is noteworthy that the results were confirmed in a cynomolgus monkey model. Moreover, topically administrated cNPs showed low in vivo toxicity because of their retention in skin. Mechanistic analyses of cytokine expression in the psoriatic site, cfDNA levels in circulation and inflamed skin, skin permeation, and biodistribution of cNPs also matched the therapeutic outcomes. Therefore, we present a previously unidentified strategy of nanomedicine to treat skin inflammatory diseases, which demonstrates great potential for clinical application.

Efficacy and safety of guselkumab compared with placebo and adalimumab in Korean patients with moderate-to-severe psoriasis: post-hoc analysis from the phase III, double-blind, placebo- and active-comparator-controlled VOYAGE 1/2 trials

Background: The phase 3 studies, VOYAGE 1 and 2, were conducted to assess guselkumab in the treatment of patients with moderate-to-severe psoriasis.Objectives: To investigate the efficacy and safety of guselkumab in Korean patients.Methods: The Korean sub-population of VOYAGE 1 and 2 study patients were included in this analysis. Efficacy and safety were evaluated through Weeks 24 and 28, respectively.Results: Of 126 randomized Korean patients, 30, 63, and 33 received placebo, guselkumab, and adalimumab, respectively. At Week 16, guselkumab was superior to placebo in achieving an Investigator's Global Assessment (IGA) score of 0 or 1 (cleared or minimal; 90.5 vs. 20.0%, p<.001) and a Psoriasis Area and Severity Index (PASI) 90 response (71.4 vs. 3.3%, p<.001). At week 24, a significantly higher proportion of guselkumab-treated patients achieved PASI 75 and IGA 0 (clear skin) responses compared to adalimumab-treated patients (PASI 75: 93.7 vs. 66.7%, p<.001; IGA 0: 52.4 vs. 21.2%, p=.004). Through Week 28, guselkumab and adalimumab showed comparable safety profiles.Conclusion: The efficacy and safety of guselkumab in Korean psoriasis patients through 28 weeks were consistent with findings for the overall VOYAGE 1 and 2 study population.

Increased risk of atherosclerotic cardiovascular disease among patients with psoriasis in Korea: A 15-year nationwide population-based cohort study

The association between psoriasis and risk of atherosclerotic cardiovascular disease has not been thoroughly evaluated in a large longitudinal cohort of an Asian population. We conducted a nationwide population-based retrospective cohort study encompassing more than 1.7 million Koreans with a 15-year follow-up period. The period prevalence of psoriasis was 0.33% among the baseline participants (1997-2000). In Cox proportional hazard analyses, the individuals with psoriasis had a higher adjusted hazard ratio (HR) for incidence of overall atherosclerotic cardiovascular disease (HR, 1.18; 95% confidence interval [CI], 1.09-1.27) compared with controls. Subgroup analyses revealed that the risk for myocardial infarction was commonly increased in both sexes with moderate to severe psoriasis (male: HR, 2.09; 95% CI, 1.35-3.24; female: HR, 3.23; 95% CI, 1.34-7.76), whereas the risk for ischemic stroke was specifically increased in female individuals with moderate to severe psoriasis (HR, 2.02; 95% CI, 1.24-3.30). Our data suggest that appropriate medical screening for possible cardiovascular comorbidities is warranted in Asian psoriatic patients according to disease severity and sex.

Treatment with TNF-α inhibitor rectifies M1 macrophage polarization from blood CD14+ monocytes in patients with psoriasis independent of STAT1 and IRF-1 activation

BACKGROUND

Psoriasis is a systemic inflammatory disease with dramatic responses to TNF-α inhibitors. TNF-α is mainly produced by macrophages. However, how macrophage polarization contributes to psoriasis remains unknown.

OBJECTIVE

We aimed to investigate the molecular mechanisms of macrophage polarization in psoriasis.

METHODS

8 patients with moderate to severe psoriasis (Male/Female: 4/4, average age: 47.9 years old) and 8 healthy controls (Male/Female: 4/4, average age: 49.3 years old) were recruited. Their peripheral CD14+ monocytes were isolated with magnetic beads and then were differentiated into macrophages. The differential macrophage polarization was compared among normal controls, psoriatic patients before and after TNF-α inhibitors. The U937 cells were used to investigate the mechanisms by which TNF-α altered the macrophage polarization.

RESULTS

The ratio of M1 to M2a macrophage polarization was higher in psoriatic patients comparing with that in controls. The decreasing M1/M2a ratio was parallel to decreasing PASI severity score after adalimumab treatment. Consistently, TNF-α blockage decreased M1/M2a ratio in U937 cells. The induction of STAT1 and IRF-1 in polarized U937 M1 cells was inhibited by TNF-α inhibitor. However, STAT1 and/or IRF-1 interference could not resume M1 polarization. In skin, the increased M1 and M2 infiltration in lesions returned to baseline after successful treatment with TNF-α inhibitor.

CONCLUSIONS

Increased M1 polarization is associated with higher disease severity in psoriasis, resuming to baseline after successful treatment by TNF-α inhibitors. TNF-α blockage inhibits M1 polarization through STAT1- and IRF-1-independent pathways. Macrophage polarization may contribute to disease progression in psoriasis.

The expression of mCTLA-4 in skin lesion inversely correlates with the severity of psoriasis

BACKGROUND

Psoriasis is a chronic inflammatory disease characterized by epidermal hyperplasia and increased T cell infiltration. Cytotoxic T lymphocyte antigen-4 (CTLA-4) is a key factor that affects T cell function and immune response. However, whether the expression of CTLA-4 affects the severity of psoriasis is still unknown.

OBJECTIVE

The aim of the project was to investigate the correlation between the expression of CTLA-4 and the severity of psoriasis.

METHODS

The plasma soluble CTLA-4 levels and membrane CTLA-4 expression were measured by enzyme-linked immunosorbent assay and immunohistochemistry analysis in mild, moderate and severe psoriasis patients, respectively. Imiquimod-induced mouse model of psoriasis was treated with CTLA-4 immunoglobulin fusion protein (CTLA-4 Ig) or anti-CTLA-4 antibody. Epidermal thickness and infiltrating CD3+ T cell counts were evaluated.

RESULTS

The plasma soluble CTLA-4 levels had no significant difference among mild, moderate, and severe patients (p > 0.05). However, the membrane CTLA-4 expression in skin was significantly higher in mild psoriasis patients compared to moderate and severe psoriasis patients (17652.86 ± 18095.66 vs 6901.36 ± 4400.77 vs 3970.24 ± 5509.15, p < 0.001). Furthermore, in imiquimod-induced mouse model of psoriasis, the results showed that mimicking CTLA-4 function improved the skin phenotype and reduced epidermal thickness (172.87 ± 28.25 vs 245.87 ± 36.61 μm, n = 6, p < 0.01) as well as infiltrating CD3+ T cell counts (5.09 ± 3.45 vs 13.45 ± 4.70, p < 0.01) compared to control group. However, blocking CTLA-4 function aggregated the skin phenotype including enhanced epidermal thickness and infiltrating CD3+ T cell counts compared to control group.

CONCLUSION

These results indicated that the expression of mCTLA-4 in skin lesion inversely correlated with the severity of psoriasis and CTLA-4 might play a critical role in the disease severity of psoriasis.

Molecular Phenotyping Small (Asian) versus Large (Western) Plaque Psoriasis Shows Common Activation of IL-17 Pathway Genes but Different Regulatory Gene Sets

Psoriasis is present in all racial groups, but in varying frequencies and severity. Considering that small plaque psoriasis is specific to the Asian population and severe psoriasis is more predominant in the Western population, we defined Asian small and intermediate plaque psoriasis as psoriasis subtypes, and compared their molecular signatures with classic subtype of Western large plaque psoriasis. Two different characteristics of psoriatic spreading—vertical growth and radial expansion—were contrasted between subtypes, and genomic data were correlated to histologic and clinical measurements. Compared to Western large plaque psoriasis, Asian small plaque psoriasis revealed limited psoriasis spreading, but IL-17A and IL-17-regulated pro-inflammatory cytokines were highly expressed. Paradoxically, IL-17A and IL-17-regulated pro-inflammatory cytokines were lower in Western large plaque psoriasis, while T cells and dendritic cells in total psoriatic skin area were exponentially increased. Negative immune regulators, such as CD69 and FAS, were decreased in both Western large plaque psoriasis and psoriasis with accompanying arthritis or obesity, and their expression was correlated with psoriasis severity index. Based on the disease subtype comparisons, we propose that dysregulation of T cell expansion enabled by downregulation of immune negative regulators is the main mechanism for development of large plaque psoriasis subtypes.

The MARCOPOLO Study of Ustekinumab Utilization and Efficacy in a Real-World Setting: Treatment of Patients with Plaque Psoriasis in Asia-Pacific Countries

Background

Ustekinumab is a fully human monoclonal antibody approved for the treatment of chronic moderate-to-severe plaque psoriasis in adults. However, factors including efficacy, tolerability, ease of use, and cost burden may affect ustekinumab utilization. Noncompliance may, in turn, affect treatment response.

Objective

To evaluate ustekinumab utilization in the real-world setting in Asia-Pacific countries.

Methods

In this phase 4 observational study conducted in Indonesia, Malaysia, Singapore, Korea, and Taiwan, adults with plaque psoriasis receiving ustekinumab were followed for up to 52 weeks. Study endpoints were the proportion of all patients using ustekinumab according to label-recommended intervals and the proportion of Korean patients who achieved a psoriasis area severity index 75 response at week 16. Safety was assessed by monitoring adverse events.

Results

Overall, 169 patients received ustekinumab (Korea, n=102; other countries, n=67). Just over half (56.2%) of patients used ustekinumab with the label-recommended interval from baseline to week 40; the proportion was higher in Korea (73.5%) than in other countries (29.9%), probably because ustekinumab was provided without charge for Korean patients up to week 40. Noncompliance increased after week 40 in Korea and from week 28 in other Asia-Pacific countries, with cost cited as the most common reason. At week 16, 56.9% of Korean patients achieved a Psoriasis Area Severity Index 75 response. Safety results were in line with those seen in previous studies.

Conclusion

More than half of all patients in Asia-Pacific countries used ustekinumab as per the label-recommended dose interval, but reimbursement variations between countries may have confounded overall results.

A specific molecular signature for psoriasis and eczema

Psoriasis and eczema seem to present a specific distinctive gene expression pattern. In the Science Translation Medicine (Sci Transl Med), Quaranta et al. reported a specific molecular signature of psoriasis and eczema. By using an intraindividual genome expression analysis in patients affected by both diseases, the authors identified genes and signaling pathways that are regulated in common and that are exclusive for each disease.

Clinical improvement in psoriasis with specific targeting of interleukin-23

Psoriasis is a chronic inflammatory skin disorder that affects approximately 2-3% of the population worldwide and has severe effects on patients' physical and psychological well-being. The discovery that psoriasis is an immune-mediated disease has led to more targeted, effective therapies; recent advances have focused on the interleukin (IL)-12/23p40 subunit shared by IL-12 and IL-23. Evidence suggests that specific inhibition of IL-23 would result in improvement in psoriasis. Here we evaluate tildrakizumab, a monoclonal antibody that targets the IL-23p19 subunit, in a three-part, randomized, placebo-controlled, sequential, rising multiple-dose phase I study in patients with moderate-to-severe psoriasis to provide clinical proof that specific targeting of IL-23p19 results in symptomatic improvement of disease severity in human subjects. A 75% reduction in the psoriasis area and severity index (PASI) score (PASI75) was achieved by all subjects in parts 1 and 3 (pooled) in the 3 and 10 mg kg(-1) groups by day 196. In part 2, 10 out of 15 subjects in the 3 mg kg(-1) group and 13 out of 14 subjects in the 10 mg kg(-1) group achieved a PASI75 by day 112. Tildrakizumab demonstrated important clinical improvement in moderate-to-severe psoriasis patients as demonstrated by improvements in PASI scores and histological samples.

The pathophysiological role of dendritic cell subsets in psoriasis

Psoriasis is a chronic inflammatory disorder characterized by an erythematous scaly plaque of the skin and is occasionally accompanied by systemic complications. In the psoriatic lesions, an increased number of cytokine-producing dendritic cells and activated T cells are observed, which indicate that psoriasis is a prototype of an immune-mediated dermatosis. During the last decade, emerging studies demonstrate novel roles for the dendritic cell subsets in the process of disease initiation and maintenance of psoriasis. In addition, recently discovered anti-psoriatic therapies, which specifically target inflammatory cytokines produced by lesional dendritic cells, bring much better clinical improvement compared to conventional treatments. These new therapies implicate the crucial importance of dendritic cells in psoriasis pathogenesis. This review will summarize and discuss the dendritic cell subsets of the human skin and their pathophysiological involvement in psoriasis based on mouse- and patient-oriented studies. [BMB Reports 2014; 47(2): 60-68]

Interplay between CXCR2 and BLT1 facilitates neutrophil infiltration and resultant keratinocyte activation in a murine model of imiquimod-induced psoriasis

Psoriasis is an inflammatory skin disease with accelerated epidermal cell turnover. Neutrophil accumulation in the skin is one of the histological characteristics of psoriasis. However, the precise mechanism and role of neutrophil infiltration remain largely unknown. In this article, we show that orchestrated action of CXCR2 and leukotriene B4 receptor BLT1 plays a key role in neutrophil recruitment during the development of imiquimod (IMQ)-induced psoriatic skin lesions in mice. Depletion of neutrophils with anti-Ly-6G Ab ameliorated the disease severity, along with reduced expression of proinflammatory cytokine IL-1β in the skin. Furthermore, CXCR2 and BLT1 coordinately promote neutrophil infiltration into the skin during the early phase of IMQ-induced inflammation. In vitro, CXCR2 ligands augment leukotriene B4 production by murine neutrophils, which, in turn, amplifies chemokine-mediated neutrophil chemotaxis via BLT1 in autocrine and/or paracrine manners. In agreement with the increased IL-19 expression in IMQ-treated mouse skin, IL-1β markedly upregulated expression of acanthosis-inducing cytokine IL-19 in human keratinocytes. We propose that coordination of chemokines, lipids, and cytokines with multiple positive feedback loops might drive the pathogenesis of psoriasis and, possibly, other inflammatory diseases as well. Interference to this positive feedback or its downstream effectors could be targets of novel anti-inflammatory treatment.

Association of IL-12B gene rs6887695 polymorphism with hereditary susceptibility and clinical characterization of psoriasis vulgaris in the Chinese Han population

We aimed to investigate the role of IL-12B gene polymorphism (rs6887695) in the disease susceptibility and clinical phenotypes of psoriasis vulgaris patients in the Chinese Han population. The genotype data of the IL-12B gene polymorphism (rs6887695) in 575 psoriasis patients and 1,403 normal controls were investigated using TaqMan technology. The Chi-square test was used to compare the genotype and allele frequency distribution among the groups. The genotypic and allelic frequencies of rs6887695 in the IL-12B gene between the cases and controls, as well as between the guttate and plaque psoriasis cases, were statistically significant (P genotype <0.01, P allele <0.01). However, the differences between the pediatric and adult onset psoriasis patients, between familial and sporadic cases, and between female and male cases were not statistically significant (P > 0.05). The genetic polymorphism of the IL-12B gene (rs6887695) may be associated with the psoriasis susceptibility in the Chinese Han population, especially for the plaque cases, but not associated with the age at onset, family history, or sex.

IL-1R1 signaling facilitates Munro's microabscess formation in psoriasiform imiquimod-induced skin inflammation

Munro's microabscesses contain polymorphonuclear leukocytes and form specifically in the epidermis of psoriasis patients. The mechanism whereby the neutrophils are recruited into the epidermis is poorly understood. Using a combination of human and mouse primary keratinocyte cell cultures and the imiquimod-induced psoriasis-like mouse model of skin inflammation, we explored the role of IL-1 signaling in microabscess formation. In vitro imiquimod stimulated production of IL-1α and neutrophil recruiting chemokines. Imiquimod-activated chemokine expression was dependent upon adenosine signaling and independent of IL-1α and IL-1 receptor type 1 (IL-1R1); nevertheless, IL-1α could enhance chemokine expression initiated by imiquimod. Topical application of imiquimod in vivo led to epidermal microabscess formation, acanthosis, and increased IL-1α and chemokine expression in the skin of wild-type mice. However, in IL-1R1-deficient mice these responses were either absent or dramatically reduced. These results demonstrate that IL-1α and IL-1R1 signaling is essential for microabscess formation, neutrophil recruiting chemokine expression, and acanthosis in psoriasis-like skin inflammation induced by imiquimod.

The IL-23/T17 pathogenic axis in psoriasis is amplified by keratinocyte responses

Psoriasis is a complex inflammatory process resulting from activation of the well-defined interleukin (IL)-23/T17 cytokine axis. We review the role of key cytokines IL-17 and IL-23 in psoriasis, as well as tumor necrosis factor (TNF)α, focusing on therapeutic cytokine interventions and what they reveal about psoriatic inflammation. The potential role of recently described epidermal IL-36RN and CARD14 genetic mutations in psoriasis pathogenesis is also explored, because they augment keratinocyte responses to proinflammatory cytokines. The discovery of these genetic mutations in familial and pustular psoriasis suggests new links between cytokine-induced gene products and IL-1 family members from keratinocytes, which may regulate features of the disease, including epidermal hyperplasia and neutrophil infiltrating responses.

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.

Meta-analysis derived (MAD) transcriptome of psoriasis defines the "core" pathogenesis of disease

The cause of psoriasis, a common chronic inflammatory skin disease, is not fully understood. Microarray experiments have been widely used in recent years to identify genes associated with psoriasis pathology, by comparing expression levels of lesional (LS) with adjacent non-lesional (NL) skin. It is commonly observed that the differentially expressed genes (DEGs) differ greatly across experiments, due to variations introduced in the microarray experiment pipeline. Therefore, a statistically based meta-analytic approach, which combines the results of individual studies, is warranted. In this study, a meta-analysis was conducted on 5 microarray data sets, including 193 LS and NL pairs. We termed this the Meta-Analysis Derived (MAD) transcriptome. In “MAD-5” transcriptome, 677 genes were up-regulated and 443 were down-regulated in LS skin compared to NL skin. This represents a much larger set than the intersection of DEGs of these 5 studies, which consisted of 100 DEGs. We also analyzed 3 of the studies conducted on the Affymetrix hgu133plus2 chips and found a greater number of DEGs (1084 up- and 748 down-regulated). Top canonical pathways over-represented in the MAD transcriptome include Atherosclerosis Signaling and Fatty Acid Metabolism, while several “new” genes identified are involved in Cardiovascular Development and Lipid Metabolism. These findings highlight the relationship between psoriasis and systemic manifestations such as the metabolic syndrome and cardiovascular disease. Then, the Meta Threshold Gradient Descent Regularization (MTGDR) algorithm was used to select potential markers distinguishing LS and NL skin. The resulting set (20 genes) contained many genes that were part of the residual disease genomic profile (RDGP) or “molecular scar” after successful treatment, and also genes subject to differential methylation in LS tissues. To conclude, this MAD transcriptome yielded a reference list of reliable psoriasis DEGs, and represents a robust pool of candidates for further discovery of pathogenesis and treatment evaluation.

Interleukin-23: as a drug target for autoimmune inflammatory diseases

Interleukin-23 (IL-23) is a member of the IL-12 family of cytokines with pro-inflammatory properties. Its ability to potently enhance the expansion of T helper type 17 (Th17) cells indicates the responsibility for many of the inflammatory autoimmune responses. Emerging data demonstrate that IL-23 is a key participant in central regulation of the cellular mechanisms involved in inflammation. Both IL-23 and IL-17 form a new axis through Th17 cells, which has evolved in response to human diseases associated with immunoactivation and immunopathogeny, including bacterial or viral infections and chronic inflammation. Targeting of IL-23 or the IL-23 receptor or IL-23 axis is a potential therapeutic approach for autoimmune diseases including psoriasis, inflammatory bowel disease, rheumatoid arthritis and multiple sclerosis. The current review focuses on the immunobiology of IL-23 and summarizes the most recent findings on the role of IL-23 in the pre-clinical and ongoing clinical studies.

Psoriasis

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

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.

Targeting IL-23 in human diseases

IMPORTANCE OF THE FIELD

IL-23 is one of the most intriguing cytokine for its many immunological functions, which are the basis of its important role in host defense but also of its possible contribution to the pathogenesis of several diseases.

AREAS COVERED IN THIS REVIEW

The literature and patents about IL-23 pathway and their targeting in therapeutic potential applications. Findings published within the last 5 years receive particular attention.

WHAT THE READER WILL GAIN

An overview of the emerging role of IL-23 in physiological and pathological conditions and a review of the different approaches (IL-23 pathway-based) currently used for autoimmune diseases and cancer therapies and the results obtained both in preclinical models and in clinical trials.

TAKE HOME MESSAGE

Inhibition/targeting of IL-23 may be a good and novel therapeutic strategy, especially in the treatment of diseases like psoriasis, for which current treatments show more pronounced side effects than those of IL-23-blocking and employed as part of specific patient-tailored therapies in inflammatory bowel diseases.

Post-genomics and skin inflammation

Atopic dermatitis and psoriasis are two chronic skin inflammatory diseases that have so far received a greater attention within the scientific community through different post-genomic approaches; on the contrary, acne, which is undoubtedly one of the most common skin disorders involving inflammatory processes, seems to be still quite neglected under the post-genomic point of view. In this paper, we will review how post-genomic technologies have provided new fundamental tools for the analysis of these three conditions and we will cast light on their potential in addressing future research challenges.

Assessment of the psoriatic transcriptome in a large sample: additional regulated genes and comparisons with in vitro models

To further elucidate molecular alterations in psoriasis, we performed a gene expression study of 58 paired lesional and uninvolved psoriatic and 64 control skin samples. Comparison of involved psoriatic (PP) and normal (NN) skin identified 1,326 differentially regulated transcripts encoding 918 unique genes (549 up- and 369 downregulated), of which over 600 are to our knowledge previously unreported, including S100A7A, THRSP, and ELOVL3. Strongly upregulated genes included SERPINB4, PI3, DEFB4, and several S100-family members. Strongly downregulated genes included Wnt-inhibitory factor-1 (WIF1), beta-cellulin (BTC), and CCL27. Enriched gene ontology categories included immune response, defense response, and keratinocyte differentiation. Biological processes regulating fatty acid and lipid metabolism were enriched in the down-regulated gene set. Comparison of the psoriatic transcriptome to the transcriptomes of cytokine-stimulated cultured keratinocytes (IL-17, IL-22, IL-1alpha, IFN-gamma, TNF-alpha, and OSM) showed surprisingly little overlap, with the cytokine-stimulated keratinocyte expression representing only 2.5, 0.7, 1.5, 5.6, 5.0, and 1.9% of the lesional psoriatic dysregulated transcriptome, respectively. This comprehensive analysis of differentially regulated transcripts in psoriasis provides additional insight into the pathogenic mechanisms involved and emphasizes the need for more complex yet tractable experimental models of psoriasis.

A subpopulation of CD163-positive macrophages is classically activated in psoriasis

Macrophages are important cells of the innate immune system, and their study is essential to gain greater understanding of the inflammatory nature of psoriasis. We used immunohistochemistry and double-label immunofluorescence to characterize CD163(+) macrophages in psoriasis. Dermal macrophages were increased in psoriasis compared with normal skin and were identified by CD163, RFD7, CD68, lysosomal-associated membrane protein 2 (LAMP2), stabilin-1, and macrophage receptor with collagenous structure (MARCO). CD163(+) macrophages expressed C-lectins CD206/macrophage mannose receptor and CD209/DC-SIGN, as well as costimulatory molecules CD86 and CD40. They did not express mature dendritic cell (DC) markers CD208/DC-lysosomal-associated membrane glycoprotein, CD205/DEC205, or CD83. Microarray analysis of in vitro-derived macrophages treated with IFN-γ showed that many of the genes upregulated in macrophages were found in psoriasis, including STAT1, CXCL9, Mx1, and HLA-DR. CD163(+) macrophages produced inflammatory molecules IL-23p19 and IL-12/23p40 as well as tumor necrosis factor (TNF) and inducible nitric oxide synthase (iNOS). These data show that CD163 is a superior marker of macrophages, and identifies a subpopulation of "classically activated" macrophages in psoriasis. We conclude that macrophages are likely to contribute to the pathogenic inflammation in psoriasis, a prototypical T helper 1 (Th1) and Th17 disease, by releasing key inflammatory products.

The Increased Expression of Matrix Metalloproteinase-9 Messenger RNA in the Non-lesional Skin of Patients with Large Plaque Psoriasis Vulgaris

BACKGROUND

A difference of the interleukin-18 (IL-18) mRNA expression among several proinflammatory genes was previously observed between large plaque (LP) psoriasis patients (more than 5 cm lesions are typical) and small plaque (SP) psoriasis patients (1~2 cm lesions are typical). Therefore, it is necessary to test whether there is any difference in the expression of the genes that activate IL-18 or the expression of genes that are induced by IL-18.

OBJECTIVE

To test the differential mRNA expressions of caspase-1, STAT-6, MMP-1, MMP-2, MMP-9 and TIMP-1 according to the clinical types of psoriasis vulgaris lesions in Korean patients, we have analyzed the skin samples of psoriasis vulgaris patients.

METHODS

The total cellular RNA of skin samples from groups of patient with LP and SP psoriasis was analyzed by performing real-time PCR (the Taqman method) to compare the differences in the mRNA expressions.

RESULTS

The caspase-1 and STAT-6 mRNA expression levels from the SP lesional skin of the patients were increased compared with the caspase-1 and STAT-6 mRNA expression levels from SP non-lesional skin or normal skin, but these expression levels from the SP non-lesional skin were not significantly different from those of the LP non-lesional skin. Among MMP-1, MMP-2, MMP-9 and TIMP-1, the expressions of MMP-1, MMP-2 and MMP-9 mRNA were increased in the SP lesional skin compared with those of the SP non-lesional skin. The MMP-1 mRNA expressions in both the LP and SP lesional skin were increased compared with those in the normal skin (p=0.028 and p=0.007 respectively). The MMP-9 mRNA expression in the LP non-lesional skin was elevated compared with the MMP-9 mRNA expression in the SP non-lesional skin (p=0.047). The TIMP-1 mRNA expression levels from the non-lesional skin and the lesional skin of the psoriasis patients and the normal skin samples were not significantly different.

CONCLUSION

The increased expression of MMP-9 mRNA in the LP non-lesional skin compared to that of the SP non-lesional skin in the psoriatic skin suggests that the increased MMP-9 mRNA expression is related to the large size type of lesion.

Interleukin-1 regulates keratinocyte expression of T cell targeting chemokines through interleukin-1 receptor associated kinase-1 (IRAK1) dependent and independent pathways

IL-1 is a potent pro-inflammatory cytokine that activates intracellular signaling cascades some of which may involve IL-1 receptor associated kinase-1 (IRAK1). Psoriasis is a T cell dependent chronic inflammatory condition of the skin of unknown cause. IL-1 has been implicated in psoriasis pathology, but the mechanism has not been elucidated. Interestingly, expression of IRAK1 is elevated in psoriatic skin. To identify a potential link between IL-1, keratinocytes and T cells in skin inflammation we employed pathway-focused microarrays to evaluate IL-1 dependent gene expression in keratinocytes. Several candidate mRNAs encoding known T cell chemoattractants were identified in primary keratinocytes and the stable keratinocyte cell line HaCaT. CCL5 and CCL20 mRNA and protein levels were confirmed up-regulated by IL-1 in concentration and time-dependent manners. Furthermore IL-1 synergized with IFN-gamma and TNF-alpha. Expression of CXCL9, CXCL10 and CXCL11 mRNAs was also increased in response to IL-1, but protein could only be detected in medium from cells treated with IFN-gamma alone or in combination with IL-1. Over-expression of IRAK1 led to increased constitutive and cytokine induced production of CCL5 and CCL20. Inhibition of IRAK1 activity through RNAi or expression of a dominant negative mutant blocked production of CCL5 and CCL20 but had no effect upon the IL-1 enhancement of IFN-gamma induced CXCL9, CXCL10 and CXCL11 production. In conclusion IL-1 regulates T cell targeting chemokine production in keratinocytes through IRAK1 dependent and independent pathways. These pathways may contribute to acute and chronic skin inflammation.

Comparison of acute responses of mice livers to short-term exposure to nano-sized or micro-sized silver particles

Mice were fed either 13 nm silver nanoparticles or 2-3.5 mum silver microparticles. The livers were then obtained after 3 days and subjected to a histopathological analysis. The nanoparticle-fed and microparticle-fed livers both exhibited lymphocyte infiltration in the histopathological analysis, suggesting the induction of inflammation. In vitro, a human hepatoma cell line (Huh-7) was treated with the same silver nanoparticles and microparticles. The mitochondrial activity and glutathione production were hardly affected. However, the DNA contents decreased 15% in the nanoparticle-treated cells and 10% in the microparticle-treated cell, suggesting a more potent induction of apoptosis by the nanoparticles. From a microarray analysis of the RNA from the livers of the nano- and micro-particle-fed mice, the expression of genes related to apoptosis and inflammation was found to be altered. These gene expression changes in the nanoparticle-treated livers lead to phenotypical changes, reflecting increased apoptosis and inflammation. The changes in the gene expression were confirmed by using a semi-quantitative RT-PCR.

Cytokines and anticytokines in psoriasis

BACKGROUND

Psoriasis is a chronic autoimmune hyperproliferative skin disease of varying severity affecting approximately 2-3% of the general population in the USA and Europe. Although the pathogenesis of psoriasis has not been fully elucidated, an immunologic-genetic relationship is likely. Cutaneous and systemic overexpression of various proinflammatory cytokines (TNF, interleukins, interferon-gamma) has been demonstrated in psoriatic patients.

METHODS

We reviewed the current database literature and summarized the involvement of cytokines and their receptors in the pathogenesis and treatment of psoriasis.

RESULTS

Although many cytokine/anti-cytokine therapies have been conducted, TNF antagonists in the treatment of both psoriasis arthropatica and vulgaris appear to be the most widely used clinically. Interestingly, the efficacy and tolerability of some cytokines (rhIL-11 or ABX-IL-8,) were found to be much lower than expected.

CONCLUSIONS

Preliminary results obtained with cytokine and anti-cytokine therapies appear promising and as such continued research is clearly indicated.

Interleukin-12, interleukin-23, and psoriasis: Current prospects

The clinical phenotype of psoriasis results from infiltration of T cells in the skin and elaboration of inflammatory cytokines. Interleukin (IL)-12 and, more recently, IL-23 have been implicated in the pathogenesis of psoriatic lesions. New therapies, including a monoclonal antibody against a subunit shared by IL-12 and IL-23, have been developed to treat psoriasis. Our purpose was to review the literature on IL-12 and IL-23 as a basis for understanding the use of anti-IL-12/IL-23 therapy for psoriasis. A review of English-language articles was performed using PubMed to identify articles pertaining to IL-12, IL-23, and psoriasis. IL-12 and IL-23 share a common subunit (p40) and have a distinct subunit (p35 and p19, respectively). Transgenic mice that overexpress IL-12 p40 develop inflammatory skin lesions. Both IL-12 knockout mice, which are deficient in IL-12, and human beings with a genetic IL-12 deficiency show increased susceptibility to intracellular pathogens and defective delayed-type hypersensitivity responses. These genetic deficiency states suggest the potential for adverse side effects from clinical administration of anti IL-12 p40 therapy. IL-12 p40 antibody was well tolerated in a phase I clinical trial with few adverse events and substantial improvements in psoriasis in most individuals. There was dose-dependent efficacy and substantial improvement in a larger cohort of patients in a phase II clinical trial. Larger and longer trials of anti IL-12/IL-23 therapies are needed to assess their clinical use and potential for infection and other adverse events.

Amelioration of epidermal hyperplasia by TNF inhibition is associated with reduced Th17 responses

Biological agents have dramatically improved treatment options for patients with severe psoriasis. Etanercept (tumor necrosis factor [TNF] receptor–immunoglobulin fusion protein) is an effective treatment for many psoriasis patients, and blockade of TNF is considered to be its primary action. However, in this clinical trial, we show that etanercept has early inhibitory effects on a newly appreciated type of T cells: T helper type 17 (Th17) cells. Etanercept reduced the inflammatory dendritic cell products that drive Th17 cell proliferation (interleukin [IL] 23), as well as Th17 cell products and downstream effector molecules (IL-17, IL-22, CC chemokine ligand 20, and β-defensin 4). In contrast, Th1 cellular products and effector molecules (interferon γ, lymphotoxin α, and myxovirus resistance 1) were reduced late in disease resolution. This study suggests a role for Th17 in addition to Th1 cells in the pathogenesis of psoriasis. Th17 cells may be particularly important in driving epidermal activation in psoriatic plaques, whereas Th1 cells must also be eliminated for final disease resolution.

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.

Pathogenesis and therapy of psoriasis

Psoriasis is one of the most common human skin diseases and is considered to have key genetic underpinnings. It is characterized by excessive growth and aberrant differentiation of keratinocytes, but is fully reversible with appropriate therapy. The trigger of the keratinocyte response is thought to be activation of the cellular immune system, with T cells, dendritic cells and various immune-related cytokines and chemokines implicated in pathogenesis. The newest therapies for psoriasis target its immune components and may predict potential treatments for other inflammatory human diseases.

Observations of Psoriasis in the Absence of Therapeutic Intervention Identifies Two Unappreciated Morphologic Variants, Thin-Plaque and Thick-Plaque Psoriasis, and their Associated Phenotypes

Psoriatic plaque thickness is a clinical measure of psoriasis severity. We have observed that patients tend to revert to a baseline thickness of psoriatic plaques when in an untreated state, and hypothesized that other features of psoriasis could associate with this trait. Data prospectively collected on 500 participants in the Utah Psoriasis Initiative were used for the study. In response to a question assessing plaque thickness when disease was at its worst, 144 (28.8%) reported thick plaques, 123 (24.6%) reported thin plaques, and 233 (46.6%) reported intermediate thickness. For patients with "worst-ever" disease at enrollment (n=122), there was significant correlation of thickness between assessment by the patient and the physician (r=0.448, P-value 0.01). Thick plaques associated with male gender, increased body mass index, nail disease, psoriatic arthritis, larger plaques, more body sites, and greater total body surface area affected. Thin plaques associated with eczema, guttate psoriasis, and skin cancer. We suggest that this is preliminary evidence that plaque thickness is an easily measured trait that associates with other clinical features of psoriasis, and that stratification on this phenotype may be useful in further defining the genetic basis of this disease.

Prominent Production of IL-20 by CD68+/CD11c+ Myeloid-Derived Cells in Psoriasis: Gene Regulation and Cellular Effects

We assessed expression of IL-20 and its receptors in psoriasis, given the recent implication of IL-20 in epidermal hyperplasia. Psoriatic lesional (LS) skin consistently expressed more IL-20 mRNA than nonlesional (NL) skin. Immunoreactivity to IL-20 protein was greater in LS tissue and mainly localized to infiltrating CD68+/CD11c+ (myeloid-derived) dermal leukocytes. Because this contrasted with earlier reports of a keratinocyte source, we assessed IL-20 mRNA expression in a variety of cells in vitro, and confirmed a myeloid-derived cellular source (monocytes). Plastic adhesion, activation of beta2 integrins, and incubation with tumor necrosis factor-alpha stimulated expression in these cells. IL-20 receptor (IL-20R)alpha and IL-20Rbeta mRNA was decreased in LS versus NL skin, which also contrasted with earlier findings. To investigate the relationship between IL-20 and disease activity, we examined psoriasis patients treated with the CD2-targeted agent alefacept. In therapeutic responders, lesional IL-20 mRNA decreased to NL levels, suggesting that CD2+ leukocytes may proximally regulate IL-20. Finally, to assess IL-20 function, we used microarrays to screen IL-20-treated keratinocytes, which demonstrated upregulation of disease-related and IFN-gamma-induced genes. Hence, IL-20 may influence inflammation through IFN-like effects. Together, these data indicate that IL-20 may be an important effector cytokine in psoriasis, and that its inhibition may represent a potential therapeutic target.

Familial aggregation and linkage analysis of autoantibody traits in pedigrees multiplex for systemic lupus erythematosus

Autoantibodies are clinically relevant biomarkers for numerous autoimmune disorders. The genetic basis of autoantibody production in systemic lupus erythematosus (SLE) and other autoimmune diseases is poorly understood. In this study, we characterized autoantibody profiles in 1,506 individuals from 229 multiplex SLE pedigrees. There was strong familial aggregation of antinuclear antibodies (ANAs), anti-double-stranded DNA (dsDNA), anti-La/SSB, anti-Ro/SSA, anti-Sm, anti-nRNP (nuclear ribonucleoprotein), IgM antiphospholipid (aPL) antibodies (Abs) and rheumatoid factor (RF) across these families enriched for lupus. We performed genome-wide linkage analyses in an effort to map genes that contribute to the production of the following autoantibodies: Ro/SSA, La/SSB, nRNP, Sm, dsDNA, RF, nuclear and phospholipids. Using an approach to minimize false positives and adjust for multiple comparisons, evidence for linkage was found to anti-La/SSB Abs on chromosome 3q21 (adjusted P=1.9 x 10(-6)), to anti-nRNP and/or anti-Sm Abs on chromosome 3q27 (adjusted P=3.5 x 10(-6)), to anti-Ro/SSA and/or anti-La/SSB Abs on chromosome 4q34-q35 (adjusted P=3.4 x 10(-4)) and to anti-IgM aPL Abs on chromosome 13q14 (adjusted P=2.3 x 10(-4)). These results support the hypothesis that autoantibody production is a genetically complex trait. Identification of the causative alleles will advance our understanding of critical molecular mechanisms that underlie SLE and perhaps other autoimmune diseases.