The erythema Q-score, an imaging biomarker for redness in skin inflammation.

Physician rating of cutaneous erythema is central to clinical dermatological assessment as well as quantification of outcome measures in clinical trials in a number of dermatologic conditions. However, issues with inter-rater reliability and variability in the setting of higher Fitzpatrick skin types make visual erythema assessment unreliable. We developed and validated a computer-assisted image-processing algorithm (EQscore) to reliably quantify erythema (across a range of skin types) in the dermatology clinical setting. Our image processing algorithm evaluated erythema based upon green light suppression differentials between affected and unaffected skin. A group of four dermatologists used a 4-point Likert scale as a human evaluation of similar erythematous patch tests. The algorithm and dermatologist scores were compared across 164 positive patch test reactions. The intra-class correlation coefficient of groups and the correlation coefficient between groups were calculated. The EQscore was validated on and independent image set of psoriasis, minimal erythema dose testing and steroid-induced blanching images. The reliability of the erythema quantification method produced an intra-class correlation coefficient of 0.84 for the algorithm and 0.67 for dermatologists. The correlation coefficient between groups was 0.85. The EQscore demonstrated high agreement with clinical scoring and superior reliability compared with clinical scoring, avoiding the pitfalls of erythema underrating in the setting of pigmentation. The EQscore is easily accessible (http://lab.rockefeller.edu/krueger/EQscore), user-friendly, and may allow dermatologists to more readily and accurately rate the severity of dermatological conditions and the response to therapeutic treatments.

Molecular and Cellular Responses to the TYK2/JAK1 Inhibitor PF-06700841 Reveal Reduction of Skin Inflammation in Plaque Psoriasis.

The IL-23/T helper type 17 cell axis is a target for psoriasis. The TYK2/Janus kinase 1 inhibitor PF-06700841 will directly suppress TYK2-dependent IL-12 and IL-23 signaling and Janus kinase 1-dependent signaling in cells expressing these signaling molecules, including T cells and keratinocytes. This clinical study sought to define the inflammatory gene and cellular pathways through which PF-06700841 improves the clinical manifestations of psoriasis. Patients (n = 30) with moderate-to-severe psoriasis were randomized to once-daily 30 mg (n = 14) or 100 mg (n = 7) PF-06700841 or placebo (n = 9) for 28 days. Biopsies were taken from nonlesional and lesional skin at baseline and weeks 2 and 4. Changes in the psoriasis transcriptome and genes induced by IL-17 in keratinocytes were evaluated with microarray profiling and reverse transcriptase-PCR. Reductions in IL-17A, IL-17F, and IL-12B mRNA were observed as early as 2 weeks and approximately 70% normalization of lesional gene expression after 4 weeks. Immunohistochemistry showed significant decreases in markers of keratinocyte activation, epidermal thickness, KRT16 and Ki-67 expression, and immune cell infiltrates CD3+/CD8+ (T cells) and CD11c (dendritic cells) after 2 weeks of treatment, corresponding with improvement in histologic score. PF-06700841 improves clinical symptoms of chronic plaque psoriasis by inhibition of proinflammatory cytokines that require TYK2 and Janus kinase 1 for signal transduction.

IL-17A inhibition by secukinumab induces early clinical, histopathologic, and molecular resolution of psoriasis.

BACKGROUND: Hyperactivity of the IL-23/IL-17 axis is central to plaque psoriasis pathogenesis. Secukinumab, a fully human mAb that selectively inhibits IL-17A, is approved for treatment of psoriasis, psoriatic arthritis, and ankylosing spondylitis. Secukinumab improves the complete spectrum of psoriasis manifestations, with durable clinical responses beyond 5 years of treatment. In the feed-forward model of plaque chronicity, IL-17A has been hypothesized as the key driver of pathogenic gene expression by lesional keratinocytes, but in vivo evidence in human subjects is lacking. METHODS: We performed a randomized, double-blind, placebo-controlled study (NCT01537432) of patients receiving secukinumab at the clinically approved dose up to 12 weeks. We then correlated plaque and nonlesional skin transcriptomic profiles with histopathologic and clinical measures of efficacy. RESULTS: After 12 weeks of treatment, secukinumab reversed plaque histopathology in the majority of patients and modulated thousands of transcripts. Suppression of the IL-23/IL-17 axis by secukinumab was evident at week 1 and continued through week 12, including reductions in levels of the upstream cytokine IL-23, the drug target IL-17A, and downstream targets, including ß-defensin 2. Suppression of the IL-23/IL-17 axis by secukinumab at week 4 was associated with clinical and histologic responses at week 12. Secukinumab did not affect ex vivo T-cell activation, which is consistent with its favorable long-term safety profile. CONCLUSION: Our data suggest that IL-17A is the critical node within the multidimensional pathogenic immune circuits that maintain psoriasis plaques and that early reduction of IL-17A-dependent feed-forward transcripts synthesized by hyperplastic keratinocytes favors plaque resolution.

Inflammasome Signaling and Impaired Vascular Health in Psoriasis.

Objective- Psoriasis is an inflammatory skin disease which heightens the risk of cardiovascular disease. This study directly investigated vascular endothelial health and systemically altered pathways in psoriasis and matched controls. Approach and Results- Twenty patients (mean age, 40 years; 50% male) with active psoriasis and 10 age-, sex-matched controls were recruited. To investigate systemically alerted pathways, a deep sequencing omics approach was applied, including unbiased blood transcriptomic and targeted proteomic analysis. Vascular endothelial health was assessed by transcriptomic profiling of endothelial cells obtained from the brachial veins of recruited participants. Blood transcriptomic profiling identified inflammasome signaling as the highest differentially expressed canonical pathway ( Z score 1.6; P=1×10-7) including upregulation of CASP5 and interleukin ( IL) -1ß. Proteomic panels revealed IL-6 as a top differentially expressed cytokine in psoriasis with pathway analysis highlighting IL-1ß ( Z score 3.7; P=1.02×10-23) as an upstream activator of the observed upregulated proteins. Direct profiling of harvested brachial vein endothelial cells demonstrated inflammatory transcript (eg, IL-1ß, CXCL10, VCAM-1, IL-8, CXCL1, Lymphotoxin beta, ICAM-1, COX-2, and CCL3) upregulation between psoriasis versus controls. A linear relationship was seen between differentially expressed endothelial inflammatory transcripts and psoriasis disease severity. IL-6 levels correlated with inflammatory endothelial cell transcripts and whole blood inflammasome-associated transcripts, including CASP5 and IL-1ß. Conclusions- An unbiased sequencing approach demonstrated the inflammasome as the most differentially altered pathway in psoriasis versus controls. Inflammasome signaling correlated with psoriasis disease severity, circulating IL-6, and proinflammatory endothelial transcripts. These findings help better explain the heightened risk of cardiovascular disease in psoriasis. Clinical Trial Registration- URL: http://www.clinicaltrials.gov . Unique identifier: NCT03228017.

Atopic dermatitis in African American patients is TH2/TH22-skewed with TH1/TH17 attenuation.

BACKGROUND: African Americans (AA) are disproportionately impacted by atopic dermatitis (AD), with increased prevalence and therapeutic challenges unique to this population. Molecular profiling data informing development of targeted therapeutics for AD are derived primarily from European American (EA) patients. These studies are absent in AA, hindering development of effective treatments for this population. OBJECTIVE: We sought to characterize the global molecular profile of AD in the skin of AA patients as compared with that of EA AD and healthy controls. METHODS: We performed RNA-Seq with reverse transcription polymerase chain reaction validation and immunohistochemistry studies in lesional and nonlesional skin of AA and EA AD patients vs healthy controls. RESULTS: African American AD lesions were characterized by greater infiltration of dendritic cells (DCs) marked by the high-affinity immunoglobulin E (IgE) receptor (FcεR1+) compared with EA AD (P < .05). Both AD cohorts showed similarly robust up-regulation of Th2-related (CCL17/18/26) and Th22-related markers (interleukin [IL]-22, S100A8/9/12), but AA AD featured decreased expression of innate immune (tumor necrosis factor [TNF], IL-1ß), Th1-related (interferon gamma [IFN-γ], MX1, IL-12RB1), and Th17-related markers (IL-23p19, IL-36G, CXCL1) vs EA AD (P < .05). The Th2 (IL-13) and Th22-related products (IL-22, S100A8/9/12) and serum IgE were significantly correlated with clinical severity (Scoring of Atopic Dermatitis [SCORAD]) in AA. Fillagrin (FLG) was exclusively down-regulated in EA AD, whereas loricrin (LOR) was down-regulated in both AD cohorts and negatively correlated with SCORAD in AA. CONCLUSION: The molecular phenotype of AA AD skin is characterized by attenuated Th1 and Th17 but similar Th2/Th22-skewing to EA AD. Our data encourages a personalized medicine approach accounting for phenotype-specific characteristics in future development of targeted therapeutics and clinical trial design for AD.

Novel immune signatures associated with dysplastic naevi and primary cutaneous melanoma in human skin.

Dysplastic naevi (DN) are benign lesions with atypical features intermediate between that of common melanocytic naevi (CMN) and malignant melanoma (MM). Debate remains over whether DN represent progressive lesions from CMN. Through gene expression profiling and analysis of molecular gene signatures, our study revealed progressive increases in immune activation and regulation, along with pathways implicated in melanomagenesis, from CMN to DN to MM. Using criteria of 1.5-fold change and false discovery rate ≤0.05, we found differential expression of 7186 probes (6370 unique genes) with the largest difference detected between DN and MM from the standpoint of genomic melanoma progression. Despite progressive increases in the T-helper type 1 (Th1)-inducing gene (IL-12), RT-PCR indicated impaired Th1 or cytotoxic T-cell response (decreased IFN-γ) in MM. Concordantly, our results indicated progressive increases in molecular markers associated with regulatory T cells, exhausted T cells and tolerogenic dendritic cells, including detection of increased expression of suppressor of cytokine signalling 3 (SOCS3) in dendritic cells associated with MM. All together, our findings suggest that the increased immunosuppressive microenvironment of melanoma may contribute to unhampered proliferation of neoplastic cells. In addition, the detection of increased markers associated with tolerogenic dendritic cells in MM suggests that targeting these suppressive immune cell types may represent an alternative avenue for future immunotherapy.

Baseline IL-22 expression in patients with atopic dermatitis stratifies tissue responses to fezakinumab.

BACKGROUND: IL-22 is potentially a pathogenic cytokine in patients with atopic dermatitis (AD), but the molecular effects of IL-22 antagonism have not been defined in human subjects. OBJECTIVE: We sought to evaluate the cellular and molecular effects of IL-22 blockade in tissues from patients with moderate-to-severe AD. METHODS: We assessed lesional and nonlesional skin from 59 patients with moderate-to-severe AD treated with anti-IL-22 (fezakinumab) versus placebo (2:1) using transcriptomic and immunohistochemistry analyses. RESULTS: Greater reversal of the AD genomic profile was seen with fezakinumab versus placebo, namely 25.3% versus 10.5% at 4 weeks (P = 1.7 × 10-5) and 65.5% versus 13.9% at 12 weeks (P = 9.5 × 10-19), respectively. Because IL-22 blockade showed clinical efficacy only in patients with severe AD, we used baseline median IL-22 mRNA expression to stratify for high (n = 30) and low (n = 29) IL-22 expression groups. Much stronger mean transcriptomic improvements were seen with fezakinumab in the IL-22-high drug-treated group (82.8% and 139.4% at 4 and 12 weeks, respectively) than in the respective IL-22-high placebo-treated group (39.6% and 56.3% at 4 and 12 weeks) or the IL-22-low groups. Significant downregulations of multiple immune pathways, including TH1/CXCL9, TH2/CCL18/CCL22, TH17/CCL20/DEFB4A, and TH22/IL22/S100A's, were restricted to the IL-22-high drug group (P < .05). Consistently, tissue predictors of clinical response were mostly genes involved in T-cell and dendritic cell activation and differentiation. CONCLUSIONS: This is the first report showing a profound effect of IL-22 blockade on multiple inflammatory pathways in AD. These data, supported by robust effects in patients with high IL-22 baseline expression, suggest a central role for IL-22 in AD, indicating the need for a precision medicine approach for improving therapeutic outcomes in patients with AD.

Psoriatic skin molecular and histopathologic profiles after treatment with risankizumab versus ustekinumab.

BACKGROUND: IL-23 contributes to the activation, maintenance, and proliferation of TH17 cells and plays a major role in psoriasis pathophysiology. IL-23p19 inhibition with risankizumab resulted in superior clinical responses in patients with psoriasis compared with ustekinumab (dual IL-12/IL-23 inhibitor), but comparative molecular effects have not been established. OBJECTIVE: We investigated the similarities and differences in molecular and histopathologic profiles in skin lesions from patients with psoriasis receiving risankizumab versus ustekinumab at an early time point. METHODS: Lesional skin biopsy samples from 81 patients with moderate-to-severe plaque psoriasis participating in 2 different studies (a phase I risankizumab study and a phase II study of risankizumab vs ustekinumab) were analyzed by using histopathology, immunohistochemistry, and RNA sequencing. RESULTS: Risankizumab induced a rapid decrease in levels of proteins and transcriptomic biomarkers associated with the IL-23 pathway, which were maintained through 8 weeks. At week 4, risankizumab decreased histopathologic expression of biomarkers, including K16, Ki67, CD3, lipocalin-2, CD11c, dendritic cell lysosome-associated membrane glycoprotein, ß-defensin 2, and S100A7; global histopathologic scoring revealed that 54% and 69% of patients treated with 90 or 180 mg of risankizumab, respectively, were graded as experiencing "excellent improvement" versus 29% of patients treated with ustekinumab. At week 4, there was a common decrease in expression of 2645 genes expressed in lesional skin between patients receiving risankizumab and ustekinumab and a significant decrease in 2682 genes unique to risankizumab treatment. Risankizumab more strongly downregulated expression of genes associated with keratinocytes, epidermal cells, and monocytes, versus ustekinumab. CONCLUSION: Risankizumab demonstrated more pronounced changes in the molecular and histopathologic profile of psoriatic skin lesions compared with ustekinumab at week 4.

Impact of Zostavax Vaccination on T-Cell Accumulation and Cutaneous Gene Expression in the Skin of Older Humans After Varicella Zoster Virus Antigen-Specific Challenge.

Background: The live attenuated vaccine Zostavax was developed to prevent varicella zoster virus (VZV) reactivation that causes herpes zoster (shingles) in older humans. However, the impact of vaccination on the cutaneous response to VZV is not known. Methods: We investigated the response to intradermal VZV antigen challenge before and after Zostavax vaccination in participants >70 years of age by immunohistological and transcriptomic analyses of skin biopsy specimens collected from the challenge site. Results: Vaccination increased the proportion of VZV-specific CD4+ T cells in the blood and promoted the accumulation of both CD4+ and CD8+ T cells in the skin after VZV antigen challenge. However, Zostavax did not alter the proportion of resident memory T cells (CD4+ and CD8+) or CD4+Foxp3+ regulatory T cells in unchallenged skin. After vaccination, there was increased cutaneous T-cell proliferation at the challenge site and also increased recruitment of T cells from the blood, as indicated by an elevated T-cell migratory gene signature. CD8+ T-cell-associated functional genes were also highly induced in the skin after vaccination. Conclusion: Zostavax vaccination does not alter the abundance of cutaneous resident memory T cells but instead increases the recruitment of VZV-specific T cells from the blood and enhances T-cell activation, particularly cells of the CD8+ subset, in the skin after VZV antigen challenge.

Efficacy and safety of fezakinumab (an IL-22 monoclonal antibody) in adults with moderate-to-severe atopic dermatitis inadequately controlled by conventional treatments: A randomized, double-blind, phase 2a trial.

BACKGROUND: Interleukin 22 promotes epidermal hyperplasia and inhibits skin barrier function. OBJECTIVE: Evaluate interleukin 22 blockade in adults with moderate-to-severe atopic dermatitis (AD). METHODS: We performed a randomized, double-blind, placebo-controlled trial with intravenous fezakinumab monotherapy every 2 weeks for 10 weeks, with follow-up assessments until 20 weeks. The change in SCOring AD (SCORAD) score from baseline at 12 weeks served as the primary end point. RESULTS: At 12 weeks, the mean declines in SCORAD for the entire study population were 13.8 ± 2.7 in the fezakinumab arm and 8.0 ± 3.1 in the placebo arm (P = .134). In the severe AD patient subset (with a baseline SCORAD of ≥50), SCORAD decline was significantly stronger in the drug-treated patients than placebo-treated patients at 12 weeks (21.6 ± 3.8 vs 9.6 ± 4.2, P = .029) and 20 weeks (27.4 ± 3.9 vs 11.5 ± 5.1, P = .010). At 12 weeks, improvements in body surface area involvement in the entire population were significantly stronger in the drug-treated than placebo-treated patients (12.4% ± 2.4 vs 6.2% ± 2.7; P = .009), and in the severe AD subset, the decline in Investigator Global Assessment was significantly higher in the drug-treated than placebo-treated patients (0.7 ± 0.2 vs 0.3 ± 0.1; P = .034). All scores showed progressive improvements after last dosing (10 weeks) until end of study (20 weeks). Common adverse events were upper respiratory tract infections. LIMITATIONS: The limited sample size and lack of assessment with Eczema Area and Severity Index and a pruritus numerical rating scale were limiting factors. Significance was primarily obtained in severe AD. CONCLUSION: Fezakinumab was well-tolerated, with sustained clinical improvements after last drug dosing.

Enhancement of cutaneous immunity during aging by blocking p38 mitogen-activated protein (MAP) kinase-induced inflammation.

BACKGROUND: Immunity decreases with age, which leads to reactivation of varicella zoster virus (VZV). In human subjects age-associated immune changes are usually measured in blood leukocytes; however, this might not reflect alterations in tissue-specific immunity. OBJECTIVES: We used a VZV antigen challenge system in the skin to investigate changes in tissue-specific mechanisms involved in the decreased response to this virus during aging. METHODS: We assessed cutaneous immunity based on the extent of erythema and induration after intradermal VZV antigen injection. We also performed immune histology and transcriptomic analyses on skin biopsy specimens taken from the challenge site in young (<40 years) and old (>65 years) subjects. RESULTS: Old human subjects exhibited decreased erythema and induration, CD4+ and CD8+ T-cell infiltration, and attenuated global gene activation at the site of cutaneous VZV antigen challenge compared with young subjects. This was associated with increased sterile inflammation in the skin in the same subjects related to p38 mitogen-activated protein kinase-related proinflammatory cytokine production (P < .0007). We inhibited systemic inflammation in old subjects by means of pretreatment with an oral small-molecule p38 mitogen-activated protein kinase inhibitor (Losmapimod; GlaxoSmithKline, Brentford, United Kingdom), which reduced both serum C-reactive protein levels and peripheral blood monocyte secretion of IL-6 and TNF-α. In contrast, cutaneous responses to VZV antigen challenge were increased significantly in the same subjects (P < .0003). CONCLUSION: Excessive inflammation in the skin early after antigen challenge retards antigen-specific immunity. However, this can be reversed by inhibition of inflammatory cytokine production that can be used to promote vaccine efficacy and the treatment of infections and malignancy during aging.

IFNγ-Dependent Tissue-Immune Homeostasis Is Co-opted in the Tumor Microenvironment.

Homeostatic programs balance immune protection and self-tolerance. Such mechanisms likely impact autoimmunity and tumor formation, respectively. How homeostasis is maintained and impacts tumor surveillance is unknown. Here, we find that different immune mononuclear phagocytes share a conserved steady-state program during differentiation and entry into healthy tissue. IFNγ is necessary and sufficient to induce this program, revealing a key instructive role. Remarkably, homeostatic and IFNγ-dependent programs enrich across primary human tumors, including melanoma, and stratify survival. Single-cell RNA sequencing (RNA-seq) reveals enrichment of homeostatic modules in monocytes and DCs from human metastatic melanoma. Suppressor-of-cytokine-2 (SOCS2) protein, a conserved program transcript, is expressed by mononuclear phagocytes infiltrating primary melanoma and is induced by IFNγ. SOCS2 limits adaptive anti-tumoral immunity and DC-based priming of T cells in vivo, indicating a critical regulatory role. These findings link immune homeostasis to key determinants of anti-tumoral immunity and escape, revealing co-opting of tissue-specific immune development in the tumor microenvironment.

Autoantigens ADAMTSL5 and LL37 are significantly upregulated in active Psoriasis and localized with keratinocytes, dendritic cells and other leukocytes.

Psoriasis is a common immune-mediated disease that affects 2%-4% of individuals in North America and Europe. In the past decade, advances in research have led to an improved understanding of immune pathways involved in the pathogenesis of psoriasis and has spurred the development of targeted therapeutics. Recently, three psoriasis autoantigens have been described: cathelicidin (LL37), a disintegrin and metalloprotease domain containing thrombospondin type 1 motif-like 5 (ADAMTSL5), and lipid antigens generated by phospholipase A2 (PLA2) group IVD (PLA2G4D). It is important to establish the expression, regulation and therapeutic modulation of these psoriasis autoantigens. In this study, we performed immunohistochemistry and two-colour immunofluorescence on non-lesional and lesional psoriasis skin to characterize ADAMTSL5 and LL37, and their co-expression with T cells, dendritic cells, neutrophils and macrophages, which are the main immune cells that drive this disease. Our results showed that ADAMTSL5 and LL37 are significantly (P<.05) increased in lesional skin and are co-expressed by many dendritic cells, macrophages and some T cells in the dermis. Gene expression analysis showed significant (P<.05) upregulation of LL37 in lesional skin and significant downregulation following treatment with etanercept. ADAMTSL5 and LL37 are also significantly decreased by IL-17 or TNF-α blockade, suggesting feed-forward induction of psoriasis autoantigens by disease-related cytokines.

Cutting Edge: Selective Oral ROCK2 Inhibitor Reduces Clinical Scores in Patients with Psoriasis Vulgaris and Normalizes Skin Pathology via Concurrent Regulation of IL-17 and IL-10.

Targeted inhibition of Rho-associated kinase (ROCK)2 downregulates the proinflammatory T cell response while increasing the regulatory arm of the immune response in animals models of autoimmunity and Th17-skewing human cell culture in vitro. In this study, we report that oral administration of a selective ROCK2 inhibitor, KD025, reduces psoriasis area and severity index scores by 50% from baseline in 46% of patients with psoriasis vulgaris, and it decreases epidermal thickness as well as T cell infiltration in the skin. We observed significant reductions of IL-17 and IL-23, but not IL-6 and TNF-α, whereas IL-10 levels were increased in peripheral blood of clinical responders after 12 wk of treatment with KD025. Collectively, these data demonstrate that an orally available selective ROCK2 inhibitor downregulates the Th17-driven autoimmune response and improved clinical symptoms in psoriatic patients via a defined molecular mechanism that involves concurrent modulation of cytokines without deleterious impact on the rest of the immune system.

Aberrant connective tissue differentiation towards cartilage and bone underlies human keloids in African Americans.

Keloids are benign fibroproliferative tumors more frequently found among African Americans. Until now, keloid etiopathogenesis is not fully understood. To characterize keloids in African Americans, we performed transcriptional profiling of biopsies from large chronic keloids, adjacent non-lesional (NL) skin (n=3) and a newly formed keloid lesion using Affymetrix HGU133 2.0 plus arrays. Quantitative RT-PCR (qRT-PCR) and immunohistochemistry (IHC) staining were performed to confirm increased expression of relevant genes. We identified 1202 upregulated and 961 downregulated differentially expressed genes (DEGs) between keloid and NL skin; 1819 up- and 1867 downregulated DEGs between newly formed keloid and NL skin; and 492 up- and 775 downregulated DEGs between chronic and newly formed keloid (fold change >2, false discovery rate <0.05). Many of the top upregulated DEGs between chronic keloid and NL skin and between newly formed keloid and NL skin are involved in bone/cartilage formation including Fibrillin 2 (FBN2), Collagen type X alpha 1, Asporin (ASPN), Cadherin 11 (CDH11), Bone morphogenic protein 1 (BMP1), Secreted phosphoprotein 1 and Runt-related transcription factor 2 (RUNX2). qRT-PCR confirmed significant (P<.05) upregulation of BMP1, RUNX2, CDH11 and FBN2 in chronic keloid compared to NL skin. IHC staining showed increased protein expression of ASPN, CDH11, BMP1 and RUNX2 on chronic and newly formed keloid compared to NL skin. Our study shows that large keloids in African Americans represent a dysplasia of cutaneous connective tissue towards immature cartilage or bone differentiation. The phenotype is potentially regulated by overexpression of RUNX2. This knowledge may give insights to guide the development of better treatment for the disease in the future.

Palmoplantar pustular psoriasis (PPPP) is characterized by activation of the IL-17A pathway.

BACKGROUND: Palmoplantar pustular psoriasis (PPPP) is a variant of psoriasis, which has significant negative impact on quality of life. The cellular and molecular inflammatory pathways involved in PPPP have not been well studied. OBJECTIVE: Study the expression of cytokines and chemokines involved in the IL-17/IL-23 axis in palmoplantar pustular psoriasis and other difficult to treat psoriasis areas (palms, scalp, elbows and lower legs). METHODS: Skin biopsies were performed on a total of 80 patients with PPPP, non-pustular palmoplantar psoriasis (NPPPP), or psoriasis located on elbows, knees and scalp as well as 10 healthy subjects. RT-PCR, immunohistochemistry and flow cytometry on cells extracted from skin biopsies were used to compare PPPP to other forms of psoriasis. RESULTS: There was a significant (p<0.05) increase in the expression of IL-1ß, IL-6, LL-37, IL-19, IL-17A, CXCL1 and CXCL2 in PPPP as compared to NPPPP. However, there was no significant difference in expression of IL-23 in PPPP as compared to NPPPP and other forms of psoriasis. The proportion of IL-22+ but not IL-17A+ mast cells was higher in PPPP as compared to NPPPP (p<0.05). CONCLUSION: These results suggest that the IL-17A pathway may play a more important role in PPPP than in NPPPP.

Efficacy and safety of ustekinumab treatment in adults with moderate-to-severe atopic dermatitis.

Atopic dermatitis (AD) is the most common inflammatory skin disease, but treatment options for moderate-to-severe disease are limited. Ustekinumab is an IL-12/IL-23p40 antagonist that suppresses Th1, Th17 and Th22 activation, commonly used for psoriasis patients. We sought to assess efficacy and safety of ustekinumab in patients with moderate-to-severe AD. In this phase II, double-blind, placebo-controlled study, 33 patients with moderate-to-severe AD were randomly assigned to either ustekinumab (n=16) or placebo (n=17), with subsequent crossover at 16 weeks, and last dose at 32 weeks. Background therapy with mild topical steroids was allowed to promote retention. Study endpoints included clinical (SCORAD50) and biopsy-based measures of tissue structure and inflammation, using protein and gene expression studies. The ustekinumab group achieved higher SCORAD50 responses at 12, 16 (the primary endpoint) and 20 weeks compared to placebo, but the difference between groups was not significant. The AD molecular profile/transcriptome showed early robust gene modulation, with sustained further improvements until 32 weeks in the initial ustekinumab group. Distinct and more robust modulation of Th1, Th17 and Th22 but also Th2-related AD genes was seen after 4 weeks of ustekinumab treatment (i.e. MMP12, IL-22, IL-13, IFN-γ, elafin/PI3, CXCL1 and CCL17; P<.05). Epidermal responses (K16, terminal differentiation) showed faster (4 weeks) and long-term regulation (32 weeks) from baseline in the ustekinumab group. No severe adverse events were observed. Ustekinumab had clear clinical and molecular effects, but clinical outcomes might have been obscured by a profound "placebo" effect, most likely due to background topical glucocorticosteroids and possibly insufficient dosing for AD.