Külli Kingo

Mechanisms of IFN-γ–induced apoptosis of human skin keratinocytes in patients with atopic dermatitis

BACKGROUND Enhanced apoptosis of keratinocytes is the main cause of eczema and spongiosis in patients with the common inflammatory skin disease atopic dermatitis (AD). OBJECTIVE The aim of the study was to investigate molecular mechanisms of AD-related apoptosis of keratinocytes. METHODS Primary keratinocytes isolated from patients with AD and healthy donors were used to study apoptosis by using annexin V/7-aminoactinomycin D staining. Illumina mRNA Expression BeadChips, quantitative RT-PCR, and immunofluorescence were used to study gene expression. In silico analysis of candidate genes was performed on genome-wide single nucleotide polymorphism data. RESULTS We demonstrate that keratinocytes of patients with AD exhibit increased IFN-γ-induced apoptosis compared with keratinocytes from healthy subjects. Further mRNA expression analyses revealed differential expression of apoptosis-related genes in AD keratinocytes and skin and the upregulation of immune system-related genes in skin biopsy specimens of chronic AD lesions. Three apoptosis-related genes (NOD2, DUSP1, and ADM) and 8 genes overexpressed in AD skin lesions (CCDC109B, CCL5, CCL8, IFI35, LYN, RAB31, IFITM1, and IFITM2) were induced by IFN-γ in primary keratinocytes. The protein expression of IFITM1, CCL5, and CCL8 was verified in AD skin. In line with the functional studies and AD-related mRNA expression changes, in silico analysis of genome-wide single nucleotide polymorphism data revealed evidence of an association between AD and genetic markers close to or within the IFITM cluster or RAB31, DUSP1, and ADM genes. CONCLUSION Our results demonstrate increased IFN-γ responses in skin of patients with AD and suggest involvement of multiple new apoptosis- and inflammation-related factors in the development of AD.

Genome-Wide Meta-Analysis of Psoriatic Arthritis Identifies Susceptibility Locus at REL

Psoriatic arthritis (PsA) is a chronic inflammatory musculoskeletal disease affecting up to 30% of psoriasis vulgaris (PsV) cases and approximately 0.25% to 1% of the general population. To identify common susceptibility loci, we performed a meta-analysis of three imputed genome-wide association studies (GWAS) on psoriasis, stratified for PsA. A total of 1,160,703 SNPs were analyzed in the discovery set consisting of 535 PsA cases and 3,432 controls from Germany, the United States and Canada. We followed up two SNPs in 1,931 PsA cases and 6,785 controls comprising six independent replication panels from Germany, Estonia, the United States and Canada. In the combined analysis, a genome-wide significant association was detected at 2p16 near the REL locus encoding c-Rel (rs13017599, P=1.18×10−8, OR=1.27, 95% CI=1.18–1.35). The rs13017599 polymorphism is known to associate with rheumatoid arthritis (RA), and another SNP near REL (rs702873) was recently implicated in PsV susceptibility. However, conditional analysis indicated that rs13017599, rather than rs702873, accounts for the PsA association at REL. We hypothesize that c-Rel, as a member of the Rel/NF-κB family, is associated with PsA in the context of disease pathways that involve other identified PsA and PsV susceptibility genes including TNIP1, TNFAIP3 and NFκBIA.

Genome-wide Association Analysis of Psoriatic Arthritis and Cutaneous Psoriasis Reveals Differences in Their Genetic Architecture

Psoriasis vulgaris (PsV) is a common inflammatory and hyperproliferative skin disease. Up to 30% of people with PsV eventually develop psoriatic arthritis (PsA), an inflammatory musculoskeletal condition. To discern differences in genetic risk factors for PsA and cutaneous-only psoriasis (PsC), we carried out a genome-wide association study (GWAS) of 1,430 PsA case subjects and 1,417 unaffected control subjects. Meta-analysis of this study with three other GWASs and two targeted genotyping studies, encompassing a total of 9,293 PsV case subjects, 3,061 PsA case subjects, 3,110 PsC case subjects, and 13,670 unaffected control subjects of European descent, detected 10 regions associated with PsA and 11 with PsC at genome-wide (GW) significance. Several of these association signals (IFNLR1, IFIH1, NFKBIA for PsA; TNFRSF9, LCE3C/B, TRAF3IP2, IL23A, NFKBIA for PsC) have not previously achieved GW significance. After replication, we also identified a PsV-associated SNP near CDKAL1 (rs4712528, odds ratio [OR] = 1.16, p = 8.4 × 10(-11)). Among identified psoriasis risk variants, three were more strongly associated with PsC than PsA (rs12189871 near HLA-C, p = 5.0 × 10(-19); rs4908742 near TNFRSF9, p = 0.00020; rs10888503 near LCE3A, p = 0.0014), and two were more strongly associated with PsA than PsC (rs12044149 near IL23R, p = 0.00018; rs9321623 near TNFAIP3, p = 0.00022). The PsA-specific variants were independent of previously identified psoriasis variants near IL23R and TNFAIP3. We also found multiple independent susceptibility variants in the IL12B, NOS2, and IFIH1 regions. These results provide insights into the pathogenetic similarities and differences between PsC and PsA.

Enhanced meta-analysis and replication studies identify five new psoriasis susceptibility loci.

Psoriasis is a chronic autoimmune disease with complex genetic architecture. Previous genomewide association studies (GWAS) and a recent meta-analysis using Immunochip data have uncovered 36 susceptibility loci. Here, we extend our previous meta-analysis of European ancestry by refined genotype calling and imputation and by the addition of 5,033 cases and 5,707 controls. The combined analysis, consisting of over 15,000 cases and 27,000 controls, identifies five new psoriasis susceptibility loci at genomewide significance (p < 5 × 10−8). The newly identified signals include two that reside in intergenic regions (1q31.1 and 5p13.1) and three residing near PLCL2 (3p24.3), NFKBIZ (3q12.3), and CAMK2G (10q22.2). We further demonstrate that NFKBIZ is a TRAF3IP2–dependent target of IL-17 signaling in human skin keratinocytes, thereby functionally linking two strong candidate genes. These results further integrate the genetics and immunology of psoriasis, suggesting new avenues for functional analysis and improved therapies.

Secukinumab is superior to ustekinumab in clearing skin of subjects with moderate-to-severe plaque psoriasis up to 1 year: Results from the CLEAR study

Background: Secukinumab demonstrated superior efficacy to ustekinumab at week 4 and week 16 of the CLEAR study, with comparable safety, in subjects with moderate‐to‐severe plaque psoriasis. Objective: To compare the efficacy and safety of secukinumab and ustekinumab use over 52 weeks. Methods: Analysis of 52‐week data from CLEAR, a randomized, double‐blind, phase 3b study. Results: Among 676 randomized subjects, secukinumab demonstrated superiority to ustekinumab at week 52 in the proportion of subjects with ≥90% improvement in Psoriasis Area and Severity Index (PASI 90) (76% vs 61% [P < .0001]); PASI 100 responses were 46% versus 36% (P = .0103) and Investigators Global Assessment responses of clear/almost clear skin were 80% versus 65% (P < .0001). Subjects on secukinumab reported greater reductions in psoriasis‐related pain, itching, and scaling, and greater improvement across all quality‐of‐life measures evaluated (Dermatology Life Quality Index [DLQI], EuroQoL 5‐Dimension Health Questionnaire, Work Productivity and Activity Impairment Questionnaire‐Psoriasis, and Health Assessment Questionnaire‐Disability Index). At week 52, 72% of subjects on secukinumab versus 59% on ustekinumab (P = .0008) reported no impact of skin disease on their lives (DLQI 0/1 response). Safety and tolerability was comparable. Limitations: There was no placebo arm. Conclusion: In this head‐to‐head, double‐blind study, secukinumab demonstrated sustained superior efficacy in comparison with ustekinumab in clearing skin through week 52, greater improvement in quality of life, and a favorable and comparable safety profile.

The EGALITY study: a confirmatory, randomized, double‐blind study comparing the efficacy, safety and immunogenicity of GP2015, a proposed etanercept biosimilar, vs. the originator product in patients with moderate‐to‐severe chronic plaque‐type psoriasis

GP2015 is a proposed etanercept biosimilar.

Association analysis of IL19, IL20 and IL24 genes in palmoplantar pustulosis.

Background  Interleukin (IL) 19, IL‐20 and IL‐24 belong to the IL‐10 cytokine family and have been identified to play a role in the regulation of epidermal functions and in inflammation. The genes encoding IL‐19, IL‐20 and IL‐24 are located within a gene cluster on chromosome 1q31–32 and carry frequent genetic variations.

Palmoplantar Pustular Psoriasis Is Associated with Missense Variants in CARD14, but Not with Loss-of-Function Mutations in IL36RN in European Patients

Cite this article as: Rotraut Mössner, Yvonne Frambach, Dagmar WilsmannTheis, Sabine Löhr, Arnd Jacobi, Ansgar Weyergraf, Michael Müller, Sandra Philipp, Regina Renner, Heiko Traupe, Harald Burkhardt, Külli Kingo, Sulev Kõks, Steffen Uebe, Michael Sticherling, Heinrich Sticht, Vinzenz Oji, Ulrike Hüffmeier, Palmoplantar Pustular Psoriasis is Associated with Missense Variants in CARD14, but not with loSs-of-Function Mutations in IL36RN in European Patients, Journal of Investigative Dermatology accepted article preview 19 May 2015; doi: 10.1038/jid.2015.186.

Quality of life and emotional state in vitiligo in an Estonian sample: comparison with psoriasis and healthy controls.

The impact of vitiligo on quality of life is controversial. The aim of this study was to observe the impairment of quality of life and emotional state in adults with vitiligo compared with subjects with psoriasis and unaffected controls. The study group comprised 54 subjects with vitiligo, 57 with psoriasis and 57 unaffected controls. All subjects were examined and interviewed using the Dermatology Life Quality Index (DLQI) and Emotional State questionnaires. The total mean DLQI score in vitiligo was 4.7, compared with 0.6 in healthy controls (p<0.001) and 13.1 in psoriasis (p<0.001). In vitiligo, females experienced a greater impact on feelings and men experienced a greater impact on relationships. Lower quality of life in vitiligo was associated with active stage of the disease, extension of pigment loss, depigmentation on the hands, and earlier onset of disease. The results demonstrate that vitiligo has less impact on quality of life than psoriasis.

Genome-wide association studies of autoimmune vitiligo identify 23 new risk loci and highlight key pathways and regulatory variants

Vitiligo is an autoimmune disease in which depigmented skin results from the destruction of melanocytes, with epidemiological association with other autoimmune diseases. In previous linkage and genome-wide association studies (GWAS1 and GWAS2), we identified 27 vitiligo susceptibility loci in patients of European ancestry. We carried out a third GWAS (GWAS3) in European-ancestry subjects, with augmented GWAS1 and GWAS2 controls, genome-wide imputation, and meta-analysis of all three GWAS, followed by an independent replication. The combined analyses, with 4,680 cases and 39,586 controls, identified 23 new significantly associated loci and 7 suggestive loci. Most encode immune and apoptotic regulators, with some also associated with other autoimmune diseases, as well as several melanocyte regulators. Bioinformatic analyses indicate a predominance of causal regulatory variation, some of which corresponds to expression quantitative trait loci (eQTLs) at these loci. Together, the identified genes provide a framework for the genetic architecture and pathobiology of vitiligo, highlight relationships with other autoimmune diseases and melanoma, and offer potential targets for treatment.