Association of the chromosome 11p13.5 variant and atopic dermatitis with a family history of atopy in the Chinese Han population.

BACKGROUND: Recent genome-wide association studies (GWAS) and a meta-analysis of GWAS for atopic dermatitis (AD) have identified some AD genetic loci in European and Japanese populations. OBJECTIVE: To investigate whether some novel susceptibility loci are associated with AD in the Chinese Han population. METHODS: We first selected eight novel susceptibility loci to replicate in 2,205 AD patients and 2,116 healthy controls using the Sequenom platform. Data were analyzed with PLINK 1.07 software. RESULTS: We found that rs12634229 (3q13.2), rs7927894 (11p13.5) and rs878860 (11p15.4) showed a slight association with AD (P = 0.012, P = 0.033, P = 0.020, respectively); rs6780220 (3p21.33) was preferentially related to AD with keratosis pilaris, but did not reach the threshold of significance after correction. The frequency of rs7927894 allele T was significantly different between AD patients with a positive and negative family history of atopy. CONCLUSION: The loci rs7927894 (11p13.5) are related to AD with a positive family history of atopy in Chinese Han population, providing novel insight into the genetic pathogenesis of AD.

Association analyses identifying two common susceptibility loci shared by psoriasis and systemic lupus erythematosus in the Chinese Han population.

BACKGROUND: Genome-wide association studies (GWASs) have revealed a large number of genetic risk loci for many autoimmune diseases. One clear finding emerging from the published genetic studies of autoimmunity is that different autoimmune diseases, such as psoriasis and systemic lupus erythematosus (SLE), share susceptibility loci. Our study explores additional susceptibility loci shared by psoriasis and SLE in the Chinese Han population. METHODS: In total, 20 single nucleotide polymorphisms (SNPs) in 17 previously reported psoriasis susceptibility loci and 34 SNPs from 24 previously reported SLE susceptibility loci were investigated in our initial psoriasis and SLE GWAS dataset. Among these SNPs, we selected two SNPs (rs8016947 and rs4649203) with association values of p<5×10(-2) for both diseases in the GWAS data for further investigation in psoriasis (7260 cases and 9842 controls) and SLE (2207 cases and 9842 controls) using a Sequenom MassARRAY system. RESULTS: We found that these two SNPs (rs8016947 and rs4649203) in two loci (NFKBIA and IL28RA) were associated with psoriasis and SLE with genome-wide significance (Pcombined<5×10(-8) in psoriasis and Pcombined<5×10(-8) in SLE): rs8016947 at NFKBIA (Pcombined-psoriasis=3.90×10(-10), Pcombined-SLE=1.08×10(-13)) and rs4649203 at IL28RA (Pcombined-psoriasis=3.91×10(-12), Pcombined-SLE=9.90×10(-9)). CONCLUSIONS: These results showed that two common susceptibility loci (NFKBIA and IL28RA) are shared by psoriasis and SLE in the Chinese Han population.

Variants in TNFSF4, TNFAIP3, TNIP1, BLK, SLC15A4 and UBE2L3 interact to confer risk of systemic lupus erythematosus in Chinese population.

Our previous genome-wide association studies on SLE have identified several susceptibility genes involved in NF-κB signaling pathway, including TNFSF4, TNFAIP3, TNIP1, BLK, SLC15A4 and UBE2L3. The aim of this study is to investigate the association model (additive, dominant, recessive) of these genes and search for possible gene-gene interactions between them. In this study, we explored the association model of these six genes and search for possible gene-gene interactions based on identified single-nucleotide polymorphisms (SNPs) among them by using logistic regression analysis in the combined sample of 4,199 cases and 8,255 controls. The most significant association evidence was observed under recessive model for all of these SNPs. Besides, significant interactions between these SNPs were observed in this study: the TNFSF4 and TNIP1 SNPs (P adjusted = 1.68E-10), the TNFSF4 and SLC15A4 SNPs (P adjusted = 3.55E-08), the TNFSF4 and UBE2L3 SNPs (P adjusted = 8.74E-13), the TNIP1 and BLK SNPs (P adjusted = 9.45E-10), the TNIP1 and UBE2L3 SNPs (P adjusted = 8.25E-11), the TNFAIP3 and UBE2L3 SNPs (P adjusted = 3.06E-14) and the BLK and SLC15A4 SNPs (P adjusted = 4.51E-12). These results may contribute to our understanding of SLE genetic interactions and account for the additional risk of certain patients to develop SLE.

One novel susceptibility locus associate with systemic lupus erythematosus in Chinese Han population.

The aim of the study is to explore additional susceptibility factors for systemic lupus erythematosus (SLE) in Chinese Hans. Based on our previous GWAS of SLE, we performed a multistage replication study involving 3,152 cases and 7,050 controls from China to identify additional susceptibility loci for SLE by using the Sequenom MassArray system. All Chinese Han samples used in this study were obtained from doctors through collaboration with multiple hospitals in two geographic regions (central and southern China). Single-marker association analyses were performed using logistic regression with gender as a covariate in each case-control cohort. The joint analysis of all combined samples was performed using logistic regression with gender and sample cohorts as covariates. The significant association evidence for rs906868 (OR = 1.14, 95% CI 1.08-1.20, P combined = 7.71 × 10(-10)) and rs7579944 (OR = 1.13, 95% CI 1.07-1.19, P combined = 5.55 × 10(-9)) was observed, which located at 2p23.1. In this region, limb bud and heart development homolog (LBH) was the only gene indicated, suggesting LBH might be a susceptibility gene for SLE, although its function was still unknown. The results indicated that the SNP rs7579944, rs906868 at 2p23.1 showed significant association with SLE. The genes LBH which located in this loci might be the predisposing genes of SLE.

Proteomic Analyses Reveal Higher Levels of Neutrophil Activation in Men Than in Women With Systemic Lupus Erythematosus.

Objective: Systemic Lupus Erythematosus (SLE) is a systemic autoimmune disease that displays a significant gender difference in terms of incidence and severity. However, the underlying mechanisms accounting for sexual dimorphism remain unclear. The aim of this work was to reveal the heterogeneity in the pathogenesis of SLE between male and female patients. Methods: PBMC were collected from 15 patients with SLE (7 males, 8 females) and 15 age-matched healthy controls (7 males, 8 females) for proteomic analysis. The proteins of interest were validated in independent samples (6 male SLE, 6 female SLE). Biomarkers for neutrophil activation (calprotectin), neutrophil extracellular traps (cell-free DNA and elastase), and reactive oxygen species (glutathione) were measured, using enzyme-linked immunosorbent assay, in plasma obtained from 52 individuals. Results: Enrichment analysis of proteomic data revealed that type I interferon signaling and neutrophil activation networks mapped to both male and female SLE, while male SLE has a higher level of neutrophil activation compared with female SLE. Western blot validated that PGAM1, BST2, and SERPINB10 involved in neutrophil activation are more abundant in male SLE than in female SLE. Moreover, biomarkers of neutrophil activation and reactive oxygen species were increased in male SLE compared with female SLE. Conclusion: Type I interferon activation is a common signature in both male and female SLE, while neutrophil activation is more prominent in male SLE compared with female SLE. Our findings define gender heterogeneity in the pathogenesis of SLE and may facilitate the development of gender-specific treatments.

Follow-up study identifies two novel susceptibility loci PRKCB and 8p11.21 for systemic lupus erythematosus.

OBJECTIVE: We have performed a large-scale replication study based on our previous genome-wide association study (GWAS) of SLE in the Chinese Han population to further explore additional genetic variants affecting susceptibility to SLE. METHODS: Thirty-eight single nucleotide polymorphisms from our GWAS were genotyped in two additional Chinese Han cohorts (total 3152 cases and 7050 controls) using the Sequenom Massarray system. Association analyses were performed using logistic regression with gender or sample cohorts as a covariate. RESULTS: Association evidence for rs16972959 (PRKCB at 16p11.2) and rs12676482 (8p11.21) with SLE was replicated independently in both replication cohorts (P < 0.05), showing high significance for SLE in combined all 4199 cases and 8255 controls of Chinese Han [rs16972959: odds ratio (OR) = 0.81; 95% CI 0.76, 0.87; P(combined) = 1.35 × 10(-9); rs12676482: OR = 1.26; 95% CI 1.15, 1.38; P(combined) = 6.68 × 10(-7)). PRKCB is related to the established SLE immune-related pathway (NF-κB) and 8p11.21 contains important candidate genes such as IKBKB and DKK4. IKBKB is a critical component of NF-κB and DKK4 is an inhibitor of canonical Wnt signalling pathway. Interestingly, PRKCB is required for recruiting IKBKB into lipid rafts, up-regulating NF-κB-dependent survival signal. CONCLUSIONS: Our findings provided novel insights into the genetic architecture of SLE and emphasized the contribution of multiple variants of modest effect. Further study focused on PRKCB, 8p11.21, should advance our understanding on the pathogenesis of SLE.

Real-world data on the use of secukinumab as treatment for moderate-to-severe psoriasis in Chinese patients.

BACKGROUND: The efficacy and safety of secukinumab, an interleukin-17 inhibitor, as systemic treatment for patients with moderate-to-severe psoriasis have been demonstrated, but real-world data pertaining to this is limited in China. OBJECTIVE: To evaluate the efficacy and safety of secukinumab in clinical practice in Chinese psoriasis patients with or without psoriatic arthritis (PsA) and identify potential baseline factors that affect the response of patients to secukinumab treatment. MATERIALS & METHODS: Data from 81 patients treated with secukinumab for at least 16 weeks were analysed in a retrospective observational study. RESULTS: After 16 weeks of treatment with secukinumab, 91.1%, 73%, and 38.3% of patients achieved a PASI 75 (75% improvement based on the Psoriasis Area and Severity Index), PASI 90, and PASI 100, respectively. A significant improvement in the quality of life of patients was also observed. Notably, baseline factors, such as young age, lower BMI, no scalp involvement and absence of concomitant PsA, were associated with better clinical response to secukinumab. Approximately 42% of patients (34/81) experienced adverse events, of which the most common was pruritus. CONCLUSION: The results demonstrated that secukinumab appears to be an effective treatment alternative for the majority of Chinese plaque psoriasis patients. Baseline factors, including age, BMI, scalp involvement and concomitant presence of PsA, were associated with response to secukinumab.

GWAS Follow-up Study Discovers a Novel Genetic Signal on 10q21.2 for Atopic Dermatitis in Chinese Han Population.

Atopic dermatitis (AD) is a common inflammatory skin disease with high heritability. Two susceptibility loci have been confirmed in our previous AD genome-wide association study (GWAS). To look for additional genetic factors in Chinese Han ethnicity, we performed a large-scale GWAS follow-up study. Forty-nine top single nucleotide polymorphisms (SNPs) that had never been reported previously were genotyped using Sequenom Massarray system in an independent cohort, which consist of northern Chinese (1634 cases and 1263 controls) and southern Chinese (2985 cases and 9526 controls). Association analyses were performed using PLINK 2 software. Three SNPs in northern and ten SNPs in southern were found exhibiting association evidence with AD (P < 0.05). Finally, SNP rs224108 on 10q21.2 showed high significance for AD in joint analysis of GWAS and replication study (P meta = 4.55 × 10-9, OR = 1.21), and was confirmed as an independent genetic marker by Linkage disequilibrium calculation and conditional logistic regression analysis. Bioinformatics analysis strongly suggested that rs224108 may have the potential to alter the target gene expression through non-coding epigenetic regulation effects. Meanwhile, SNP rs11150780 on 17q25.3 was also found suggestive association with AD (P meta = 7.64 × 10-7, OR = 1.18). Our findings confirmed a novel susceptibility signal on 10q21.2 for AD in Chinese Han population and advanced the understanding of the genetic contribution to AD.

A variant on chromosome 2p13.3 is associated with atopic dermatitis in Chinese Han population.

BACKGROUND: Multi-ancestry genome-wide association study (GWAS) has recently identified 11 new susceptibility loci for Atopic dermatitis (AD). The replication of these new susceptibility loci in different populations should not be ignored. OBJECTIVE: To examine whether these 11 new identified susceptibility loci are also associated with AD in the Chinese Han population. METHODS: These 11 variants were imputed using our genome-wide array dataset. The selected SNPs with suggestive signals were genotyped in a large-scale replication study with a total of 4619 cases and 10,789 controls using the Sequenom Massarray system. Association analyses were performed using PLINK 1.07 software. Results were combined across our previous AD-GWAS stage and the replication stage by meta-analysis. Bioinformatic analysis was done to predict the possible causal gene. RESULTS: Of the 11 SNPs investigated, four SNPs showed suggestive association (P<0.05) in our previously published GWAS datasets. Association evidence for an intergenic variant rs112111458 at 2p13.3 with AD was replicated in Chinese Han population (P=7.37×10-7, OR=0.86), showing significance in Meta analysis of GWAS and replication study (Pmeta=8.18×10-08, OR=0.69). Further functional annotation by HaploReg indicated that transcriptional regulation activity exists at this locus for the CD207 gene in skin tissue. CONCLUSIONS: Our study confirmed a previously reported susceptibility loci in the Chinese Han population, which implicates CD207 might be a new susceptibility gene for AD and highlights the crucial role of immune responses in AD.

Variation at HLA-DPB1 is associated with dermatomyositis in Chinese population.

Dermatomyositis (DM) is a polygenic disorder characterized by inflammation of skeletal muscle and skin. To date, the exact etiopathogenesis of DM remains elusive. To explore the genetic basis of DM, we conducted genome-wide genotyping analysis of 127 patients and 1566 healthy controls by Illumina Human OmniZhongHua-8 BeadChips in the Chinese Han population. We investigated whether the three SNP (rs7750458, rs9501251 and rs9500928) at 6p21.32 in the HLA-DPB1 gene were significantly associated with DM (P < 5 × 10-8 ) and identified two susceptibility loci at 7q34 (PIP, rs9986765, P = 7.45 × 10-7 , odds ratio [OR] = 2.71) and 10q24.2 (CPN1, rs3750716, P = 9.04 × 10-7 , OR = 4.39) with suggestive evidence. We imputed 6674 classical human leukocyte antigen (HLA) alleles, amino acids and SNP from the discovery dataset, and stepwise analysis revealed that HLA-DPB1*17 in class II HLA genes were significantly associated with DM susceptibility. This study represents the first genome-wide association study (GWAS) of DM in the Chinese Han population. For the first time, HLA-DPB1 was found to be associated with DM in this population. Moreover, we identified two novel suggestive susceptibility loci (PIP and CPN1) and confirmed four previously reported genes (DMB, DQA1, DQB1 and DRB1) having potential associations with DM in the Chinese Han population. Our GWAS results in this population should provide important information regarding the genetic etiopathogenesis of DM and facilitate the development of new therapies for the treatment of DM and the prevention of DM progression.

Increased expression of IL-28RA mRNA in peripheral blood mononuclear cells from patients with systemic lupus erythematosus.

Systemic lupus erythematosus (SLE) is a systemic autoimmune and inflammatory disease with a strong genetic contribution and characterized by kinds of immune reactions. Our previous genome-wide association studies have identified IL-28RA as a susceptibility gene for SLE. In this study, we performed a quantitative reverse transcription polymerase chain reaction (RT-PCR) in 62 patients with SLE and 69 controls to investigate the different expression levels of IL-28RA in peripheral blood mononuclear cells (PBMCs) from SLE patients and healthy controls and the association between IL-28RA expression and systemic lupus erythematosus disease activity index (SLEDAI) or the variant of the single-nucleotide polymorphism (SNP) rs4649203. The expression levels of IL-28RA messenger RNA (mRNA) in SLE patients were significantly increased compared with those of healthy controls. In addition, there were also significant differences in the expression levels of IL-28RA between active (SLEDAI ≥ 6) or inactive (SLEDAI < 6) SLE groups and healthy controls. However, no correlation was observed between IL-28RA mRNA expression level and SLEDAI. There was no association between the variant of the SNP rs4649203 and IL-28RA mRNA expression levels neither. These results indicated that expression of IL-28RA mRNA may be correlated with the pathogenesis of SLE.

Association analyses confirm five susceptibility loci for systemic lupus erythematosus in the Han Chinese population.

INTRODUCTION: Systemic lupus erythematosus (SLE) is a multisystem autoimmune disease. Currently, numerous genetic loci of SLE have been confirmed. Here we try to further explore additional genes contributing to SLE susceptibility in this study. METHODS: Forty nine single nucleotide polymorphisms (SNPs) with moderate-risk for SLE in previous study were genotyped in a large-scale replication study with a total of 3,522 cases and 8,252 controls using the Sequenom Massarray system. Association analyses were performed using logistic regression with gender or sample cohorts as a covariate through PLINK 1.07 software. RESULTS: This replication effort confirmed five reported SLE susceptibility loci reaching genome-wide levels of significance (P(meta) <5.00 × 10(-08)): TNFSF4 (rs1418190, odds ratio (OR) = 0.81, P(meta) = 1.08 × 10(-08); rs4916219, OR = 0.80, P(meta )= 7.77 × 10(-09)), IRF8 (rs2934498, OR = 1.25, P(meta) = 4.97 × 10(-09)), miR-146a (rs2431697, OR = 0.69, P(meta) = 1.15 × 10(-22)), CD44 (rs2732547, OR = 0.82, P(meta) = 1.55 × 10(-11)), and TMEM39A (rs12494314, OR = 0.84, P(meta) = 1.01 × 10(-09)). Further logistic regression analysis indicated that the genetic effects within TNFSF4 detected in this study are independent from our previously reported signals. CONCLUSIONS: This study increases the number of established susceptibility loci for SLE in Han Chinese population and highlights the contribution of multiple variants of modest effect. Although further studies will be required to identify the causal alleles within these loci, the findings make a significant step forward in our understanding of the genetic contribution to SLE in Chinese population.

Identification of a missense variant in LNPEP that confers psoriasis risk.

Psoriasis is a chronic inflammatory disease with a complex genetic architecture. To further advance gene discovery, we extended our genome-wide association study data set of 1,139 cases and 2,234 controls and replicated two independent cohorts of 7,200 cases and 10,491 controls. We identified the missense variant rs2303138 (p.Ala763Thr) within the LNPEP gene associated with psoriasis (Pcombined=1.83 × 10(-13), odds ratio=1.16) and validated four previously reported genes: IL28RA, NFKBIA, TRAF3IP2, and CARD14 (9.74 × 10(-11)P9.37 × 10(-5)), which confirmed the involvement of the nuclear factor-κB signaling pathway in psoriasis pathogenesis. LNPEP, also named insulin-responsive aminopeptidase, was identified as an angiotensin IV receptor. Protein function prediction suggested that this missense variant of LNPEP was most likely deleterious. Expression analysis showed that LNPEP was significantly downregulated in psoriatic lesions compared with the control skin (P=1.44 × 10(-6)) and uninvolved patient skin (P=2.95 × 10(-4)). Pathway analysis indicated that LNPEP was involved in the renin-angiotensin system, which also has a key role in cardiovascular disease and diabetes. These results provided genetic evidence that psoriasis might share common mechanisms with hypertension and diabetes, which was consistent with clinical observations. Our study identified a genetic susceptibility factor and provided genetic evidence of insight into psoriasis pathogenesis with the involvement of the renin-angiotensin system pathway.

Association analysis of single nucleotide polymorphisms at five loci: comparison between atopic dermatitis and asthma in the Chinese Han population.

Atopic diseases, such as atopic dermatitis (AD) and asthma, are closely related to clinical phenotypes with hypersensitivity, and often share some similar genetic and pathogenic bases. Our recent GWAS identified three susceptibility gene/loci FLG (rs11204971 and rs3126085), 5q22.1 (rs10067777, rs7701890, rs13360927 and rs13361382) and 20q13.33 (rs6010620) to AD. The effect of these AD associated polymorphisms in asthma is so far unknown. To investigate whether AD relevant genetic variants is identical to asthma and reveal the differences in genetic factors between AD and asthma in Chinese Han population, seven AD associated single nucleotide polymorphisms (SNPs) as well as 3 other SNPs (rs7936562 and rs7124842 at 11q13.5 and rs4982958 at 14q11.2) from our previous AD GWAS were genotyped in 463 asthma patients and 985 controls using Sequenom MassArray system. We found rs4982958 at 14q11.2 was significantly associated with asthma (P = 3.04×10(-4), OR = 0.73). We also detected one significant risk haplotype GGGA from the 4 SNPs (rs10067777, rs7701890, rs13360927 and rs13361382) at 5q22.1 in AD cases (P(correction) = 3.60×10(-10), OR = 1.26), and the haplotype was suggestive of risk in asthma cases in this study (P = 0.014, P(correction) = 0.084, OR = 1.38). These SNPs (rs11204971, rs3126085, rs7936562, rs712484 and rs6010620) at AD susceptibility genes/loci FLG, 11q13.5 and 20q13.33 were not associated with asthma in this study. Our results further comfirmed that 14q11.2 was an important candidate locus for asthma and demonstrated that 5q22.1 might be shared by AD and asthma in Chinese Han population.

Exome sequencing identifies MVK mutations in disseminated superficial actinic porokeratosis.

Disseminated superficial actinic porokeratosis (DSAP) is an autosomal dominantly inherited epidermal keratinization disorder whose etiology remains unclear. We performed exome sequencing in one unaffected and two affected individuals from a DSAP family. The mevalonate kinase gene (MVK) emerged as the only candidate gene located in previously defined linkage regions after filtering against existing SNP databases, eight HapMap exomes and 1000 Genomes Project data and taking into consideration the functional implications of the mutations. Sanger sequencing in 57 individuals with familial DSAP and 25 individuals with sporadic DSAP identified MVK mutations in 33% and 16% of these individuals (cases), respectively. All 14 MVK mutations identified in our study were absent in 676 individuals without DSAP. Our functional studies in cultured primary keratinocytes suggest that MVK has a role in regulating calcium-induced keratinocyte differentiation and could protect keratinocytes from apoptosis induced by type A ultraviolet radiation. Our results should help advance the understanding of DSAP pathogenesis.

Genome-wide association study in a Chinese Han population identifies nine new susceptibility loci for systemic lupus erythematosus.

We performed a genome-wide association study (GWAS) of systemic lupus erythematosus (SLE) in a Chinese Han population by genotyping 1,047 cases and 1,205 controls using Illumina Human610-Quad BeadChips and replicating 78 SNPs in two additional cohorts (3,152 cases and 7,050 controls). We identified nine new susceptibility loci (ETS1, IKZF1, RASGRP3, SLC15A4, TNIP1, 7q11.23, 10q11.22, 11q23.3 and 16p11.2; 1.77 x 10(-25) < or = P(combined) < or = 2.77 x 10(-8)) and confirmed seven previously reported loci (BLK, IRF5, STAT4, TNFAIP3, TNFSF4, 6q21 and 22q11.21; 5.17 x 10(-42) < or = P(combined) < or = 5.18 x 10(-12)). Comparison with previous GWAS findings highlighted the genetic heterogeneity of SLE susceptibility between Chinese Han and European populations. This study not only advances our understanding of the genetic basis of SLE but also highlights the value of performing GWAS in diverse ancestral populations.