A multilocus genetic study in a cohort of Italian SLE patients confirms the association with STAT4 gene and describes a new association with HCP5 gene

LncRNA-HHCP5 Regulates KLF5 in ceRNA and m6A Pathways to Inhibit the Progression of Osteoarthritis

BACKGROUND

Osteoarthritis (OA) is one of the most common bone disorders and has a serious impact on the quality of life of patients. LncRNA-HCP5 (HCP5) is downregulated in OA tissues. However, the latent function and regulatory mechanisms of HCP5 in OA are unclear.

METHODS

In the current study, IL-1β-induced C28/I2 cells were used to establish an in vitro model of OA. The expression of HCP5 in OA cartilage tissue and in the in vitro model of OA was detected by RT-qPCR. Cell viability and apoptosis were assessed by CCK-8 and Annexin V-PI double staining. Western blotting was employed to detect the protein expression of MMP-13 and aggrecan.

RESULTS

The results showed that the findings suggested that HCP5 was downregulated in OA cartilage tissue and IL-1β-induced C28/I2 cells. HCP5 overexpression greatly enhanced IL-1β-induced proliferation of C28/I2 cells, as well as prevented cell apoptosis and degradation of extracellular matrix (ECM). Besides, we have shown that HCP5 is a ceRNA that regulates KLF5 by sponging miR-375. Furthermore, KLF5 is also regulated by m6A regulation induced by HCP5. Finally, overexpression of miR-375, the m6A modification inhibitor, as well as KLF5 inhibition reversed the impact of HCP5 on IL-1β-induced C28/I2 cells.

CONCLUSION

In summary, the present study demonstrated that the HCP5/KLF5 axis inhibited the progression of osteoarthritis.

Large-scale DNA sequencing identifies rare variants associated with Systemic Lupus Erythematosus susceptibility in known risk genes

The identification of rare genetic variants associated to Systemic Lupus Erythematosus (SLE) could also help to understand the pathogenic mechanisms at the basis of the disease. In this study we have analyzed a cohort of 200 Italian SLE patients in order to explore the rare protein-coding variants in five genes (TNFAIP3, STAT4, IL10, TRAF3IP2, and HCP5) already investigated for commons variants found associated in our previous studies. Genomic DNA of 200 SLE patients was sequenced by whole exome sequencing. The identified variants were filtered by frequency and evaluated by in silico predictions. Allelic association analysis was performed with standard Fisher's exact test. Introducing a cutoff at MAF < 0.01, a total of 19 rare variants were identified. Seven of these variants were ultra-rare (MAF < 0.001) and six were absent in the GnomAD database. For TNFAIP3 gene, the variant c.A1939C was observed in 4 SLE patients and it is located in a region enriched in phosphorylation sites and affects the predict affinity of specific kinases. In TRAF3IP2 gene, we observed 5 different rare variants, including the novel variant c.G410A, located in the region that mediates interaction with TRAF6, and therefore a possible risk factor for SLE development. In STAT4 gene, we identified 6 different rare variants. Among these, three missense variants decrease the stability of this protein. Moreover, 3 novel rare variants were detected in 3 SLE patients. In particular, c.A767T variant was predicted as damaging by six prediction tools. Concluding, we have observed that even in genes whose common variability is associated with SLE susceptibility, it is possible to identify rare variants that could have a strong effect in the disease development and could therefore allow a better understanding of the functional domain involved.

Organ damage in Systemic Lupus Erythematosus patients: A multifactorial phenomenon

The prevention of chronic damage, especially in early disease phases, remains an unmet need in the management of Systemic Lupus Erythematous (SLE) patients, despite the application of a so-called treat-to-target strategy. The high proportion of SLE patients developing chronic damage suggests a multifactorial aetiology. Thus, besides disease activity, other factors may contribute to the development of damage. The revision of data published so far underlines that, next to disease activity, it is possible to identify other factors playing a relevant role in damage development and progression. In summary, the presence of antiphospholipid antibodies and drugs used to treat SLE patients, in particular glucocorticoids, is strongly associated with SLE-related damage. Furthermore, recent data suggests the possible role of genetic background in determining the development of specific organ damage, in particular renal and neurological. Nonetheless, demographic factors, such as age, sex and disease duration could exert a role along with the presence of comorbidities. The contribution of different factors in determining damage development suggests the need for new outcomes to assess a comprehensive disease control including not only the assessment of disease activity, but also the evaluation of chronic damage development.

Genotype-phenotype correlations in Graves' disease

Graves' disease (GD) is a heterogeneous autoimmune disease affecting with varying degrees of severity the thyroid gland, orbital tissues and skin. The pathogenesis of GD involves a complex interplay between multiple genetic, environmental and endogenous factors. Although the genetic predisposition to GD is well established, the significance of genotype-phenotype correlations and the role of epigenetic modifications in the disease pathogenesis remains largely unknown. In this review, we provide an up-to-date overview of genotype-phenotype correlations and summarize possible clinical implications of genetic and epigenetic markers in GD patients. We will specifically discuss the association of genetic markers and epigenetic modifications with age of GD onset, severity of Graves' hyperthyroidism and the development of clinically evident Graves' orbitopathy.

A Polynesian-specific copy number variant encompassing the MICA gene associates with gout

Gout is of particularly high prevalence in the Māori and Pacific (Polynesian) populations of Aotearoa New Zealand (NZ). Here, we investigated the contribution of common population-specific copy number variation (CNV) to gout in the Aotearoa NZ Polynesian population. Microarray-generated genome-wide genotype data from Aotearoa NZ Polynesian individuals with (n = 1196) and without (n = 1249) gout were analyzed. Comparator population groups were 552 individuals of European ancestry and 1962 of Han Chinese ancestry. Levels of circulating major histocompatibility complex (MHC) class I polypeptide-related sequence A (MICA) were measured by enzyme-linked immunosorbent assay. Fifty-four CNV regions (CNVRs) appearing in at least 10 individuals were detected, of which seven common (>2%) CNVRs were specific to or amplified in Polynesian people. A burden test of these seven revealed associations of insertion/deletion with gout (odds ratio (OR) 95% confidence interval [CI] = 1.80 [1.01; 3.22], P = 0.046). Individually testing of the seven CNVRs for association with gout revealed nominal association of CNVR1 with gout in Western Polynesian (Chr6: 31.36-31.45 Mb, OR = 1.72 [1.03; 2.92], P = 0.04), CNVR6 in the meta-analyzed Polynesian sample sets (Chr1: 196.75-196.92 Mb, OR = 1.86 [1.16; 3.00], P = 0.01) and CNVR9 in Western Polynesian (Chr1: 189.35-189.54 Mb, OR = 2.75 [1.15; 7.13], P = 0.03). Analysis of European gout genetic association data demonstrated a signal of association at the CNVR1 locus that was an expression quantitative trait locus for MICA. The most common CNVR (CNVR1) includes deletion of the MICA gene, encoding an immunomodulatory protein. Expression of MICA was reduced in the serum of individuals with the deletion. In summary, we provide evidence for the association of CNVR1 containing MICA with gout in Polynesian people, implicating class I MHC-mediated antigen presentation in gout.

Biomarkers of lymphoma in Sjögren's syndrome: what's the latest?

INTRODUCTION

Primary Sjögren's syndrome (pSS) is a chronic autoimmune disease standing in the crossroads of autoimmunity and lymphomagenesis, characterized by chronic B-cell hyperactivity and ectopic lymphoid tissue neoformation, potentially driving lymphoid malignant transformation. Lymphoma development is considered the most serious complication of pSS.

AREAS COVERED: “

Old-classical" biomarkers (clinical, serological, hematological, and histological) validated in the past are analyzed under the perspective of recently published research. Biomarkers that have emerged during the last decade are subdivided to "old-new" and "newly proposed-novel" ones, including biomarkers pathophysiologically related to B-cell differentiation, lymphoid organization, and immune responses, identified in serum and tissue, both at genetic and protein level. Upcoming new imaging biomarkers, promising for further patient stratification, are also analyzed.

EXPERT OPINION

Salivary gland enlargement and cryoglobulinemia still remain the best validated "classical-old" biomarkers for lymphoma development. Though new biomarkers still need to be validated, some can be used for the identification of high-risk patients long before lymphoma diagnosis, some might be more relevant in distinct age subgroups, while others have an added value in the assessment of lymphoma remission or relapse. Future development of composite indices integrating old and recently proposed biomarkers could contribute to a more precise lymphoma prediction model.

The interplay between HLA-B and NLRP3 polymorphisms may be associated with the genetic susceptibility of gout

BACKGROUND

HLA and NLRP3 play an important role in the development of various autoimmune and autoinflammatory diseases. Gout is an autoinflammatory disease associated with multiple genetic and environmental factors. The objective of the present study was to evaluate the interaction and association between genetic polymorphisms of HLA-B and the NLRP3 gene in Mexican patients with gout.

METHODS AND RESULTS

Eighty-one patients with gout were included and compared with 95 healthy subjects. The polymorphisms rs4349859, rs116488202, rs2734583 and rs3099844 (within the HLA-B region) and rs3806268 and rs10754558 of the NLRP3 gene were genotyped using TaqMan probes in a Rotor-Gene device. The interactions were determined using the multifactorial dimensionality reduction (MDR) method, while the associations were determined through logistic regression models. The MDR analysis revealed significant interactions between the rs116488202 and rs10754558 polymorphisms with an entropy value of 4.31% (p < 0.0001). Significant risk associations were observed with rs4349859 and rs116488202 polymorphisms (p < 0.01); however, no significant associations were observed with the polymorphisms of the NLRP3 gene.

CONCLUSIONS

The results suggest that HLA-B polymorphisms and their interaction with NLRP3 may contribute to the genetic susceptibility of gout.

Impact of TRAF3IP2, IL10 and HCP5 Genetic Polymorphisms in the Response to TNF-i Treatment in Patients with Psoriatic Arthritis

Psoriatic arthritis (PsA) is a chronic inflammatory rheumatic disease. The introduction of therapy with biological drugs is promising, even if the efficacy is very variable. Since the response to drugs is a complex trait, identifying genetic factors associated to treatment response could help define new biomarkers for a more effective and personalized therapy. This study aimed to evaluate the potential role of polymorphisms in genes involved in PsA susceptibility as predictors of therapy efficacy. Nine polymorphisms were analyzed in a cohort of 163 PsA patients treated with TNF-i. To evaluate the treatment response, the DAPsA score was estimated for each patient. The possible association between the selected SNPs and mean values of DAPsA differences, at 22 and 54 weeks from the beginning of the treatment, were evaluated by t-test. Patients carrying the variant allele of TRAF3IP2 seemed to respond better to treatment, both at 22 and 54 weeks. This variant allele was also associated with an improvement in joint involvement. In contrast, patients carrying the IL10 variant allele showed an improvement lower than patients with the wild-type genotype at 54 weeks. Our results suggest that polymorphisms in genes associated with PsA susceptibility could also play a role in TNF-i treatment response.

Cardiac Manifestations of Systemic Lupus Erythematous: An Overview of the Incidence, Risk Factors, Diagnostic Criteria, Pathophysiology and Treatment Options

Systemic lupus erythematosus (SLE) is a complex connective tissue disease that can potentially affect every organ of the human body. In some cases, SLE may present with diverse cardiac manifestations including pericarditis, myocarditis, valvular disease, atherosclerosis, thrombosis, and arrhythmias. Heart disease in SLE is associated with increased morbidity and mortality. It is unclear whether traditional treatments for coronary artery disease significantly impact mortality in this population. Current therapeutic agents for SLE include glucocorticoids, hydroxychloroquine, mycophenolate mofetil, azathioprine, methotrexate, cyclophosphamide, and B cell-directed therapies. This article will provide a comprehensive review and update on this important disease state.

Identification of LINC00173 in Myasthenia Gravis by Integration Analysis of Aberrantly Methylated- Differentially Expressed Genes and ceRNA Networks

Myasthenia gravis (MG) is an autoimmune disease associated with autoantibody production that leads to skeletal muscle weakness. The molecular mechanisms underlying MG are not fully understood. We analyzed the gene expression profile (GSE85452) and methylation profile (GSE85647) of MG samples from the GEO database to identify aberrantly methylated-differentially expressed genes. By integrating the datasets, we identified 143 hypermethylation-low expression genes and 91 hypomethylation-high expression genes. Then we constructed PPI network and ceRNA networks by these genes. Phosphatase and tensin homolog (PTEN) and Abelson tyrosine-protein kinase (ABL)1 were critical genes in both PPI networks and ceRNA networks. And potential MG associated lncRNAs were selected by comprehensive analysis of the critical genes and ceRNA networks. In the hypermethylation-low expression genes associated ceRNA network, sirtuin (SIRT)1 was the most important gene and the lncRNA HLA complex (HC) P5 had the highest connection degree. Meanwhile, PTEN was the most important gene and the lncRNA LINC00173 had the highest connection degree in the hypomethylation-high expression genes associated ceRNA network. LINC00173 was validated to be upregulated in MG patients by qRT-PCR (P = 0.005), which indicated LINC00173 might be a potential biomarker for MG. These results provide a basis for future studies on the molecular pathogenesis of MG.

Psoriasis Susceptibility 1 Candidate 1 (PSORS1C1) Polymorphism is Associated with Autoimmune Thyroid Disease in a Chinese Han Population

BACKGROUND

Autoimmune thyroid disease (AITD) is an inherited, complex gene- and immune-related disorder that mainly includes Graves' disease (GD) and Hashimoto's thyroiditis (HT). Psoriasis susceptibility 1 candidate 1 (PSORS1C1) is a susceptibility gene associated with many autoimmune diseases, but its role in an individual's predisposition to AITD is unknown.

METHODS

This study included 1065 Chinese Han patients with AITD and 943 matched healthy individuals. The rs3130983, rs3778638, rs3815087, and rs4959053 single nucleotide polymorphisms (SNPs) in PSORS1C1 were determined using multiplex polymerase chain reaction technology.

RESULTS

Of the four SNPs, only the distribution of the rs3778638 genotypes was different between the AITD (AA, 2.67%; AG, 19.15%; and GG, 78.18%) and control (AA, 1.52%; AG, 22.2%; and GG, 75.87%) groups (P = .046). An association between rs3778683 and GD was observed (p = .039) but not with HT. No linkage disequilibrium was observed for rs3130983, rs3815087, rs3778638, and rs4959053 in PSORS1C1 among the patients with AITD and controls.

CONCLUSION

This study suggests the influence of PSORS1C1 rs3778638 on the susceptibility to GDs, supporting this locus as a common autoimmunity risk factor.

Human Cytomegalovirus and Autoimmune Diseases: Where Are We?

Human cytomegalovirus (HCMV) is a ubiquitous double-stranded DNA virus belonging to the β-subgroup of the herpesvirus family. After the initial infection, the virus establishes latency in poorly differentiated myeloid precursors from where it can reactivate at later times to cause recurrences. In immunocompetent subjects, primary HCMV infection is usually asymptomatic, while in immunocompromised patients, HCMV infection can lead to severe, life-threatening diseases, whose clinical severity parallels the degree of immunosuppression. The existence of a strict interplay between HCMV and the immune system has led many to hypothesize that HCMV could also be involved in autoimmune diseases (ADs). Indeed, signs of active viral infection were later found in a variety of different ADs, such as rheumatological, neurological, enteric disorders, and metabolic diseases. In addition, HCMV infection has been frequently linked to increased production of autoantibodies, which play a driving role in AD progression, as observed in systemic lupus erythematosus (SLE) patients. Documented mechanisms of HCMV-associated autoimmunity include molecular mimicry, inflammation, and nonspecific B-cell activation. In this review, we summarize the available literature on the various ADs arising from or exacerbating upon HCMV infection, focusing on the potential role of HCMV-mediated immune activation at disease onset.

An Intronic HCP5 Variant Is Associated With Age of Onset and Susceptibility to Graves Disease in UK and Polish Cohorts

CONTEXT

The genetic background of young-onset Graves disease (GD) remains largely unknown. An intronic variant in human leukocyte antigen (HLA) complex P5 (HCP5) has previously been associated with GD susceptibility and age of onset in a cohort of Polish patients.

OBJECTIVE

We aimed to investigate the association of the HCP5 variant rs3094228 with GD susceptibility and age of onset in a UK cohort and conduct a meta-analysis of UK and Polish data.

DESIGN AND PARTICIPANTS

rs3094228 was genotyped in 469 UK patients with GD using Taqman chemistry. Genotype frequencies were compared with genotypic data available from the Wellcome Trust case-control consortium using logistic regression analysis. To determine whether rs3094228 is independently associated with age of GD onset, the HLA DRB1*0301 tagging variant, rs535777, was also genotyped.

RESULTS

The C allele of rs3094228 was overrepresented in the UK GD cohort compared with controls (P allele=5.08 × 10-9, odds ratio 1.76; [95% confidence interval, 1.46-2.13]). This association was more marked in young-onset GD (<30 years) (P allele=1.70 × 10-10 vs P allele=0.0008). The meta-analysis of UK and Polish data supported the association of the C allele with GD susceptibility (P allele=1.79 × 10-5) and age of onset (P allele=5.63 × 10-8). Haplotype analysis demonstrated that rs3094228 is associated with age of GD onset (P = 2.39 × 10-6) independent of linkage disequilibrium with HLA DRB1*0301.

CONCLUSION

The rs3094228 HCP5 polymorphism is independently associated with GD susceptibility and age of onset in a UK GD cohort. Our findings indicate a potential role of long noncoding ribonucleic acids, including HCP5, in GD pathogenesis, particularly in the younger population.

A novel TRAF3IP2 variant causing familial scarring alopecia with mixed features of discoid lupus erythematosus and folliculitis decalvans

Discoid lupus erythematosus (DLE) is an autoimmune disorder with a poorly defined etiology. Despite epidemiologic gender and ethnic biases, a clear genetic basis for DLE remains elusive. In this study, we used exome and RNA sequencing technologies to characterize a consanguineous Lebanese family with four affected individuals who presented with classical scalp DLE and generalized folliculitis. Our results unraveled a novel biallelic variant c.1313C > A leading to a missense substitution p.(Thr438Asn) in TRAF3IP2(NM_147200.3). Expression studies in cultured cells revealed mis-localization of the mutated protein. Functional characterization of the mutated protein showed significant reduction in the physical interaction with the interleukin 17-A receptor (IL17RA), while interaction with TRAF6 was unaffected. By conducting a differential genome-wide transcriptomics analysis between affected and non-affected individuals, we showed that the hair follicle differentiation pathway is drastically suppressed, whereas cytokine and inflammation responses are significantly upregulated. Furthermore, our results were highly concordant with molecular signatures in patients with DLE from a public dataset. In conclusion, this is the first report on a new putative role for TRAF3IP2 in the etiology of DLE. The identified molecular features associated with this gene could pave the way for better DLE-targeted treatment.

Long non-coding RNA HCP5 serves as a ceRNA sponging miR-17-5p and miR-27a/b to regulate the pathogenesis of childhood obesity via the MAPK signaling pathway

Background This study aimed to investigate the completing endogenous RNA (ceRNA) network involved in childhood obesity. Methods The microarray dataset GSE9624 was downloaded from the Gene Expression Omnibus (GEO) database. Differentially expressed long non-coding RNAs (lncRNAs) (DELs) and messenger RNAs (DEMs) were isolated between the childhood obesity and non-obesity tissue samples. Then, Gene Ontology (GO) functional and the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses of isolated DEMs were performed. DELs and DEMs targeted miRNAs were predicted to construct a ceRNA regulatory network. Finally, critical lncRNAs were validated in another dataset. Results A total of 1257 differentially expressed RNAs were screened, including 28 lncRNAs and 1229 mRNAs. In addition, these RNAs were mainly involved in defense response, cell cycle, mitogen-activated protein kinase (MAPK) signaling pathway, apoptosis, etc. Three lncRNAs (human leukocyte antigen complex 5 [HCP5], long intergenic non-protein coding RNA 839 [LINC00839] and receptor activity modifying protein 2 [RAMP2-AS1]) and two related miRNAs (hsa-miR-17-5p and hsa-miR-27a/b-3p) were identified as key RNAs in childhood obesity. Specifically, lncRNA HCP5 interacted with miR-17-5p and miR-27a/b to regulate nemo-like kinase (NLK) and Ras-related protein 2 (RRAS2) via the MAPK signaling pathway. Finally, four genes (RRAS2, NLK, bcl2/adenovirus E1B protein-interacting protein 3 [BNIP3] and phorbol-12-myristate-13-acetate-induced protein 1 [PMAIP1]) targeted by miRNAs were predicted as critical genes and might be novel diagnostic biomarkers of childhood obesity. Conclusions lncRNA HCP5 could serve as a ceRNA sponging miR-17-5p and miR-27a/b to regulate the pathogenesis of childhood obesity via NLK and RRAS2 in the MAPK signaling pathway.

Do lncRNAs and circRNAs expression profiles influence discoid lupus erythematosus progression?-a comprehensive analysis

Background

Long noncoding RNAs (lncRNAs) and circular RNAs (circRNAs)are involved in the progression of discoid lupus erythematosus (DLE), but an understanding of their underlying mechanisms remains elusive. To explore the expression profiles of lncRNAs and circRNAs in DLE, we surveyed the lncRNA/circRNA and mRNA expression profiles in the epithelia of oral DLE and adjacent normal tissues.

Methods

The lesional and non-lesional lower lips of three DLE patients were analysed by RNA-sequencing (RNA-seq). The principal functions of the significantly deregulated genes were identified using Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses. And the correlated expression networks (coding-noncoding co-expression and lncRNAs-transcription factor-mRNA) were evaluated as well.

Results

Hundreds of significantly changed lncRNAs and mRNAs and dozens of significantly changed circRNAs were identified. lncRNA lnc-MIPOL1-6 and IncRNA IncDDX47-3 expressions were correlated with immune response-related genes, including IL19, CXCL1, CXCL11, and TNFSF15. Up-regulated IncRNA-TF network consists of 8 TFs and 74 related lncRNAs. The lncRNA-TF-gene trans-regulation consisting of 204 lncRNAs,39 TFs, and correlated 3 genes.

Conclusions

These results demonstrate that lncRNAs and circRNAs can influence the progression of DLE. Certain mRNAs/lncRNAs/circRNAs may have substantial value in DLE diagnosis and therapy.

The role of Epstein-Barr virus infection in primary Sjögren's syndrome

PURPOSE OF REVIEW

The purpose of this article is to draw attention to the role of Epstein-Barr virus (EBV) virus in the pathogenesis of the primary Sjögren's syndrome. The article introduces the problem of consequences of EBV acute infection, and its reactivation, in association with the immune response modulation by the virus and with an increased risk of developing systemic autoimmune diseases and EBV-associated cancers.

RECENT FINDINGS

The knowledge about the mechanisms by which the virus may stay for years in a latent phase, unrecognized by the host response immune cells is constantly expanding. There are several mechanisms and theories about EBV influence on the autoimmune process in Sjogren's syndrome (pSS), including the similarity (molecular mimicry) between viral EBNA-2 protein and Ro-60 antigen or EBER-1 and EBER-2 viral proteins and La antigen.

SUMMARY

The influence of EBV infection on the development and course of pSS has been proven. It has also been established that both EBV and pSS result in the increased risk of tumor (especially lymphoma) development. In the light of these findings, new ways to manage EBV infections are being sought. Optimal methods for assessing EBV infection status are being devised. Research also aims at finding therapies, which target EBV through the inhibition of the autoimmune process and of viral activity. The present article is an attempt to discuss the most important phenomena and elements linking EBV infection to the primary Sjögren's syndrome.

TNFAIP3 Gene Polymorphisms in Three Common Autoimmune Diseases: Systemic Lupus Erythematosus, Rheumatoid Arthritis, and Primary Sjogren Syndrome-Association with Disease Susceptibility and Clinical Phenotypes in Italian Patients

Autoimmune diseases (AIDs) are complex diseases characterized by persistent or recurrent inflammation, alteration of immune response, and production of specific autoantibodies. It is known that different AIDs share several susceptibility genetic loci. Tumor necrosis factor alpha inducible protein 3 (TNFAIP3) encodes the ubiquitin-modifying enzyme A20, which downregulates inflammation by restricting NF-κB, a transcription factor that regulates expression of various proinflammatory genes. Variants in TNFAIP3 gene have been described as associated with susceptibility to several AIDs. Here, we analyzed two TNFAIP3 polymorphisms in Italian patients with systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), and primary Sjogren's syndrome (pSS), to verify if the genetic variability of TNFAIP3 gene is involved in genetic predisposition to AIDs also in the Italian population. We recruited 313 SLE patients, 256 RA patients, 195 pSS patients, and 236 healthy controls. Genotyping of rs2230926 and rs6920220 in TNFAIP3 gene was performed by an allelic discrimination assay. We carried out a case/control association study and a genotype/phenotype correlation analysis. A higher risk to develop SLE was observed for rs2230926 (P = 0.02, OR = 1.92). No association was observed between this SNP and the susceptibility to pSS or RA. However, the rs2230926 variant allele seems to confer a higher risk to develop lymphoma in pSS patients, while in RA patients, the presence of RF resulted significantly associated with the variant allele. Regarding the rs6920220 SNP, we observed a significant association of the variant allele with SLE (P = 0.03, OR = 1.53), pSS (P = 0.016, OR = 1.69), and RA (P = 0.0001, OR = 2.35) susceptibility. Furthermore, SLE patients carrying the variant allele showed a higher risk to develop pericarditis, pleurisy, and kidney complications. Our results support the importance of the TNFAIP3 gene variant role in the development of different autoimmune diseases in the Italian population and furtherly confirm a sharing of genetic predisposing factors among these three pathologies.

Influence of ERAP1 and ERAP2 gene polymorphisms on disease susceptibility in different populations

The endoplasmic reticulum aminopeptidases (ERAPs), ERAP1 and ERAP2, makes a role in shaping the HLA class I peptidome by trimming peptides to the optimal size in MHC-class I-mediated antigen presentation and educating the immune system to differentiate between self-derived and foreign antigens. Association studies have shown that genetic variations in ERAP1 and ERAP2 genes increase susceptibility to autoimmune diseases, infectious diseases, and cancers. Both ERAP1 and ERAP2 genes exhibit diverse polymorphisms in different populations, which may influence their susceptibly to the aforementioned diseases. In this article, we review the distribution of ERAP1 and ERAP2 gene polymorphisms in various populations; discuss the risk or protective influence of these gene polymorphisms in autoimmune diseases, infectious diseases, and cancers; and highlight how ERAP genetic variations can influence disease associations.

STAT4, TRAF3IP2, IL10, and HCP5 Polymorphisms in Sjögren's Syndrome: Association with Disease Susceptibility and Clinical Aspects

Sjögren's syndrome (SS) is a chronic autoimmune condition characterized by autoantibody production, sicca syndrome, and periepithelial lymphocytic lesions in target tissues. A predisposing genetic background is likely, and, to date, several polymorphisms in non-HLA genes have been explored with interesting results. We investigated the association between the STAT4, TRAF3IP2, HCP5, and IL10 polymorphisms and SS susceptibility and their possible role in the modulation of clinical and laboratory features. 195 consecutive patients with SS were enrolled and clinical and laboratory data were collected. 248 age- and sex-matched healthy subjects were used as controls. Genotyping was performed by allelic discrimination assays. A case-control association study and a phenotype-genotype correlation analysis were performed. A genetic risk profile was developed considering the risk alleles. Both the variant alleles of rs7574865 in the STAT4 gene and rs3099844 in the HCP5 gene were significantly more prevalent in patients than in controls (OR = 1.91 and OR = 2.44, respectively). The variant allele of rs3024505 of IL10 resulted to be a susceptibility allele (OR = 1.52), while the variant allele of rs1800872 seemed to confer a protective effect for the development of the disease (OR = 0.65). A risk genetic profile showed a higher probability to develop the disease in subjects with at least three risk alleles; subjects with 4 risk alleles were not observed in the controls. HCP5 rs3099844 was associated with anti-SSA (P = 0.006, OR = 3.07) and anti-SSB (P = 0.005, OR = 2.66) antibodies, severity of focus score (P = 0.03, OR = 12), and lymphoma development (P = 0.002, OR = 7.23). Patients carrying the STAT4 rs7574965 variant allele had a higher risk of monoclonal component and leukopenia (P = 0.002, OR = 7.6; P = 0.048, OR = 2.01, respectively). We confirmed the association of SS with the STAT4 and IL10 genes and we describe a novel association with HCP5. In particular, we describe an association of this specific SNP of HCP5 not only with disease development but also with autoantibody production and focus score suggesting a potential contribution of this variant to a more severe phenotype.

Paediatric-onset and adult-onset Graves' disease share multiple genetic risk factors

BACKGROUND

Graves' disease (GD) is an autoimmune thyroid disease (AITD) with a peak incidence between 30 and 50 years of age. Although children and adolescents may also develop the disease, the genetic background of paediatric-onset GD (POGD) remains largely unknown. Here, we looked for similarities and differences in the genetic risk factors for POGD and adult-onset GD (AOGD) as well as for variants associated with age of GD onset.

MATERIALS AND METHODS

A total of 1267 GD patients and 1054 healthy controls were included in the study. Allele frequencies of 40 established and suggested GD/AITD genetic risk variants (39 SNPs and HLA-DRB1*03) were compared between POGD (N = 179), AOGD (N = 1088) and healthy controls. Subsequently, multiple linear regression was used to explore the relationship between age of GD onset and genotype for each locus.

RESULTS

We identified six POGD risk loci, all of them were also strongly associated with AOGD. Although for some of the analysed variants, including HCP5 (rs3094228), PRICKLE1 (rs4768412) and SCGB3A2 (rs1368408), allele frequencies differed nominally between POGD and AOGD patients, these differences were not significant after applying multiple testing correction (P_cor  = 0.05/40 = 1.25 × 10^-3 ). Regression analysis showed that patients with higher number of HCP5 risk alleles tend to have a significantly earlier onset of GD (P = 6.9 × 10^-5 ).

CONCLUSIONS

The results of our study revealed that POGD and AOGD share multiple common genetic risk variants. Moreover, we demonstrated for the first time that HCP5 polymorphism is associated with an earlier age of GD onset in a dose-dependent manner.

Cardiac Manifestations in Systemic Lupus Erythematosus: A Case Report and Review of the Literature

BACKGROUND

Systemic Lupus Erythematosus (SLE) is a chronic autoimmune disease with a wide range of clinical features and variable clinical course. SLE tends to affect women during childbearing years and is characterized by multi-organ involvement. Cardiac complications in SLE, which have been described to occur in about 50% of the cases, contributes to significant morbidity and mortality in this population. We describe a patient with SLE and established lupus nephritis who subsequently developed cardiac manifestations including valvular abnormalities, arrythmia and end stage heart failure. The clinical features, work up and management will be discussed.

CASE PRESENTATION

A 35 year-old African American woman diagnosed with SLE in her twenties presented to our hospital for evaluation of shortness of breath. After SLE diagnosis, the patient had been prescribed hydrochloroquine and low dose steroids for joint and skin manifestations. Four years after initial presentation, she developed biopsy proven lupus nephritis for which standard induction therapy was administered. She was placed on maintenance immunosuppression with stable renal function. On admission, the patient's symptoms included dyspnea on exertion, chest pain, palpitations, and a non-productive cough. Initial evaluation identified atrial fibrillation and new onset of heart failure given elevated brain natriuretic peptide (BNP) levels and left ventricular ejection fraction (EF) of 15% by echocardiogram. Cardiac catheterization revealed global hypokinesis and non-obstructive coronary artery disease (CAD). The patient was deemed not a suitable candidate for cardiac transplant and was offered a life vest as bridging to an implantable cardioverter (ICD). Twenty-four months after discharge, the patient continued to be managed medically and has not had any subsequent hospitalizations.

CONCLUSION

Cardiac complications, reported in about 50% of SLE patients, are associated with high morbidity and mortality. Pericarditis is the most common, however conduction defects, valvular damage and heart failure are also observed among SLE patients. The pathogenesis of cardiac involvement seems to be multifactorial. The management of heart failure in SLE entails medical therapy and implantable device use. Further research is needed to explore new options to arrest the development and progression of cardiac disease among lupus patients.

A plausibly causal functional lupus-associated risk variant in the STAT1-STAT4 locus

Systemic lupus erythematosus (SLE or lupus) (OMIM: 152700) is a chronic autoimmune disease with debilitating inflammation that affects multiple organ systems. The STAT1-STAT4 locus is one of the first and most highly replicated genetic loci associated with lupus risk. We performed a fine-mapping study to identify plausible causal variants within the STAT1-STAT4 locus associated with increased lupus disease risk. Using complementary frequentist and Bayesian approaches in trans-ancestral Discovery and Replication cohorts, we found one variant whose association with lupus risk is supported across ancestries in both the Discovery and Replication cohorts: rs11889341. In B cell lines from patients with lupus and healthy controls, the lupus risk allele of rs11889341 was associated with increased STAT1 expression. We demonstrated that the transcription factor HMGA1, a member of the HMG transcription factor family with an AT-hook DNA-binding domain, has enriched binding to the risk allele compared with the non-risk allele of rs11889341. We identified a genotype-dependent repressive element in the DNA within the intron of STAT4 surrounding rs11889341. Consistent with expression quantitative trait locus (eQTL) analysis, the lupus risk allele of rs11889341 decreased the activity of this putative repressor. Altogether, we present a plausible molecular mechanism for increased lupus risk at the STAT1-STAT4 locus in which the risk allele of rs11889341, the most probable causal variant, leads to elevated STAT1 expression in B cells due to decreased repressor activity mediated by increased binding of HMGA1.

Anti-carbamylated protein antibodies as a new biomarker of erosive joint damage in systemic lupus erythematosus

Background

The application of more sensitive imaging techniques, such as ultrasonography (US), changed the concept of non-erosive arthritis in systemic lupus erythematosus (SLE), underlining the need for biomarkers to identify patients developing the erosive phenotype. Anti-citrullinated peptide antibodies (ACPA), associated with erosions in inflammatory arthritis, have been identified in about 50% of patients with SLE with erosive arthritis. More recently, anti-carbamylated proteins antibodies (anti-CarP) have been associated with erosive damage in rheumatoid arthritis. We aimed to assess the association between anti-CarP and erosive damage in a large SLE cohort with joint involvement.

Methods

We evaluated 152 patients (male/female patients 11/141; median age 46 years, IQR 16; median disease duration 108 months, IQR 168). All patients underwent blood draw to detect rheumatoid factor (RF) and ACPA (commercial enzyme-linked immunosorbent assay (ELISA) kit), and anti-CarP (“home-made” ELISA, cutoff 340 aU/mL). The bone surfaces of the metacarpophalangeal and proximal interphalangeal joints were assessed by US: the presence of erosions was registered as a dichotomous value (0/1), obtaining a total score (0–20).

Results

The prevalence of anti-CarP was 28.3%, similar to RF (27.6%) and significantly higher than ACPA (11.2%, p = 0.003). Erosive arthritis was identified in 25.6% of patients: this phenotype was significantly associated with anti-CarP (p = 0.004). Significant correlation between anti-CarP titer and US erosive score was observed (r = 0.2, p = 0.01).

Conclusions

Significant association was identified between anti-CarP and erosive damage in SLE-related arthritis, in terms of frequency and severity, suggesting that these antibodies can represent a biomarker of severity in patients with SLE with joint involvement.

Polymorphisms in miRNA genes and their involvement in autoimmune diseases susceptibility

MicroRNAs (miRNAs) are small non-coding RNA molecules that negatively regulate the expression of multiple protein-encoding genes at the post-transcriptional level. MicroRNAs are involved in different pathways, such as cellular proliferation and differentiation, signal transduction and inflammation, and play crucial roles in the development of several diseases, such as cancer, diabetes, and cardiovascular diseases. They have recently been recognized to play a role also in the pathogenesis of autoimmune diseases. Although the majority of studies are focused on miRNA expression profiles investigation, a growing number of studies have been investigating the role of polymorphisms in miRNA genes in the autoimmune diseases development. Indeed, polymorphisms affecting the miRNA genes can modify the set of targets they regulate or the maturation efficiency. This review is aimed to give an overview about the available studies that have investigated the association of miRNA gene polymorphisms with the susceptibility to various autoimmune diseases and to their clinical phenotypes.

Unfolding the pathogenesis of scleroderma through genomics and epigenomics

With unknown etiology, scleroderma (SSc) is a multifaceted disease characterized by immune activation, vascular complications, and excessive fibrosis in internal organs. Genetic studies, including candidate gene association studies, genome-wide association studies, and whole-exome sequencing have supported the notion that while genetic susceptibility to SSc appears to be modest, SSc patients are genetically predisposed to this disease. The strongest genetic association for SSc lies within the MHC region, with loci in HLA-DRB1, HLA-DQB1, HLA-DPB1, and HLA-DOA1 being the most replicated. The non-HLA genes associated with SSc are involved in various functions, with the most robust associations including genes for B and T cell activation and innate immunity. Other pathways include genes involved in extracellular matrix deposition, cytokines, and autophagy. Among these genes, IRF5, STAT4, and CD247 were replicated most frequently while SNPs rs35677470 in DNASE1L3, rs5029939 in TNFAIP3, and rs7574685 in STAT4 have the strongest associations with SSc. In addition to genetic predisposition, it became clear that environmental factors and epigenetic influences also contribute to the development of SSc. Epigenetics, which refers to studies that focus on heritable phenotypes resulting from changes in chromatin structure without affecting the DNA sequence, is one of the most rapidly expanding fields in biomedical research. Indeed extensive epigenetic changes have been described in SSc. Alteration in enzymes and mediators involved in DNA methylation and histone modification, as well as dysregulated non-coding RNA levels all contribute to fibrosis, immune dysregulation, and impaired angiogenesis in this disease. Genes that are affected by epigenetic dysregulation include ones involved in autoimmunity, T cell function and regulation, TGFβ pathway, Wnt pathway, extracellular matrix, and transcription factors governing fibrosis and angiogenesis. In this review, we provide a comprehensive overview of the current findings of SSc genetic susceptibility, followed by an extensive description and a systematic review of epigenetic research that has been carried out to date in SSc. We also summarize the therapeutic potential of drugs that affect epigenetic mechanisms, and outline the future prospective of genomics and epigenomics research in SSc.

Polymorphisms in STAT4, PTPN2, PSORS1C1 and TRAF3IP2 Genes Are Associated with the Response to TNF Inhibitors in Patients with Rheumatoid Arthritis

Objective

Rheumatoid Arthritis (RA) is a progressive autoimmune disease characterized by chronic joint inflammation and structural damage. Remission or at least low disease activity (LDA) represent potentially desirable goals of RA treatment. Single nucleotide polymorphisms (SNPs) in several genes might be useful for prediction of response to therapy. We aimed at exploring 4 SNPs in candidate genes (STAT4, PTPN2, PSORS1C1 and TRAF3IP2) in order to investigate their potential role in the response to therapy with tumor necrosis factor inhibitors (TNF-i) in RA patients.

Methods

In 171 RA patients we investigated the following SNPs: rs7574865 (STAT4), rs2233945 (PSORS1C1), rs7234029 (PTPN2) and rs33980500 (TRAF3IP2). Remission, LDA, and EULAR response were registered at 6 months and 2 years after initiation of first line TNF-i [Adalimumab (ADA) and Etanercept (ETN)].

Results

STAT4 variant allele was associated with the absence of a good/moderate EULAR response at 2 years of treatment in the whole RA group and in ETN treated patients. The PTPN2 SNP was associated with no good/moderate EULAR response at 6 months in ADA treated patients. Patients carrying PSORS1C1 variant allele did not reach LDA at 6 months in both the whole RA group and ETN treated patients. TRAF3IP2 variant allele was associated with the lack of LDA and remission achievement at 6 months in all RA cohort while an association with no EULAR response at 2 years of treatment occurred only in ETN treated patients.

Conclusions

For the first time, we reported that SNPs in STAT4, PTPN2, PSORS1C1, and TRAF3IP2 are associated with response to TNF-i treatment in RA patients; however, these findings should be validated in a larger population.

Autophagy in Dendritic Cells and B Cells Is Critical for the Inflammatory State of TLR7-Mediated Autoimmunity

Individuals suffering from autoimmune disorders possess a hyperactive cellular phenotype where tolerance to self-antigens is lost. Autophagy has been implicated in both the induction and prevention of autoimmunity, and modulators of this cellular recycling process hold high potential for the treatment of autoimmune diseases. In this study, we determine the effects of a loss of autophagy in dendritic cells (DCs), as well as both B cells and DCs, in a TLR7-mediated model of autoimmunity, similar to systemic lupus erythematosus, where both cell types are critical for disease. Although a loss of DC autophagy slowed disease, the combined loss of autophagy in both cell types resulted in a lethal sepsis-like environment, which included tissue inflammation and hyperproduction of inflammasome-associated cytokines. Ablation of B cell signaling reversed this phenotype, indicating that activation of these cells is an essential step in disease induction. Thus, autophagy plays a dichotomous role in this model of disease.

A polymorphism upstream MIR1279 gene is associated with pericarditis development in Systemic Lupus Erythematosus and contributes to definition of a genetic risk profile for this complication

Recently, a study has shown that a polymorphism in the region of MIR1279 modulates the expression of the TRAF3IP2 gene. Since polymorphisms in the TRAF3IP2 gene have been described in association with systemic lupus erithematosus (SLE) susceptibility and with the development of pericarditis, our aim is to verify if the MIR1279 gene variability could also be involved. The rs1463335 SNP, located upstream MIR1279 gene, was analyzed by allelic discrimination assay in 315 Italian SLE patients and 201 healthy controls. Moreover, the MIR1279 gene was full sequenced in 50 patients. A case/control association study and a genotype/phenotype correlation analysis were performed. We also constructed a pericarditis genetic risk profile for patients with SLE. The full sequencing of the MIR1279 gene in patients with SLE did not reveal any novel or known variation. The variant allele of the rs1463335 SNP was significantly associated with susceptibility to pericarditis ( P = 0.017 and OR = 1.67). A risk profile model for pericarditis considering the risk alleles of MIR1279 and three other genes (STAT4, PTPN2 and TRAF3IP2) showed that patients with 4 or 5 risk alleles have a higher risk of developing pericarditis ( OR = 4.09 with P = 0.001 and OR = 6.04 with P = 0.04 respectively). In conclusion, we describe for the first time the contribution of a MIR1279 SNP in pericarditis development in patients with SLE and a genetic risk profile model that could be useful to identify patients more susceptible to developing pericarditis in SLE. This approach could help to improve the prediction and the management of this complication.

The genetic basis of systemic lupus erythematosus: What are the risk factors and what have we learned

The genome-wide association study is a free-hypothesis approach based on screening of thousands or even millions of genetic variants distributed throughout the whole human genome in relation to a phenotype. The relevant role of the genome-wide association studies in the last decade is undisputed because it has permitted to elucidate multiple risk genetic factors associated with the susceptibility to several human complex diseases. Regarding systemic lupus erythematosus (SLE) this approach has allowed to identify more than 60 risk loci for SLE susceptibility across populations to date, increasing our understanding on the pathogenesis of this disease. We present the latest findings in the genetic of SLE across populations using genome-wide approaches. These studies revealed that most of the genetic risk is shared across borders and ethnicities. Finally, we focus on describing the most important risk loci for SLE attempting to cover the genetic findings in relation to functional polymorphisms, such as missense single nucleotide polymorphisms (SNPs) or regulatory variants involved in the development of the disease. The functional studies try to identify the causality of some GWAS-associated variants, many of which fall in non-coding regions of the genome, suggesting a regulatory role. Many loci show an environmental interaction, another aspect revealed by the studies of epigenetic modifications and those associated with genetic variants. Finally, new-generation sequencing technologies can open other paths in the research on SLE genetics, the role of rare variants and the detailed identification of causal regulatory variation. The clinical relevance of the genetic factors will be shown when we are able to use them or in combination with other molecular measurements to re-classify a heterogeneous disease such as SLE.

Polymorphisms in STAT-4, IL-10, PSORS1C1, PTPN2 and MIR146A genes are associated differently with prognostic factors in Italian patients affected by rheumatoid arthritis

Rheumatoid arthritis (RA) is a systemic autoimmune disease resulting in chronic inflammation of the synovium and consequent cartilage and bone erosion. RA is associated strongly with the presence of rheumatoid factor (RF), and consists of clinical subsets of anti-citrullinated protein antibody (ACPA)-positive and -negative patients. This study was designed to evaluate whether relevant single nucleotide polymorphisms (SNPs) associated with RA and other autoimmune disorders are related to RF, ACPA and clinical phenotype in a cohort of biologic drugs naive Italian RA patients; 192 RA patients and 278 age-matched healthy controls were included. Clinical and laboratory data were registered. We analysed a total of 12 single nucleotide polymorphisms (SNPs) in signal transducer and activator of transcription-4 (STAT-4), interleukin (IL)-10, psoriasis susceptibility 1 candidate 1 (PSORS1C1), protein tyrosine phosphatase, non-receptor type 2 (PTPN2), endoplasmic reticulum aminopeptidase 1 (ERAP1), tumour necrosis factor receptor-associated 3 interacting protein 2 (TRAF3IP2) and microRNA 146a (MIR146A) genes by allelic discrimination assays. Case-control association studies and genotype/phenotype correlation analyses were performed. A higher risk to develop RA was observed for rs7574865 in the STAT-4 gene, while the rs1800872 in the IL-10 gene showed a protective effect. The presence of RF was associated significantly with rs1800872 variant in IL-10, while rs2910164 in MIR146A was protective. ACPA were associated significantly with rs7574865 in STAT-4. The SNP rs2233945 in the PSORS1C1 gene was protective regarding the presence of bone erosions, while rs2542151 in PTPN2 gene was associated with joint damage. Our results confirm that polymorphisms in STAT-4 and IL-10 genes confer susceptibility to RA. For the first time, we described that SNPs in PSORS1C1, PTPN2 and MIR146A genes were associated differently with a severe disease phenotype in terms of autoantibody status and radiographic damage in an Italian RA population.

Milk fat globule E-8 and interleukin 17 in systemic lupus erythematosus: partners in crime?

Objectives

Systemic lupus erythematosus (SLE) is a multi-factorial, autoimmune disease with a wide array of manifestations. The pro-inflammatory cytokine interleukin (IL)-17 has been implicated in the inflammatory response and tissue damage in SLE; however, its correlation with disease activity is still questionable. Meanwhile, efficient clearance of apoptotic cells is required for immune tolerance. An abnormally low or high level of milk fat globule (MFG-E8) can result in impaired apoptotic cell clearance and the subsequent autoimmune response. In this study, we endeavoured to compare the levels of MFG-E8 and IL-17 in SLE patients and healthy controls and to reveal the alleged association of these levels with SLE disease activity.

Material and methods

Serum samples from 57 SLE patients and 30 healthy control subjects were examined for quantitation of MFG-E8 and IL-17 levels using ELISA. Systemic lupus erythematosus disease activity was calculated using the SLE Disease Activity Index (SLEDAI). Clinical manifestations and laboratory findings of the patients were also recorded.

Results

We report that serum MFG-E8 levels were significantly elevated in the sera of SLE patients compared to healthy controls (p-value = 0.019). Likewise, IL-17 levels were higher in SLE patients (p-value < 0.001). A positive correlation was revealed between MFG-E8 level and proteinuria. Surprisingly, there was a poor correlation between disease activity and the levels of either IL-17 or MFG-E8.

Conclusions

Although serum MFG-E8 and IL-17 levels were higher in SLE patients than in normal controls, our results indicate that they cannot accurately reflect the disease activity. Meanwhile, further studies are needed to assess MFG-E8 and IL-17 as potential therapeutic targets in SLE patients.

Tumor necrosis factor receptor-associated factor 1 (TRAF1) polymorphisms and susceptibility to autoimmune thyroid disease

Former studies have revealed the link between the tumor necrosis factor (TNF) receptor-associated factor 1 (TRAF1) polymorphisms and autoimmunity. In the present study, we took an opportunity to investigate the association between TRAF1 and autoimmune thyroid disease (AITD) in order to find a new susceptibility gene. A total of 1029 AITD patients [677 Graves' disease (GD) patients and 352 Hashimoto thyroiditis (HT) patients] and 899 controls were enrolled. We used matrix-assisted laser desorption ionization-time of flight mass spectrometer (MALDI-TOF-MS) to detect the polymorphisms of rs4836834, rs10760130, rs10818488, rs2239658, rs2900180. We also explored the association between polymorphisms and clinical subphenotypes. Genotype frequencies of the five loci in all AITD patients were significantly different from those of controls. Genotype frequencies of rs10760130, rs2239658 and rs2900180 in GD patients were significantly different from controls. Allele analysis found that T allele of rs4836834, G allele of rs10760130, A allele of rs10818488, T allele of rs2239658 and T allele of rs2900180 were significantly higher in GD and AITD patients. No significant differences were found between HT patients and controls. Haplotype analysis found three haplotypes including ACAGC, TTGAT and TCGAC. ACAGC frequencies were significantly lower in GD and HT patients. However, TTGAT frequency was only significantly higher in GD patients. No significant results were found between polymorphisms and clinical subphenotypes. Our study reveals TRAF1 as a susceptibility gene of AITD in Chinese Han population.

Genetic Factors in Systemic Lupus Erythematosus: Contribution to Disease Phenotype

Genetic factors exert an important role in determining Systemic Lupus Erythematosus (SLE) susceptibility, interplaying with environmental factors. Several genetic studies in various SLE populations have identified numerous susceptibility loci. From a clinical point of view, SLE is characterized by a great heterogeneity in terms of clinical and laboratory manifestations. As widely demonstrated, specific laboratory features are associated with clinical disease subset, with different severity degree. Similarly, in the last years, an association between specific phenotypes and genetic variants has been identified, allowing the possibility to elucidate different mechanisms and pathways accountable for disease manifestations. However, except for Lupus Nephritis (LN), no studies have been designed to identify the genetic variants associated with the development of different phenotypes. In this review, we will report data currently known about this specific association.

The association of CD40 polymorphisms with CD40 serum levels and risk of systemic lupus erythematosus

Background

Current evidence shows that the CD40–CD40 ligand (CD40–CD40L) system plays a crucial role in the development, progression and outcome of systemic lupus erythematosus (SLE). The aim of this study was to investigate whether a CD40 gene single nucleotide polymorphism (SNP) is associated with SLE and CD40 expression in the Chinese population. We included controls (n = 220) and patients with either SLE (n =205) in the study.

Methods

The gene polymorphism was measured using Snapshot SNP genotyping assays and confirmed by sequencing. We analyzed three single nucleotide polymorphisms of CD40 gene rs1883832C/T, rs1569723A/C and rs4810485G/T in 205 patients with SLE and 220 age-and sex-matched controls. Soluble CD40 (sCD40) levels were measured by ELISA.

Results

There were significant differences in the genotype and allele frequencies of CD40 gene rs1883832C/T polymorphism between the group of patients with SLE and the control group (P < 0.05). sCD40 levels were increased in patients with SLE compared with controls (P < 0.01). Moreover, genotypes carrying the CD40 rs1883832 C/T variant allele were associated with increased CD40 levels compared to the homozygous wild-type genotype in patients with SLE. The rs1883832C/T polymorphism of CD40 and its sCD40 levels were associated with SLE in the Chinese population.

Conclusions

Our results suggest that CD40 gene may play a role in the development of SLE in the Chinese population.

Variants of MicroRNA Genes: Gender-Specific Associations with Multiple Sclerosis Risk and Severity

Multiple sclerosis (MS) is an autoimmune neuro-inflammatory disease arising from complex interactions of genetic, epigenetic, and environmental factors. Variations in genes of some microRNAs--key post-transcriptional regulators of many genes--can influence microRNAs expression/function and contribute to MS via expression changes of protein-coding target mRNA genes. We performed an association study of polymorphous variants of MIR146A rs2910164, MIR196A2 rs11614913, MIR499A rs3746444 MIR223 rs1044165 and their combinations with MS risk and severity. 561 unrelated patients with bout-onset MS and 441 healthy volunteers were enrolled in the study. We observed associations of MS risk with allele MIR223*T and combination (MIR223*T + MIR146A*G/G) carriage in the entire groups and in women at Bonferroni-corrected significance level (pcorr < 0.05). Besides, MIR146A*G/G association with MS was observed in women with nominal significance (pf = 0.025). No MS associations were found in men. A more severe MS course (MSSS value > 3.5) was associated with the carriage of MIR499A*C/T and, less reliably, of MIR499A*C (pcorr = 0.006 and pcorr = 0.024, respectively) and with the carriage of combinations (MIR499A*C/T + MIR196A2*C) and (MIR499A*C + MIR196A2*C) (pcorr = 0.00078 and pcorr = 0.0059, respectively). These associations also showed gender specificity, as they were not significant in men and substantially reinforced in women. The strongest association with MS severity was observed in women for combination (MIR499A*C/T + MIR196A2*C): pcorr = 4.43 × 10(-6) and OR = 3.23 (CI: 1.99-5.26).

Genetics and novel aspects of therapies in systemic lupus erythematosus

Autoimmune diseases, such as rheumatoid arthritis, multiple sclerosis, autoimmune hepatitis and inflammatory bowel disease, have complex pathogeneses and the factors which cause these disorders are not well understood. But all have in common that they arise from a dysfunction of the immune system, interpreting self components as foreign antigens. Systemic lupus erythematosus (SLE) is one of these complex inflammatory disorders that mainly affects women and can lead to inflammation and severe damage of virtually any tissue and organ. Recently, the application of advanced techniques of genome-wide scanning revealed more genetic information about SLE than previously possible. These case-control or family-based studies have provided evidence that SLE susceptibility is based (with a few exceptions) on an individual accumulation of various risk alleles triggered by environmental factors and also help to explain the discrepancies in SLE susceptibility between different populations or ethnicities. Moreover, during the past years new therapies (autologous stem cell transplantation, B cell depletion) and improved conventional treatment options (corticosteroids, traditional and new immune-suppressants like mycophenolate mofetile) changed the perspective in SLE therapeutic approaches. Thus, this article reviews genetic aspects of this autoimmune disease, summarizes clinical aspects of SLE and provides a general overview of conventional and new therapeutic approaches in SLE.

Systemic Lupus Erythematosus with and without Anti-dsDNA Antibodies: Analysis from a Large Monocentric Cohort

Objectives. The anti-dsDNA antibodies are a marker for Systemic Lupus Erythematosus (SLE) and 70–98% of patients test positive. We evaluated the demographic, clinical, laboratory, and therapeutical features of a monocentric SLE cohort according to the anti-dsDNA status. Methods. We identified three groups: anti-dsDNA + (persistent positivity); anti-dsDNA ± (initial positivity and subsequent negativity during disease course); anti-dsDNA − (persistent negativity). Disease activity was assessed by the European Consensus Lupus Activity Measurement (ECLAM). Results. We evaluated 393 patients (anti-dsDNA +: 62.3%; anti-dsDNA ±: 13.3%; anti-dsDNA −: 24.4%). The renal involvement was significantly more frequent in anti-dsDNA + (30.2%), compared with anti-dsDNA ± and anti-dsDNA − (21.1% and 18.7%, resp.; P = 0.001). Serositis resulted significantly more frequent in anti-dsDNA − (82.3%) compared to anti-dsDNA + and anti-dsDNA ± (20.8% and 13.4%, resp.; P < 0.0001). The reduction of C4 serum levels was identified significantly more frequently in anti-dsDNA + and anti-dsDNA ± (40.0% and 44.2%, resp.) compared with anti-dsDNA − (21.8%, P = 0.005). We did not identify significant differences in the mean ECLAM values before and after modification of anti-dsDNA status (P = 0.7). Conclusion. Anti-dsDNA status influences the clinical and immunological features of SLE patients. Nonetheless, it does not appear to affect disease activity.

Assessment of disease activity in Systemic Lupus Erythematosus: Lights and shadows

The assessment of disease activity in patients affected by Systemic Lupus Erythematosus (SLE) represents an important issue, as recommended by the European League Against Rheumatism (EULAR). Two main types of disease activity measure have been proposed: the global score systems, providing an overall measure of activity, and the individual organ/system assessment scales, assessing disease activity in different organs. All the activity indices included both clinical and laboratory items, related to the disease manifestations. However, there is no gold standard to measure disease activity in patients affected by SLE. In this review, we will analyze the lights and shadows of the disease activity indices, by means of a critical approach. In particular, we will focus on SLE Disease Activity Index (SLEDAI) and British Isles Lupus Assessment Group (BILAG), the most frequently used in randomized controlled trials and observational studies. The evaluation of data from the literature underlined some limitations of these indices, making their application in clinical practice difficult and suggesting the possible use of specific tools in the different subset of SLE patients, in order to capture all the disease features.