TRAF3IP2 gene and systemic lupus erythematosus: association with disease susceptibility and pericarditis development

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.

Molecular consideration relevant to the mechanism of the comorbidity between psoriasis and systemic lupus erythematosus (Review)

Systemic lupus erythematosus (SLE), a common autoimmune disease with a global incidence and newly diagnosed population estimated at 5.14 (range, 1.4-15.13) per 100,000 person-years and 0.40 million people annually, respectively, affects multiple tissues and organs; for example, skin, blood system, heart and kidneys. Accumulating data has also demonstrated that psoriasis (PS) can be a systemic inflammatory disease, which can affect organs other than the skin and occur alongside other autoimmune diseases, such as inflammatory bowel disease, multiple sclerosis, rheumatoid arthritis and SLE. The current explanations for the possible comorbidity of PS and SLE include: i) The two diseases share susceptible gene loci; ii) they share a common IL-23/T helper 17 (Th17) axis inflammatory pathway; and iii) the immunopathogenesis of the two conditions is a consequence of the interactions between IL-17 cytokines with effector Th17 cells, T regulatory cells, as well as B cells. In addition, the therapeutic efficacy of IL-17 or TNF-α inhibitors has been demonstrated in PS, and has also become evident in SLE. However, the mechanisms have not been investigated. To the best of our knowledge, there remains a lack of substantial studies on the correlation between PS and SLE. In the present review, the literature, with regards to the epidemiology, genetic predisposition, inflammatory mechanisms and treatment of the patients with both PS and SLE, has been reviewed. Further investigations into the molecular pathogenic mechanism may provide drug targets that could benefit the patients with concomitant PS and SLE.

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.

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.

Pregnancy outcome in systemic lupus erythematosus patients: a monocentric cohort analysis

OBJECTIVE

SLE is an autoimmune disease, mainly affecting women of childbearing age, with possible impact on pregnancy. In this study, we evaluated pregnancy outcomes in all pregnant patients affected by SLE, followed in the context of a rheumatology/gynaecology multi-disciplinary team.

METHODS

Since 2008, we evaluated 70 consecutive pregnancies occurring in 50 SLE patients referring to the Lupus Clinic of Sapienza University of Rome; as controls we evaluated 100 consecutive pregnancies in 100 women without autoimmune diseases.

RESULTS

By comparing SLE patients and controls, we did not find differences in terms of pregnancy outcomes, except for the occurrence of small for gestational age, which was significantly higher in the SLE group (22.8% vs 11%, P =0.003). Small for gestational age was associated with the positivity for anti-dsDNA, anti-Sm and anti-RNP (P =0.009, P =0.02, P =0.002, respectively). A disease flare was reported in 28 pregnancies (40%) and in 31 puerperium periods (44.3%). Flare during pregnancy was associated with anti-SSA (P =0.02), while puerperium relapse with previous MMF treatment (P =0.01) and haematological flare during pregnancy (P =0.03).

CONCLUSION

The present study confirms how pre-gestational counselling and a multi-disciplinary approach could result in positive pregnancy outcomes for SLE patients. The high percentage of disease relapse justifies even more the need for multi-disciplinary management.

Systemic Lupus Erythematosus before and after COVID-19 Lockdown: How the Perception of Disease Changes through the Lenses of Narrative Medicine

BACKGROUND

The COVID-19 pandemic contributes to the burden of living with different diseases, including Systemic Lupus Erythematosus (SLE). We described, from a narrative point of view, the experiences and perspectives of Italian SLE adults during the COVID-19 emergency, by distinguishing the illness experience before and after the lockdown.

METHODS

Fifteen patients were invited to participate. Illness narratives were collected between 22 and 29 March 2020 using a written modality to capture patients' perspectives before and after the COVID-19 lockdown. We performed a two-fold analysis of collected data by distinguishing three narrative types and a qualitative analysis of content to identify the relevant themes and sub-themes reported.

RESULTS

Eight narratives included in the final analysis (mean length 436.9 words) have been written by eight females (mean age 43.3 ± 9.9 years, mean disease duration 13.1 ± 7.4 years). Six patients provided a quest narrative, one a chaos and the remaining one a restitution narrative. By text content analysis, we identified specific themes, temporally distinct before and after the lockdown. Before COVID-19, all the patients referred to a good control of disease, however the unexpected arrival of the COVID-19 emergency broke a balance, and patients perceived the loss of health status control, with anxiety and stress.

CONCLUSIONS

We provided unique insight into the experiences of people with SLE at the time of COVID-19, underlining the perspective of patients in relation to the pandemic.

Genetic diversity of Staphylococcus aureus influences disease phenotype of systemic lupus erythematosus

OBJECTIVE

We investigated the genetic diversity, molecular epidemiology and evolutionary dynamics of Staphylococcus aureus (SA) isolated from SLE patients by means of phylogenetic analysis.

METHODS

Consecutive SLE patients (ACR 1997 criteria) were enrolled: clinical/laboratory data were collected and nasal swab for SA identification was performed. On the basis of the translation elongation factor (tuf) gene, a phylogenetic analysis was performed to investigate relationships and to assess significant clades. Selective pressure analysis was used to investigate the evolution of the SA tuf gene. The gene sequences from non-SLE individuals, downloaded from the GenBank database, were compared through phylogenetic analysis with the tuf gene from SLE patients.

RESULTS

We enrolled 118 patients [M/F 10/108; median (interquartile range (IQR)) age 45.5 (13.2) years; median (IQR) disease duration 120 (144) months]. Twenty-four patients (20.3%) were SA carriers (SA+), three of them MRSA. SA+ SLE showed significantly higher SLEDAI-2k values [SA+: median (IQR) 2 (3.75); SA-: 0 (2); P = 0.04]. The phylogenetic analysis, restricted to 21 non-MRSA SA+, revealed a statistically supported larger clade (A, n = 17) and a smaller one (B, n = 4). Patients located in clade A showed a significantly higher prevalence of joint involvement (88.2%) in comparison with clade B (50.0%, P < 0.0001) and SA- (62.7%, P < 0.0001). Haematological manifestations were significantly more frequent in clade A (64.7%) compared with B (50.0%, P = 0.004).

CONCLUSION

We suggest a possible role of SA nasal carriage status in SLE disease activity. Moreover, our findings support the hypothesis that bacterial genetic variants may be associated with specific disease features.

Psoriatic arthritis: A systematic review of non-HLA genetic studies and important signaling pathways

Psoriatic arthritis (PsA) is a common, chronic inflammatory disease with complex pathogenesis. In recent years, a number of susceptibility non-human leukocyte antigen (HLA) genes of PsA have been revealed, which also act as important factors in the pathogenesis of PsA as well as HLA genes. By searching the databases National Center for Biotechnology Information, Google and PubMed, 37 articles are included and 50 susceptibility non-HLA genes for PsA are presented, such as IL23A, TNIP1, TYK2, STAT4, IL12B, RUNX3 and TRAF3IP2. In these non-HLA genes, some are common genes shared with other diseases, whereas most of these susceptibility genes are related to the pathogenesis of PsA by activation or inhibition of the signaling pathways. Several signaling pathways possibly implicated in the pathogenesis of PsA are introduced in this paper, including the 2 mainly signaling pathways, IL23/Th17 signaling pathway and NF-κB signaling pathway, and the other involved signaling pathways, such as JAK-STAT signaling pathway and MAPK signaling pathway.

Caffeine intake influences disease activity and clinical phenotype in systemic lupus erythematosus patients

OBJECTIVE

Caffeine, one of the most widely consumed products in the world, seems to interact with multiple components of the immune system by acting as a non-specific phosphodiesterase inhibitor. In vitro dose-dependent treatment with caffeine down-regulates mRNA levels of key inflammation-related genes in peripheral blood mononuclear cells. So far, no robust data are available about the possible contribution of caffeine in systemic lupus erythematosus (SLE). The aim of this study was to evaluate the impact of caffeine consumption on SLE-related disease phenotype and activity, in terms of clinimetric assessment and cytokine serum levels.

METHODS

We performed a cross-sectional study, enrolling consecutive patients and reporting their clinical and laboratory data. Disease activity was assessed by SLE Disease Activity Index 2000 (SLEDAI-2K). Caffeine intake was evaluated by a 7-day food frequency questionnaire, including all the main sources of caffeine. As previously reported, patients were divided into four groups according to the daily caffeine intake: <29.1 mg/day (group 1), 29.2-153.7 mg/day (group 2), 153.8-376.5 mg/day (group 3) and >376.6 mg/day (group 4). At the end of questionnaire filling, blood samples were collected from each patient to assess cytokine levels. These were assessed by using a panel by Bio-Plex assays to measure the levels of IL-6, IL-10, IL-17, IL-27, IFNγ, IFNα and BLyS.

RESULTS

We enrolled 89 consecutive SLE patients. We observed a negative correlation between caffeine consumption and disease activity, measured with SLEDAI-2K. A significantly higher prevalence of lupus nephritis, neuropsychiatric involvement, haematological manifestations, hypocomplementaemia and anti-dsDNA positivity was observed in patients with a low intake of caffeine. Furthermore, patients with a low intake of caffeine were more frequently treated with glucocorticoids. Regarding cytokine analysis, a negative correlation between daily caffeine consumption and serum level of IFNγ was found (p = 0.03, r = -0.2); furthermore, patients with a high intake of caffeine showed lower serum levels of IFNα (p = 0.02), IL-17 (p = 0.01) and IL-6 (p = 0.003).

CONCLUSIONS

In this report we demonstrated the impact of caffeine on SLE disease activity status, as confirmed by the inverse correlation between its intake and both SLEDAI-2K values and cytokine levels. Moreover, patients with a low caffeine consumption seem to have a more severe disease phenotype.

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.

Integrative network analysis identifies differential regulation of neuroimmune system in Schizophrenia and Bipolar disorder

Background

Neuropsychiatric disorders such as Schizophrenia (SCZ) and Bipolar disorder (BPD) pose a broad range of problems with different symptoms mainly characterized by some combination of abnormal thoughts, emotions, behaviour, etc. However, in depth molecular and pathophysiological mechanisms among different neuropsychiatric disorders have not been clearly understood yet. We have used RNA-seq data to investigate unique and overlapping molecular signatures between SCZ and BPD using an integrative network biology approach.

Methods

RNA-seq count data were collected from NCBI-GEO database generated on post-mortem brain tissues of controls (n = 24) and patients of BPD (n = 24) and SCZ (n = 24). Differentially expressed genes (DEGs) were identified using the consensus of DESeq2 and edgeR tools and used for downstream analysis. Weighted gene correlation networks were constructed to find non-preserved (NP) modules for SCZ, BPD and control conditions. Topological analysis and functional enrichment analysis were performed on NP modules to identify unique and overlapping expression signatures during SCZ and BPD conditions.

Results

We have identified four NP modules from the DEGs of BPD and SCZ. Eleven overlapping genes have been identified between SCZ and BPD networks, and they were found to be highly enriched in inflammatory responses. Among these eleven genes, TNIP2, TNFRSF1A and AC005840.1 had higher sum of connectivity exclusively in BPD network. In addition, we observed that top five genes of NP module from SCZ network were downregulated which may be a key factor for SCZ disorder.

Conclusions

Differential activation of the immune system components and pathways may drive the common and unique pathogenesis of the BPD and SCZ.

Staphylococcus aureus Nasal Carriage and Autoimmune Diseases: From Pathogenic Mechanisms to Disease Susceptibility and Phenotype

The role of infective agents in autoimmune diseases (ADs) development has been historically investigated, but in the last years has been strongly reconsidered due to the interest in the link between the microbiome and ADs. Together with the gut, the skin microbiome is characterized by the presence of several microorganisms, potentially influencing innate and adaptive immune response. S. aureus is one of the most important components of the skin microbiome that can colonize anterior nares without clinical manifestations. Data from the literature demonstrates a significantly higher prevalence of nasal colonization in ADs patients in comparison with healthy subjects, suggesting a possible role in terms of disease development and phenotypes. Thus, in the present narrative review we focused on the mechanisms by which S. aureus could influence the immune response and on its relationship with ADs, in particular granulomatosis with polyangiitis, rheumatoid arthritis, and systemic lupus erythematosus.

Adaptive and Innate Immunity in Psoriasis and Other Inflammatory Disorders

Over the past three decades, a considerable body of evidence has highlighted T cells as pivotal culprits in the pathogenesis of psoriasis. This includes the association of psoriasis with certain MHC (HLA) alleles, oligoclonal expansion of T cells in some cases, therapeutic response to T cell-directed immunomodulation, the onset of psoriasis following bone marrow transplantation, or induction of psoriasis-like inflammation by T cells in experimental animals. There is accumulating clinical and experimental evidence suggesting that both autoimmune and autoinflammatory mechanisms lie at the core of the disease. Indeed, some studies suggested antigenic functions of structural proteins, and complexes of self-DNA with cathelicidin (LL37) or melanocytic ADAMTSL5 have been proposed more recently as actual auto-antigens in some cases of psoriasis. These findings are accompanied by various immunoregulatory mechanisms, which we increasingly understand and which connect innate and adaptive immunity. Specific adaptive autoimmune responses, together with our current view of psoriasis as a systemic inflammatory disorder, raise the question of whether psoriasis may have connections to autoimmune or autoinflammatory disorders elsewhere in the body. While such associations have been suspected for many years, compelling mechanistic evidence in support of this notion is still scant. This review sets into context the current knowledge about innate and adaptive immunological processes in psoriasis and other autoimmune or autoinflammatory diseases.

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.

Act1 is a negative regulator in T and B cells via direct inhibition of STAT3

Although Act1 (adaptor for IL-17 receptors) is necessary for IL-17-mediated inflammatory responses, Act1- (but not Il17ra-, Il17rc-, or Il17rb-) deficient mice develop spontaneous SLE- and Sjögren's-like diseases. Here, we show that Act1 functions as a negative regulator in T and B cells via direct inhibition of STAT3. Mass spectrometry analysis detected an Act1-STAT3 complex, deficiency of Act1 (but not Il17ra-, Il17rc-, or Il17rb) results in hyper IL-23- and IL-21-induced STAT3 activation in T and B cells, respectively. IL-23R deletion or blockade of IL-21 ameliorates SLE- and Sjögren's-like diseases in Act1-/- mice. Act1 deficiency results in hyperactivated follicular Th17 cells with elevated IL-21 expression, which promotes T-B cell interaction for B cell expansion and antibody production. Moreover, anti-IL-21 ameliorates the SLE- and Sjögren's-like diseases in Act1-deficient mice. Thus, IL-21 blocking antibody might be an effective therapy for treating SLE- and Sjögren's-like syndrome in patients containing Act1 mutation.

Intracellular B Lymphocyte Signalling and the Regulation of Humoral Immunity and Autoimmunity

B lymphocytes are critical for effective immunity; they produce antibodies and cytokines, present antigens to T lymphocytes and regulate immune responses. However, because of the inherent randomness in the process of generating their vast repertoire of antigen-specific receptors, B cells can also cause diseases through recognizing and reacting to self. Therefore, B lymphocyte selection and responses require tight regulation at multiple levels and at all stages of their development and activation to avoid diseases. Indeed, newly generated B lymphocytes undergo rigorous tolerance mechanisms in the bone marrow and, subsequently, in the periphery after their migration. Furthermore, activation of mature B cells is regulated through controlled expression of co-stimulatory receptors and intracellular signalling thresholds. All these regulatory events determine whether and how B lymphocytes respond to antigens, by undergoing apoptosis or proliferation. However, defects that alter regulated co-stimulatory receptor expression or intracellular signalling thresholds can lead to diseases. For example, autoimmune diseases can result from altered regulation of B cell responses leading to the emergence of high-affinity autoreactive B cells, autoantibody production and tissue damage. The exact cause(s) of defective B cell responses in autoimmune diseases remains unknown. However, there is evidence that defects or mutations in genes that encode individual intracellular signalling proteins lead to autoimmune diseases, thus confirming that defects in intracellular pathways mediate autoimmune diseases. This review provides a synopsis of current knowledge of signalling proteins and pathways that regulate B lymphocyte responses and how defects in these could promote autoimmune diseases. Most of the evidence comes from studies of mouse models of disease and from genetically engineered mice. Some, however, also come from studying B lymphocytes from patients and from genome-wide association studies. Defining proteins and signalling pathways that underpin atypical B cell response in diseases will help in understanding disease mechanisms and provide new therapeutic avenues for precision therapy.

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.

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.

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.

TRAF3IP2 mediates aldosterone/salt-induced cardiac hypertrophy and fibrosis

Aberrant activation of the renin-angiotensin-aldosterone system (RAAS) contributes to adverse cardiac remodeling and eventual failure. Here we investigated whether TRAF3 Interacting Protein 2 (TRAF3IP2), a redox-sensitive cytoplasmic adaptor molecule and an upstream regulator of nuclear factor-κB (NF-κB) and activator protein-1 (AP-1), mediates aldosterone-induced cardiac hypertrophy and fibrosis. Wild type (WT) and TRAF3IP2-null mice were infused with aldosterone (0.2 mg/kg/day) for 4 weeks along with 1%NaCl in drinking water. Aldosterone/salt, but not salt alone, upregulated TRAF3IP2 expression in WT mouse hearts. Further, aldosterone elevated blood pressure to a similar extent in both WT and TRAF3IP2-null groups. However, TRAF3IP2 gene deletion attenuated aldosterone/salt-induced (i) p65 and c-Jun activation, (ii) extracellular matrix (collagen Iα1 and collagen IIIα1), matrix metalloproteinase (MMP2), lysyl oxidase (LOX), inflammatory cytokine (IL-6 and IL-18), chemokine (CXCL1 and CXCL2), and adhesion molecule (ICAM1) mRNA expression in hearts, (iii) IL-6, IL-18, and MMP2 protein levels, (iv) systemic IL-6 and IL-18 levels, and (iv) cardiac hypertrophy and fibrosis. These results indicate that TRAF3IP2 is a critical signaling intermediate in aldosterone/salt-induced myocardial hypertrophy and fibrosis, and thus a potential therapeutic target in hypertensive heart disease.

Liver-specific NG37 overexpression leads to diet-dependent fatty liver disease accompanied by cardiac dysfunction

BACKGROUND

Environmental factors are well-known causes of diseases. However, aside from a handful of risk indicators, genes' encoding susceptibility to chronic illnesses and their associated environmental triggers are largely unknown. In this era of increasingly rich diets, such genetic predispositions would be immensely helpful from a public health perspective. The novel transgenic mouse model with liver-specific NG37 overexpression characterized in this article identifies the diet-dependent function of NG37 in the pathogenesis of fatty liver disease and cardiac arrhythmia.

RESULTS

The liver-specific NG37 overexpression transgenic mouse model described here was generated using the Alb-SV40 polyA expression plasmid backbone. NG37 cDNA under control of the albumin promoter for liver-specific expression was fused with a 5' terminal M2 FLAG sequence and a SV40 early region transcription terminator/polyadenylation site attached at the 3'-UTR. These NG37 transgenic mice developed normally and were physiologically normal on a standard diet. However, in comparison to non-transgenic (nTG) litter mates, these mice develop dramatic phenotypes within 12-18 days of starting a high-fat diet: (i) increased body weight (28.5 ± 12.3 g), (ii) increased liver weight (87.4 ± 35.7 mg), (iii) increased heart weight (140 ± 38.4 mg), and (iv) cardiac arrhythmia. The enlarged livers of high-fat diet NG37 transgenic mice was histologically similar to human fatty liver disease and contained Maltese cross birefringent active depositions in hepatocytes that are indicative of fatty liver disease. We also confirmed via X-ray diffraction the steatotic vesicles in the diseased hepatocytes of our high-fat diet NG37 mice was composed of cholesteryl derivatives also found in human fatty liver disease. In addition to cardiac enlargement, NG37 transgenic mice on high-fat diet also exhibited highly irregular bradycardia not present in either high-fat diet nTG littermates or normal-diet transgenic litter mates.

CONCLUSIONS

The dramatic high-fat diet-dependent symptoms (increased body weight, cardiac enlargement, fatty liver, and cardiac arrhythmias) characterized in our liver-specific NG37 overexpression mouse model identifies NG37 as a gene encoding latent lipid metabolism pathology induced only in the presence of an environmental factor relevant to human health: high-fat diet.

Current knowledge on psoriasis and autoimmune diseases

Psoriasis is a prevalent, chronic inflammatory disease of the skin, mediated by crosstalk between epidermal keratinocytes, dermal vascular cells, and immunocytes such as antigen presenting cells (APCs) and T cells. Exclusive cellular “responsibility” for the induction and maintenance of psoriatic plaques has not been clearly defined. Increased proliferation of keratinocytes and endothelial cells in conjunction with APC/T cell/monocyte/macrophage inflammation leads to the distinct epidermal and vascular hyperplasia that is characteristic of lesional psoriatic skin. Despite the identification of numerous susceptibility loci, no single genetic determinant has been identified as responsible for the induction of psoriasis. Thus, numerous other triggers of disease, such as environmental, microbial and complex cellular interactions must also be considered as participants in the development of this multifactorial disease. Recent advances in therapeutics, especially systemic so-called “biologics” have provided new hope for identifying the critical cellular targets that drive psoriasis pathogenesis. Recent recognition of the numerous co-morbidities and other autoimmune disorders associated with psoriasis, including inflammatory bowel disease, multiple sclerosis, rheumatoid arthritis, and systemic lupus erythematosus suggest common signaling elements and cellular mediators may direct disease pathogenesis. In this review, we discuss common cellular pathways and participants that mediate psoriasis and other autoimmune disorders that share these cellular signaling pathways.

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.

The effect of non-coding DNA variations on P53 and cMYC competitive inhibition at cis-overlapping motifs

Non-coding DNA variations play a critical role in increasing the risk for development of common complex diseases, and account for the majority of SNPs highly associated with cancer. However, it remains a challenge to identify etiologic variants and to predict their pathological effects on target gene expression for clinical purposes. Cis-overlapping motifs (COMs) are elements of enhancer regions that impact gene expression by enabling competitive binding and switching between transcription factors. Mutations within COMs are especially important when the involved transcription factors have opposing effects on gene regulation, like P53 tumor suppressor and cMYC proto-oncogene. In this study, genome-wide analysis of ChIP-seq data from human cancer and mouse embryonic cells identified a significant number of putative regulatory elements with signals for both P53 and cMYC. Each co-occupied element contains, on average, two COMs, and one common SNP every two COMs. Gene ontology of predicted target genes for COMs showed that the majority are involved in DNA damage, apoptosis, cell cycle regulation, and RNA processing. EMSA results showed that both cMYC and P53 bind to cis-overlapping motifs within a ChIP-seq co-occupied region in Chr12. In vitro functional analysis of selected co-occupied elements verified enhancer activity, and also showed that the occurrence of SNPs within three COMs significantly altered enhancer activity. We identified a list of COM-associated functional SNPs that are in close proximity to SNPs associated with common diseases in large population studies. These results suggest a potential molecular mechanism to identify etiologic regulatory mutations associated with common diseases.

The chronic damage in systemic lupus erythematosus is driven by flares, glucocorticoids and antiphospholipid antibodies: results from a monocentric cohort

OBJECTIVES

Literature data suggest a significantly higher mortality in patients affected by systemic lupus erythematosus (SLE) developing chronic damage. Therefore, damage prevention is a major goal in the management of SLE patients. In the present study, we assessed damage by means of the Systemic Lupus International Collaborative Clinics/American College of Rheumatology (SLICC/ACR) damage index (SDI), in a large cohort of SLE patients. Additionally, we aimed at evaluating its association with demographic and clinical features as well as with disease activity and laboratory findings.

PATIENTS AND METHODS

We enrolled consecutive patients affected by SLE diagnosed according to the American College of Rheumatology (ACR) 1997 revised criteria. Chronic damage was determined by SDI calculated at the last examination in all patients with at least six months of follow-up. Disease activity was assessed by the Systemic Lupus Erythematosus Disease Activity Index 2000 (SLEDAI-2K); flare was defined as an increase of SLEDAI-2K ≥ 4 compared with the previous visit.

RESULTS

We evaluated 349 SLE patients (M/F 25/324, mean age ± SD 42.7 ± 12.4 years, mean disease duration ± SD 164.9 ± 105.2 months). Among the enrolled patients, 125 (35.8%) showed a SDI ≥ 1 (mean SDI ± SD 1.7 ± 0.9, range 0-5). The musculo-skeletal was the most frequently involved organ/system in SDI score (41/349 patients, 11.7%), with deforming/erosive arthritis in 21/349 (6.0%). The presence of chronic damage was associated with age (P < 0.001), disease duration (P < 0.001), number of flares (P = 0.02) and with the use of glucocorticoids (P = 0.02). The logistic regression analysis revealed the association between neuropsychiatric damage and antiphospholipid syndrome (P = 0.01, OR = 3.9) and between the presence of cardiovascular damage and anti-β2GPI antibodies (P = 0.01, OR 6.2).

CONCLUSIONS

In the present study chronic damage was identified in about one third of SLE patients. The association between SDI and the number of flares claim for a thigh-control of the disease activity in order to prevent the chronic damage. The possible role of antiphospholipid antibodies (aPL) in the development of neuropsychiatric and cardiovascular damage may suggest a more careful assessment of such aPL positive patients.

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.

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.

A pharmacogenetics study in Mozambican patients treated with nevirapine: full resequencing of TRAF3IP2 gene shows a novel association with SJS/TEN susceptibility

Steven–Johnson Syndrome (SJS) and Toxic Epidermal Necrolysis (TEN) are severe adverse drug reactions, characterized by extensive epidermal detachment and erosions of mucous membrane. SJS/TEN is one of the most serious adverse reactions to Nevirapine (NVP) treatment, commonly used in developing countries as first-line treatment of human immunodeficiency virus infection. In the last years TRAF3IP2 gene variants had been described as associated with susceptibility to several diseases such as psoriasis and psoriatic arthritis. We hypothesized that this gene, involved in immune response and in NF-κB activation, could also be implicated in the SJS/TEN susceptibility. We performed a full resequencing of TRAF3IP2 gene in a population of patients treated with NVP. Twenty-seven patients with NVP-induced SJS/TEN and 78 controls, all from Mozambique, were enrolled. We identified eight exonic and three intronic already described variants. The case/control association analysis highlighted an association between the rs76228616 SNP in exon 2 and the SJS/TEN susceptibility. In particular, the variant allele (C) resulted significantly associated with a higher risk to develop SJS/TEN (p = 0.012 and OR = 3.65 (95% CI 1.33–10.01)). A multivariate analysis by logistic regression confirmed its significant contribution (p = 0.027, OR = 4.39 (95% CI 1.19–16.23)). In conclusion, our study suggests that a variant in TRAF3IP2 gene could be involved in susceptibility to SJS/TEN.

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.

Signaling mechanisms regulating B-lymphocyte activation and tolerance

It is becoming more and more accepted that, in addition to producing autoantibodies, B lymphocytes have other important functions that influence the development of autoimmunity. For example, autoreactive B cells are able to produce inflammatory cytokines and activate pathogenic T cells. B lymphocytes can react to extracellular signals with a range of responses from anergy to autoreactivity. The final outcome is determined by the relative contribution of signaling events mediated by activating and inhibitory pathways. Besides the B cell antigen receptor (BCR), several costimulatory receptors expressed on B cells can also induce B cell proliferation and survival, or regulate antibody production. These include CD19, CD40, the B cell activating factor receptor, and Toll-like receptors. Hyperactivity of these receptors clearly contributes to breaking B-cell tolerance in several autoimmune diseases. Inhibitors of these activating signals (including protein tyrosine phosphatases, deubiquitinating enzymes and several adaptor proteins) are crucial to control B-cell activation and maintain B-cell tolerance. In this review, we summarize the inhibitory signaling mechanisms that counteract B-cell activation triggered by the BCR and the coreceptors.

High-density genotyping of immune loci in Kawasaki disease and IVIG treatment response in European-American case-parent trio study

Kawasaki disease (KD) is a diffuse and acute small-vessel vasculitis observed in children, and has genetic and autoimmune components. We genotyped 112 case-parent trios of European decent (confirmed by ancestry informative markers) using the immunoChip array, and performed association analyses with susceptibility to KD and intravenous immunoglobulin (IVIG) non-response. KD susceptibility was assessed using the transmission disequilibrium test, whereas IVIG non-response was evaluated using multivariable logistic regression analysis. We replicated single-nucleotide polymorphisms (SNPs) in three gene regions (FCGR, CD40/CDH22 and HLA-DQB2/HLA-DOB) that have been previously associated with KD and provide support to other findings of several novel SNPs in genes with a potential pathway in KD pathogenesis. SNP rs838143 in the 3'-untranslated region of the FUT1 gene (2.7 × 10(-5)) and rs9847915 in the intergenic region of LOC730109 | BRD7P2 (6.81 × 10(-7)) were the top hits for KD susceptibility in additive and dominant models, respectively. The top hits for IVIG responsiveness were rs1200332 in the intergenic region of BAZ1A | C14orf19 (1.4 × 10(-4)) and rs4889606 in the intron of the STX1B gene (6.95 × 10(-5)) in additive and dominant models, respectively. Our study suggests that genes and biological pathways involved in autoimmune diseases have an important role in the pathogenesis of KD and IVIG response mechanism.

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

Background

Systemic lupus erythematosus (SLE) is an autoimmune disease with complex pathogenesis in which genes and environmental factors are involved. We aimed at analyzing previously identified loci associated with SLE or with other autoimmune and/or inflammatory disorders (STAT4, IL10, IL23R, IRAK1, PSORS1C1, HCP5, MIR146a, PTPN2, ERAP1, ATG16L1, IRGM) in a sample of Italian SLE patients in order to verify or confirm their possible involvement and relative contribution in the disease.

Materials and methods

Two hundred thirty-nine consecutive SLE patients and 278 matched healthy controls were enrolled. Study protocol included complete physical examination, and clinical and laboratory data collection. Nineteen polymorphisms were genotyped by allelic discrimination assays. A case-control association study and a genotype-phenotype correlation were performed.

Results

STAT4 was the most associated gene [P = 3×10⁻⁷, OR = 2.13 (95% CI: 1.59–2.85)]. IL10 confirmed its association with SLE [rs3024505: P = 0.02, OR = 1.52 (95% CI: 1.07–2.16)]. We describe a novel significant association between HCP5 locus and SLE susceptibility [rs3099844: P = 0.01, OR = 2.06 (95% CI: 1.18–3.6)]. The genotype/phenotype correlation analysis showed several associations including a higher risk to develop pericarditis with STAT4, and an association between HCP5 rs3099844 and anti-Ro/SSA antibodies.

Conclusions

STAT4 and IL10 confirm their association with SLE. We found that some SNPs in PSORS1C1, ATG16L1, IL23R, PTPN2 and MIR146a genes can determine particular disease phenotypes. HCP5 rs3099844 is associated with SLE and with anti-Ro/SSA. This polymorphism has been previously found associated with cardiac manifestations of SLE, a condition related with anti-Ro/SSA antibodies. Thus, our results may provide new insights into SLE pathogenesis.

Ultrasonographic evaluation of renal resistive index in patients with lupus nephritis: correlation with histologic findings

We analyzed the association between the renal arterial resistive index (RI) and the histologic features of lupus nephritis. All consecutive patients with systemic lupus erythematosus (SLE) who required a kidney biopsy were enrolled. The study protocol included ultrasonographic assessment to measure the RI and kidney biopsy (International Society of Nephrology/Renal Pathology Society classification). A RI > 0.7 was considered pathologic. Patients with non-renal SLE and healthy patients were studied as control groups. We enrolled 42 patients with renal SLE, 10 with non-renal SLE and 14 healthy patients: their mean (±standard deviation) RI values were 0.64 ± 0.08, 0.60 ± 0.04 and 0.59 ± 0.01, respectively (p = not significant). RIs > 0.7 were recorded only in patients with renal SLE (5/42, 11.9%). The percentage of patients with a pathologic RI was significantly higher in class IV nephritis in comparison with other classes (p < 0.009). In conclusion, we found a significant correlation between pathologic RI and class IV nephritis, suggesting a role for RI as a severity marker.

The differential regulation of human ACT1 isoforms by Hsp90 in IL-17 signaling

IL-17 is a proinflammatory cytokine implicated in the pathogenesis of autoimmune diseases including psoriasis. ACT1 is an essential adaptor molecule in the IL-17 signaling pathway. A missense single nucleotide polymorphism (rs33980500; SNP-D10N) that resulted in the substitution of an asparagine for an aspartic acid at position 10 of ACT1 (ACT1-D10N) is associated with psoriasis susceptibility. Due to alternative splicing in humans, SNP-D10N encodes two mutated ACT1 proteins, ACT1-D10N and ACT1-D19N. Although both ACT1 isoforms are Hsp90 client proteins, the nine additional amino acids in ACT1-D19N provide an additional Hsp90 binding site that is absent in ACT1-D10N. Therefore, whereas ACT1-D10N is a dead protein that is unable to transduce IL-17 signals for gene expression, ACT1-D19N is fully responsive to IL-17. Intriguingly, the two ACT1 isoforms are differentially expressed in ACT1(D10N/D10N) fibroblasts and T cells. Fibroblasts express both isoforms equally, enabling ACT1-D19N to compensate for the loss of ACT1-D10N function. ACT1(D10N/D10N) T cells, however, express predominantly ACT1-D10N. Lacking this compensatory mechanism, ACT1(D10N/D10N) T cells behave like ACT1-deficient T cells, exhibiting a dysregulated and hyperactive Th17 phenotype with overproduction of IL-22 and IL-17. The hyperactive Th17 response combined with fully responsive fibroblasts likely synergized to contribute to psoriasis susceptibility in SNP-D10N patients.

Cardiovascular involvement in autoimmune diseases

Autoimmune diseases (AD) represent a broad spectrum of chronic conditions that may afflict specific target organs or multiple systems with a significant burden on quality of life. These conditions have common mechanisms including genetic and epigenetics factors, gender disparity, environmental triggers, pathophysiological abnormalities, and certain subphenotypes. Atherosclerosis (AT) was once considered to be a degenerative disease that was an inevitable consequence of aging. However, research in the last three decades has shown that AT is not degenerative or inevitable. It is an autoimmune-inflammatory disease associated with infectious and inflammatory factors characterized by lipoprotein metabolism alteration that leads to immune system activation with the consequent proliferation of smooth muscle cells, narrowing arteries, and atheroma formation. Both humoral and cellular immune mechanisms have been proposed to participate in the onset and progression of AT. Several risk factors, known as classic risk factors, have been described. Interestingly, the excessive cardiovascular events observed in patients with ADs are not fully explained by these factors. Several novel risk factors contribute to the development of premature vascular damage. In this review, we discuss our current understanding of how traditional and nontraditional risk factors contribute to pathogenesis of CVD in AD.

Clinical perspectives on lupus genetics: advances and opportunities

In recent years, genome-wide association studies have led to an expansion in the identification of regions containing confirmed genetic risk variants within complex human diseases, such as systemic lupus erythematosus (SLE). Many of the strongest SLE genetic associations can be divided into groups based on their potential roles in different processes implicated in lupus pathogenesis, including ubiquitination, DNA degradation, innate immunity, cellular immunity, lymphocyte development, and antigen presentation. Recent advances have also shown several genetic associations with SLE subphenotypes and subcriteria. Many areas for further exploration remain to move lupus genetic studies toward clinically informative end points.

Aurora-A V57I (rs1047972) polymorphism and cancer susceptibility: a meta-analysis involving 27,269 subjects

BACKGROUND

The association between Aurora-A V57I (rs1047972, G>A) polymorphism and cancer susceptibility has been widely studied. However, the results are inconsistent.

METHODOLOGY/PRINCIPAL FINDINGS

To obtain a more precise evaluation of the relationship, we performed a meta-analysis of 14 case-control studies involving a total of 11,245 cancer cases and 16,024 controls. Our results demonstrated that there was a borderline evidence of an association between the Aurora-A V57I polymorphism and the decreased risk of overall cancer in two genetic models: AA vs. GA+GG and AA vs. GG. In a stratified analysis by cancer type, significant association between Aurora-A V57I polymorphism and the decreased risk of breast cancer was identified in one genetic model: AA vs. GG. In a stratified analysis by ethnicity, in three genetic models, significant decreased cancer risk was observed among Caucasians (AA vs. GA+GG; AA vs. GG and A vs. G) instead of Asians. Furthermore, a stratified analysis by ethnicity in breast cancer subgroup, five genetic models (AA+GA vs. GG; AA vs. GA+GG; AA vs. GG; AA vs. GA and A vs. G), significant decreased cancer risk was observed among Caucasians, but not among Asians. A slight publication bias was observed in our meta-analysis, thus nonparametric "trim-and-fill" method was utilized to detect the stability of our results. The adjusted odds ratios and confidence intervals showed that Aurora-A V57I polymorphism might be a protective factor for cancer risk, suggesting the reliability of our findings.

CONCLUSION

In summary, this meta-analysis suggests that Aurora-A V57I polymorphism may be a protective factor for cancer risk.

High prevalence of antinuclear antibodies in children with thyroid autoimmunity

BACKGROUND

Antinuclear antibodies (ANA) are a hallmark of many autoimmune diseases and can be detected many years before disease onset. Autoimmune thyroid diseases (AITD) are frequently associated with other organ- and non-organ-specific autoimmune disorders. Objectives. To assess the prevalence of ANA in pediatric patients with AITD and their clinical correlations.

METHODS

Ninety-three consecutive pediatric patients with AITD were enrolled (86 children with chronic lymphocytic thyroiditis and 7 with Graves' disease). ANA, anti-double DNA (anti-dsDNA) antibodies, anti-extractable nuclear antigen (anti-ENA), anti-cyclic citrullinated peptide antibodies (anti-CCP), and rheumatoid factor (RF) was obtained. Signs and symptoms potentially related to rheumatic diseases in children were investigated by a questionnaire.

RESULTS

ANA positivity was found in 66/93 children (71%), anti-ENA in 4/93 (4.3%), anti-dsDNA in 1/93 (1.1%), RF in 3/93 (3.2%), and anti-CCP in none. No significant differences were found between the ANA-positive and ANA-negative groups with respect to age, sex, L-thyroxine treatment, or prevalence of other autoimmune diseases. Overall, parental autoimmunity was found in 23%.

CONCLUSIONS

ANA positivity was demonstrated in 71% of children with AITD. ANA positivity was not related to overt immune-rheumatic diseases. However, because the positivity of ANA can occur even many years before the onset of systemic autoimmune diseases, prospective studies are warranted.

TRAF5 and TRAF3IP2 gene polymorphisms are associated with Behçet's disease and Vogt-Koyanagi-Harada syndrome: a case-control study

Background

TRAF5 and TRAF3IP2 have been reported to be associated with several autoimmune diseases. Behçet's disease (BD) and Vogt-Koyanagi-Harada (VKH) syndrome are two autoimmune uveitis entities whereby both genetic and environmental factors are thought to be involved.

Objective

The role of TRAF5 and TRAF3IP2 in BD and VKH has not yet been reported and was therefore the subject of this study.

Methods

The study included 789 BD patients, 940 VKH patients and 1601 healthy unrelated individuals. Genotyping was performed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) or TaqMan® SNP Genotyping Assay. Real-Time PCR was used to detect mRNA expression from PBMCs obtained from healthy controls with (n = 22) or without (n = 79) stimulation. Levels of TNF-α, IL-6 and IL-8 in culture supernatants were measured by ELISA (n = 22).

Results

Three SNPs (rs6540679, rs12569232, rs10863888) of TRAF5 and rs13210247 of TRAF3IP2 were significantly associated with Behçet's disease and VKH syndrome (corrected P values ranging from 9.45×10⁻¹² to 0.027). TRAF3IP2 rs33980500 and rs13190932 were not polymorphic in Han Chinese. Following stimulation by lipopolysaccharide (LPS), carriers of the GG genotype of rs6540679/TRAF5 had a higher TRAF5 mRNA expression (p = 0.004) and an increased TNF-α (p = 0.0052) and IL-6 (p = 0.0014) level compared with AA and AG genotype carriers.

Conclusion

This study provides evidence that TRAF5 and TRAF3IP2 genes are involved in the development of BD and VKH syndrome. Functional research suggested that TRAF5 gene polymorphisms may regulate TRAF5 expression and downstream inflammatory cytokines such as TNF-α and IL-6.