Prediction model for developing neuropsychiatric systemic lupus erythematosus in lupus patients.

OBJECTIVE: This study aimed to construct a predictive model for assessing the risk of development of neuropsychiatric systemic lupus erythematosus (NPSLE) among patients with SLE based on clinical, laboratory, and meteorological data. METHODS: A total of 2232 SLE patients were included and were randomly assigned into training and validation sets. Variables such as clinical and laboratory data and local meteorological data were screened by univariate and least absolute shrinkage and selection operator (LASSO) logistic regression modelling. After 10-fold cross-validation, the predictive model was built by multivariate logistic regression, and a nomogram was constructed to visualize the risk of NPSLE. The efficacy and accuracy of the model were assessed by receiver operating characteristic (ROC) curve and calibration curve analysis. Net clinical benefit was assessed by decision curve analysis. RESULTS: Variables that were included in the predictive model were anti-dsDNA, anti-SSA, lymphocyte count, hematocrit, erythrocyte sedimentation rate, pre-albumin, retinol binding protein, creatine kinase isoenzyme MB, Nterminal brain natriuretic peptide precursor, creatinine, indirect bilirubin, fibrinogen, hypersensitive C-reactive protein, CO, and mild contamination. The nomogram showed a broad prediction spectrum; the area under the curve (AUC) was 0.895 (0.858-0.931) for the training set and 0.849 (0.783-0.916) for the validation set. CONCLUSION: The model exhibits good predictive performance and will confer clinical benefit in NPSLE risk calculation. Key Points • Clinical, laboratory, and meteorological data were incorporated into a predictive model for neuropsychiatric systemic lupus erythematosus (NPSLE) in SLE patients. • Anti-dsDNA, anti-SSA, LYM, HCT, ESR, hsCRP, IBIL, PA, RBP, CO, Fib, NT-proBNP, Crea, CO, and mild contamination are predictors of the development of NPSLE and may have potential for research. • The nomogram has good predictive performance and clinical value and can be used to guide clinical diagnosis and treatment.

Bioinformatics analyses of gene expression profile to identify pathogenic mechanisms for COVID-19 infection and cutaneous lupus erythematosus.

Objective: The global mortality rates have surged due to the ongoing coronavirus disease 2019 (COVID-19), leading to a worldwide catastrophe. Increasing incidents of patients suffering from cutaneous lupus erythematosus (CLE) exacerbations after either contracting COVID-19 or getting immunized against it, have been observed in recent research. However, the precise intricacies that prompt this unexpected complication are yet to be fully elucidated. This investigation seeks to probe into the molecular events inciting this adverse outcome. Method: Gene expression patterns from the Gene Expression Omnibus (GEO) database, specifically GSE171110 and GSE109248, were extracted. We then discovered common differentially expressed genes (DEGs) in both COVID-19 and CLE. This led to the creation of functional annotations, formation of a protein-protein interaction (PPI) network, and identification of key genes. Furthermore, regulatory networks relating to these shared DEGs and significant genes were constructed. Result: We identified 214 overlapping DEGs in both COVID-19 and CLE datasets. The following functional enrichment analysis of these DEGs highlighted a significant enrichment in pathways related to virus response and infectious disease in both conditions. Next, a PPI network was constructed using bioinformatics tools, resulting in the identification of 5 hub genes. Finally, essential regulatory networks including transcription factor-gene and miRNA-gene interactions were determined. Conclusion: Our findings demonstrate shared pathogenesis between COVID-19 and CLE, offering potential insights for future mechanistic investigations. And the identification of common pathways and key genes in these conditions may provide novel avenues for research.

Aberrant Immune Features after Recovery from COVID-19 in Patients with Systemic Lupus Erythematosus and Other Autoimmune Diseases.

Considering the large number of individuals who have already been infected and may have reinfection, the post-infection effects of COVID-19 are of great importance for clinical practice and predicting disease trends. However, our understanding of the potential long-term effects, particularly on immunity, after recovering from COVID-19 remains limited. The aim of this study was to investigate the abnormal immunological factors that contribute to the prolonged immunological effects of COVID-19. Two groups of patients were enrolled in the study, including 11 individuals with various autoimmune diseases (AIDs) and 16 patients diagnosed with systemic lupus erythematosus (SLE). Detailed clinical symptoms were closely monitored, and peripheral mononuclear cells were analyzed using flow cytometry. The clinical status was evaluated using the SLE Disease Activity Index (SLEDAI) and the Clinical Global Impressions (CGI) index. The proportions of follicular T helper cells (Tfh) exhibited significant increases in both cohorts (AID: p = 0.03; SLE: p = 0.0008). Conversely, the percentages of Foxp3+ and CD4+ regulatory T cells (Treg) were reduced in patients following COVID-19 infection (AID: p = 0.009, 0.05, resp.; SLE: p = 0.02, 0.0009, resp.). The percentages of Th2 and Th17 cells were significantly increased in SLE patients (p < 0.05). Exacerbated conditions were observed in SLE patients two months after infection (SLEDAI, p < 0.05). Our findings show that COVID-19 infection increases Tfh cells and decreases Treg cells in patients of AIDs, worsening pathogenetic immune status in post-recovery populations.

SHP2: its association and roles in systemic lupus erythematosus.

OBJECTIVE: Systemic lupus erythematosus (SLE) is an autoimmune inflammatory disease. Src homology 2 domain containing protein tyrosine phosphatase (SHP2) is a member of the protein tyrosine phosphatases (PTPs) family. To date, relationship between SHP2 and SLE pathogenesis is not elucidated. METHOD: We measured plasma levels of SHP2 in 328 SLE patients, 78 RA patients, 80 SS patients and 79 healthy controls by ELISA, and discussed association of SHP2 in SLE patients, potential of plasma SHP2 as a SLE biomarker. Moreover, histological and serological changes were evaluated by flow cytometry, HE/Masson examination, immunofluorescence test in pristane-induced lupus mice after SHP2 inhibitor injection to reveal role of SHP2 in lupus development. RESULTS: Results indicated that SHP2 plasma levels were upregulated in SLE patients and correlated with some clinical, laboratory characteristics such as proteinuria, pyuria, and may be a potential biomarker for SLE. After SHP2 inhibitor treatment, hepatosplenomegaly and histological severity of the kidney in lupus mice were improved. SHP2 inhibitor reversed DCs, Th1, and Th17 cells differentiation and downregulated inflammatory cytokines (IL-4, IL-6, IL-10, IL-17A, IFN-γ and TNF-α) and autoantibodies (ANA, anti-dsDNA) production in pristane-lupus mice. CONCLUSION: In summary, SHP2 correlated with SLE pathogenesis and promoted the development of lupus.

IL-38, a potential therapeutic agent for lupus, inhibits lupus progression.

BACKGROUND: Previous studies reported that IL-38 was abnormally expressed in patients with systemic lupus erythematosus (SLE). However, the involvement of IL-38 in the pathophysiology of SLE remains unknown. METHODS: The therapeutic potential of IL-38 was tested in pristane-treated wild-type (WT) and IL-38-/- mice. Thus, SLE was induced via pristane in WT and IL-38-/- mice. Afterwards, the liver, spleen, and kidney of each mouse were obtained. The flow cytometric analysis of the immune cells, serologic expression of inflammatory cytokines and autoantibodies, renal histopathology, and inflammatory signaling were evaluated. RESULTS: WT mice with pristane-induced lupus exhibited hepatomegaly, splenomegaly, severe kidney damages, increased lymphoproliferation, enhanced lymphoproliferation, and upregulated inflammatory cytokines, such as IL-6, IL-13, IL-17A, MIP-3α, IL-12p70, and IFNγ, and elevated levels of autoantibodies, such as ANA IgG, anti-dsDNA IgG, and total IgG. IL-38-/- mice whose lupus progressed, had elevated cells of CD14+, CD19+, CD3+, and Th1, upregulated inflammatory cytokines and autoantibodies, and severe pathological changes in kidney. Administration of recombinant murine IL-38 to pristane-treated IL-38-/- mice improved their renal histopathology, which depended on ERK1/2, JNK1/2, p38, NF-κB p65, and STAT5 signaling pathways. CONCLUSION: IL-38 regulates SLE pathogenesis. Furthermore, targeting IL-38 is critical in the treatment of SLE.

Dehydroevodiamine suppresses inflammatory responses in adjuvant-induced arthritis rats and human fibroblast-like synoviocytes.

Dehydroevodiamine (DHE) is an effective natural active substance extracted from Euodiae Fructus, which is a widely used herbal drug in traditional Chinese medicine. The focus of this study was to test the possibility of using DHE in the treatment of rheumatoid arthritis (RA) diseases. A rat model of adjuvant-induced arthritis (AIA) was generated using Complete Freund's Adjuvant (CFA). Body weight changes, arthritis scores, ankle pathology, tumor necrosis factor-alpha (TNF-α), interleukin-1ß(IL-1ß), interleukin-6 (IL-6), and interleukin-17 (IL-17) secretion, as well as matrix metalloproteinase (MMP) expression in joint tissue, were measured as indicators of viability of DHE medicated AIA rats. Human fibroblast-like synoviocytes (MH7A cells) were connected to check these impacts. The results confirmed that DHE administration had an excellent therapeutic impact on the AIA rat model, substantially relieving joint swelling, inhibiting synovial pannus hyperplasia, and decreasing joint scores. In addition, the serum enzyme-linked immunosorbent assay (ELISA) showed that DHE treatment reduced the expression of pro-inflammatory factors in AIA rats. The immunohistochemical results showed that DHE treatment could reduce the synthesis of MMPs such as matrix metalloproteinase-1(MMP-1) and matrix metalloproteinase-3 (MMP-3) in the ankle tissue of AIA rats. In vitro, DHE inhibited cell proliferation, mRNA transcription, protein synthesis of proinflammatory factors such as IL-1ßand IL-6, and matrix metalloproteinases such as MMP-1 and MMP-3. Furthermore, DHE inhibited the phosphorylation levels of p38, JNK, and ERK proteins in TNF-α-treated MH7A cells.This work assessed the effect of DHE in AIA rats and revealed its mechanism in vitro.

Bioinformatics analyses of gene expression profile identify key genes and functional pathways involved in cutaneous lupus erythematosus.

BACKGROUND: Lupus erythematosus is an autoimmune disease that causes damage to multiple organs ranging from skin lesions to systemic manifestations. Cutaneous lupus erythematosus (CLE) is a common type of lupus erythematosus (LE), but its molecular mechanisms are currently unknown. The study aimed to explore changes in the gene expression profiles and identify key genes involved in CLE, hoping to uncover its molecular mechanism and identify new targets for CLE. METHOD: We analyzed the microarray dataset (GSE109248) derived from the Gene Expression Omnibus (GEO) database, which was a transcriptome profiling of CLE cutaneous lesions. The differentially expressed genes (DEGs) were identified, and the functional annotation of DEGs was performed with Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses. Protein-protein interaction (PPI) network was also constructed to identify hub genes involved in CLE. RESULT: A total of 755 up-regulated DEGs and 405 down-regulated DEGs were identified. GO enrichment analysis showed that defense response to virus, immune response, and type I interferon signaling pathway were the most significant enrichment items in DEGs. The KEGG pathway analysis identified 51 significant enrichment pathways, which mainly included systemic lupus erythematosus, osteoclast differentiation, cytokine-cytokine receptor interaction, and primary immunodeficiency. Based on the PPI network, the study identified the top 10 hub genes involved in CLE, which were CXCL10, CCR7, FPR3, PPARGC1A, MMP9, IRF7, IL2RG, SOCS1, ISG15, and GSTM3. By comparison between subtypes, the results showed that ACLE had the least DEGs, while CCLE showed the most gene and functional changes. CONCLUSION: The identified hub genes and functional pathways found in this study may expand our understanding on the underlying pathogenesis of CLE and provide new insights into potential biomarkers or targets for the diagnosis and treatment of CLE. Key Points • The bioinformatics analysis based on CLE patients and healthy controls was performed and 1160 DEGs were identified • The 1160 DEGs were mainly enriched in biological processes related to immune responses, including innate immune response, type I interferon signaling pathway, interferon-γ-mediated signaling pathway, positive regulation of T cell proliferation, regulation of immune response, antigen processing, and presentation via MHC class Ib and so on • KEGG pathway enrichment analysis indicated that DEGs were mainly enriched in several immune-related diseases and virus infection, including systemic lupus erythematosus, primary immunodeficiency, herpes simplex infection, measles, influenza A, and so on • The hub genes such as CXCL10, IRF7, MMP9, CCR7, and SOCS1 may become new markers or targets for the diagnosis and treatment of CLE.

Supranutritional selenium suppresses ROS-induced generation of RANKL-expressing osteoclastogenic CD4+ T cells and ameliorates rheumatoid arthritis.

OBJECTIVE: The benefit of Se supplementation in rheumatoid arthritis (RA) has been tested in clinical trials, but results remain inconclusive. The objective of this study was to specifically investigate the potential benefit of supranutritional Se by examining human samples from an area with supranutritional Se intake and testing a mouse model of RA. METHODS: Peripheral blood mononuclear cells (PBMCs) from RA patients (N = 57) and healthy controls (HC, N = 71) from an area of supranutritional Se intake (Enshi, Hubei, China) were analysed by flow cytometry. Serum cytokine and Se levels were measured by cytometric beads array (CBA) and inductively coupled plasma mass spectrometry (ICP-MS), respectively. With sufficient or supranutritional selenium intake, mice were induced with collagen-induced arthritis (CIA) and examined for disease activity and immunopathology. The influence of Se supplementation in the generation of RANKL-expressing osteoclastogenic CD4+ T cells was investigated by in vitro assays. RESULTS: In Enshi city, HC showed the above-normal concentrations of serum Se concentrations while RA patients were enriched in the normal range (70-150 ng mL-1) or below. RA patients with higher Se levels demonstrated milder disease and lower levels of C-reactive protein, IL-6, RANKL and Th17 cells. In the mouse CIA model, supranutritional Se supplementation delayed disease onset, ameliorated joint pathology and reduced CD4+CD44+RANKL+ T cells. Se supplementation could suppress RANKL expression in cultured mouse Th17 cells. CONCLUSION: Supranutritional Se suppresses RANKL-expressing osteoclastogenic CD4+ T cells and could be beneficial to RA, which warrants formal testing in randomised clinical trials.

Association of CD40 Gene Polymorphisms With Systemic Lupus Erythematosus and Rheumatoid Arthritis in a Chinese Han Population.

Systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA) are complex autoimmune diseases. CD40 participates in inflammatory response, and promotes fibroblast proliferation, leading to occurrence and progression of SLE, RA. This study explores CD40 gene polymorphisms in SLE and RA patients from a Chinese Han population. Two hundred SLE patients, 340 RA patients, and 900 healthy controls were enrolled. Genomic DNA was extracted from peripheral blood, and six polymorphisms of CD40 gene (rs3765456, rs1569723, rs73115010, rs13040307, rs1883832, and rs4810485) were detected by KASP method. Frequencies of rs1569723 genotypes AA, AC, AA+AC were significantly higher in RA patients as compared to those in healthy controls (P = 0.049, P = 0.024, P = 0.022). Frequencies of genotypes CT, CC+CT of rs1883832, and GT, GG+GT of rs4810485 were significantly higher in RA patients as compared to those in healthy controls (P = 0.012, P = 0.018, P = 0.009, P = 0.015). RA patients carrying rs13040307 C allele and rs73115010 T allele showed increased number of swollen joints. Moreover, frequency of allele T of rs13040307 was lower in SLE patients with positive anti-dsDNA and hematuria as compared to that in patients without these parameters (P = 0.038, P = 0.045). There were increased frequencies of genotype TT, allele T for rs13040307 and lower frequencies of genotype TT, allele T for rs73115010 in lupus patients with myositis (all P<0.05). Interestingly, frequencies of rs1569723 A allele, rs4810485 T allele were higher in SLE patients with myositis, and frequencies of rs3765456 A allele, rs1883832 T allele were lower in SLE patients with myositis (All P<0.05). In conclusion, CD40 gene polymorphisms may associate with susceptibility to SLE and RA.

COVID-19 infection in patients with connective tissue disease: A multicity study in Hubei province, China.

Novel Coronavirus disease 2019 (COVID-19) has spread rapidly around the world. Individuals with immune dysregulation and/or on immunosuppressive therapy, such as rheumatic patients, are considered at greater risk for infections. However, the risks of patients with each subcategory of rheumatic diseases have not been reported. Here, we identified 100 rheumatic patients from 18,786 COVID-19 patients hospitalized in 23 centers affiliated to Hubei COVID-19 Rheumatology Alliance between January 1 and April 1, 2020. Demographic information, medical history, length of hospital stay, classification of disease severity, symptoms and signs, laboratory tests, disease outcome, computed tomography, and treatments information were collected. Compared to gout and ankylosing spondylitis (AS) patients, patients with connective tissue disease (CTD) tend to be more severe after COVID-19 infection (p = 0.081). CTD patients also had lower lymphocyte counts, hemoglobin, and platelet counts (p values were 0.033, < 0.001, and 0.071, respectively). Hydroxychloroquine therapy and low- to medium-dose glucocorticoids before COVID-19 diagnosis reduced the progression of COVID-19 to severe/critical conditions (p = 0.001 for hydroxychloroquine; p = 0.006 for glucocorticoids). Our data suggests that COVID-19 in CTD patients may be more severe compared to patients with AS or gout.

Association of IL-35 expression and gene polymorphisms in rheumatoid arthritis.

Interleukin (IL)-35 is the newest member of the IL-12 family. It is expressed in many immune cells and has been recognized as a novel inflammatory cytokine that may have bifunctional properties. Recent findings have indicated that the expression of IL-35 is abnormal in rheumatoid arthritis (RA) patients. However, the results were inconsistent. In this study, 400 RA patients were recruited to evaluate serum levels of IL-35 in a Chinese Han population by enzyme-linked immunosorbent assay. The association of IL-35 gene polymorphisms and RA genetic susceptibility was investigated in 400 RA patients and 612 healthy controls. The results showed that serum levels of IL-35 were elevated in 100 RA patients compared to 51 healthy controls, relating to disease activity and synovial fluid IL-35 expression in the training cohort. Another independent 300 RA patients and 369 other rheumatic disease patients (98 lupus, 95 osteoarthritis, 95 gout, 42 Sjogren's syndrome and 39 ankylosing spondylitis patients) confirmed that serum levels of IL-35 were elevated in RA patients, and serum IL-35 has good diagnostic ability for differentiating RA from the other rheumatic diseases. The genotyping of 10 IL-35 polymorphisms, including rs2227314, rs2243115, rs2243123, rs2243131, rs568408, rs583911, rs428253, rs4740, rs9807813 and rs4905, revealed that rs2227314, rs2243131, rs9807813, and rs583911 were correlated with RA risk. Different genotypes (rs2227314, rs583911, and rs9807813) exhibited different expression of IL-35. These findings demonstrate that serum levels of IL-35 are increased in RA patients and that IL-35 polymorphisms are correlated with RA risk.

Human umbilical cord mesenchymal stem cells ameliorate skin fibrosis development in a mouse model of bleomycin-induced systemic sclerosis.

Mesenchymal stem cell (MSC) infusion has become a novel therapeutic strategy for complex autoimmune diseases; however, few detailed studies have been performed to investigate the benefit and mechanism of MSC treatment on systemic sclerosis (SSc). The present study aimed to evaluate the therapeutic effect of human umbilical cord derived-MSCs (UC-MSCs) on bleomycin-induced SSc in mice and explore the potential underlying mechanism. The murine SSc model was established by daily subcutaneous injection of bleomycin for 4 weeks, followed with two UC-MSC infusions every 7 days. Skin fibrosis was assessed by H&E and Masson staining. Flow cytometry was used to determine IL-17A, IFN-γ, tumor necrosis factor-ß, IL-10 and IL-12 levels in serum samples and T cell subsets in murine spleen. Additionally, gene expression levels of cytokines and fibrosis markers in skin samples were measured by reverse transcription-quantitative PCR. Immunofluorescence staining was performed to track UC-MSC localization and lymphocyte cell infiltration in vivo. UC-MSC treatment exerted an anti-fibrotic role in bleomycin-induced SSc mice, as confirmed by histological improvement, decreased collagen synthesis, and reduced collagen-1α1, collagen-1α2, fibronectin-1 and α-smooth muscle actin gene expression levels. The results indicated that UC-MSC treatment only had a limited systematic effect on cytokine production in serum samples and T cell activation in the spleen. By contrast, T helper (Th)17 cell infiltration and activation in skin were efficiently inhibited after UC-MSC infusion, as evidenced by the decreased IL-17A and retinoic acid-related orphan receptor γt gene expression as well as IL-17A production. UC-MSC administration significantly ameliorated bleomycin-induced skin fibrosis and collagen formation primarily by eliminating local inflammation and Th17 cell activation in the skin; however, the systemic inhibitory effect of UM-MSCs on cytokines was less profound.

IL-38: A novel cytokine in systemic lupus erythematosus pathogenesis.

IL-38 is a newly identified cytokine that belongs to the IL-1 family. In our previous study, we found elevated plasma levels of IL-38 in patients with systemic lupus erythematosus (SLE). However, the clear relationship of IL-38 expression in plasma, peripheral blood mononuclear cells (PBMCs) and clinical and laboratory features needs elucidation. Additionally, we evaluated the possible role of IL-38 in regulating production of inflammatory cytokines in PBMCs in vitro. A pristane-induced murine lupus model was used to further demonstrate the effects of IL-38 on cytokines in vivo and discuss the significance of IL-38 in lupus development. The results showed that mRNA expression of IL-38 in PBMCs of patients with SLE was elevated compared with volunteers, and expression of IL-38 in both plasma and PBMCs was strongly related to clinical features, such as haematuria and proteinuria, and correlated with a SLEDAI score. Plasma levels of TNF-α, IL-1ß, IL-6 and IL-23 were elevated in patients with SLE and were related to plasma levels of IL-38. In vitro, PBMCs of patients with SLE stimulated with IL-38 showed a decreased expression of the four inflammatory cytokines compared with PBMCs of patients without treatment. Interestingly, IL-38 administration in lupus mice significantly reduced the development of lupus, such as reduced proteinuria, improved histological examinations of the kidneys and down-regulated inflammatory cytokines. In conclusion, IL-38 may suppress synthesis of pro-inflammatory cytokines and therefore regulate lupus pathogenesis.

COVID-19 in patients with rheumatic disease in Hubei province, China: a multicentre retrospective observational study.

BACKGROUND: In the ongoing COVID-19 pandemic, the susceptibility of patients with rheumatic diseases to COVID-19 remains unclear. We aimed to investigate susceptibility to COVID-19 in patients with autoimmune rheumatic diseases during the ongoing COVID-19 pandemic. METHODS: We did a multicentre retrospective study of patients with autoimmune rheumatic diseases in Hubei province, the epicentre of the COVID-19 outbreak in China. Patients with rheumatic diseases were contacted through an automated telephone-based survey to investigate their susceptibility to COVID-19. Data about COVID-19 exposure or diagnosis were collected. Families with a documented history of COVID-19 exposure, as defined by having at least one family member diagnosed with COVID-19, were followed up by medical professionals to obtain detailed information, including sex, age, smoking history, past medical history, use of medications, and information related to COVID-19. FINDINGS: Between March 20 and March 30, 2020, 6228 patients with autoimmune rheumatic diseases were included in the study. The overall rate of COVID-19 in patients with an autoimmune rheumatic disease in our study population was 0·43% (27 of 6228 patients). We identified 42 families in which COVID-19 was diagnosed between Dec 20, 2019, and March 20, 2020, in either patients with a rheumatic disease or in a family member residing at the same physical address during the outbreak. Within these 42 families, COVID-19 was diagnosed in 27 (63%) of 43 patients with a rheumatic disease and in 28 (34%) of 83 of their family members with no rheumatic disease (adjusted odds ratio [OR] 2·68 [95% CI 1·14-6·27]; p=0·023). Patients with rheumatic disease who were taking hydroxychloroquine had a lower risk of COVID-19 infection than patients taking other disease-modifying anti-rheumatic drugs (OR 0·09 [95% CI 0·01-0·94]; p=0·044). Additionally, the risk of COVID-19 was increased with age (adjusted OR 1·04 [95%CI 1·01-1·06]; p=0·0081). INTERPRETATION: Patients with autoimmune rheumatic disease might be more susceptible to COVID-19 infection than the general population. FUNDING: National Natural Science Foundation of China and the Tongji Hospital Clinical Research Flagship Program.

Association of MASP2 levels and MASP2 gene polymorphisms with systemic lupus erythematosus.

Systemic lupus erythematosus (SLE) is a chronic inflammatory autoimmune disorder. MASP2 is a mediator that plays an important role in complement system. As dysregulation of the complement system has been demonstrated to correlate with SLE pathogenesis, the role of MASP2 in lupus has not been widely discussed. In the present study, serum levels of MASP2 were evaluated in 61 lupus patients and 98 healthy controls by training cohort, and then a validation cohort including 100 lupus, 100 rheumatoid arthritis, 100 osteoarthritis, 100 gout, 44 Sjogren's syndrome, 41 ankylosing spondylitis patients confirmed the findings. Receiver operating characteristic (ROC) curve analysis determined the discriminatory capacity for serum MASP2. PCR methods tested the association of MASP2 gene polymorphisms (rs7548659, rs17409276, rs2273346, rs1782455 and rs6695096) and SLE risk. Impact of polymorphism on MASP2 serum levels was evaluated as well. Results showed that serum levels of MASP2 were significantly higher in lupus patients and correlated with some clinical, laboratory characteristics in the training cohort, and were much higher as compared to that in different rheumatic diseases patients in the validation cohort. Serum MASP2 showed a good diagnostic ability for lupus. Genotype frequencies and allele frequency of polymorphisms rs7548659, rs2273346 were strongly related to SLE risk, and genotypes of rs17409276, rs1782455, rs76695096 were significantly correlated with lupus genetic susceptibility. Interestingly, patients carrying GA genotype of rs17409276, TT, TC genotype of rs6695096 showed higher levels of serum MASP2. The findings suggested that MASP2 may be a potential disease marker for lupus, and correlate with SLE pathogenesis.

IRAK family in inflammatory autoimmune diseases.

Innate immune signaling plays an important role in inflammation, and dysregulation of signaling components within this pathway has been focused as a critical mediator in initiation, progression of inflammatory autoimmune diseases. Toll-like receptors (TLRs) are the most upstream pattern recognition receptors in the immune cells, detecting pathogen associated molecular patterns, initiating signal transduction, by which interleukin-1 receptor-associated kinase (IRAK) family mediates activating signal from TLRs and interleukin-1 receptor. The family comprises of four members, IRAK1, IRAK2, IRAK-M, IRAK4. The family members have a role in either positive or negative regulation of innate immunity, adaptive immunity and inflammation. Accumulated evidence proves that IRAK performs significantly in the pathogenesis of inflammatory autoimmune disorders. On the one hand, both patients and animal modes reported abnormal expression of the family members. On the other hand, functional study in vivo and in vitro demonstrated that the members are implicated in the development of the diseases. Interestingly, IRAK inhibition has potential therapeutic benefits. In this review, we focus on the family, review the physiological roles in different immune cells, and summarize emerging data for highlighting the importance of them in inflammatory autoimmunity.

Biology of IL-36 Signaling and Its Role in Systemic Inflammatory Diseases.

Interleukin (IL)-36 is a member of the IL-1 superfamily and includes three agonists (IL-36α, IL-36ß, and IL-36γ) and an antagonist (IL-36Ra). IL-36 agonists bind to heterodimeric receptor complexes. Then, the heterotrimer complexes signal via intracellular functional domains, binding to downstream signaling proteins and inducing inflammatory responses. In this review, we summarized the current knowledge about the biological role of IL-36 and its correlation with systemic inflammatory diseases. The information collected will help to increase the understanding of the potential of IL-36 and may give clues for developing novel therapeutic strategies.

Insights into IL-29: Emerging role in inflammatory autoimmune diseases.

Interleukin-29 (IL-29) is a newly discovered member of type III interferon. It mediates signal transduction via binding to its receptor complex and activates downstream signalling pathways, and therefore induces the generation of inflammatory components. Recent studies reported that expression of IL-29 is dysregulated in inflammatory autoimmune diseases, such as rheumatoid arthritis, systemic lupus erythematosus, osteoarthritis, Sjögren's syndrome, psoriasis and systemic sclerosis. Furthermore, functional analysis revealed that IL-29 may involve in the pathogenesis of the inflammatory autoimmune disorders. In this review, we will systematically review the current knowledge about IL-29. The information collected revealed the regulatory role of IL-29 and may give important implications for its potential in clinical treatment.

Altered expression of circular RNA in primary Sjögren's syndrome.

OBJECTIVES: This study evaluated expression of circRNA in primary Sjögren's syndrome (pSS) patients so as to find novel biomarkers for pSS screening and discussed possible role of circRNA in pSS. We also evaluated expression profile of circRNA in systemic lupus erythematosus (SLE) patients. METHODS: Microarray analysis detected circRNA expression in PBMCs from five paired pSS, SLE patients, and controls. Then, differentially expressed circRNAs were validated in 30 pSS patients as compared to 30 SLE patients, healthy controls. CircRNAs interacting with miRNAs were discussed by Arraystar's homemade miRNA target prediction software. ROC analysis assessed the diagnostic value. RESULTS: We identified 234 differentially expressed circRNAs in pSS patients and verified five selected circRNAs (including hsa_circRNA_001264, hsa_circRNA_104121, hsa_circRNA_045355, hsa_circRNA_103461, hsa_circRNA_105034). Expression of hsa_circRNA_001264, hsa_circRNA_104121, and hsa_circRNA_045355 was strongly related to some clinical, laboratory parameters, and disease activity index in pSS patients. ROC analysis indicated potential diagnostic ability for the three circRNAs in pSS patients. One hundred and forty-eight circRNAs were differently expressed between lupus patients and controls. CONCLUSION: This study provides evidence that hsa_circRNA_001264, hsa_circRNA_104121, and hsa_circRNA_045355 might be biomarkers for pSS, correlate with pSS etiology.Key Points• Many circRNAs were dysregulated in pSS patients.• Differentially expressed circRNAs correlated with pSS clinical, laboratory features.• CircRNAs may be biomarkers for pSS.

Association of IRF5 rs2004640 polymorphism and systemic lupus erythematosus: A meta-analysis.

BACKGROUND: This study aimed to discuss the relationship between interferon regulatory factor (IRF)5 gene rs2004640 T/G polymorphism and systemic lupus erythematosus (SLE) susceptibility. METHODS: A meta-analysis was calculated on the association between rs2004640 polymorphism and SLE by allelic contrast (T vs G), additive model (TT vs GG), recessive model (TT vs TG + GG) and dominant model (TT + TG vs GG). RESULTS: A total of 28 comparisons were identified, including 11 228 SLE cases and 14 374 controls. Meta-analysis revealed a significant association between allele T and SLE in overall populations (odds ratio [OR] = 1.393, 95% CI: 1.276-1.522, P < 0.001). Stratification by ethnicity indicated strong associations between T allele and SLE in Asians, Europeans and Latin Americans (OR = 1.256, 95% CI: 1.073-1.469, P = 0.004; OR = 1.338, 95% CI: 1.080-1.659, P = 0.008; OR = 1.853, 95% CI: 1.488-2.308, P < 0.001). Results also showed significant associations between the additive model and SLE in all subjects and Asians (OR = 1.999, 95% CI: 1.442-2.771, P < 0.001; OR = 1.544, 95% CI: 1.009-2.362, P < 0.045). In addition, we found significant associations between the dominant model and SLE in all populations and Asians (OR = 1.521, 95% CI: 1.257-1.841, P < 0.001; OR = 1.270, 95% CI: 1.136-1.421, P < 0.001). A marginal association was detected between the recessive mode and SLE in overall subjects (OR = 1.480, 95% CI: 1.022-2.144, P = 0.038). CONCLUSION: The current study suggested that individuals carrying rs2004640 T allele correlated with a high risk of SLE, and the IRF5 rs2004640 polymorphism was associated with SLE susceptibility.