HSCs-derived exosomes regulate the levels of inflammatory cytokines in HIBECs through miR-122-5p mediated p38 MAPK signaling pathway.

PBC is an autoimmune-mediated liver disease, and intrahepatic biliary epithelial cells (IBECs) are the target cells of early damage. Previous studies found that miRNAs and inflammation is closely related to PBC. In this study, we extracted exosomes from serum and human IBECs supernatant, and RNA-sequence analyzed the expression profiles of miRNAs. Elisa measured the levels of inflammatory cytokines. RT- qPCR and western blot detected the levels of miR-122-5p, p38 and p-p38. The results showed that 263 differentially expressed (DE) miRNAs were identified in serum exosomes of PBC patients. The levels of IL-1ß, IL-6, IL-12, IL-17 A, IFN-γ, TNF-α and TGF-ß1 in peripheral blood of PBC patients were higher than those of normal controls. According to the validation results and previous literature, exosomal miR-122-5p was finally selected as the study object, and correlated with inflammatory factors. In vitro experiments further found that exosomal miR-122-5p may derive from hepatic stellate cells (HSCs), and can be HIBECs intake, and influence HIBECs inflammatory factor levels though p38 MAPK signaling pathways. This may provide a new strategy for the treatment of PBC.

Aberrant DNA Methylation Profile of Dickkopf-1 in Ankylosing Spondylitis.

In recent years, the impact of methylation modifications on Dickkopf-1 (DKK1) in relation to ankylosing spondylitis (AS) has remained elusive. Our objective was to investigate the potential link between DKK1 methylation patterns and transcript levels and AS susceptibility. DNA methylation level of DKK1 was measured in 82 AS and 82 healthy controls (HCs) using targeted bisulfite sequencing. In addition, the transcript level of DKK1 in peripheral blood mononuclear cells from 35 AS patients and 35 HCs was detected using real-time quantitative transcription-polymerase chain reaction. Our study showed that the DKK1 was significantly hypomethylated in AS patients (P < 0.001). The Receiver operating characteristic curve (ROC) showed that DKK1 methylation may be a potential biomarker. The results showed that the difference in DKK1 transcript levels between AS and HCs was not statistically significant. Further analysis showed that DKK1 methylation levels were positively correlated with age and negatively correlated with C-reactive protein levels, neutrophil/lymphocyte ratio (NLR) and platelet/lymphocyte ratio (PLR). The methylation level of DKK1 in PBMC of AS patients was significantly lower than that of HCs, and DKK1 methylation may be associated with susceptibility to AS. In addition, DNA methylation levels of DKK1 were negatively correlated with the level of inflammation in AS patients.

METTL14-m6A-FOXO3a axis regulates autophagy and inflammation in ankylosing spondylitis.

The role of m6A in ankylosing spondylitis (AS) remains largely obscure. In this study, we found that m6A modification was decreased in T cells of AS, and the abnormal m6A modification was attributed to the downregulation of methyltransferase-like 14 (METTL14). METTL14 exerted a critical role in regulating autophagy activity and inflammation via targeting Forkhead box O3a (FOXO3a). Mechanistically, the loss of METTL14 decreased the expression of FOXO3a, leading to the damage of autophagic flux and the aggravation of inflammation. Inversely, the forced expression of METTL14 upregulated the expression of FOXO3a, thereby activating autophagy and alleviating inflammation. Furthermore, our results revealed that METTL14 targeted FOXO3a mRNA and regulated its expression and stability in a m6A-dependent manner. These findings uncovered the functional importance of m6A methylation mechanisms in the regulation of autophagy and inflammation, which expanded our understanding of this interaction and was critical for the development of therapeutic strategies for AS.

Efficacy and safety of tripterygium wilfordii Hook F plus TNF inhibitor for active rheumatoid arthritis: A multicentre, randomized, double-blind, triple-dummy controlled trial.

An investigator-initiated, multicentre, randomized, double-blind, triple-dummy, controlled trial was conducted at 14 tertiary rheumatology centers in China to evaluate the efficacy and safety of Tripterygium wilfordii Hook F (TwHF) with recombinant human TNF receptor IgGFc fusion protein (rhTNFR-Fc) in active Rheumatoid Arthritis (RA). Primary endpoint was the proportion of patients achieved a 50% improvement of American College of Rheumatology criteria (ACR50) in TwHF+rhTNFR-Fc vs. methotrexate (MTX) group at week 12. ACR50 was achieved in 57.1% (72/126), 41.3% (52/126), 23.0% (29/126), and 26.2% (33/126) patients receiving TwHF+rhTNFR-Fc, MTX + rhTNFR-Fc, TwHF and MTX monotherapy, respectively, at week 12 (TwHF+rhTNFR-Fc vs. other three groups, all p < 0.05). No statistical difference in serious adverse events or adverse events leading to discontinuation of study across all groups was documented. TwHF+rhTNFR-Fc was superior to MTX for active RA, and was more effective than MTX + rhTNFR-Fc on ACR50, with a similar safety profile. Trial registration:ClinicalTrials.govNCT03589833.

The gut ecosystem and immune tolerance.

The gastrointestinal tract is home to the largest microbial population in the human body. The gut microbiota plays significant roles in the development of the gut immune system and has a substantial impact on the maintenance of immune tolerance beginning in early life. These microbes interact with the immune system in a dynamic and interdependent manner. They generate immune signals by presenting a vast repertoire of antigenic determinants and microbial metabolites that influence the development, maturation and maintenance of immunological function and homeostasis. At the same time, both the innate and adaptive immune systems are involved in modulating a stable microbial ecosystem between the commensal and pathogenic microorganisms. Hence, the gut microbial population and the host immune system work together to maintain immune homeostasis synergistically. In susceptible hosts, disruption of such a harmonious state can greatly affect human health and lead to various auto-inflammatory and autoimmune disorders. In this review, we discuss our current understanding of the interactions between the gut microbiota and immunity with an emphasis on: a) important players of gut innate and adaptive immunity; b) the contribution of gut microbial metabolites; and c) the effect of disruption of innate and adaptive immunity as well as alteration of gut microbiome on the molecular mechanisms driving autoimmunity in various autoimmune diseases.

Frailty predicts knee pain trajectory over 9 years: results from the Osteoarthritis Initiative.

OBJECTIVE: Frailty is a multisystem syndrome and its relationship with symptomatic osteoarthritis has been reported. We aimed to identify trajectories of knee pain in a large prospective cohort and to describe the effect of frailty status at baseline on the pain trajectories over 9 years. METHODS: We included 4419 participants (mean age 61.3 years, 58% female) from the Osteoarthritis Initiative cohort. Participants were classified as "no frailty," "pre-frailty," or "frailty" at baseline, based on 5 characteristics (ie, unintentional weight loss, exhaustion, weak energy, slow gait speed, and low physical activity). Knee pain was evaluated annually using the Western Ontario and McMaster Universities Osteoarthritis Index pain subscale (0-20) from baseline to 9 years. RESULTS: Of the participants included, 38.4%, 55.4%, and 6.3% were classified as "no frailty," "pre-frailty," and "frailty," respectively. Five pain trajectories were identified: "No pain" (n = 1010, 22.8%), "Mild pain" (n = 1656, 37.3%), "Moderate pain" (n = 1149, 26.0%), "Severe pain" (n = 477, 10.9%), and "Very Severe pain" (n = 127, 3.0%). Compared to participants with no frailty, those with pre-frailty and frailty were more likely to have more severe pain trajectories (pre-frailty: odds ratios [ORs] 1.5 to 2.1; frailty: ORs 1.5 to 5.0), after adjusting for potential confounders. Further analyses indicated that the associations between frailty and pain were mainly driven by exhaustion, slow gait speed, and weak energy. CONCLUSIONS: Approximately two-thirds of middle-aged and older adults were frail or pre-frail. The role of frailty in predicting pain trajectories suggests that frailty may be an important treatment target for knee pain.

New-onset autoimmune phenomena post-COVID-19 vaccination.

Coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has led to an unprecedented setback for global economy and health. Vaccination is one of the most effective interventions to substantially reduce severe disease and death due to SARS-CoV-2 infection. Vaccination programmes are being rolled out globally, but most of these vaccines have been approved without extensive studies on their side-effects and efficacy. Recently, new-onset autoimmune phenomena after COVID-19 vaccination have been reported increasingly (e.g. immune thrombotic thrombocytopenia, autoimmune liver diseases, Guillain-Barré syndrome, IgA nephropathy, rheumatoid arthritis and systemic lupus erythematosus). Molecular mimicry, the production of particular autoantibodies and the role of certain vaccine adjuvants seem to be substantial contributors to autoimmune phenomena. However, whether the association between COVID-19 vaccine and autoimmune manifestations is coincidental or causal remains to be elucidated. Here, we summarize the emerging evidence about autoimmune manifestations occurring in response to certain COVID-19 vaccines. Although information pertaining to the risk of autoimmune disease as a consequence of vaccination is controversial, we merely propose our current understanding of autoimmune manifestations associated with COVID-19 vaccine. In fact, we do not aim to disavow the overwhelming benefits of mass COVID-19 vaccination in preventing COVID-19 morbidity and mortality. These reports could help guide clinical assessment and management of autoimmune manifestations after COVID-19 vaccination.

COVID-19 and inflammatory bowel disease crosstalk: From emerging association to clinical proposal.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection can cause coronavirus disease 2019 (COVID-19), an acute respiratory inflammation that has emerged worldwide since December 2019, and it quickly became a global epidemic. Inflammatory bowel disease (IBD) is a group of chronic nonspecific intestinal inflammatory diseases whose etiology has not been elucidated. The two have many overlapping symptoms in clinical presentation, such as abdominal pain, diarrhea, pneumonia, etc. Imbalance of the autoimmune system in IBD patients and long-term use of immunosuppressive drugs may increase the risk of infection; and systemic symptoms caused by COVID-19 may also induce or exacerbate intestinal inflammation. It has been found that the SARS-CoV-2 receptor angiotensin converting enzyme 2, which is highly expressed in the lung and intestine, is an inflammatory protective factor, and is downregulated and upregulated in COVID-19 and IBD, respectively, suggesting that there may be a coregulatory pathway. In addition, the immune activation pattern of COVID-19 and the cytokine storm in the inflammatory response have similar roles in IBD, indicating that the two diseases may influence each other. Therefore, this review aimed to address the following research questions: whether SARS-CoV-2 infection leads to the progression of IBD; whether IBD increases the risk of COVID-19 infection and poor prognosis; possible common mechanisms and genetic cross-linking between the two diseases; new treatment and care strategies for IBD patients, and the feasibility and risk of vaccination in the context of the COVID-19 epidemic.

Differential immune response to xenobiotic-modified self-molecule in simple and connective tissue disease-associated primary biliary cholangitis.

BACKGROUND AND AIMS: Our previous studies demonstrated that 2-octynoic acid (2OA) might alter the conformational structure of the inner lipoic acid (LA) binding domain (ILD) in the E2 subunit of pyruvate dehydrogenase complex (PDC-E2), leading to the loss of immune tolerance in simple primary biliary cholangitis (S-PBC). Here, we further explore if this etiological mechanism also accounts for connective tissue disease-associated PBC (CTD-PBC). METHODS: Intein-mediated protein ligation was used to prepare ILD, LA-ILD and 2OA-ILD, and their reactivity with serum samples from 124 S-PBC and 132 CTD-PBC patients was examined. The antibodies to LA, 2OA, LA-ILD and 2OA-ILD, the isotypes of antibodies to LA, 2OA and ILD, were comparatively detected between the two patient groups by enzyme-linked immunosorbent assay and immunoblotting. RESULTS: Both the percentage and reactivity of antibody to 2OA in S-PBC were significantly higher than in CTD-PBC. Antibodies to 2OA and to LA between the two groups separately shared the same characteristics. Remarkably, coexistence of the antibodies to LA-ILD and to 2OA, and coexistence of the antibodies to LA and to 2OA in S-PBC were both significantly more frequent than in CTD-PBC, whereas the percentage of anti-LA antibody without anti-2OA antibody in S-PBC was markedly lower than in CTD-PBC. Moreover, the isotype of antibody to LA was predominantly IgG in CTD-PBC, whilst this isotype was mainly IgM in S-PBC. CONCLUSION: Xenobiotic 2OA might play less important pathogenic role in CTD-PBC than in S-PBC, suggesting that different underlying mechanisms are involved in their immune intolerance to PDC-E2.

DNA Methylation and mRNA Expression of B7-H3 Gene in Ankylosing Spondylitis: A Case-Control Study.

BACKGROUND: Ankylosing spondylitis (AS) is a common inflammatory arthritis, with a high prevalence in patients in their mid-20s. Its pathogenesis is not well understood; however, genetic factors likely play a critical role. Epigenetic DNA changes may be involved in the pathogenesis of AS. In this study, we explored the methylation and transcription levels of the B7-H3 gene and its association with AS in an eastern Chinese Han population. METHODS: Peripheral blood of AS patients and healthy controls was used to extract genomic DNA and B7-H3 methylation levels were analyzed using sodium bisulfite followed by multiplex polymerase chain reaction. SPSS software was used to determine the statistical significance of the results. RESULTS: Hypomethylation of the promoter of the B7-H3 gene was observed in AS patients, whereas the B7-H3 gene expression was significantly enhanced in AS patients. CONCLUSION: Epigenetic modifications of B7-H3 were associated with susceptibility to AS. Hypomethylation of the B7-H3 promoter, which leads to B7-H3 overexpression, may be involved in the pathogenesis of AS.

Efficacy of tocilizumab for refractory Takayasu arteritis: a retrospective study and literature review.

To evaluate the efficacy and safety of tocilizumab (TCZ) in the treatment of refractory Takayasu arteritis (TAK). Eleven refractory TAK patients treated with TCZ at the First Affiliated Hospital of Anhui Medical University between 2017 July and 2020 December were respectively analyzed. We also respectively analyzed the studies on TCZ efficacy in patients with TAK, from PubMed/MEDLINE, Elsevier Science Direct between January 2010 and April 2021. The median age of 11 patients was 34(19-46) years. After 3 months of TCZ, a significant drop was found in median NIH (3[2-5] at baseline vs 1[0-2] after 6 months; p < 0.05), ITAS-2010 score (8.5[6-11] vs 6[1-10]; p < 0.05). One (9%) patient experienced relapse during TCZ treatment. After withdrawal of TCZ, one patient (9%) underwent relapse and nine patients (81%) were spared of GC use. In literature review, a total of 211 patients (mean age 35 years) were analyzed, including 80 (38%) Chinese and 169 females (80%). Among the 211 patients, (154 patients) 73% achieved remission after the last infusion of TCZ; TAK relapsed in 6% of patients during TCZ treatment and 5% of the TCZ patients after the withdrawal of TCZ. A total of 95 types of adverse events were observed in the literature. Infection was the most common adverse effect, occurring in 50% of patients. TCZ could serve as an efficacious and safe agent for refractory TAK.

Association of MALAT-1 gene single nucleotide polymorphisms with genetic susceptibility to systemic lupus erythematosus.

Background: Abnormal expression and function of long non-coding RNAs (lncRNAs) are closely related to the pathogenesis of systemic lupus erythematosus (SLE). In this study, we aimed to investigate the association of lncRNA metastasis-associated lung adenocarcinoma transcript 1 (MALAT-1) gene single-nucleotide polymorphisms (SNPs) with susceptibility and clinical characteristics of SLE patients. Methods: A case-control study including 489 SLE patients and 492 healthy controls was conducted. Four MALAT-1 SNPs (rs4102217, rs591291, rs11227209, and rs619586) were genotyped in all subjects, their correlation with SLE susceptibility and clinical characteristics were also analyzed. Results: Results showed that the rs4102217 locus was associated with the risk of SLE. In recessive models, the GG+CG genotype of rs4102217 was associated with the decreased risk of SLE compared to CC (p = 0.036, OR = 0.348, 95% CI: 0.124-0.975). In additive models, the GG genotype of rs4102217 was associated with the decreased risk of SLE compared to CC (p = 0.040, OR = 0.355, 95% CI: 0.127-0.996). However, no association was found between MALAT-1 gene polymorphism and clinical manifestations of SLE (all p > 0.05). Conclusion: In summary, MALAT-1 rs4102217 is associated with susceptibility to SLE, suggesting that MALAT-1 may play a role in SLE.

Emerging role of ficolins in autoimmune diseases.

Ficolins are pattern-recognition molecules (PRMs) that could form complexes with mannose-binding lectin-associated serine proteases (MASPs) to trigger complement activation via the lectin pathway, thereby mediating a series of immune responses including opsonization, phagocytosis and cytokine production. In the past few decades, accumulating evidence have suggested that ficolins play a major role in the onset and development of several autoimmune diseases (ADs), including systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), systemic sclerosis (SSc), Type 1 diabetes (T1D), inflammatory bowel disease (IBD), etc. In this review, we synthesized previous literatures and recent advances to elucidate the immunological regulations of ficolins and discuss the potential diagnostic ability of ficolins in ADs, as well as giving an insight into the future therapeutic options for ficolins in ADs.

Serum Levels of Hepcidin in Rheumatoid Arthritis and Its Correlation with Disease Activity and Anemia: A Meta-analysis.

Present studies on serum hepcidin levels in patients with rheumatoid arthritis (RA) are inconsistent. We aimed to synthetically evaluate the relationship between hepcidin and RA, and the correlation of serum hepcidin levels and RA disease activity as well as anemia associated with RA. Multiple electronic databases were searched. Pooled standard mean difference (SMD) with 95% confidence interval (CI) and correlation coefficients between hepcidin levels and rheumatoid factor (RF), disease activity for 28 joints (DAS28), and erythrocyte sedimentation rate (ESR) were calculated. Totally, 13 articles were available for this meta-analysis. The results revealed that serum levels of hepcidin were higher in RA patients compared to healthy controls (SMD = 0.573, 95% CI = 0.317 to 0.829, p < .001); RA patients with anemia had higher serum hepcidin levels than RA patients without anemia (SMD = 0.400, 95% CI = 0.080 to 0.720, p = .014); RA patients with pure ACD had higher serum hepcidin levels than RA patients with ACD and IDA (SMD = 0.658, 95% CI = 0.018 to 1.299, p = .044). Moreover, the result of correlation coefficients identified a significant positive correlation between hepcidin levels and RF, DAS28 as well as ESR. Serum hepcidin levels may be closely associated with the development of RA.

Interleukin-17 Gene Polymorphism (Rs2275913 G/A, Rs763780 C/T) in Rheumatoid arthritis：Meta-analysis Based on Ethnicity.

INTRODUCTION: The association between interleukin(IL)-17A and IL-17 F gene polymorphism with rheumatoid arthritis (RA) were inconsistent among previous studies. This meta-analysis aimed to determine the association between IL-17A and IL-17 F gene polymorphism with RA. METHODS: We searched Medline up to February 2020. Meta-analyses were performed for the comparisons of allele and multiple genetic models, including dominant, recessive, heterozygous, and homozygous models using fixed or random effects models. Odds ratios (OR) with 95% confidence intervals (95%CI) were utilized to assess the potential relationship. RESULTS: A total of 2315 confirmed cases and 2342 controls were included from eligible 10 case-controls studies. Meta analysis suggested that rs2275913 G allele increased the risk of RA in Caucasians (G vs A: OR = 1.14, 95% CI = 1.00-1.29, P = .044), but not in Mongolians (P > .05). Pooled analysis suggested that a significant associations between rs763780 C allele with RA susceptibility (C vs T: OR = 1.83, 95% CI = 1.13-2.97, P = .014). Subgroup analysis by ethnicity indicated that rs763780 C allele was closely related to RA risk in two races (P < .001). TSA plot revealed that the present study sufficient to draw a conclusion. CONCLUSIONS: This meta-analysis demonstrates IL-17A and IL-17 F genes play a significant role in RA, but its role in Mongolian populations needs further exploration.

Red Cell Distribution Width and Mean Platelet Volume in Patients With Ankylosing Spondylitis: A Systematic Review and Meta-analysis.

OBJECTIVE: The results of previous studies regarding the relationship between red cell distribution width (RDW) or mean platelet volume (MPV) levels and ankylosing spondylitis (AS) are inconsistent. Therefore, we conducted this meta-analysis to systematically evaluate the associations. METHODS: The Web of Science, PubMed, and Cochrane Library (as of February 14, 2019) were used to retrieve relevant articles. Pooled standard mean difference (SMD) and its 95% confidence interval (CI) were calculated. All statistical analyses were performed using the "meta" and "metafor" packages of the R 3.5.1 software. RESULTS: Nine studies on RDW, including 775 AS patients and 972 healthy controls, and 8 studies on MPV, including 743 AS patients and 571 healthy controls, were included. The results showed that RDW levels were significantly higher in AS patients (SMD = 0.67; 95% CI, 0.30 to 1.05; p < 0.001) compared with healthy controls, whereas MPV levels (SMD = 0.01; 95% CI, -0.28 to 0.30; p = 0.929) were not significantly different from healthy controls. CONCLUSIONS: Our current study shows that the elevated levels of RDW may be associated with AS, whereas MPV levels may be not associated with AS.

Association between IL-17A and IL-17F gene polymorphism and susceptibility in inflammatory arthritis: A meta-analysis.

OBJECTIVES: The association between Interleukin (IL)-17A and IL-17F gene polymorphism with inflammatory arthritis were inconsistent among previous studies. This meta-analysis aimed to determine the association between IL-17A and IL-17F gene polymorphism with ankylosing spondylitis (AS), osteoarthritis (OA) and rheumatoid arthritis (RA). METHODS: We searched Medline up to August 2019. The summary Odds Ratio (OR) with corresponding 95% confidence intervals (CIs) was calculated to evaluate the relationship between IL-17A and IL-17F gene polymorphism with genetic susceptibility of AS, OA and RA. RESULTS: A total of 19 studies with 5298 cases and 5675 healthy controls were included. There were significant associations between rs2275913 G allele with OA, RA susceptibility (P < .05) but not AS. Subgroup analysis by ethnicity indicated that rs763780 C allele was closely related to AS and OA in Caucasian populations (P < .001) but not Mongolians. A significant association between rs763780 and RA susceptibility was detected in Caucasian populations (P < .05). CONCLUSION: IL-17F gene rs763780 C allele confers increased risk of inflammatory arthritis in Caucasians; IL-17A gene rs2275913 G allele are protective for OA susceptibility in Mongolians. More well-designed studies with larger sample size are needed to elucidate the role of IL-17A gene rs2275913 G allele in inflammatory arthritis, especially AS.

B7-H3: A promising therapeutic target for autoimmune diseases.

B7-H3 as a newly identified costimulatory molecule that belongs to B7 ligand family, is broadly expressed in both lymphoid and non-lymphoid tissues. The overexpression of B7-H3 has been verified to be correlated with the poor prognosis and poor clinical outcome of several human cancers. In recent years, researchers reveal that B7-H3 is involved in the pathogenesis of various autoimmune diseases, such as systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), multiple sclerosis (MS), Sjögren's syndrome (SS), ankylosing spondylitis (AS), etc. In this review, we will discuss the biological function of B7-H3 and summarize the progress made over past years regarding its role in the occurrence and development of autoimmune diseases. The insights gained from these findings could serve as the foundation for future therapies of these diseases.

Glycomic analysis of antibody indicates distinctive glycosylation profile in patients with autoimmune cholangitis.

Glycosylation of antibodies, particularly in the Fc domain, critically modulate the ability of antibodies to bind to FcRs, maintaining immune quiescence to achieve a finely orchestrated immune response. The removal of sialic acid and galactose residues dramatically alters the physiological function of IgGs, and alterations of Ig glycosylation have been associated with several autoimmune disorders. However, Ig glycosylation has not been extensively studied in autoimmune cholangitis. We applied triple quadruple mass spectroscopy with subsequent multiple reaction monitoring to elucidate the profile, composition and linkage of sugar residues of antibody glycans in patients with primary biliary cholangitis (PBC), primary sclerosing cholangitis (PSC) and healthy controls (HC). Agalactosylated, HexNAc terminated IgG1 glycoforms were enriched in both PBC and PSC. Levels of IgM glycans at site N439 and fucosylated glycans in J chain, were significantly decreased in PBC compared to PSC and HC. PSC patients had decreased bisecting glycoforms and increased biantennary glycoforms on IgA compared to PBC. Importantly, our data demonstrate the association of distinct branching and composition patterns of Ig glycoforms with disease severity and liver cirrhosis, which highlight the importance of glycan biology as a potential mechanism and/or a disease specific signal of inflammation.

Discovery of new serum biomarker panels for systemic lupus erythematosus diagnosis.

OBJECTIVE: Clinical diagnosis of SLE is currently challenging due to its heterogeneity. Many autoantibodies are associated with SLE and are considered potential diagnostic markers, but systematic screening and validation of such autoantibodies is lacking. This study aimed to systematically discover new autoantibodies that may be good biomarkers for use in SLE diagnosis. METHODS: Sera from 15 SLE patients and 5 healthy volunteers were analysed using human proteome microarrays to identify candidate SLE-related autoantibodies. The results were validated by screening of sera from 107 SLE patients, 94 healthy volunteers and 60 disease controls using focussed arrays comprised of autoantigens corresponding to the identified candidate antibodies. Logistic regression was used to derive and validate autoantibody panels that can discriminate SLE disease. Extensive ELISA screening of sera from 294 SLE patients and 461 controls was performed to validate one of the newly discovered autoantibodies. RESULTS: A total of 31, 11 and 18 autoantibodies were identified to be expressed at significantly higher levels in the SLE group than in the healthy volunteers, disease controls and healthy volunteers plus disease control groups, respectively, with 25, 7 and 13 of these differentially expressed autoantibodies being previously unreported. Diagnostic panels comprising anti-RPLP2, anti-SNRPC and anti-PARP1, and anti-RPLP2, anti-PARP1, anti-MAK16 and anti- RPL7A were selected. Performance of the newly discovered anti-MAK16 autoantibody was confirmed by ELISA. Some associations were seen with clinical characteristics of SLE patients, such as disease activity with the level of anti-PARP1 and rash with the level of anti-RPLP2, anti-MAK16 and anti- RPL7A. CONCLUSION: The combined autoantibody panels identified here show promise for the diagnosis of SLE and for differential diagnosis of other major rheumatic immune diseases.