Biomarkers For Rheumatoid Arthritis Research Articles

Integrated multi-omics revealed that dysregulated lipid metabolism played an important role in RA patients with metabolic diseases

ObjectivesPatients with rheumatoid arthritis (RA) commonly experience a high prevalence of multiple metabolic diseases (MD), leading to higher morbidity and premature mortality. Here, we aimed to investigate the pathogenesis of MD in RA patients (RA_MD) through an integrated multi-omics approach.MethodsFecal and blood samples were collected from a total of 181 subjects in this study for multi-omics analyses, including 16S rRNA and internally transcribed spacer (ITS) gene sequencing, metabolomics, transcriptomics, proteomics and phosphoproteomics. Spearman’s correlation and protein-protein interaction networks were used to assess the multi-omics data correlations. The Least Absolute Shrinkage and Selection Operator (LASSO) machine learning algorithm were used to identify disease-specific biomarkers for RA_MD diagnosis.ResultsOur results found that RA_MD was associated with differential abundance of gut microbiota such as Turicibacter and Neocosmospora, metabolites including decreased unsaturated fatty acid, genes related to linoleic acid metabolism and arachidonic acid metabolism, as well as downregulation of proteins and phosphoproteins involved in cholesterol metabolism. Furthermore, a multi-omics classifier differentiated RA_MD from RA with high accuracy (AUC: 0.958). Compared to gouty arthritis and systemic lupus erythematosus, dysregulation of lipid metabolism showed disease-specificity in RA_MD.ConclusionsThe integration of multi-omics data demonstrates that lipid metabolic pathways play a crucial role in RA_MD, providing the basis and direction for the prevention and early diagnosis of MD, as well as new insights to complement clinical treatment options.

Serum Galectin-3 Level in Patients with Rheumatoid Arthritis: A Systematic Review and Meta-analysis

Rheumatoid arthritis (RA) is a chronic inflammatory disease characterized by synovial tissue transformation and fibroblast-like synoviocyte (FLS) proliferation. Galectin-3 is gaining attention as a diagnostic and prognostic biomarker for RA diagnosis. Elevated levels of Galectin-3 cause RA[1]FLSs to stimulate and generate proinflammatory agents, contributing to cartilage degradation and osteoclast formation. This systematic review and meta-analysis aimed to evaluate published evidence and support future investigation of Galectin-3 as an early biomarker for RA. A systematic search was performed through four databases, including PubMed, the Web of Science, Scopus, and Embase, to find the studies examining Galectin-3 in individuals with RA compared to healthy controls. The risk of bias was evaluated using the Newcastle-Ottawa Quality Assessment Scale. Random-effects meta-analysis comparing serum/plasma Galectin-3 levels between individuals with RA and healthy control groups was performed to determine the standardized mean differences (SMD) along with 95% confidence intervals. Following the initial search, studies went through screening. 12 studies, involving 773 patients with RA and 411 healthy controls, were included. Meta-analysis of the included studies revealed that individuals with RA had significantly higher levels of circulatory Galectin-3 compared to healthy control groups (SMD 0.957, 95% CI 0.393 to 1.520). Univariable meta-regression showed no significant association between age, publication year, sample size, or the male percentage with effect size. According to the results, Galectin-3 might be useful as a biomarker for RA. To support these findings, further investigations of Galectin-3 as a possible early biomarker of RA is necessary.

Genomic and Serological Rheumatoid Arthritis Biomarkers, MUC5B Promoter Variant, and Interstitial Lung Abnormalities.

Rheumatoid arthritis (RA) has been implicated in interstitial lung disease (ILD) as majority of studies have been comprised of patients with known RA. However, it remains unclear whether an underlying risk for RA in combination with genetic risk for pulmonary fibrosis is associated with radiological markers of early lung injury and fibrosis in broader population samples. Determine whether genetic and serological biomarkers of RA risk in combination with the MUC5B (rs35705950) risk allele (T) are associated with interstitial lung abnormalities (ILA) on computed tomography (CT) scans. Associations of RA-risk HLA-DRB1 alleles (*04:01, *04:08, *04:05, *04:04, *10:01) and serum RA autoantibodies with ILA in the Multi-Ethnic Study of Atherosclerosis (MESA, n=4,018) and COPDGene (n=5,963) cohorts were modeled using logistic regression and adjusted for age, sex, self-reported race and ethnicity, smoking history, body mass index, and principal components of genetic ancestry. The prevalence of an RA risk HLA-DRB1 allele was 16.5% and 21.9% in MESA and COPDGene, respectively. ILA was present in 3.9% and 11% in MESA and COPDGene, respectively. An RA risk HLA-DRB1 allele was not significantly associated with ILA in MESA and COPDGene. In MESA, higher serum levels of IgA rheumatoid factor (RF) and anti-cyclic citrullinated peptide were associated with an odds ratio (OR) for ILA of 1.20 (95% CI 1.07-1.35) and 1.19 (95% CI 1.04-1.37), respectively. Among smokers without baseline ILA, per doubling of IgM RF was associated with an OR for ILA 10 years later of 1.25 (95% CI 1.08-1.43). Associations were not significantly different by MUC5B risk allele status. RA-related HLA-DRB1 alleles were not associated with ILA, whereas higher serum levels of IgM RF among smokers without baseline ILA were associated with subsequent ILA.

Serum lncRNA ITGB2-AS1 and ICAM-1 as novel biomarkers for rheumatoid arthritis and osteoarthritis diagnosis.

The complete circulating long non-coding RNAs (lncRNAs) signature of rheumatoid arthritis (RA) and osteoarthritis (OA) is still uncovered. The lncRNA integrin subunit beta 2 (ITGB2)-anti-sense RNA 1 (ITGB2-AS1) affects ITGB2 expression; however, there is a gap in knowledge regarding its expression and clinical usefulness in RA and OA. This study investigated the potential of serum ITGB2-AS1 as a novel diagnostic biomarker and its correlation with ITGB2 expression and its ligand intercellular adhesion molecule-1 (ICAM-1), disease activity, and severity in RA and primary knee OA patients. Forty-three RA patients, 35 knee OA patients, and 22 healthy volunteers were included. Compared with healthy controls, serum ITGB2-AS1 expression was upregulated in RA patients but wasn't significantly altered in knee OA patients, whereas serum ICAM-1 protein levels were elevated in both diseases. ITGB2-AS1 showed discriminative potential for RA versus controls (AUC = 0.772), while ICAM-1 displayed diagnostic potential for both RA and knee OA versus controls (AUC = 0.804, 0.914, respectively) in receiver-operating characteristic analysis. In the multivariate analysis, serum ITGB2-AS1 and ICAM-1 were associated with the risk of developing RA, while only ICAM-1 was associated with the risk of developing knee OA. A panel combining ITGB2-AS1 and ICAM-1 showed profound diagnostic power for RA (AUC = 0.9, sensitivity = 86.05%, and specificity = 91.67%). Interestingly, serum ITGB2-AS1 positively correlated with disease activity (DAS28) in RA patients and with ITGB2 mRNA expression in both diseases, while ICAM-1 positively correlated with ITGB2 expression in knee OA patients. Our study portrays serum ITGB2-AS1 as a novel potential diagnostic biomarker of RA that correlates with disease activity. A predictive panel combining ITGB2-AS1 and ICAM-1 could have clinical utility in RA diagnosis. We also spotlight the association of ICAM-1 with knee OA diagnosis. The correlation of serum ITGB2-AS1 with ITGB2 expression in both diseases may be insightful for further mechanistic studies.

Association Between Pharmacotherapy And Circulating Hematological Profile In Rheumatoid Arthritis

Background — Hematological indices are useful predictors and prognostic biomarkers in rheumatoid arthritis (RA). Some antirheumatic drugs (ARD) have a negative effect on circulating blood cells and bone marrow and therefore may bias the interpretation of biomarker value. Objective — Our cross-sectional study aimed to demonstrate the effect of ADR use on peripheral blood indices in RA patients. Methods — This cross-sectional study was conducted on 103 adult RA patients and 21 healthy subjects at Rizgari Teaching Hospital in collaboration with the Department of Clinical Pharmacy and College of Pharmacy, Hawler Medical University, Erbil, Iraq, from January 2020 through December 2022. Patients were treated with methotrexate (MTX), hydroxychloroquine (HCQ), biologics (BL), MTX+HCQ, MTX+BL, and HCQ+BL. RA activity and complete blood count were obtained from patient records. Results — Our results implied that HCQ was associated with significantly lower hemoglobin levels, while MTX+BL was accompanied by significantly lower mean corpuscular volume. The mean platelet volume was significantly higher in all treatment groups than in healthy subjects. Conclusion — We concluded that BL use was statistically significantly associated with changes in hematological indices and ratios in patients with RA. It is important to consider the category of pharmacotherapy when interpreting circulating blood cell indices as predictors or prognostic biomarkers in RA.

Anti-inflammatory potential of polyphenols: Combining in silico prediction and in vivo data

Introduction: Rheumatoid arthritis (RA) is a chronic inflammatory disease characterized by joint inflammation and destruction, leading to significant pain and disability. Adenosine deaminase (ADA) is identified as a biomarker for RA’s inflammatory process. This study aims to investigate the potential of flavonoids and phenolic acids to inhibit ADA activity (in silico) and evaluate their anti-inflammatory effects in a RA model (in vivo). Methods: The molecular docking study was conducted using YASARA Structure 19.12.14. software following the Auto Dock 4.2 protocol. A rat model with pristane-induced arthritis was used to test the anti-inflammatory effect of selected polyphenols. The consistency of the development of the rat model was evaluated through the following indicators artistic score, paw volume, and body weight. Quercetin was administered intragastrically at doses of 150 and 400 mg/kg over 15 days. The C-reactive protein (CRP) level in serum was measured with an automatic biochemical analyzer. Statistical analyses were performed using SPSS 29.0.2.0. Results: Molecular docking simulations showed flavonoids inhibited ADA activity with inhibition constants ranging from 0.012 mM to 0.190 mM. In the in vivo RA model, quercetin significantly reduced joint inflammation and serum CRP levels at a higher dose of 400 mg/kg. Conclusion: Quercetin shows promise as an anti-inflammatory agent for RA by targeting ADA, suggesting that flavonoid-rich plant extracts could enhance RA treatment.

Mannose-Binding Lectin Gene Variants as Disease Susceptibility Biomarkers in Rheumatoid Arthritis.

Background: Rheumatoid arthritis (RA) is a chronic, inflammatory autoimmune disease characterized by progressive destruction of peripheral joints. About 1% of the human population worldwide is suffering from this disease. The pathophysiology of RA is largely being influenced by immune dysregulation. Mannose-binding lectin (MBL), an acute-phase protein, has been reported to play an important role in pathogenesis of RA by the activation of complement pathway. Various studies documented the established the role of MBL in pathogenesis of various autoimmune diseases, including RA. MBL protein is encoded by gene MBL2, mapped on chromosome 10q11.2-q21. Objective: Both MBL serum levels and activity are mainly determined genetically by its variants. So considering the putative clinical role of MBL2, this case-control association study was designed to assess its six functional variants in a northwestern Indian cohort. Methods: Genetic typing of six MBL2 variants was done by amplification refractory mutation system-polymerase chain reaction. Data were analyzed using suitable statistical tools. Results: Significant difference has been observed in genotypic and allelic distribution between cases and controls for rs11003125. Comparison of allelic distribution for rs1800450 showed significantly high prevalence of A allele in cases than controls. Conclusion: These results indicate that MBL2 variants may act as plausible marker for susceptibility toward RA. Keeping this in view, it is pertinent to screen these variants in other population groups of India.

Identification of diagnostic biomarkers of rheumatoid arthritis based on machine learning-assisted comprehensive bioinformatics and its correlation with immune cells

BackgroundRheumatoid arthritis (RA) is a chronic systemic autoimmune disease characterized by inflammatory cell infiltration, which can lead to chronic disability, joint destruction and loss of function. At present, the pathogenesis of RA is still unclear. The purpose of this study is to explore the potential biomarkers and immune molecular mechanisms of rheumatoid arthritis through machine learning-assisted bioinformatics analysis, in order to provide reference for the early diagnosis and treatment of RA disease. MethodsRA gene chips were screened from the public gene GEO database, and batch correction of different groups of RA gene chips was performed using Strawberry Perl. DEGs were obtained using the limma package of R software, and functional enrichment analysis such as gene ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), disease ontology (DO), and gene set (GSEA) were performed. Three machine learning methods, least absolute shrinkage and selection operator regression (LASSO), support vector machine recursive feature elimination (SVM-RFE) and random forest tree (Random Forest), were used to identify potential biomarkers of RA. The validation group data set was used to verify and further confirm its expression and diagnostic value. In addition, CIBERSORT algorithm was used to evaluate the infiltration of immune cells in RA and control samples, and the correlation between confirmed RA diagnostic biomarkers and immune cells was analyzed. ResultsThrough feature screening, 79 key DEGs were obtained, mainly involving virus response, Parkinson's pathway, dermatitis and cell junction components. A total of 29 hub genes were screened by LASSO regression, 34 hub genes were screened by SVM-RFE, and 39 hub genes were screened by Random Forest. Combined with the three algorithms, a total of 12 hub genes were obtained. Through the expression and diagnostic value verification in the validation group data set, 7 genes that can be used as diagnostic biomarkers for RA were preliminarily confirmed. At the same time, the correlation analysis of immune cells found that γδT cells, CD4+ memory activated T cells, activated dendritic cells and other immune cells were positively correlated with multiple RA diagnostic biomarkers, CD4+ naive T cells, regulatory T cells and other immune cells were negatively correlated with multiple RA diagnostic biomarkers. ConclusionsThe results of novel characteristic gene analysis of RA showed that KYNU, EVI2A, CD52, C1QB, BATF, AIM2 and NDC80 had good diagnostic and clinical value for the diagnosis of RA, and were closely related to immune cells. Therefore, these seven DEGs may become new diagnostic markers and immunotherapy markers for RA.

Biomarkers in Rheumatoid Arthritis. Review of the current state of knowledge

Biomarkers in Rheumatoid Arthritis. Review of the current state of knowledge

Rheumatoid meningitis sine arthritis: An emerging cause of isolated pachymeningitis and leptomeningitis with typical features

Background and purposeRheumatoid meningitis (RM) is a meningeal inflammation rarely occurring during the course of rheumatoid arthritis (RA). Anti-citrullinated protein antibodies (ACPA), which are highly specific biomarkers of RA, may allow RM sine arthritis (RMSA) to be diagnosed as an extra-articular early lesion of RA. MRI typically displays pachymeningitis and/or leptomeningitis predating convexity, and CSF diffusivity is focally restricted. Blood ACPA is a strong clue and intrathecal synthesis of ACPA is characteristic although rarely reported. MethodsWe report two cases of RMSA that were confirmed by meningeal biopsy and intrathecal synthesis. ResultsRMSA abated after steroids alone or associated with rituximab. No arthritis occurred during the follow-up. ConclusionRM can occur in the absence of RA.

Diagnostic Value of Interleukin 6, Interleukin 12P70, Serum Amyloid A, and Procalcitonin for Rheumatoid Arthritis and Their Relationship With the Disease Activity

To observe the diagnostic value of four serum inflammatory biomarkers, including interleukin 6 (IL-6), interleukin 12P70 (IL-12P70), serum amyloid A (SAA), and procalcitonin (PCT), in rheumatoid arthritis (RA) and to analyze their relationship with the disease activity. The study included 60 RA patients admitted to the Department of Rheumatology at Anhui Provincial Hospital of Traditional Chinese Medicine between December 2022 and December 2023. Thirty healthy individuals from the hospital's physical examination center served as the control group. Serum levels of IL-6 and IL-12P70 were detected using flow cytometry. SAA levels were determined by immunoturbidimetry, and PCT levels were assessed by chemiluminescence. Erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), rheumatoid factor (RF), and anticyclic citrullinated peptide (ACCP) were detected using an automated biochemical analyzer. The 28-joint disease activity scores (DAS28-ESR) based on ESR were observed. Statistical analysis included t-tests, rank-sum tests, and Kruskal-Wallis H tests to compare the expression differences of the biomarkers among different groups. The diagnostic value of these biomarkers for RA was analyzed by ROC curve analysis. Spearman correlation analysis was performed to assess the relationships between the four inflammatory biomarkers and CRP, ESR, RF, ACCP, and DAS28-ESR. 1) The expression levels of SAA, IL-6, and IL-12P70 in the RA group were significantly higher than those in the control group (P<0.01). 2) ROC curve analysis showed that the area under the curve (AUC) for PCT was 0.611 (95% confidence interval [CI]: 0.488-0.735, P>0.05), for SAA, it was 0.819 (95% CI: 0.733-0.906, P<0.01), for IL-6, it was 0.875 (95% CI: 0.803-0.946, P<0.01), and for IL-12P70, it was 0.832 (95% CI: 0.746-0.917, P<0.01). The combined index of IL-6, IL-12P70, SAA, and PCT had an AUC of 0.973 (95% CI: 0.942-1.000, P<0.01). This indicates that the four inflammatory biomarkers can assist in the diagnosis of rheumatoid arthritis. 3) The expression levels of PCT and SAA varied significantly among the high, moderate, and low activity RA groups (P<0.01). 4) In RA patients, CRP was positively correlated with SAA (rs =0.75, P<0.01), and IL-6 (rs =0.52, P<0.01). ESR was positively correlated with SAA (rs =0.36, P<0.01). DAS28-ESR was positively correlated with PCT (rs =0.34, P=0.01), SAA (rs =0.51, P<0.01) and IL-6 (rs =0.33, P=0.01). The four inflammatory biomarkers (PCT, SAA, IL-6, and IL-12P70) are closely related to rheumatoid arthritis disease activity and can serve as serum indicators to assist in the diagnosis and assessment of RA.

Role of CXCL-10 as a Biomarker for Rheumatoid Arthritis

Abstract Background CXCL-10 has been detected within sera, synovial fluid, and synovial tissue in patients with RA and identified as a pro-inflammatory chemokine that mediate leukocyte trafficking and modulate innate and adaptive immune responses. It plays a critical role in the inflammatory response and is involved in several biological processes. Objective To evaluate the predicative significance of chemokine CXCL10 in rheumatoid arthritis (RA) and to focus on its relation to disease activity. Patients and Methods A case control study included 30 patients; were diagnosed with RA, and 30 healthy controls. Clinical examination was done for all patients. Measurement of serum CXCL10 level was done by ELISA, while assessment of disease activity in patients was done using disease activity score (DAS-28). Serum levels of CXCL10 were significantly higher in RA patients than controls. Results Serum level of CXCL-10 was ranging from 349–1380 pg/ml with a mean of 784.6 ± 152.2 in RA patients, which was very high level compared to control group the serum level was ranging from 137 – 476.8 pg/ml with a mean of 338.1 ± 125.5. The difference was statistically highly significant (p &amp;lt; 0.001). AUC for CXCL-10 was 0.951 and the 95% CI was ≤ 1. The cutoff point of CXCL-10 was 450 pg/mL were able to differentiate between RA patients and control group. Most of RA patients (70%) were on methotrexate with dose ranged from 12.5–25 mg per week. Thirty-five (58.3%) patients were on steroids with dose 5-20 mg per day. Comparison of CXCL-10 levels in patients with different grades of disease activity had a statistically significant difference between different grades. Conclusion Our study supports the critical role of CXCL10 in the RA inflammatory cascade. The correlation of CXCL10 with clinical disease activity suggests that CXCL10 plays a central role in RA inflammation and may serve as a disease activity marker in RA. CXCL10 has a significant role as a biomarker for prediction of RA.

Anti-carbamylated Protein Antibodies Positivity in Rheumatoid Arthritis and Its Association With Rheumatoid Factor and Anti-cyclic Citrullinated Protein Antibodies.

Background Rheumatoid arthritis (RA) is a widespread autoimmune disease affecting millions of people worldwide. The current markers include anti-cyclic citrullinated peptide (anti-CCP) antibodiesand rheumatoid factor (RF), which are nonspecific and elevated in variousconditions and do not have a prognostic value. They are also elevated in the later stages of the disease. Anti-carbamylated protein (anti-CarP) antibodies have been reported to be associated with joint damage in RA. Therefore, this study aimed to evaluate the sensitivity and specificity of anti-CarP antibodies in individuals with RA and their relationship with inflammatory markers such as C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR). Methods This was a cross-sectional case-control study conducted from April 2020 to March 2021 at the Saveetha Medical College, Chennai, India. The age makeup of the three groups was evaluated: Group 1 comprised anti-CCP and RF-positive patients; Group 2 comprised anti-CCP and RF-negative patients; and Group 3 was the control group, which comprised healthy volunteers. Patient samples, including blood and serum, have been utilized to conduct various assessments aimed at evaluating biomarkers such as CRP, ESR, RF, and autoantibodies like anti-CCP and anti-CarP. Results This study examined the role of various autoantibodies and biomarkers in RA across three distinct groups. Group 1 predominantly consisted of middle-aged individuals, and women constituted the majority in both Group 1 and Group 2, consistent with higher RA prevalence among females. In Group 1, 65.7% of patients tested positive for anti-CarP, while in Group 2, 48.6% tested positiveeven when RF and anti-CCP antibodies were absent. This suggests a potential diagnostic role for anti-CarP antibodies in identifying RA patients early. CRP and ESR levels were significantly elevated in RA patients (Groups 1 and 2) compared to healthy controls (Group 3), indicating higher inflammatory activity in affected individuals. We also observed that anti-CarPantibodies had a specificity of 69.1% and a sensitivity of 78.2%. Positive correlations between the diagnosis of RA and anti-CarP antibody positivity were observed across the groups and correlated well with the inflammatory markers and signs such as joint damage. The data were found to be statistically significant. Conclusions Our study showed a significant correlation between joint damage and CRP levels and a positive correlation between anti-CarP antibodies and ESR and CRP values. These findings suggest that anti-CarP antibodies can offer certain advantages over RF and anti-CCP antibodies in RA diagnosis due to their early detection potential, higher specificity, complementary diagnostic role, and predictive value for disease severity.

Do Ultrasound Lung Abnormalities Correlate to Biomarkers and Male Gender in Rheumatoid Arthritis Patients? A Monocentric Cross-Sectional Study.

Background: Lung ultrasound (LUS) is a tool of growing interest in Rheumatoid Arthritis (RA) oligo- symptomatic ILD to avoid. Objective: We aimed to evaluate (i) the prevalence of pleural (PLUS) and parenchymal (PAUS) abnormalities in LUS in the RA population and their possible correlation to biomarkers; (ii) the predictivity of gender, smoking habits, previous infections (past COVID-19 tuberculosis), and treatments; (iii) the differences in LUS between sexes. Methods: We collected the data of 155 (15 early and 140 late) RA patients with mild respiratory symptoms, evaluating PLUS and PAUS, in fourteen lung areas and also summing the scores (LUS-T). Results: Only 13/155 (8.4%) were completely negative; LUS correlated to age (all parameters p 0.0001), rheumatoid factor IgM (PLUS p 0.0006, PAUS p 0.02, LUS-T p 0.001) and ACPA (p 0.001, 0.006, 0.001, respectively), and PLUS also correlated to IL6 (p 0.02). The male gender was predictive of all LUS evaluations (p 0.001, 0.05, 0.001, respectively), which were higher than in women (p 0.001, 0.01, 0.001, respectively). Other potential risk factors were independent, except biological treatments, which showed a low predictivity to PLUS (p < 0.05). Conclusions: We can conclude that LUS is a useful technique in RA low respiratory symptoms and correlates with age, the most important RA biomarkers, and male sex.

The peculiar features, diversity and impact of citrulline-reactive autoantibodies.

Since entering the stage 25 years ago as a highly specific serological biomarker for rheumatoid arthritis, anti-citrullinatedprotein antibodies (ACPAs) have been a topic of extensive research. This hallmark B cell response arises years before disease onset, displays interpatient autoantigen variability, and is associated with poor clinical outcomes. Technological and scientific advances have revealed broad clonal diversity and intriguing features including high levels of somatic hypermutation, variable-domain N-linked glycosylation, hapten-like peptide interactions, and clone-specific multireactivity to citrullinated, carbamylated and acetylated epitopes. ACPAs have been found in different isotypes and subclasses, in both circulation and tissue, and are secreted by both plasmablasts and long-lived plasma cells. Notably, although some disease-promoting features have been reported, results now demonstrate that certain monoclonal ACPAs therapeutically block arthritis and inflammation in mouse models. A wealth of functional studies using patient-derived polyclonal and monoclonal antibodies have provided evidence for pathogenic and protective effects of ACPAs in the context of arthritis. To understand the roles of ACPAs, one needs to consider their immunological properties by incorporating different facets such as rheumatoid arthritis B cell biology, environmental triggers and chronic antigen exposure. The emerging picture points to a complex role of citrulline-reactive autoantibodies, in which the diversity and dynamics of antibody clones could determine clinical progression and manifestations.

Sinomenine treats rheumatoid arthritis by inhibiting MMP9 and inflammatory cytokines expression: bioinformatics analysis and experimental validation

Rheumatoid arthritis (RA) is a chronic systemic autoimmune disease marked by inflammatory cell infiltration and joint damage. The Chinese government has approved the prescription medication sinomenine (SIN), an effective anti-inflammation drug, for treating RA. This study evaluated the possible anti-inflammatory actions of SIN in RA based on bioinformatics analysis and experiments. Six microarray datasets were acquired from the gene expression omnibus (GEO) database. We used R software to identify differentially expressed genes (DEGs) and perform function evaluations. The CIBERSORT was used to calculate the abundance of 22 infiltrating immune cells. The weighted gene co-expression network analysis (WGCNA) was used to discover genes associated with M1 macrophages. Four public datasets were used to predict the genes of SIN. Following that, function enrichment analysis for hub genes was performed. The cytoHubba and least absolute shrinkage and selection operator (LASSO) were employed to select hub genes, and their diagnostic effectiveness was predicted using the receiver operator characteristic (ROC) curve. Molecular docking was undertaken to confirm the affinity between the SIN and hub gene. Furthermore, the therapeutic efficacy of SIN was validated in LPS-induced RAW264.7 cells line using Western blot and Enzyme-linked immunosorbent assay (ELISA). The matrix metalloproteinase 9 (MMP9) was identified as the hub M1 macrophages-related biomarker in RA using bioinformatic analysis and molecular docking. Our study indicated that MMP9 took part in IL-17 and TNF signaling pathways. Furthermore, we found that SIN suppresses the MMP9 protein overexpression and pro-inflammatory cytokines, including tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) in the LPS-induced RAW264.7 cell line. In conclusion, our work sheds new light on the pathophysiology of RA and identifies MMP9 as a possible RA key gene. In conclusion, the above findings demonstrate that SIN, from an emerging research perspective, might be a potential cost-effective anti-inflammatory medication for treating RA.

Safety of Tocilizumab on Rheumatoid Arthritis in Patients with Interstitial Lung Disease.

The prognosis of rheumatoid arthritis (RA) with interstitial lung disease (ILD) is particularly poor. Although drugs that do not contribute to the progression of ILD should be used in RA treatment, none have been established. This study evaluated the safety of tocilizumab in terms of ILD activity. This study prospectively enrolled all 55 patients with RA complicated by ILD who were treated with tocilizumab at Dokkyo Medical University Saitama Medical Center from April 2014 to June 2022. The outcome measures were MMP-3 and KL-6 as biomarkers of RA and ILD activity, respectively, and the relationship between them was analyzed. Both MMP-3 and KL-6 were significantly improved at 6 months of treatment (P < 0.001 and P < 0.05, respectively), and a weak correlation between MMP-3 and KL-6 was observed (R2 = 0.086, P = 0.087). The group with increased MMP-3 due to RA progression had significantly higher KL-6 at 6 months compared with the group with RA improvement (P < 0.05). Also, the group with ILD progression on computed tomography had significantly higher MMP-3 compared with the groups with improvement or no change of ILD (P < 0.05 and P < 0.01, respectively). The mortality rate was 0% at 6 months, 2.0% at 1 year, 16.7% at 2 years, and 32.4% at 3 years, and mortality from acute exacerbation of ILD due to respiratory infection increased over time. RA activity and ILD activity were found to be related at 6 months of treatment. Tocilizumab does not seem to affect the mechanism of ILD progression, as most patients showed improvement in both MMP-3 and KL-6 with tocilizumab within 6 months, when this drug would be expected to affect the lungs directly. However, respiratory infection exacerbated ILD from 1 year after the start of treatment. As immunosuppressive drugs, including tocilizumab, have a risk of respiratory infection, it is important to identify early signs of infection.

Combination of scavenger receptor-A with anti-cyclic citrullinated peptide antibody for the diagnosis of rheumatoid arthritis.

The routine biomarkers for rheumatoid arthritis (RA), including anticyclic citrullinated peptide antibody (anti-CCP), rheumatoid factor (RF), immunoglobulin M (IgM), erythrocyte sedimentation rate (ESR), and C-reaction protein (CRP) have limited sensitivity and specificity. Scavenger receptor-A (SR-A) is a novel RA biomarker identified by our group recently, especially for seronegative RA. Here, we performed a large-scale multicentre study to further assess the diagnostic value of SR-A in combination with other biomarkers for RA. The performance of SR-A in combination with other biomarkers for RA diagnosis was first revealed by a pilot study, and was further elucidated by a large-scale multicentre study. A total of 1129 individuals from 3 cohorts were recruited in the study, including RA patients, healthy controls, and patients with other common rheumatic diseases. Diagnostic properties were evaluated by the covariate-adjusted receiver-operating characteristic (AROC) curve, sensitivity, specificity and clinical association, respectively. Large-scale multicentre analysis showed that SR-A and anti-CCP dual combination was the optimal method for RA diagnosis, increasing the sensitivity of anti-CCP by 13% (87% vs 74%) while maintaining a specificity of 90%. In early RA patients, SR-A and anti-CCP dual combination also showed promising diagnostic value, increasing the sensitivity of anti-CCP by 7% (79% vs 72%) while maintaining a specificity of 94%. Moreover, SR-A and anti-CCP dual combination was correlated with ESR, IgM, and autoantibodies of RA patients, further revealing its clinical significance. SR-A and anti-CCP dual combination could potentially improve early diagnosis of RA, thus improving the prognosis and reducing mortality.

Differences in the expression of long noncoding RNAs in peripheral blood mononuclear cells indicate potential biomarkers for rheumatoid arthritis

ObjectiveLong noncoding RNAs (lncRNAs) play an increasingly important role in various autoimmune diseases. We aimed to characterize the expression profiles of lncRNAs in peripheral blood mononuclear cells (PBMCs) from RA patients and to assess the potential of these lncRNAs as RA biomarkers. MethodsWhole-transcriptome sequencing was used to establish a lncRNA expression profile. A total of 155 RA patients, 145 healthy controls, 59 systemic lupus erythematosus (SLE) patients and 59 primary Sjögren’s syndrome (pSS) patients were recruited for this study. Four candidate lncRNAs (linc00152, lnc-ADM-1, ITSN1-2, and lnc-FTH1-7) were validated via qRT-PCR in independent samples, and their expression, association with RA clinical features and value as RA biomarkers were evaluated. ResultsLinc00152 and lnc-ADM-1 exhibited upregulated expression (p = 0.001, p = 0.014, respectively), while ITSN1-2 and lnc-FTH1-7 exhibited downregulated expression (both p < 0.001, respectively) in RA patients compared to controls. Lnc-ADM-1 and lnc-FTH1-7 expression correlated positively with the C4 level (p = 0.016 and p = 0.012, respectively). ITSN1-2 levels were negatively associated with CRP levels (p = 0.024). Linc00152, lnc-ADM-1, ITSN1-2, and lnc-FTH1-7 showed potential as RA biomarkers, with the four-lncRNA panel distinguishing RA patients from controls, SLE patients, or pSS patients (AUC = 0.886, 0.746, and 0.749, respectively). ConclusionThe altered expression of linc00152, lnc-ADM-1, ITSN1-2 and lnc-FTH1-7 in RA patients suggested that these genes may serve as potential biomarkers for RA and could be involved in its pathogenesis.

SLAMF8 as a potential biomarker for rheumatoid arthritis identified by comparing peripheral blood mononuclear cells, fibroblast‐like synoviocytes, and synovial tissue using bioinformatics analysis

AbstractBackgroundRheumatoid arthritis (RA) is a chronic autoimmune inflammatory disease. Its pathogenesis is not fully understood, and early diagnosis is challenging owing to the lack of effective biomarkers. This study aimed to analyze different samples to identify potential biomarkers and therapeutic targets.MethodsMicroarray datasets of RA, osteoarthritis (OA), and healthy control (HC) were downloaded from the Gene Expression Omnibus database. R software was used to identify differentially expressed genes (DEGs), which were visualized using volcano and heat maps. Venn diagrams, principal component analysis, gene set enrichment analysis, gene ontology, and Kyoto Encyclopedia of genes and genomes were used to analyze the data. A protein–protein interaction network was constructed, and synovial tissues from patients with RA and OA were collected for verification using the collagen‐induced arthritis mouse model.ResultsMore DEGs were found in synovial tissues than in peripheral blood mononuclear cells or fibroblast‐like synoviocytes. Principal component analysis revealed significant differences between the RA and OA samples, highlighting the unique advantages of synovial tissue. Enrichment analysis revealed that metabolic and cytokine signaling pathways play crucial roles in the development of RA. Further analysis of the four synovial datasets identified 54 DEGs, of which signaling lymphocytic activation molecule family (SLAMF) 8 was identified as the key molecule. SLAMF8 levels were increased in the synovial tissue of patients with RA compared to those of patients with OA (0.38 ± 0.19 vs. 12.40 ± 1.66), and SLAMF8 levels were similarly elevated in collagen‐induced arthritis model mice compared with those in the healthy mice (1.13 ± 0.47 vs. 9.05 ± 2.52).ConclusionsThis study established the unique advantages of synovial tissue for RA research and identified metabolic and cytokine signaling pathways as important for RA development. Thus, SLAMF8 may be a potential therapeutic target for RA.