Diagnostic Markers For Rheumatoid Arthritis Research Articles

What Could Lead to the Production of Anti-Rheumatoid Antibodies in Patients with Brucellosis Spondylodiscitis: Possible Causes.

High titers of specific antibodies to cyclic citrulline peptide (ACCP) are often present in the serum of patients with rheumatoid arthritis (RA) and, together with rheumatoid factor (RF), are a diagnostic marker of RA. Brucellosis is a zoonotic infection in which osteoarticular involvement occurs in 10-85% of patients. RF in brucellosis patients is significantly higher than in healthy people. We presented 2 cases of brucellosis spondylodiscitis with positive results for RF and ACCP, which aroused great interest among the rheumatologists of our center. Both patients described were men (27 and 60 years old) with arthritis, back pain, and high levels of rheumatoid arthritis-specific antibodies. These patients were suspected of having tuberculous spondylitis, but the tuberculous process was excluded using specific tests. During antibacterial therapy, there is a dynamic decrease in antirheumatoid antibodies. X-rays of the hand joints revealed no signs of erosive arthritis. All cases of arthritis, spondylitis, and spondylodiscitis in endemic areas require careful analysis and comparison of patients' clinical and laboratory-instrumental data to prevent misdiagnosis. With brucellosis infection, against the background of adequate antibacterial therapy, inflammation of the joints and spine is reversible.

The association between body mass index, diagnostic markers and disease activity score with progression of rheumatoid arthritis in a sample of Iraqi patients

Background: Rheumatoid arthritis (RA) is a widespread, chronic, systemically inflammatory disease which, if improperly treated, can cause deformed joints and functional disability. For best disease management, greater chances of recovery, and the avoidance of irreversible clinical and radiographic damage, RA must be diagnosed and treated as soon as possible.Objectives: The purpose of this study was to evaluate body mass index utilizing DAS and levels of diagnostic tests in rheumatoid arthritis patients.Materials and methods: 120 patients with rheumatoid arthritis (60 newly diagnosed untreated patients and 60 others under treatment) were collected from Al-Yarmouk Hospital in Baghdad and 60 control individuals. Body mass index (BMI) was measured by equation and diagnostic tests, then vitamin D3 with the COPAS 111 device. Results: The prevalence of the disease in females was 91%, while males were 9%. Diagnostic tests recorded clear significance (p < 0.05) differences between patients and healthy persons, and it increased with the severity of the disease. Additionally, patients' levels of vitamin D3 reduced significantly when compared to controls, and there was a significant disparity between patients and healthy participants' sugar levels, and the BMI correlated with disease activity.Conclusions: The current study concluded that there is a relationship between weight gain and disease severity, that diagnostic tests increased in patients, and that vitamin D3 can be used as a diagnostic marker for rheumatoid arthritis. Keywords: Body mass index (BMI),disease activity score DAS-28, diagnostic marker.

Validation of new immune and inflammation-related diagnostic biomarkers for RA.

Rheumatoid arthritis (RA) is a chronic, systemic autoimmune disease, whose development is associated with immune cells and persistent inflammation. Exploring the biomarkers of RA holds immense significance in terms of the prevention, diagnosis, and treatment of RA. The differentially expressed genes (DEGs) in RA patients and the control group were screened by limma package. Through DEGs intersection overlapping 200 inflammatory response-related genes and 2498 immune-related genes, differentially expressed immune and inflammation-related genes (DE-IIRGs) were identified. Lasso regression analysis screened RA diagnostic biomarkers and constructed PPI networks. Finally, immune infiltration analysis and drug prediction were performed. A total of 20 DE-IIRGs were identified by overlapping DEGs with 2498 immune-related genes and 200 inflammatory response-related genes. These DE-IIRGs were primarily enriched in the cytokine-cytokine receptor interaction and other biological processes, and then five biomarker genes (TNFSF10, IL1R1, CXCL9, ACVR1B, and IL15) were identified. It was found that the expression levels of CXCL9, IL15, and TNFSF10 in the disease samples were significantly higher than those in the control group. These biomarker genes have more effective diagnostic potential. The RA samples exhibited significantly higher levels of cell infiltration compared to the control samples. hsa-miR-199a-5p's connections to the ACVR1B and CCR7 genes were identified by creating ceRNA networks from 20 screened DE-IIRGs. There was a connection between CCL5 and AEMA4D and hsa-miR-214-3p. We identified immune- and inflammation-related biomarkers in RA based on bioinformatics analysis and screened TNFSF10, IL1R1, CXCL9, ACVR1B, and IL15 as diagnostic markers for RA. Key Points • TNFSF10, IL1R1, CXCL9, ACVR1B, and IL15 may be new diagnostic biomarkers for RA. • These findings may provide a theoretical basis for early RA diagnosis.

Circ_0011058 alleviates RA pathology through the circ_0011058/miR-335-5p/CUL4B signal axis

Our previous study found that Cullin 4B (CUL4B) inhibited rheumatoid arthritis (RA) pathology through glycogen synthase kinase-3beta (GSK3β)/canonical Wnt signalling pathway. In this work, pre-experiment and bioinformatics analysis suggested that circ_0011058 may lead to the up-regulation of CUL4B expression by inhibiting miR-335-5p. Therefore, we studied whether circ_0011058 can promote the expression of CUL4B through sponging the miR-335-5p and further promote the pathological development of RA. Bioinformatics prediction, real-time quantitative PCR (RT-qPCR), western blot (WB), double luciferase reporter gene and other relevant methods were used to study the inhibition of circ_0011058 on RA pathology and its molecular mechanism. Results showed that the expression of circ_0011058 was significantly increased in adjuvant arthritis (AA) rats and RA fibroblast-like synoviocytes (FLS). The knockout of circ_0011058 inhibited the proliferation of AA FLS and RA FLS, decreased the levels of interleukin-1 beta (IL-1β), interleukin 6 (IL-6), interleukin 8 (IL-8), and inhibited the expression of matrix metalloproteinase 3 (MMP3), fibronectin, which showed that circ_0011058 had a strong role in promoting RA pathology. Furthermore, miR-335-5p expression was reduced in AA rats and RA FLS. The highly expressed circ_0011058 directly sponged the miR-335-5p, which led to the increase of CUL4B expression and promoted the activation of the GSK3β/canonical signalling pathway. Finally, we confirmed that miR-335-5p mediated the roles of circ_0011058 in promoting RA pathological development, which showed that the circ_0011058/miR-335-5p/CUL4B signal axis was involved in RA pathology. This work was of great significance for clarifying the roles of circ_0011058 in RA pathology, and further work was needed to establish whether circ_0011058 was a potential therapeutic target or diagnostic marker for RA.

Identification of CD8+ T cell-related biomarkers and immune infiltration characteristic of rheumatoid arthritis.

Rheumatoid arthritis (RA) is an autoimmune rheumatic disease, which do not respond well to current treatment partially. Therefore, further in-depth elucidation of the molecular mechanism and pathogenesis of RA is urgently needed for the diagnosis, personalized therapy and drug development. Herein, we collected 111 RA samples from Gene Expression Omnibus (GEO) database, and conducted differentially expressed genes and GESA analysis. Abnormal activation and imbalance of immune cells in RA were observed. WGCNA was utilized to explore the gene modules and CD8+ T cell-related genes (CRGs) were chosen for KEGG and GO analysis. Besides, to explore biomarkers of RA in depth, machine learning algorithms and bioinformatics analysis were used, and we identified GDF15, IGLC1, and IGHM as diagnostic markers of RA, which was confirmed by clinical samples. Next, ssGSEA algorithms were adopted to investigate the differences in immune infiltration of 23 immune cell subsets between RA and healthy control group. Finally, optimal classification analysis based on consensus clustering combined with ssGSEA algorithms were conducted. GDF15 was revealed that to be positively correlated with mast cells and type 2 T helper cells, but negatively correlated with most other immune cells. On the other hand, IGHM and IGLC1 were negatively correlated with CD56dim natural killer cells, while positively associated with other immune cells. Finally, RA samples in subtype A exhibited a higher immune infiltration status. This study could provide guidance for individualized treatment of RA patients and provide new targets for drug design.

The Role of Collagen Triple-Helix Repeat-Containing 1 (CTHRC1) as a Diagnostic Biomarker for Rheumatoid Arthritis

Background Many patients are seronegative for anti-citrullinated protein antibodies (ACPA) and rheumatoid factor (RF), and there is a need for novel serological biomarkers to help close this serological gap and improve early diagnosis. The purpose of this study was to determine whether plasma levels of the collagen triple helix repeat containing 1 (CTHRC1) protein can serve as a blood-based biomarker for improved diagnosis of rheumatoid arthritis (RA) patients. Objective Evaluate the levels of the collagen triple helix repeat containing-1 (CTHRC1) protein in RA patients' serum in order to detect its role as a diagnostic biomarker in Rheumatoid Arthritis patients & determine its value in assessment of disease activity in Rheumatoid Arthritis patients. Methods This study included twenty five adult patients with clinical evidence of rheumatoid arthritis and twenty five healthy matched age and sex as control subjects. All underwent history taking, clinical examination, assessment of disease activity with modified Disease Activity 28 (DAS28), Laboratory investigations including Complete blood count (CBC), erythrocytes sedimentation rate (ESR), C-Reactive Protein (CRP), Liver function tests, Kidney function tests, qualitative assessment of RF, anti CCP Ab and CTHRC1 serum levels. Special attention had been given to patients (nine out of twenty five patients) diagnosed in early disease process (1-2 months). Results Serum levels of CTHRC1 were significantly higher in patients than control group (p > 0,001) with sensitivity of 100% and specificity of 88%. It showed significant positive correlation with Anti-CCP (r = 0.498) (p < 0.011) and with RF (t= -6.489) (p <<0.001) as diagnostic markers for RA. Serum levels of CTHRC1 showed statistically significant difference between patients in early, late disease process and controls. Conclusion serum CTHRC1 level was higher in RA patients which serve as a diagnostic marker for RA with statistically significant correlation with early disease process highlighting its role as a diagnostic marker for RA.

Interleukin -37 in rheumatoid arthritis: Correlation with clinical severity and genetic polymorphisms in Mosul city, Iraq

The contribution of anti-inflammatory cytokines to rheumatoid arthritis (RA) is not fully comprehended. In the current research we assessed the serum concentration of interleukin (IL)-37 anti-inflammatory cytokine in RA, studied its association to disease activity score 28 (DAS28) and investigated single nucleotide polymorphism (rs2723176) of IL-37 gene as a threat for RA development. The case-control study included 60 RA patients and 30 normal control individuals. Serum IL-37 was assessed by ELISA and genotyped by "sequence-specific primer-polymerase chain reaction (SSP-PCR)". The mean IL-37 was elevated in RA patients (69.42 ng /l ± 62.99) compared to control individuals (14.66 ng /l ± 23.58, p < 0.001). IL-37 tended to increase with age where highest levels were noted in patients more than 60 years (p = 0.037). No Gender influence was found on IL-37 level (p>0.05). At best cut-off value of 31.5 ng/ l, IL-37 had a sensitivity of 73.3% and specificity of 83.3%. No correlation of IL-37 with DAS 28 score was observed (r=0.1497, p=0.2535). For IL-37 (rs2723176) gene polymorphism, C/C genotype was prevailing in both RA (90%) and normal controls (93.3%) compared to A/C or A/A. Also, no variation was found between patents and controls in regard to C/C genotype (OR = 0.643, 95% CI (0.122-3.39, p=0.603). The mean IL-37 concentration in RA patients with C/C genotype (59.70± 67.92) was not different from AC genotype (80.54± 94.18, p=0.4748). We concluded that serum IL-37 had the implication as a diagnostic marker in RA. However, it did not correlate with clinical severity of the disease. Meanwhile, IL-37 (rs2723176) gene polymorphism did not seem to be as a risk factor for RA, nor contributed to the increase of IL-37 level among patients.

Identification of PSMB9 and CXCL13 as Immune-related Diagnostic Markers for Rheumatoid Arthritis by Machine Learning.

Rheumatoid arthritis (RA) is a chronic inflammatory disease that causes significant physical and psychological damage. Although researchers have gained a better understanding of the mechanisms of RA, there are still difficulties in diagnosing and treating RA. We applied a data mining approach based on machine learning algorithms to explore new RA biomarkers and local immune cell status. We extracted six RA synovial microarray datasets from the GEO database and used bioinformatics to obtain differentially expressed genes (DEGs) and associated functional enrichment pathways. In addition, we identified potential RA diagnostic markers by machine learning strategies and validated their diagnostic ability for early RA and established RA, respectively. Next, CIBERSORT and ssGSEA analyses explored alterations in synovium-infiltrating immune cell subpopulations and immune cell functions in the RA synovium. Moreover, we examined the correlation between biomarkers and immune cells to understand their immune-related molecular mechanisms in the pathogenesis of RA. We obtained 373 DEGs (232 upregulated and 141 downregulated genes) between RA and healthy controls. Enrichment analysis revealed a robust correlation between RA and immune response. Comprehensive analysis indicated PSMB9, CXCL13, and LRRC15 were possible potential markers. PSMB9 (AUC: 0.908, 95% CI: 0.853-0.954) and CXCL13 (AUC: 0.890, 95% CI: 0.836-0.937) also showed great diagnostic ability in validation dataset. Infiltrations of 16 kinds of the immune cell were changed, with macrophages being the predominant infiltrating cell type. Most proinflammatory pathways in immune cell function were activated in RA. The correlation analysis found the strongest positive correlation between CXCL13 and plasma cells, PSMB9, and macrophage M1. There is a robust correlation between RA and local immune response. The immune-related CXCL13 and PSMB9 were identified as potential diagnostic markers for RA based on a machine learning approach. Further in-depth exploration of the target genes and associated immune cells can deepen the understanding of RA pathophysiological processes and provide new insights into diagnosing and treating RA.

The Effect of Inhaled Air Particulate Matter SRM 1648a on the Development of Mild Collagen-Induced Arthritis in DBA/J Mice

Air pollution is considered to be one of a risk factor for rheumatoid arthritis (RA). Collagen-induced arthritis (CIA) is commonly used as a mouse model of human RA. However, the impact of specific particulate matter (PM) components on the incidence and severity of RA has still not been established. The aim of this study was to develop an experimental model of CIA suitable to test arthritogenicity of inhaled PM. A mild form of CIA was induced in DBA1/J mice inhaled with various components of SRM 1648a PM. The incidence and severity of arthritis was assessed, and the selected serum markers of autoimmunity and inflammation were determined. Clinical arthritis was observed from the booster CII immunisation onward. Anti-cyclic citrullinated peptide antibodies, a diagnostic marker of RA, were detected in serum of these mice. All inhaled pollutants, crude PM, PM with reduced organic content, ferric, and silica nanoparticles markedly increased CIA incidence and severity. The fastest progression of CIA development was caused by crude PM and was linked to enhanced serum levels of anti-CII IgG, the prominent arthritogenic autoantibodies. On the other hand, inhaled nanoparticles enhanced serum levels of TNFα, a major proinflammatory arthritogenic cytokine. We recommend this experimental model of mild CIA to test the mechanisms of arthritis exacerbation by inhaled air pollutants. Further studies are necessary to determine whether PM-aggravated arthritis is caused by inflammatory mediators translocated from inflamed lung into systemic circulation or whether PM translocated into the bloodstream directly exacerbate joint inflammation.

Three key genes expression profiling in Egyptian rheumatoid arthritis patients

Rheumatoid arthritis (RA) is a multi-system autoimmune disease with synovial joints involvement. The triad of autoimmunity, genetics, and environment is the key player in RA pathogenesis. We intended to investigate gene expression of C-C Chemokine Ligand 2 (CCL2), protein tyrosine phosphatase non-receptor type 22 (PTPN22), and Cytotoxic T-lymphocyte associated protein 4 (CTLA-4) in RA patients versus controls, and its correlation with the activity of the disease. The relative expression of PTPN22, CTLA-4, and CCL2 in the peripheral blood of 59 RA patients and 50 controls was determined using RT-PCR. There was a significantly higher median (inter-quartile range) expression of CTLA-4 and CCL2 in RA patients in comparison to controls (P < 0.05). However, in RA patients, PTPN22 expression was significantly lower than in controls (P=0.0001). A weak significant correlation was detected between PTPN22 and either CTLA-4 or CCL2. Also, on comparing RA patients with moderate to severe disease activity versus those who have a mild disease activity, CCL2 was significantly over-expressed (P > 0.05). Thus, in Egyptian RA patients, there was a significant PTPN22 down-expression and greater expression of CTLA-4 and CCL2. Moreover, over-expression of CCL2 in RA patients with moderate-to-severe disease activity was significant. We conclude that these three key genes could become useful diagnostic markers for RA and CCL2 expression as a good prognostic tool for RA disease activity.

Anti carbamylated protein antibodies as a diagnostic marker in patients with rheumatoid arthritis and its association with disease activity

Abstract Background Despite the diagnostic contribution of anti-citrullinated protein( anti-CCP) antibody and rheumatoid factor (RF), approximately one-third of patients with rheumatoid arthritis (RA) remain seronegative .Anti-carbamylated protein (Anti-Carp) antibodies have been attracting increasing attention as a new diagnostic marker of RA. Objective evaluate levels of anti-carp antibodies in RA patients in order to detect its role as a diagnostic marker and its possible association with disease activity and severity. Methods This study included thirty adult patients with clinical evidence of rheumatoid arthritis and thirty healthy matched age and sex as controls. All underwent history taking, clinical examination, assessment of disease activity with modified Disease Activity28 (DAS28), Laboratory investigations including Complete blood count (CBC), erythrocytes sedimentation rate (ESR), C-Reactive Protein (CRP), Liver function tests, Kidney function tests, Serum uric acid, RF, anti CCP Ab, anti-Carp Ab and radiographic Assessment with Larsen score. Results Plasma levels of anti-Carp Ab were significantly higher in patients than control group (p &amp;gt; 0,001) with sensitivity of 73.33% and specificity of 100%.it showed significant positive correlation with CRP (r = 0.37 )(p &amp;lt; 0.05) as a marker of activity of RA and also there was significant positive correlation with RF and ACPA (r = 0.45)(r = 0.48) (p &amp;lt; 0.05) respectively as a diagnostic marker for RA. Plasma levels of anti-Carp Ab were higher in patients with more joints damage and erosions as assessed by Larsen radiological score as there was a highly significant correlation between Larsen score and serum Anti-Carp(r = 0.61)(p &amp;lt; 0.001).. Conclusion serum Anti–Carp antibody level was higher in RA patients which serve as a diagnostic marker for RA, also its significant correlation with CRP and Larsen score may serve as a marker for disease progression and severity.

Marker Genes Change of Synovial Fibroblasts in Rheumatoid Arthritis Patients.

Background Rheumatoid arthritis (RA) is a chronic condition that manifests as inflammation of synovial joints, leading to joint destruction and deformity. Methods We identified single-cell RNA-seq data of synovial fibroblasts from RA and osteoarthritis (OA) patients in GSE109449 dataset. RA- and OA-specific cellular subpopulations were identified, and enrichment analysis was performed. Further, key genes for RA and OA were obtained by combined analysis with differentially expressed genes (DEGs) between RA and OA in GSE56409 dataset. The diagnostic role of key genes for RA was predicted using receiver operating characteristic (ROC) curve. Finally, we identified differences in immune cell infiltration between RA and OA patients, and utilized flow cytometry, qRT-PCR, and Western blot were used to examine the immune cell and key genes in RA patients. Results The cluster 0 matched OA and cluster 3 matched RA and significantly enriched for neutrophil-mediated immunity and ECM receptor interaction, respectively. We identified 478 DEGs. In the top 20 degrees of connection in the PPI network, the key genes for RA were obtained by comparing with the gene markers of cluster 0 and cluster 3, respectively. ROC curve showed that CCL2 and MMP13 might be diagnostic markers for RA. We found aberrant levels of CD8+T, neutrophil, and B cells in RA fibroblasts, which were validated in clinical samples. Importantly, we also validated the differential expression of key genes between RA and OA. Conclusion High expression of CCL2 and MMP13 in RA may be a diagnostic and therapeutic target.

Cystatin D as a new diagnostic marker in rheumatoid arthritis

The aim of this paper was to assess the diagnostic accuracy of serum cystatin D (CST5) in rheumatoid arthritis (RA). Fifty-eight RA patients were compared with 29 healthy subjects, and the RA activity was measured using the disease activity score 28-joints-erythrocyte rate of sedimentation (DAS-28-ESR). The RA group was then classified into 29 active patients and 29 inactive patients. Serum CST5 was measured using the ELISA Kit. The rheumatoid factor (RF), C-reactive protein (CRP), anti-citrullinated protein antibody (ACPA), renal function test, and liver function test were recorded. The concentration of serum CST5 in the RA group was significantly greater than that of the healthy subjects (p < 0.0001). There was a significant difference in the serum CST5 concentrations between active and inactive RA patients. The serum CST5 concentration was negatively correlated with DAS-28-ESR, and there were significant negative correlations with the ESR as well. However, there was no significant relationship between the concentration of serum CST5 and the sociodemographic features and biochemical parameters (CRP, ACPA). The area under the curve was excellent (AUC = 0.955, p = 0.0001), with high diagnostic accuracy (86.2) in differentiating active RA from the healthy subject group. In conclusion, serum CST5 is a valid marker that can distinguish active RA patients from healthy subjects with high accuracy.

IgG anti-hinge antibodies against IgG4 F(ab\u2019)2 fragments generated using pepsin are useful diagnostic markers for rheumatoid arthritis: implications of the possible roles of metalloproteinases and IgG subclasses in generating immunogenic hinge epitopes

BackgroundPepsin agglutinators, discovered over 50 years ago, have been recently referred to as anti-hinge antibodies (AHAs) because of their reaction with the IgG hinge epitope. AHAs have different reactivity for each hinge epitope generated by each protease that cleaves the hinge region at different sites. Moreover, AHAs have different reactivity against different hinge epitopes derived from each IgG subclass even when the same protease is used. Since the expression of matrix metalloproteinase-3 (MMP-3) is enhanced in rheumatoid arthritis (RA), AHA production could also be increased. The purpose of this study was to determine whether the levels of AHAs against IgG hinge epitopes produced by MMP-3 are elevated in RA.MethodsThe serum levels of IgG or IgA AHAs against the IgG1/IgG4 F(ab’)2 fragments, generated by either MMP-3 or pepsin, were measured using ELISA in 111 patients with RA and 81 healthy controls (HC). Receiver operating characteristic (ROC) analysis was used for obtaining optimal cutoff values and cutoff values indicating high specificity (> 95%) of the AHA. The targeted epitope of a specific AHA was investigated through inhibition ELISA.ResultsSeven AHAs were statistically higher in RA patients than in HC, except IgG AHA against IgG1 F(ab’)2, which was generated by MMP-3 proteolytic cleavage. The areas under the ROC curve were 0.66–0.80, although the sensitivities at high specificity were low (5.4–24.3%). The cumulative number of positive AHAs in each individual was statistically higher in RA patients than in HC, suggesting the extreme extent of AHA repertoires in RA. Inhibition studies revealed that IgG AHAs against IgG4 F(ab’)2 fragments generated by pepsin cross-reacted with IgG1 F(ab’)2 fragments generated by pepsin. Multivariate logistic regression analysis identified the IgG AHA against IgG4 F(ab’)2 fragments generated by pepsin as an independent variable for RA diagnosis, even in RA patients who were negative for both RF and ACPA (odds ratio 1.18, 95% CI 1.06–1.32; P = 0.003). Additional experiments using non-RA patients finally strengthened the diagnostic utility.ConclusionIn RA patients, we observed diversification and amplification of AHA repertoires and diagnostic utility of the specific AHA against IgG4 F(ab’)2 fragments generated by pepsin but not MMP-3.

Serum 14-3-3η protein is associated with clinical and serologic features of Sjögren's syndrome in patients with systemic lupus erythematosus: a cross-sectional analysis.

Systemic lupus erythematosus (SLE) and Sjögren's syndrome (SS) may coexist and carry a higher risk for future comorbidities. Although 14-3-3η protein is recently a known diagnostic marker in rheumatoid arthritis (RA), its role has not been investigated in SLE. The aim of this study was to compare serum 14-3-3η protein level in SLE and RA patients and to examine its association with clinical and laboratory features in SLE patients. Eighty-four SLE patients and 39 RA patients were included. Sociodemographic, SLE disease activity index (SLEDAI), and damage index were assessed for SLE patients. Data about secondary SS were collected. 14-3-3η was measured by ELISA; titres above 0.19ng/ml were considered positive. Serum 14-3-3η protein in SLE was significantly lower than in RA (0.37 ± 0.09 vs 1.5 ± 0.51; p < 0.001). 14-3-3η protein level was comparable between SLE patients with and without arthritis (0.29 ± 0.8 vs 0.15 ± 0.08 respectively; p = 0.20). Serum 14-3-3η protein level was higher in SLE with secondary SS features compared to those without (0.22 ± 0.10IU/ml vs 0.11 ± 0.04IU/ml; respectively, p < 0.001). There were no differences in 14-3-3η positivity for other lupus criteria or correlation of 14-3-3η titer with SLEDAI. 14-3-3η protein at 1.11ng/mL yield a secondary SS diagnostic accuracy of 71%. Serum 14-3-3η protein level is high in SLE-associated SS. The 14-3-3η protein level was able to distinguish patients with secondary SS among patients with SLE. Studying the role of 14-3-3η protein in Sjögren's syndrome would be considered in further larger scale studies to confirm the impact of any association. Key Points • Serum 14-3-3η protein level is significantly higher in systemic lupus patients with secondary Sjögren's syndrome (SS) in comparison to those without. • Serum 14-3-3η protein can be used as a useful marker to distinguish patients with secondary SS among patients with systemic lupus. • 14-3-3η protein level shows no difference between systemic lupus patients with and without arthritis.

Aberrant dysregulated circular RNAs in the peripheral blood mononuclear cells of patients with rheumatoid arthritis revealed by RNA sequencing: novel diagnostic markers for RA

Circular RNAs (circRNAs) represent a newly identified class of non-coding RNAs that have been shown to be involved in several diseases, including autoimmune diseases. Two studies have revealed the aberrant circRNA expression profiles in the peripheral blood mononuclear cells (PBMCs) of patients with rheumatoid arthritis (RA) by microarrays. However, due to the intrinsic defects of microarrays, such as their inability to detect unidentified circRNAs, we examined the circRNA expression profiles in the PBMCs from four RA patients and three healthy controls by RNA sequencing (RNA-seq) and further explored the value of circRNAs in diagnosing RA. The results showed 71 markedly dysregulated circRNAs, including 41 upregulated and 30 downregulated circRNAs; these data included several previously unidentified candidate circRNAs. Gene Ontology and pathway annotation revealed that the most altered pathways and genes were associated with inflammation and transcriptional activity, such as the TNF pathway. The selected dysregulated circRNAs were verified by qRT-PCR in the PBMCs of 32 RA patients and 20 healthy controls, and the results indicated that hsa_circ_0000396 and hsa_circ_0130438 were downregulated in the RA group versus the healthy group, consistent with the RNA-seq data. The area under the receiver operating characteristic curve indicated the diagnostic value of both circRNAs for RA. Our results identified aberrant dysregulated circRNAs in RA patients, including several identified circRNAs, and the diagnostic value of circRNAs for RA, suggesting the superiority of RNA-seq versus microarrays for screening differentially expressed circRNAs and further strengthening the potential diagnostic value of circRNAs for the diagnosis of RA.

Interleukin 21 as a diagnostic marker of rheumatoid arthritis.

To investigate the role of IL-21 as diagnostic marker in diagnosis of rheumatoid arthritis. Study Design: Cross sectional study. Setting: Department of Physiology and Orthopedic Gujranwala Medical College, Gujranwala. Period: October 2017 to October 2018 in one year duration. Materials and Methods: A total of 150 patients were included in the study, main variables assessed in this study were positive predictive value negative predictive value, sensitivity, specificity and accuracy of IL-21 in diagnosis of rheumatoid arthritis. SPSS version 23 was used to analyze the data. P value less than or equal to 0.05 was taken as significant. Study was started after permission from hospital ethical committee and patients were informed in detail about disease and procedure to be done. Non probability consecutive sampling was used. Results: The estimated sensitivity was 93.6%. The estimated specificity was 50%. Positive predictive value was 96.3% and negative predictive value was 35.7%. The overall accuracy was 90.6% for diagnosing rheumatoid arthritis. Conclusion: IL-21 induces MMP3 in rheumatoid arthritis patients, identification of IL-21 from synovium of patients indicates the presence of rheumatoid arthritis. We observed 90.6% diagnostic accuracy of IL-21 for rheumatoid patients taking RA factor as gold standard of diagnostic tool.

Value of serum glucose-6-phosphate isomerase in patients with rheumatoid arthritis and correlation with disease activity: A case–control study

BACKGROUND:Rheumatoid arthritis (RA) is a common multisystemic autoimmune disease with peripheral joint involvement. Many autoantibodies have been introduced in the course of RA; some of them have diagnostic and prognostic value. In this study, our aim is to determine the value of serum glucose-6-phosphate isomerase (G6PI) antigen (Ag) as a diagnostic and prognostic marker in RA.MATERIALS AND METHODS:Eighty-seven known cases of RA who referred to an outpatient clinic of Shiraz University of Medical Sciences and 76 healthy controls were selected. Serum G6PI Ag was measured using sandwich enzyme-linked immunosorbent assay method, and the enzyme level was compared in the patient and control group, we also compared the enzyme level of patient group with disease activity, disease duration, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), rheumatoid factor (RF), and anti-cyclic citrullinated peptide (anti-CCP) antibody (Ab). The data were analyzed using SPSS V 16 software.RESULTS:Positivity for G6PI was detected in 34.5% (30/87) of RA patients and 9.2% (7/76) of control group (P < 0.001). There was no significant correlation between enzyme level and disease activity, disease duration, ESR, CRP, RF, and anti-CCP Ab.CONCLUSIONS:Overall, in our study, although there was a significant difference in serum G6PI Ag between patient and control group, no significant correlation was detected between serum G6PI level and disease activity score, ESR, CRP, and anti-CCP Ab, but relative correlation with ESR and disease duration could be challenging. G6PI Ag could be introduced as a diagnostic marker in RA, but its role as a prognostic marker is controversial.

Adenosine Deaminase Activity and HLA-DRB as Diagnostic Markers for Rheumatoid Arthritis.

Rheumatoid Arthritis (RA) is a chronic multi systemic disorder with the unclarified ethiopathology. Although several markers have been presented for recognition of RA, but none of them has been specific. New markers such as HLA typing and activity of Adenosine Deaminase (ADA) isoenzymes could be useful and specific. The aim of this study is to evaluate the pattern of ADA isoenzymes activity and HLA typing in both RA patients and healthy cases. Blood samples were collected from 55 RA patients and 60 healthy subjects, over a period of 6 months. Levels of C-reactive Protein (CRP), Rheumatoid Factor (RF) and ADA (ADA1, ADA2, total ADA) were measured using AVITEX kit and HITACHI Auto Analyzer. In addition, HLA-DRB1*01,*04 and *10 was detected using PCR-SSP. ADA activity, particularly ADA2 level, was significantly higher among RA group (Pv <0.05). The concentrations of tADA in patients with RF and CRP positive were significantly higher (Pv <0.05). The allele prevalence of DRB1*01 was significantly higher in RA patients (13.1%) compared with control group (5.5%, respectively) (P <0.05, Bonferroni adjustment P<0.003). Calculated sensitivity and specificity for diagnostic tests in this study are listed as: CRP (75%), RF (80%), ADA (84%) and RF (90%), ADA (83%), CRP (72%), respectively. Increased tADA level and the frequency of DRB1*10 and *01 caused susceptibility to RA.

Comparison of second- and third-generation immunoassays for detection of anti-cyclic citrullinated peptide antibodies

Anti-cyclic citrullinated peptide antibodies (anti-CCPs) are important diagnostic markers for rheumatoid arthritis (RA). We evaluated the analytical and clinical performance of the QUANTA Flash CCP3 (INOVA Diagnostics, USA), a fully automated third-generation anti-CCP assay, in comparison with three second-generation anti-CCP (CCP2) assays. A total of 300 sera (67 from RA patients, 64 from other rheumatic diseases, 43 from osteoarthritis [OA], and 126 from other conditions) were tested with QUANTA Flash CCP3, Kallestad Anti-CCP II (Bio-Rad, USA), Elecsys Anti-CCP (Roche Diagnostics GmbH, Germany), and ARCHITECT Anti-CCP (Abbott Diagnostics, USA). Within-run and total imprecision (% coefficient of variation) of the QUANTA Flash CCP3 were <6%, and its linearity was acceptable over the claimed range (4.0–2,749.7 chemiluminescent units). The frequency of anti-CCP was similar between QUANTA Flash CCP3 and the other CCP2 assays in the RA (67.2% vs. 62.7–70.1%), other rheumatic diseases (7.8% vs. 6.3%), and OA (2.3% vs. 0–2.3%) groups. The concordance rate between QUANTA Flash CCP3 and the other assays ranged from 96.3% to 97.7% (kappa from 0.87 to 0.92). For the diagnosis of RA, the sensitivity/specificity was 67.2%/95.7%, 62.7%/98.3%, 70.2%/96.6%, and 67.2%/97.9%, and the areas under the receiver operating characteristic curves were 0.851, 0.791, 0.853, and 0.867 for QUANTA Flash CCP3, Kallestad, Elecsys, and ARCHITECT assays, respectively. The performance of the QUANTA Flash CCP3 was satisfactory and comparable to that of the three CCP2 assays. This fully automated assay would be a practical and reasonable option in clinical laboratories.