Serum Of Rheumatoid Arthritis Patients Research Articles

ROLE OF INTERLEUKIN-23 AS A MARKER OF DISEASE ACTIVITY IN RHEUMATOID ARTHRITIS PATIENTS

ABSTRACT Background: Rheumatoid arthritis (RA) is a chronic autoimmune inflammatory disease. The pathogenesis of RA is mediated by an interdependent network of cytokines which has been extended to include the cytokine, IL-23. IL-23 production appears to be of great importance in the inflammatory reaction in RA. Objectives: We aimed in this study to estimate interleukin-23 (IL-23) level in the sera of rheumatoid arthritis (RA) patients and to determine its relation with disease activity. Subjects and methods : This study was carried out on 40 patients with RA, and 40 healthy control subjects. RA disease activity was measured by 28-joint disease activity score (DAS-28). All patients were subjected to full history taking, thorough clinical examination, radiological and laboratory investigations including c- reactive protein (CRP), erythrocyte sedimentation rate (ESR), rheumatoid factor (RF), anti cyclic-citrullinated peptide (anti-CCP) antibodies. Serum IL-23 was measured by enzyme-linked immunosorbent assay (ELISA). Results : In RA patients serum IL-23 level was significantly elevated in comparison to the healthy controls (p<0.001). There was a significant positive correlations between IL-23 level and DAS 28 score. The highest level was detected in patients with high disease activity (p=0.03). There was statistically significant correlation between IL-23 levels and ESR, CRP, RF, anti-CCP antibodies. Conclusion: IL-23 could be a useful marker for disease activity in RA. Keywords: IL-23; Rheumatoid arthritis; DAS-28

A set of conformationally well-defined L/D-peptide epitopes provides a serological bar code for autoantibody subtypes.

Which conformational parameters lead to an antibody-affine peptide antigen? And in how many different conformations can we actually present the respective conformational epitope? To provide answers from a chemical point of view, we direct the bending and tethering of peptide backbones by the utilisation of a hydrophobic cluster, disulfides, and d-amino acids. Each mutation is employed pairwise on directly opposite sides of a β-hairpin. In combination, these synthetic modules guide the formation of complementary β-sheet-like structures, whereby the oppositely configured (l/d-)bi-disulfide pairs form with high regioselectivity. The conformational properties of the peptides are assessed by NMR spectroscopy and correlated with their antibody affinity in ELISA. From a pool of thus designed peptide antigens with distinctive complementary affinities against known rheumatoid arthritis (RA) autoantibodies, we select a set of epitopes for an immunoassay with sera of RA patients. We want to put emphasis on the idea, that the different conformational properties of the chosen antigens, containing the same epitope sequence, are mirrored in the distribution of autoantibody subtypes (or of the antibody polyclonality, respectively). Such directly comparable information can only be delivered by a set of peptides, rather than a single one. The hairpin-restriction technology of l/d-configured bi-disulfide amino acid pairs is not limited to RA but applicable to other shape-persistent hairpin motifs which are supposed to identify subgroups of protein receptors.

Interleukin-34 in the Serum and Synovial Fluid of Rheumatoid Arthritis Patients: Relation to Disease Activity and Radiographic Damage

Abstract Background Interleukin 34 (IL-34) is a recently discovered proinflammatory cytokine that can promote inflammation and osteoclastogenesis in arthritic joints. In this study, we tried to assess the serum and synovial fluid (SF) levels of IL-34 in rheumatoid arthritis (RA) patients, and to determine its relationship with disease activity and radiographic damage. Patients and methods ELISA was used to evaluate IL-34 levels in the serum of RA patients (n=50), osteoarthritis (OA) patients (n=28), and healthy control subjects (n=20) and in SF isolated from RA and OA patients. Disease activity in RA patients was assessed using the disease activity score-28 (DAS 28). The extent of radiographic joint damage, narrowing, and erosions was assessed. Results Serum IL-34 level was significantly elevated in RA patients compared to that in OA patients and healthy controls (P&lt;0.0001). Synovial IL-34 level was also significantly elevated in RA patients compared to that in OA patients (P=0.0004). Serum and synovial IL-34 levels were significantly higher in cases that were rheumatoid factor (RF) positive (n=28) compared to the levels in RF-negative RA cases (n=22) (P=0.03 and P=0.04, respectively). Serum and synovial IL-34 levels were positively correlated with RF (r=0.43, P=0.02 and r=0.39, P=0.03, respectively), and with the extent of radiological damage (SENS) (P=0.0002 and P&lt;0.0001, respectively). However, no significant correlation between IL-34 levels and disease activity was found. Conclusion IL-34 appears to play a key role in the pathogenesis of RA and contribute to bone destruction, making it a potential therapeutic target in the management armamentarium of the disease.

INTERLEUKIN-22 SERUM LEVELS IN PATIENTS WITH RHEUMATOID ARTHRITIS IN SANA'A CITY, YEMEN

Objective: Interleukin (IL) -22 is a novel mediator of a member of IL-10 family cytokines that is produced by many different types of lymphocytes including both those of innate and adaptive immune system. This cytokine has potent proliferative and inflammatory effects on different cell lines. Recently, accumulated data has indicated that IL-22 plays an important role in the pathogenesis of rheumatoid arthritis (RA). We aimed to investigate the levels of IL-22 and its association with demographic, clinical data as well as serological markers in RA. Methods: IL-22 serum levels were measured in 45 newly diagnosed RA patients without any treatment and 45 healthy individuals as control by a manual Enzyme linked immunosorbent assay (ELISA). Correlations of IL-22 serum levels were sought with demographic, clinical data and serological parameters. IL-22 levels were significantly elevated in serum of RA patients (median= 86.89ng/ml and range = 896) compared to serum of healthy control (median=75.36ng/ml and range=459), p=.022. Results: The IL-22 levels were correlated positively with C-reactive protein (CRP), anti-cyclic citrullinated peptide (ACCP) antibodies in RA patients. Significant higher levels of serum IL-22 in RA patients compare with those in healthy control. Conclusion: Highly significant association between serum levels of IL-22 and the serological markers (CRP and ACCP antibodies) in the diagnosis of RA suggest the potential levels of IL-22 as a valuable biomarker for the evaluation of disease severity in RA patients. Peer Review History: Received 1 April 2018; Revised 15 April; Accepted 6 May, Available online 15 May 2018 UJPR follows the most transparent and toughest ‘Advanced OPEN peer review’ system. The identity of the authors and, reviewers will be known to each other. This transparent process will help to eradicate any possible malicious/purposeful interference by any person (publishing staff, reviewer, editor, author, etc) during peer review. As a result of this unique system, all reviewers will get their due recognition and respect, once their names are published in the papers. We expect that, by publishing peer review reports with published papers, will be helpful to many authors for drafting their article according to the specifications. Auhors will remove any error of their article and they will improve their article(s) according to the previous reports displayed with published article(s). The main purpose of it is ‘to improve the quality of a candidate manuscript’. Our reviewers check the ‘strength and weakness of a manuscript honestly’. There will increase in the perfection, and transparency. Received file: Reviewer's Comments: Average Peer review marks at initial stage: 6.5/10 Average Peer review marks at publication stage: 8.0/10 Reviewer(s) detail: Dr. Hatem Sameir Abbas, Al-Azhar University, Egypt, hsam8406@yahoo.com Dr. George Zhu, Tehran University of Medical Sciences, Tehran, Iran, sansan4240732@163.com Similar Articles: THE ASSOCIATION BETWEEN LEVELS OF HEPCIDIN, IRON STATUS AND MICRO-INFLAMMATION MARKERS AMONG HAEMODIALYSIS

SEROPREVALENCE OF ANTI-MANNOSE BINDING LECTIN AUTOANTIBODIES IN PATIENTS WITH RHEUMATOID ARTHRITIS IN SANA'A CITY- YEMEN

Objective: Rheumatoid arthritis (RA) characterized by synovial inflammation and destruction of cartilage and bone. Until now there is no single test that diagnoses RA, however, several blood tests may suggest the presence of this disease. RA is associated with the presence of a number of autoantibodies as such as rheumatoid factor (RF), anti-cyclic citrullinated peptide (ACPA) and anti-mannose binding lectin (anti-MBL). This study aimed firstly to investigate the presence of anti-MBL autoantibodies in the sera of RA patients and healthy controls and secondly to determine the diagnostic value of this marker in comparison with the classical RF, C- reactive protein (CRP) and ACPA among RA cases. Methods: This case-control study was conducted at four health establishments; two public (Al-Thawra Modern General Hospital and National Center of Central Public Health Laboratories) and two private (University of Science and Technology Hospital and Aulqi Specialized Medical Laboratories) in Sana'a city. Ninety-four individuals were enrolled in this study. Forty-seven persons were clinically diagnosed to have RA by a rheumatologist and 47 healthy subjects without RA were used as controls. Sera were separated and tested for presence of serum anti-MBL autoantibodies, ACPA, RF and CRP by a commercially available enzyme linked immunosorbent assay (ELISA) and latex agglutination technique. Results: Study results showed that the mean±SD for the levels of serum anti-MBL autoantibodies among RA cases were 394±243 ng/ml which were significantly higher than that recorded among healthy controls (217±173 ng/ml). The levels of serum anti-MBL autoantibodies were associated with positive RF and CRP tests (p=.02 and .007 respectively), but not with positive ACPA test (p=.42). Conclusion: The result of this study showed higher levels of serum anti-MBL autoantibodies among RA cases comparing with the healthy controls and reveal an association with positive results for RF and CRP, but not with ACPA. Therefore, the anti-MBL antibody levels may associated with systemic autoimmune diseases and might not exclusive to RA. Peer Review History: Received 8 May 2018; Revised 12 May; Accepted 14 May, Available online 15 May 2018 UJPR follows the most transparent and toughest ‘Advanced OPEN peer review’ system. The identity of the authors and, reviewers will be known to each other. This transparent process will help to eradicate any possible malicious/purposeful interference by any person (publishing staff, reviewer, editor, author, etc) during peer review. As a result of this unique system, all reviewers will get their due recognition and respect, once their names are published in the papers. We expect that, by publishing peer review reports with published papers, will be helpful to many authors for drafting their article according to the specifications. Auhors will remove any error of their article and they will improve their article(s) according to the previous reports displayed with published article(s). The main of it is ‘to improve the quality of a candidate manuscript’. Our reviewers check the ‘strength and weakness of a manuscript honestly’. There will increase in the perfection, and transparency. Received file: Reviewer's Comments: Average Peer review marks at initial stage: 6.5/10 Average Peer review marks at publication stage: 8.0/10 Reviewer(s) detail: Dr. Ahmad Abdelsattar El-Ebiary, Tanta University Hospitals, Tanta, Egypt, a.ebiary@med.tanta.edu.eg Dr. Anthony C. C. Egbuonu, Michael Okpara University of Agriculture, Nigeria, tonycemalukegbuonu@yahoo.com Similar Articles: PREVALENCE OF DYSLIPIDEMIA AND ITS ASSOCIATION WITH DISEASE ACTIVITY IN PATIENTS WITH RHEUMATOID ARTHRITIS IN SULAIMANI GOVERNORATE THE ASSOCIATION OF EPSTEIN-BARR VIRUS ANTIBODIES WITH RHEUMATOID ARTHRITIS AMONG YEMENI PATIENTS IN SANA’A CITY INTERLEUKIN-22 SERUM LEVELS IN PATIENTS WITH RHEUMATOID ARTHRITIS IN SANA'A CITY, YEMEN

Detection of 16α-Hydroxyestrone-histone 1 Adduct as High-Affinity Antigen for Rheumatoid Arthritis Autoantibodies.

Increased concentrations of 16α-hydroxyestrone (16α-OHE1) have been observed in rheumatoid arthritis (RA), but the underlying mechanism of this remains elusive. Here we aimed to identify the role played by 16α-OHE1 in RA. In 40 RA patients, the specificities of antibodies from the sera of these patients were checked by direct binding, inhibition ELISA, and quantitative precipitation titration. Competition ELISA was also used for the estimation of 16α-OHE1 in the serum of different RA patients. RA IgG from a patient's sera showed strong recognition to 16α-OHE1-H1 (histone 1) adduct in comparison to control subjects (p < 0.001), as the formation of this adduct brings out various biochemical changes that might generate neo-epitopes, which have been well-recognized by these antibodies. The affinity of RA antibodies for 16α-OHE1-H1 (1.10 × 10- 7 M) was high, as detected by the Langmuir plot. Comparing RA patients to the controls, no significant differences were detected in the level of 16α-OHE1 or 2-hydroxyestrone/16α-OHE1 ratio. 16α-OHE1-H1 might have an antigenic role and function as a high-affinity antigen for RA autoantibodies and, therefore, could be used as a biomarker for this disease.

Identification of novel biomarker as citrullinated inter-alpha-trypsin inhibitor heavy chain 4, specifically increased in sera with experimental and rheumatoid arthritis

BackgroundAnticitrullinated protein antibodies (ACPA) and citrullinated proteins play key roles in the pathogenesis of rheumatoid arthritis (RA). Many candidate citrullinated antigens have been identified in joints, but citrullinated proteins in sera are mostly uncertain in patients with RA. We explored the expression of citrullinated proteins in joints and sera of experimental arthritis, and we further investigated their specific expression correlated with the disease activity in patients with RA.MethodsCitrullinated protein expression in tissues was examined by IHC in peptide glucose-6-phosphate isomerase-induced arthritis (pGIA). Serum citrullinated proteins from pGIA were examined by Western blotting, and the sequence was identified by MS. With the same methods, serum citrullinated proteins were analyzed in patients with RA, primary Sjögren’s syndrome, systemic lupus erythematosus, and osteoarthritis as well as in healthy subjects, by Western blotting and MS. In patients with RA, the relationship between the expression of the identified protein (inter-alpha-trypsin inhibitor heavy chain 4 [ITIH4]) and clinical features was evaluated, and the levels of citrullinated ITIH4 were compared before and after biological treatment. The antibody response against citrullinated ITIH4 peptide was measured by enzyme-linked immunosorbent assay.ResultsCitrullinated proteins were detected specifically in arthritic joints and sera from pGIA relative to controls. In sera, a common band of citrullinated protein at 120 kDa was revealed, and it fluctuated in parallel with arthritis score of pGIA by Western blotting. Interestingly, in 82% of RA patient sera, similar bands of citrullinated protein were specifically detected. These proteins were identified as citrullinated ITIH4, and especially the R438 site was commonly citrullinated between mice and humans. Citrullinated ITIH4 levels were associated with clinical parameters such as C-reactive protein (CRP), rheumatoid factor, and Disease Activity Score in 28 joints as measured by CRP in patients with RA. Its levels were decreased in correlation with the reduction of disease activity score after effective treatment in patients with RA. Moreover, antibody response to citrullinated epitope in ITIH4 was specifically observed in patients with RA.ConclusionsOur results suggest that serum citrullinated ITIH4 was specifically increased in patients with RA and could be a novel biomarker for assessing disease activity in patients with RA.

Glycomics meets artificial intelligence – Potential of glycan analysis for identification of seropositive and seronegative rheumatoid arthritis patients revealed

In this study, one hundred serum samples from healthy people and patients with rheumatoid arthritis (RA) were analyzed. Standard immunoassays for detection of 10 different RA markers and analysis of glycan markers on antibodies in 10 different assay formats with several lectins were applied for each serum sample. A dataset containing 2000 data points was data mined using artificial neural networks (ANN). We identified key RA markers, which can discriminate between healthy people and seropositive RA patients (serum containing autoantibodies) with accuracy of 83.3%. Combination of RA markers with glycan analysis provided much better discrimination accuracy of 92.5%. Immunoassays completely failed to identify seronegative RA patients (serum not containing autoantibodies), while glycan analysis correctly identified 43.8% of these patients. Further, we revealed other critical parameters for successful glycan analysis such as type of a sample, format of analysis and orientation of captured antibodies for glycan analysis.

Acute phase reactant, Pentraxin 3, as a novel marker for the diagnosis of rheumatoid arthritis

IntroductionPentraxins are a group of highly conserved acute-phase reactant proteins and play crucial role as modulators of inflammatory processes. Pentraxin 3 (PTX3) is primarily produced and released by vascular cell wall, hence, we attempt to establish the role of PTX3 as a biomarker for Rheumatoid Arthritis (RA) compared to CRP. MethodsThirty patients having active RA as cases and 30 osteoarthritis (OA) patients as controls were recruited. Paired serum and synovial fluid samples were analysed for concentrations of both PTX3 and CRP by using high sensitivity ELISA kit and ROC curve was plotted. ResultsConcentrations of PTX3 and CRP were significantly higher in RA patient serum (p < 0.0001) as well as in synovial fluid (p < 0.0001) and correlated with disease severity. Upon correlation analysis, positive correlation was found between serum and synovial fluid concentrations of PTX3 and CRP. The diagnostic potential of PTX3 was observed in synovial fluid while combination of PTX3 and CRP showed better sensitivity in serum. ConclusionPTX3 found to be sensitive non-invasive indicator of clinical arthritic activity in RA patients when compared to traditional markers like CRP. Combination of PTX3 and CRP could serve as better differential diagnostic markers for RA after validation in larger patient cohort.

Elevated Levels of Soluble ST2 were Associated with Rheumatoid Arthritis Disease Activity and Ameliorated Inflammation in Synovial Fibroblasts.

Background:Much evidence has demonstrated that interleukin (IL)-33 plays an important role in rheumatoid arthritis (RA). However, there have been limited studies about soluble ST2, a receptor for IL-33, in RA. The aims of this study were to detect the levels of ST2 in the serum and synovial fluid of RA patients and to reveal the association of these levels with disease activity and the function of ST2 in RA.Methods:A total of 56 RA patients and 38 age-matched healthy controls were enrolled in this study. Synovial fluid samples were collected from another 30 RA patients and 20 osteoarthritis patients. Serum and synovial fluid levels of ST2 were measured by ELISA. In addition, the levels of ST2 in the serum of RA patients before and after therapy were detected. The function of ST2 in RA was revealed by the results of an in vitro cell assay, where recombinant ST2 proteins were used to treat peripheral blood mononuclear cells (PBMCs) and RA synovial fibroblasts (RASFs).Results:Serum-soluble ST2 levels were significantly higher in RA patients (127.14 ± 61.43 pg/ml) than those in healthy controls (78.37 ± 41.93 pg/ml, P < 0.01). Synovial fluid-soluble ST2 levels (41.90 ± 33.58 pg/ml) were much higher in RA patients than those in osteoarthritis patients (19.71 ± 16.72 pg/ml, P < 0.05). RA patients who received effective therapy for 6 months showed decreased serum-soluble ST2 levels (113.01 ± 53.90 pg/ml) compared to baseline (139.59 ± 68.36 pg/ml) (P = 0.01). RA patients with high disease activity had higher serum-soluble ST2 levels (162.02 ± 56.78 pg/ml) than those with low disease activity (94.67 ± 40.27 pg/ml, P = 0.001). Soluble ST2 did not affect IL-1β, IL-6, IL-8, or tumor necrosis factor-α (TNF-α) expression in PBMCs from RA patients. However, soluble ST2 ameliorated the expressions of IL-33 and IL-1β but not that of IL-6, IL-8, or TNF-α in resting RASFs. Interestingly, in the RASFs stimulated by TNF-α plus IL-1β, soluble ST2 showed extensive suppressive effects on the expression of IL-6, IL-8, and TNF-α.Conclusion:Elevated levels of ST2 in the serum and synovial fluid were associated with disease activity and ameliorated IL-33 expression and IL-33-induced inflammation in RASFs, suggesting that soluble ST2 might be a potential therapeutic candidate for RA.

Structural and immunological characterization of hydroxyl radical modified human IgG: Clinical correlation in rheumatoid arthritis

Structural alterations in proteins under oxidative stress have been widely implicated in the immuno-pathology of various disorders. This study has evaluated the extent of damage in the conformational characteristics of IgG by hydroxyl radical (OH) and studied its implications in the immuno-pathology of rheumatoid arthritis (RA). Using various biophysical and biochemical techniques, changes in aromatic microenvironment of the IgG and the protein aggregation became evident after treatment with OH. The SDS-PAGE study confirmed the protein aggregation while far ultraviolet circular dichroism spectroscopy (Far-UV CD) and fourier transform infrared spectroscopy (FTIR) inferred towards the alterations in secondary structure of IgG under OH stress. Dynamic light scattering showed that the modification increased the hydrodynamic radius and polydispersity of IgG. The free arginine and lysine content reduced upon modification. OH induced aggregation was confirmed by enhanced thioflavin-T (ThT) fluorescence and red shift in the congo red (CR) absorbance. The study on experimental animals reiterates the earlier findings of enhanced immunogenicity of OH treated IgG (OH-IgG) compared to that of native IgG. OH-IgG strongly interacted with the antibodies derived from the serum of 80 rheumatoid arthritis (RA) patients. The overwhelming and strong tendency of OH-IgG to bind the antibodies derived from the serum of RA patients points towards the modification of IgG under patho-physiological conditions in RA that generate neo-epitopes and eventually cause the generation of auto antibodies that circulate in the patient sera. Further studies on this aspect may possibly lead to the development of a biomarker for RA.

Soluble TAM receptor tyrosine kinases in rheumatoid arthritis: correlation with disease activity and bone destruction.

The TAM receptor tyrosine kinases (TAM RTK) are a subfamily of receptor tyrosine kinases, the role of which in autoimmune diseases such as systemic lupus erythematosus has been well explored, while their functions in rheumatoid arthritis (RA) remain largely unknown. In this study, we investigated the role of soluble TAM receptor tyrosine kinases (sAxl/sMer/sTyro3) in patients with RA. A total of 306 RA patients, 100 osteoarthritis (OA) patients and 120 healthy controls (HCs) were enrolled into this study. The serum concentrations of sAxl/sMer/sTyro3 were measured by enzyme-linked immunosorbent assay (ELISA), then the associations between sAxl/sMer/sTyro3 levels and clinical features of RA patients were analysed. We also investigated whether sTyro3 could promote osteoclast differentiation in vitro in RA patients. The results showed that compared with healthy controls (HCs), sTyro3 levels in the serum of RA patients were elevated remarkably and sMer levels were decreased significantly, whereas there was no difference between HCs and RA patients on sAxl levels. The sTyro3 levels were correlated weakly but positively with white blood cells (WBC), immunoglobulin (Ig)M, rheumatoid factor (RF), swollen joint counts, tender joint counts, total sharp scores and joint erosion scores. Conversely, there were no significant correlations between sMer levels and the above indices. Moreover, RA patients with high disease activity also showed higher sTyro3 levels. In-vitro osteoclast differentiation assay showed further that tartrate-resistant acid phosphatase (TRAP)+ osteoclasts were increased significantly in the presence of sTyro3. Collectively, our study indicated that serum sTyro3 levels were elevated in RA patients and correlated positively with disease activity and bone destruction, which may serve as an important participant in RA pathogenesis.

The Link Of Epstein Barr Virus Infection And Rheumatoid Arthritis Immunopathogenesis

The cause of Rheumatoid Arthritis (RA) remains unknown. Environmental factors as well as genetic factors have beenlinked to pathogenesis of RA, in particular Epstein Barr Virus (EBV) infection. Since clinical onset of RA is long timeafter primary viral exposure, it is still difficult to demonstrate the direct link of EBV infection with RA pathogenesis.However, the high levels of antibodies against several EBV proteins detected in RA patient sera, the molecular mimicryof EBV proteins with RA susceptible alleles, cross reactive of several antibodies against EBV with proteins in RAsynovium, the higher load of EBV in peripheral blood and synovial tissue of RA patients compared to non-RA patientsand EBV capability to induce ACPA production might show a clear link of EBV infection with RA pathogenesis.

Quartz crystal microbalance as an assay to detect anti-drug antibodies for the immunogenicity assessment of therapeutic biologics.

Because of their biological origins, therapeutic biologics can trigger an unwanted deleterious immune response with some patients. The immunogenicity of therapeutic biologics can affect drug efficacy and patient safety by the production of circulating anti-drug antibodies (ADA). In this study, quartz crystal microbalance (QCM) was developed as an assay to detect ADA. Etanercept (Enbrel®) was covalently grafted to dextran-modified QCM surfaces. Rabbits were immunized with etanercept to generate ADA. Results showed the QCM assay could detect purified ADA from rabbits at concentrations as low as 50ng/mL, within the sensitivity range of ELISA. The QCM assay could also assess the ADA isotype. It was shown that the ADA were composed of the IgG isotype, but not IgM, as expected. Furthermore, it was shown that QCM surfaces that had been used to detect ADA could be regenerated in glycine-HCl solution and reused. The QCM assay was also demonstrated to detect ADA in crude serum samples. Serum was collected from the rabbits and analyzed before and after etanercept immunization. ADA were clearly detected in serum from rabbits after immunization, but not in serum before immunization. Serum from patients administered with etanercept for rheumatoid arthritis (RA) treatment was also analyzed and compared to serum from healthy donors. Sera from 10 RA patients were analyzed. Results showed one of the RA patient serum samples may have ADA present. In conclusion, QCM appears to be a viable assay to detect ADA for the immunogenicity assessment of therapeutic biologics.

RETRACTED: MicroRNA-29a inhibits proliferation and induces apoptosis in rheumatoid arthritis fibroblast-like synoviocytes by repressing STAT3

Rheumatoid arthritis-fibroblast-like synoviocytes (RA-FLS) with aberrant expression of microRNA (miRNA) have been reported to be involved in the initiation, progression, and perpetuation of rheumatoid arthritis (RA). In this study, we explored the biological function and underlying mechanism of microRNA-29a (miR-29a) in cultured RA-FLS from RA patients. The expression of miR-29a in serum, synovial tissues, and FLS from RA patients and health donors was detected by real-time quantitative RT-PCR (qRT-PCR). The effects of miR-29a on cell proliferation, apoptosis, and inflammatory cytokine levels in RA-FLS were also determined using Counting Assay Kit-8 (CCK-8), flow cytometry, and enzyme-linked immunosorbent assay (ELISA) respectively. Luciferase reporter assay was carried out to identify the target genes of miR-29a. We observed that expression of miR-29a was markedly downregulated in serum, synovial tissues and FLS of RA patients. miR-29a overexpression in RA-FLS significantly inhibited proliferation, promoted apoptosis, and suppressed expression of inflammatory cytokines. Signal transducer and activator of transcription 3 (STAT3) was identified to be a direct target of miR-29a in RA-FLS. miR-29a overexpression suppressed the expression of STAT3, as well as phosphorylated STAT3(p-STAT3) and its downstream targets protein (Cyclin D1 and Bcl-2). In addition, the levels of miR-29a were inversely correlated with that of STAT3 in synovial tissues. Rescue experiments showed that overexpression of STAT3 effectively reversed the effect of miR-29a on proliferation and apoptosis in RA-FLS. These data indicate that miR-29a inhibits proliferation and induces apoptosis in RA-FLS by targeting STAT3, suggesting that promoting miR-29a expression may yield therapeutic benefits in the treatment of RA.

Interleukin-34 Promotes Fibrocyte Proliferation.

Rheumatoid arthritis (RA) is a systemic autoimmune disease affecting multiple joints. It remains unclear which factors in the circulation are associated with the systemic spread of the disease. Fibrocytes are pluripotent mesenchymal stem cells present in the circulation of RA patients. Our earlier findings implicated activated fibrocytes in the etiology of onset and pathogenesis of RA. Elevated levels of interleukin-34 (IL-34) in the serum and synovial fluid of RA patients are associated with rheumatoid factor and anticyclic citrullinated peptide antibodies, indicators of RA. Moreover, IL-34 levels are independent predictors of radiographic progression in RA patients. We provide evidence of simultaneous elevated levels of IL-34 and increased numbers of activated fibrocytes in the circulation of mice induced to develop arthritis. In vitro, IL-34 treatment induced the proliferation of fibrocytes, mediated by activation of cognate CSF-R1s on fibrocytes. Taken together, we infer that IL-34 has a role in stimulating fibrocyte proliferation and activation during arthritis, thereby contributing to both onset of RA and systemic spread of disease.

Detection of human antibodies binding with smooth and rough LPSs from Proteus mirabilis O3 strains S1959, R110, R45

Bacteria of the genus Proteus of the family Enterobacteriaceae are facultative human pathogens responsible mainly for urinary tract and wound infections, bacteremia and the development of rheumatoid arthritis (RA). We have analyzed and compared by ELISA the titer of antibodies in plasmas of healthy individuals and in sera of rheumatoid arthritis patients recognizing a potential host cross-reactive epitope (lysine-galacturonic acid epitopes) present in Proteus lipopolysaccharide (LPS). In our experiments LPSs isolated from two mutants of smooth Proteus mirabilis 1959 (O3), i.e. strains R110 and R45, were used. R110 (Ra type mutant) is lacking the O-specific polysaccharide, but possesses a complete core oligosaccharide, while R45 (Re type) has a reduced core oligosaccharide and contains two 3-deoxy-d-manno-oct-2-ulosonic acid residues and one of 4-amino-4-deoxy-l-arabinopyranose residues. Titer of P. mirabilis S1959 LPS-specific-antibodies increased with the age of blood donors. RA and blood donors’ sera contained antibodies against S and Ra and Re type of P. mirabilis O3 LPSs. Antibodies recognizing lysine-galacturonic acid epitopes of O3 LPS were detected by ELISA in some plasmas of healthy individuals and sera of rheumatoid arthritis patients. RA patients antibodies reacting with P. mirabilis S1959 S and R LPSs may indicate a potential role of anti-LPS antibodies in molecular mimicry in RA diseases.

Long noncoding RNAs expression profile and functional networks in rheumatoid arthritis.

The modifying effects of long noncoding RNAs (lncRNAs) in rheumatoid arthritis (RA) recently have drawn much attention; however, the underlying mechanisms remain largely unknown. Herein, we aim to investigate the expression profile of lncRNAs in RA and identify promising targets for RA diagnosis and treatment. Microarray screening and real-time PCR of lncRNAs were performed by use of serum samples from 3 RA patients and 3 healthy controls. Significantly differentially expressed lncRNAs were verified in serum samples from 43 RA patients and 40 healthy controls by real-time PCR. We found that there were 73 up-regulated and 61 down-regulated lncRNAs as well as 128 up-regulated and 37 down-regulated mRNAs in serum samples of RA patients. Validation in RA clinical samples indicated 5 of these lncRNAs were significantly up-regulated including RNA143598, RNA143596, HIX0032090, IGHCgamma1, and XLOC_002730. Significant association was observed between these lncRNAs and the disease course, erythrocyte sedimentation rate (ESR), rheumatoid factor (RF) as well as anti-cyclic citrullinated peptide (anti-CCP) antibody. Additionally, 55 of the differentially expressed mRNAs were associated with 41 lncRNAs and were involved in signaling pathways of toll like receptors (TLRs), nuclear factor-kappa B (NF-κB), and cytokine, especially the IRF3/IRF7 mediated signaling transduction. Our study firstly shows the specific profile of lncRNAs in the serum of RA patients and potential signaling pathways involved in RA pathogenesis, which may provide novel targets for the diagnosis and treatment of patients with RA.

Activation of Complement by Pigment Epithelium-Derived Factor in Rheumatoid Arthritis.

The aim of this study was to identify molecules that trigger complement activation in rheumatic joints. C4d, the final cleavage product of C4 activation, is found in the diseased joint and can bind covalently to complement-activating molecules. By using a highly specific Ab against a cleavage neoepitope in C4d, several molecules that were specifically bound to C4d were identified from pooled synovial fluid (SF) from four rheumatoid arthritis (RA) patients. One of these molecules, pigment epithelium-derived factor (PEDF), is a broadly expressed multifunctional member of the serine proteinase inhibitor family. Using ELISA, we confirmed the presence of various amounts of complexes between PEDF and C4d in the SF from 30 RA patients, whereas none were detected in SF from control subjects. Correlation analyses suggested that, in arthritis patients, C4d-PEDF complexes found in sera arise from the joints, as well as from other tissues, and levels of the complexes did not differ in sera of RA patients and healthy controls. When immobilized, recombinant PEDF expressed in eukaryotic cells activated the classical complement pathway but not the alternative or lectin pathways. C1q protein was demonstrated to bind immobilized PEDF, and PEDF was shown to bind to immobilized C1q, in particular its head regions, which are known to interact with other activators of the classical pathway. Our results call for further investigation into the role of PEDF in inflammatory processes in the joint, which, in combination with classical complement activation, appears to be part of a (patho-)physiologic response.

Thymosin β4 in rheumatoid arthritis: Friend or foe.

Rheumatoid arthritis (RA) has characteristic pannus tissues, which show tumor-like growth of the synovium through chronic joint inflammation. The synovium is highly penetrated by various immune cells, and the synovial lining becomes hyperplastic due to increased numbers of macrophage-like and fibroblast-like synoviocytes. Thus, a resultant hypoxic condition stimulates the expression of inflammation-related genes in various cells, in particular, vascular endothelial growth factor. Thymosin β4 (Tβ4), a 5-kDa protein, is known to play a significant role in various biological activities, such as actin sequestering, cell motility, migration, inflammation, and damage repair. Recent studies have provided evidence that Tβ4 may have a role in RA pathogenesis. The Tβ4 level has been shown to increase significantly in the joint fluid and serum of RA patients. However, whether Tβ4 stimulates or inhibits activation of RA immune responses remains to be determined. In the present study, we discuss the logical and clinical justifications for Tβ4 as a potential target for RA therapeutics.