Antibodies to citrullinated vimentin are a specific and sensitive marker for the diagnosis of rheumatoid arthritis

Deciphering the therapeutic potential of trimetazidine in rheumatoid arthritis via targeting mi-RNA128a, TLR4 signaling pathway, and adenosine-induced FADD-microvesicular shedding: In vivo and in silico study

Rheumatoid arthritis (RA) is a debilitating autoimmune condition characterized by chronic synovitis, joint damage, and inflammation, leading to impaired joint functionality. Existing RA treatments, although effective to some extent, are not without side effects, prompting a search for more potent therapies. Recent research has revealed the critical role of FAS-associated death domain protein (FADD) microvesicular shedding in RA pathogenesis, expanding its scope beyond apoptosis to include inflammatory and immune pathways. This study aimed to investigate the intricate relationship between mi-RNA 128a, autoimmune and inflammatory pathways, and adenosine levels in modulating FADD expression and microvesicular shedding in a Freund's complete adjuvant (FCA) induced RA rat model and further explore the antirheumatoid potency of trimetazidine (TMZ). The FCA treated model exhibited significantly elevated levels of serum fibrogenic, inflammatory, immunological and rheumatological diagnostic markers, confirming successful RA induction. Our results revealed that the FCA-induced RA model showed a significant reduction in the expression of FADD in paw tissue and increased microvesicular FADD shedding in synovial fluid, which was attributed to the significant increase in the expression of the epigenetic miRNA 128a gene in addition to the downregulation of adenosine levels. These findings were further supported by the significant activation of the TLR4/MYD88 pathway and its downstream inflammatory IkB/NFB markers. Interestingly, TMZ administration significantly improved, with a potency similar to methotrexate (MTX), the deterioration effect of FCA treatment, as evidenced by a significant attenuation of fibrogenic, inflammatory, immunological, and rheumatological markers. Our investigations indicated that TMZ uniquely acted by targeting epigenetic miRNA128a expression and elevating adenosine levels in paw tissue, leading to increased expression of FADD of paw tissue and mitigated FADD microvesicular shedding in synovial fluid. Furthermore, the group treated with TMZ showed significant downregulation of TLR4/MYD88 and their downstream TRAF6, IRAK and NF-kB. Together, our study unveils the significant potential of TMZ as an antirheumatoid candidate, offering anti-inflammatory effects through various mechanisms, including modulation of the FADD-epigenetic regulator mi-RNA 128a, adenosine levels, and the TLR4 signaling pathway in joint tissue, but also attenuation of FADD microvesicular shedding in synovial fluid. These findings further highlight the synergistic administration of TMZ and MTX as a potential approach to reduce adverse effects of MTX while improving therapeutic efficacy.

Anti-mutated citrullinated vimentin antibodies are increased in IPF patients

INTRO

An increased prevalence of serum anti-MCV antibody is observed in the serum of patients with idiopathic pulmonary fibrosis (IPF) but the clinical relevance of these antibodies is unknown.

METHODS

Patients from our center with a diagnosis of IPF according to the 2018 ATS/ERS/JRS/ALAT guidelines and at least one anti-MCV assay available were selected. All patients were part of the prospective cohort European IPF registry and selected between 03/2010 and 03/2018. We constituted two groups of patients according to the anti-MCV status at baseline to compare their characteristics at baseline and the evolution of lung function, survival and/or transplantation status.

RESULTS

Anti-MCV data were available for 101 patients, of whom 86 had complete clinical data available. Twenty-nine (34 %) patients had a positive anti-MCV assay (MCV+), at a low level in most patients (29 UI/mL [IQR 25-40]), and 57 (66 %) patients a negative assay (MCV-). MCV+ patients were 20 men and 9 women, with a median age of 73 years [IQR 67-78]. MCV- patients were 49 men and 8 women with a median age of 72 years [IQR 64-77]. Sixty-two (75 %) patients were ex-smokers and 5 (6 %) were active smokers. Median cumulative tobacco smoke exposure was 22.5 (15.0-38.6) and was similar in both groups. Lung function test results and HRCT pattern distribution was similar in both groups at baseline. The median duration of follow-up was 3.5 years [IQR 2.1-5.0]. Lung function decline was similar in both groups. During the study period, 31 (36 %) patients died or have been transplanted with no difference in transplant-free survival status between the two groups.

CONCLUSION

Low level anti-MCV autoimmunity was prevalent in IPF patients.

Anti-vimentin antibodies are associated with higher severity of Sjögren's disease

Vimentin is a ubiquitously present Type III intermediate filament protein, often targeted by autoimmune responses in multiple rheumatic disorders. Although previous studies have reported anti-vimentin antibodies in Sjögren's disease (SjD) patients, the clinical significance of such antibodies is unknown. To address this issue, the presence of anti-vimentin antibodies was determined in serum samples from a well-characterized cohort of primary SjD patients, non-SjD Sicca, and healthy controls. The occurrence of anti-vimentin antibodies and their association with different clinical features of the disease were evaluated. Anti-vimentin antibodies were detected in 24% of primary SjD patients, compared to 4% in non-SjD sicca patients and 3% in healthy controls. In primary SjD patients, higher levels of anti-vimentin antibodies were significantly associated with reduced saliva and tear flow and severe ocular surface damage indicators. The anti-vimentin antibody levels did not show significant associations with the presence or absence of other autoantibodies like ANA, RF, and anti-Ro/La. Our data suggest that the anti-vimentin antibody specificity arises in a subset of primary SjD patients and is associated with oral and ocular features of the disease. Anti-vimentin can potentially serve as a novel biomarker for evaluating the severity of salivary and lacrimal gland dysfunction in primary SjD.

2D-DIGE-Based Proteomic Profiling with Validations Identifies Vimentin as a Secretory Biomarker Useful for Early Detection and Poor Prognosis in Oral Cancers

Oral tongue squamous cell carcinoma (OTSCC) is an aggressive cancer with high morbidity and mortality rates, despite multimodality management. There are currently no clinically relevant molecular markers that identify patients at higher risk of recurrence and failure. We undertook 2D-DIGE proteomic profiling to study the differentially expressed proteins in OTSCC evaluating their role in prognosis. 2D-DIGE coupled with tandem mass spectrometry was performed on tissues obtained from early staged OTSCC along with its paired apparently adjacent normal tissue samples (n = 10). Top upregulated protein was validated using immunohistochemistry (n = 345), comprising of retrospective early stage OTSCC (n = 150) and prospective series of oral precancers, normal, and oral cancers (n = 195). Saliva samples collected from oral cancer and precancer samples were analyzed by ELISA (n = 146). We found statistically significant differential expression in 151 proteins out of 700 proteins quantified. Top ten differentially regulated proteins were identified using mass spectrometry analysis. We found vimentin, the mesenchymal protein, to be the most upregulated protein in tongue tumor tissues compared to adjacent apparent normal tissues. Vimentin was found to be significantly overexpressed in oral precancers along with cancers compared to normal tissues. The vimentin expression correlated significantly with differentiated states of oral precancers and cancers. Vimentin was also detected at significantly higher levels in saliva collected from oral precancer and cancer patients compared to normal healthy volunteers. Validation of vimentin in an independent series of retrospective early staged OTSCC showed that the vimentin expression is significantly associated with treatment failures and poorer DFS. The vimentin expression is useful as both poor prognostic and early detection marker in oral cancer. Vimentin detection in saliva can be a diagnostic test to detect oral precancers that may have malignant potential, needing closer follow-up, and disease monitoring.

The Prevalence of Autoimmune Diseases in Patients with Primary Open-Angle Glaucoma Undergoing Ophthalmic Surgeries

PURPOSE

To assess the prevalence of autoimmune disease (AiD) in patients with primary open-angle glaucoma (POAG) undergoing ophthalmic surgery.

DESIGN

Retrospective, cross-sectional study.

PARTICIPANTS

Patients with POAG undergoing any ophthalmic surgery and control subjects undergoing cataract surgery at the Massachusetts Eye and Ear from March 2019 to April 2020.

METHODS

All available medical records with patient demographics, ocular, and medical conditions were reviewed. Differences in AiD prevalence were assessed and adjusted for covariates using multiple logistic regression. Additionally, a subgroup analysis comparing the POAG patients with and without AiD was performed.

MAIN OUTCOME MEASURES

To assess the prevalence of AiD based on the American Autoimmune Related Diseases Association list.

RESULTS

A total of 172 patients with POAG and 179 controls were included. The overall prevalence of AiD was 17.4% in the POAG group and 10.1% in the controls (P = 0.044); 6.4% of POAG patients and 3.4% of controls had more than 1 AiD (P = 0.18). The most prevalent AiDs in POAG group were rheumatoid arthritis (4.6%) and psoriasis (4.1%), which were also the most common in controls (2.8% each). In a fully adjusted multiple logistic regression analysis accounting for steroid use, having an AiD was associated with 2.62-fold increased odds of POAG relative to controls (95% confidence interval, 1.27-5.36, P = 0.009); other risk factors for POAG derived from the analysis included age (odds ratio [OR], 1.04, P = 0.006), diabetes mellitus (OR, 2.31, P = 0.008), and non-White ethnicity (OR, 4.75, P < 0.001). In a case-only analysis involving the eye with worse glaucoma, there was no statistical difference in visual field mean deviation or retinal nerve fiber layer (RNFL) thickness in POAG patients with AiD (n = 30) and without AiD (n = 142, P > 0.13, for both).

CONCLUSIONS

A higher prevalence of AiD was found in POAG patients compared with control patients undergoing ophthalmic surgery. The presence of AiD was associated with increased risk for POAG after adjusting for covariates. Additional factors may have prevented a difference in RNFL thickness in POAG patients with and without AiD. Autoimmunity should be explored further in the pathogenesis of POAG.

Immune cells in lens injury repair and fibrosis

Immune cells, both tissue resident immune cells and those immune cells recruited in response to wounding or degenerative conditions, are essential to both the maintenance and restoration of homeostasis in most tissues. These cells are typically provided to tissues by their closely associated vasculatures. However, the lens, like many of the tissues in the eye, are considered immune privileged sites because they have no associated vasculature. Such absence of immune cells was thought to protect the lens from inflammatory responses that would bring with them the danger of causing vision impairing opacities. However, it has now been shown, as occurs in other immune privileged sites in the eye, that novel pathways exist by which immune cells come to associate with the lens to protect it, maintain its homeostasis, and function in its regenerative repair. Here we review the discoveries that have revealed there are both innate and adaptive immune system responses to lens, and that, like most other tissues, the lens harbors a population of resident immune cells, which are the sentinels of danger or injury to a tissue. While resident and recruited immune cells are essential elements of lens homeostasis and repair, they also become the agents of disease, particularly as progenitors of pro-fibrogenic myofibroblasts. There still remains much to learn about the function of lens-associated immune cells in protection, repair and disease, the knowledge of which will provide new tools for maintaining the core functions of the lens in the visual system.

Characterizing hand and wrist ultrasound pattern in primary Sjögren's syndrome: a case-control study

INTRODUCTION/OBJECTIVES

To evaluate the clinical relevance of high-resolution hand and wrist ultrasound (US) findings and their possible associations with anti-citrullinated peptide antibodies in primary Sjögren's syndrome (pSS).

METHODS

Ninety-seven consecutive pSS patients (American-European Consensus Group, 2002) without meeting the American College of Rheumatology (ACR) criteria (1987) for rheumatoid arthritis (RA); 20 RA patients (ACR/European League Against Rheumatism (EULAR) criteria, 2010); and 80 healthy individuals with comparable age, gender, and ethnicity were enrolled in a case-control study. Disease activity was assessed by EULAR Sjögren's Syndrome Disease Activity Index (ESSDAI). US was performed by one expert blinded to anti-CCP, anti-MCV, and IgM rheumatoid factor tested by ELISA.

RESULTS

Frequencies of grade 3 synovitis (9.3 vs. 0%, p = 0.004), tenosynovitis (36.1 vs. 3.8%, p < 0.001), and erosions (27.8 vs. 7.5%, p = 0.001) on US were higher in pSS patients than in healthy controls. ESSDAI presented a moderate correlation with the synovitis number (p = 0.001) and tenosynovitis (p < 0.001). Most pSS patients with erosions on US (81.5%) had negative anti-CCP. Nevertheless, anti-CCP ≥ 3× cut-off value was associated with the presence of erosions in pSS (p = 0.026). Erosions in pSS were mainly small size contrasting with moderate/large size in RA (p < 0.001), and positive power Doppler synovitis predominated in RA (p < 0.001).

CONCLUSIONS

US identified significant frequencies of grade 3 synovitis, tenosynovitis, and erosions in pSS. Synovitis and tenosynovitis numbers were correlated with ESSDAI. Association between erosions on US and anti-CCP (high titers) in pSS possibly identifies a subgroup with severe arthritis. These findings suggest that US is a useful method for assessing joint involvement in pSS.Key Points• US identified significant frequencies of grade 3 synovitis, tenosynovitis, and erosions in pSS patients in comparison with age- and race-healthy individuals.• Numbers of synovitis and tenosynovitis on US were correlated with ESSDAI values.• Most pSS patients with erosions on US were negative for anti-CCP, but anti-CCP ≥ 3× cut-off value was associated with the presence of erosions in this disease.• Erosions in pSS were mainly small size contrasting with moderate/large size in RA, and positive power Doppler synovitis predominated in RA.

Serologic Diagnosis of Rheumatoid Arthritis

Accurate diagnosis of inflammatory arthritides remains a challenge because of substantial clinical overlap. To achieve a granular classification for informing clinical decisions, numerous potential serologic biomarkers have been identified. Rheumatologists have settled on rheumatoid factor and anti-citrullinated protein antibodies for the diagnosis of rheumatoid arthritis (RA) based on specificity and sensitivity and their ability to be integrated into clinical algorithms. These biomarkers should be interpreted in their specific clinical context. This article discusses the serologic basis for the diagnosis of RA, how these biomarkers have framed conceptualization of the pathogenesis of RA, and the inherent limitations in their use.

Secretory vimentin is associated with coronary artery disease in patients and induces atherogenesis in ApoE-/- mice

PURPOSE

The present study aimed to investigate the relationship between serum levels of secretory vimentin and coronary artery disease (CAD). The biological effect of secretory vimentin was ascertained by experiments.

METHODS

We analysed serum levels of secretory vimentin in CAD patients (n = 288) and non-CAD controls (n = 195) by ELISA. To evaluate the pro-inflammatory effects of secreted vimentin, the human aortic endothelial cells (HAECs) and human peripheral blood mononuclear cells (PBMCs) were treated with recombinant vimentin or saline. Intraperitoneal injection of vimentin (1 μg/each) or saline was performed every other day for 12 weeks in ApoE^-/- mice for assessment of atherogenic effect.

RESULTS

Serum levels of secretory vimentin were significantly increased in CAD patients than in health controls (p < 0.05), and correlated with the number of diseased coronary arteries, Syntax and Gensini score (for all comparison, p < 0.01). Logistic regression analysis showed that vimentin level is an independent determinant of CAD. In experiments, recombinant vimentin protein enhanced the expression of adhesion molecules and inflammatory cytokines in both endothelial cells and macrophages. This protein also promoted macrophage-endothelial cells adhesion in vitro and the recruitment of leukocytes to mesenteric venules in C57BL/6 mice. Compared with saline, intraperitoneal injection of recombinant vimentin (1 μg/each) every other day induced atherogenesis in ApoE^-/- mice at 12-weeks, with significant increase of inflammatory cytokine and adhesion molecules expression in aortic tissue (p < 0.05).

CONCLUSION

Serum vimentin levels are associated with the presence and the severity of CAD. Vimentin protein promotes atherogenesis in ApoE^-/- mice.

Vimentin Diversity in Health and Disease

Vimentin is a protein that has been linked to a large variety of pathophysiological conditions, including cataracts, Crohn's disease, rheumatoid arthritis, HIV and cancer. Vimentin has also been shown to regulate a wide spectrum of basic cellular functions. In cells, vimentin assembles into a network of filaments that spans the cytoplasm. It can also be found in smaller, non-filamentous forms that can localise both within cells and within the extracellular microenvironment. The vimentin structure can be altered by subunit exchange, cleavage into different sizes, re-annealing, post-translational modifications and interacting proteins. Together with the observation that different domains of vimentin might have evolved under different selection pressures that defined distinct biological functions for different parts of the protein, the many diverse variants of vimentin might be the cause of its functional diversity. A number of review articles have focussed on the biology and medical aspects of intermediate filament proteins without particular commitment to vimentin, and other reviews have focussed on intermediate filaments in an in vitro context. In contrast, the present review focusses almost exclusively on vimentin, and covers both ex vivo and in vivo data from tissue culture and from living organisms, including a summary of the many phenotypes of vimentin knockout animals. Our aim is to provide a comprehensive overview of the current understanding of the many diverse aspects of vimentin, from biochemical, mechanical, cellular, systems biology and medical perspectives.

Analysis of four serum biomarkers in rheumatoid arthritis: association with extra articular manifestations in patients and arthralgia in relatives

OBJECTIVES

To evaluate the frequency of four serum biomarkers in RA patients and their relatives and identify possible associations with clinical findings of the disease.

METHODS

This was a transversal analytical study. Anti-cyclic citrullinated peptide (anti-CCP), anti-mutated citrullinated vimentin (anti-MCV) and IgA-rheumatoid factor (RF) were determined by ELISA and IgM-RF by latex agglutination in 210 RA patients, 198 relatives and 92 healthy controls from Southern Brazil. Clinical and demographic data were obtained through charts review and questionnaires.

RESULTS

A higher positivity for all antibodies was observed in RA patients when compared to relatives and controls (p<0.0001). IgA-RF was more frequent in relatives compared to controls (14.6% vs. 5.4%, p=0.03, OR=2.98; 95% CI=1.11-7.98) whereas anti-CCP was the most common biomarker among RA patients (75.6%). Concomitant positivity for the four biomarkers was more common in patients (46.2%, p<0.0001). Relatives and controls were mostly positive for just one biomarker (20.2%, p<0.0001 and 15.2%, p=0.016, respectively). No association was observed between the number of positive biomarkers and age of disease onset, functional class or tobacco exposure. In seronegative patients predominate absence of extra articular manifestations (EAMs) (p=0.01; OR=3.25; 95% CI=1.16-10.66). Arthralgia was present in positive relatives, regardless the type of biomarker.

CONCLUSIONS

A higher number of biomarkers was present in RA patients with EAMs. Positivity of biomarkers was related to arthralgia in relatives. These findings reinforce the link between distinct biomarkers and the pathophysiologic mechanisms of AR.

Comparison of two assays to determine anti-citrullinated peptide antibodies in rheumatoid arthritis in relation to other chronic inflammatory rheumatic diseases: assaying anti-modified citrullinated vimentin antibodies adds value to second-generation anti-citrullinated cyclic peptides testing

Determination of anti-citrullinated peptide antibodies (ACPA) plays a relevant role in the diagnosis of rheumatoid arthritis (RA). To date, it is still unclear if the use of several tests for these autoantibodies in the same patient offers additional value as compared to performing only one test. Therefore, we evaluated the performance of using two assays for ACPA: second-generation anti-citrullinated cyclic peptides antibodies (anti-CCP2) and anti-mutated citrullinated vimentin (anti-MCV) antibodies for the diagnosis of RA. We compared three groups: RA (n = 142), chronic inflammatory disease (CIRD, n = 86), and clinically healthy subjects (CHS, n = 56) to evaluate sensitivity, specificity, predictive values, and likelihood ratios (LR) of these two assays for the presence of RA. A lower frequency of positivity for anti-CCP2 was found in RA (66.2%) as compared with anti-MCV (81.0%). When comparing RA versus other CIRD, sensitivity increased when both assays were performed. This strategy of testing both assays had high specificity and LR+. We conclude that adding the assay of anti-MCV antibodies to the determination of anti-CCP2 increases the sensitivity for detecting seropositive RA. Therefore, we propose the use of both assays in the initial screening of RA in longitudinal studies, including early onset of undifferentiated arthritis.

Anti-cyclic citrullinated peptide (anti-CCP) and anti-mutated citrullinated vimentin (anti-MCV) relation with extra-articular manifestations in rheumatoid arthritis

We evaluated the association between anti-cyclic citrullinated peptide antibodies (anti-CCP) and anti-mutated citrullinated vimentin antibodies (anti-MCV) with the presence of extra-articular (ExRA) manifestations in 225 patients with rheumatoid arthritis (RA). Ninety-five patients had ExRA and 130 had no ExRA. There was no association of anti-CCP and anti-MCV levels with the presence of ExRA as total group (P = 0.40 and P = 0.91, resp.). Making an analysis of individual manifestations, rheumatoid nodules were associated with positivity for rheumatoid factor (RF); (P = 0.01), anti-CCP (P = 0.048), and anti-MCV (P = 0.02). Instead, RF, anti-CCP, or anti-MCV were not associated with SS, chronic anemia, or peripheral neuropathy. Levels of anti-CCP correlated with the score of the Health Assessment Questionnaire-Disability Index (HAQ-Di) (r = 0.154, P = 0.03), erythrocyte sedimentation rate (ESR); (r = 0.155, P = 0.03), and RF (P = 0.254, P < 0.001), whereas anti-MCV titres only correlated with RF (r = 0.169, P = 0.02). On adjusted analysis, ExRA was associated with longer age (P = 0.015), longer disease duration (P = 0.007), higher DAS-28 score (P = 0.002), and higher HAQ-DI score (P = 0.007), but serum levels of anti-CCP and anti-MCV were not associated. These findings show the need to strengthen the evaluation of the pathogenic mechanisms implied in each specific ExRA manifestation.

Identification of novel autoantigen in the synovial fluid of rheumatoid arthritis patients using an immunoproteomics approach

Rheumatoid arthritis (RA) is a chronic, autoimmune and inflammatory joint disease with a poorly understood etiology. Despite widespread diagnostic use of anti-citrullinated protein antibodies and rheumatoid factor proteins there is a strong demand for novel serological biomarkers to improve the diagnosis this disease. The present study was aimed to identify novel autoantigens involved in rheumatoid arthritis (RA) pathogenesis through immune-proteomic strategy. Synovial fluid samples from clinically diagnosed RA patients were separated on two-dimensional gel electrophoresis (2-DE). Samples from patients with non-RA rheumatisms (osteoarthritis and trauma) were used as controls. Immunoreactive proteins were spotted by Western blotting followed by identification through Q-TOF mass spectrometer analysis. Forty Western blots were generated using plasma from ten individual RA patients and 33 reactive spots were identified, 20 from the high molecular weight (HMW) gel and 13 from the low molecular weight (LMW) gel. Among the 33 common immunogenic spots, 18 distinct autoantigens were identified, out of which 14 are novel proteins in this context. Expression analysis of five important proteins, vimentin, gelsolin, alpha 2 HS glycoprotein (AHSG), glial fibrillary acidic protein (GFAP), and α1B-glycoprotein (A1BG) by Western blot analysis using their specific antibodies revealed their higher expression in RA synovial fluid as compared to non-RA samples. Recombinantly expressed GFAP and A1BG protein were used to develop an in-house ELISA to quantify the amount of autoantibodies in the RA patients. RA patients revealed an increase in the expression of GFAP and A1BG in the plasma as compared to osteoarthritis patients. Therefore, GFAP and A1BG can be proposed as potential new autoantigens of diagnostic importance for RA subjects. Further characterization of these proteins in rheumatoid arthritis will be helpful in understanding the role of these proteins in the disease pathogenesis providing new diagnostic tool with better specificity and accurate detection of the disease.

Old drugs, old problems: where do we stand in prediction of rheumatoid arthritis responsiveness to methotrexate and other synthetic DMARDs?

Methotrexate (MTX) is the central drug in the management of rheumatoid arthritis (RA) and other immune mediated inflammatory diseases. It is widely used either in monotherapy or in association with other synthetic and biologic disease modifying anti-rheumatic drugs (DMARDs). Although comprehensive clinical experience exists for MTX and synthetic DMARDs, to date it has not been possible to preview correctly whether or not a patient will respond to treatment with these drugs. Predicting response to MTX and other DMARDs would allow the selection of patients based on their likelihood of response, thus enabling individualized therapy and avoiding unnecessary adverse effects and elevated costs. However, studies analyzing this issue have struggled to obtain consistent, replicable results and no factor has yet been recognized to individually distinguish responders from nonresponders at treatment start. Variables possibly influencing drug effectiveness may be disease-, patient- or treatment-related, clinical or biological (genetic and nongenetic). In this review we summarize current evidence on predictors of response to MTX and other synthetic DMARDs, discuss possible causes for the heterogeneity observed and address its translation into daily clinical practice.

Greater prevalence of seropositivity for anti-cyclic citrullinated peptide antibody in unaffected first-degree relatives in multicase rheumatoid arthritis-affected families

BACKGROUND/AIMS

This study determined the prevalence and determinants of seropositivity for rheumatoid factor (RF), anti-cyclic citrullinated peptide (anti-CCP) antibody, and anti-mutated citrullinated vimentin (anti-MCV) antibody in unaffected first-degree relatives (FDRs) of rheumatoid arthritis (RA) patients.

METHODS

A total of 337 subjects (135 with RA and 202 FDRs) were enrolled in this case-control study. Serum RF, anti-CCP antibody, and anti-MCV antibody were assayed. Subjects in multicase families (≥ 2 affected FDRs within the same family) were identified. Multivariate logistic regression analysis was used to identify risk factors associated with RA-related autoantibodies.

RESULTS

Seropositivity for RF, anti-CCP antibody, or anti-MCV antibody was detected in 14.4%, 5.0%, or 13.4% of unaffected FDRs, respectively. Anti-CCP antibody seropositivity was more prevalent in FDRs in multicase families (17.8%) than in those not in multicase families (1.3%, p < 0.0001). Significant correlations between RA-associated autoantibodies were detected in the FDR group (between RF and anti-CCP antibody: r = 0.366, p < 0.0001; between RF and anti-MCV antibody: r = 0.343, p < 0.0001; and between anti-CCP antibody and anti-MCV antibody: r = 0.849, p < 0.0001). After adjustment for age and sex, anti-CCP antibody seropositivity in FDRs was significantly associated with being in a multicase family (odds ratio, 49.8; 95% confidence interval, 5.6 to 441.6).

CONCLUSIONS

The association between anti-CCP antibody seropositivity in unaffected FDRs and being in a multicase family suggests that genetic and/or environmental factors may increase the risk for RA development in unaffected FDRs.

Evaluation of anti-mutated citrullinated vimentin antibodies, anti-cyclic citrullinated Peptide antibodies and rheumatoid factor in omani patients with rheumatoid arthritis

Rheumatoid factor (RF) is currently used in the diagnosis of rheumatoid arthritis (RA). The discovery of anticitrullinated protein autoantibodies has led to the development of various new tests, such as anti-cyclic citrullinated peptide (anti-CCP) antibodies, and anti-mutated citrullinated vimentin (anti-MCV) antibodies, to diagnose RA. The aims of this study were to determine the sensitivity and specificity of anti-MCV antibodies in comparison with anti-CCP antibodies and RF in Omani Arab patients with RA and compare our findings with published values from different ethnic groups. The sensitivity of anti-MCV antibodies was 72% with 87% specificity. For anti-CCP antibodies the sensitivity was 52% and the specificity was 97%. The sensitivity of RF was 57% with 94% specificity. Anti-CCP antibodies have higher diagnostic specificity and positive predictive value than RF and anti-MCV antibodies. Anti-MCV antibodies have the highest sensitivity when compared to anti-CCP antibodies and RF. Anti-MCV antibodies do not appear to be very useful in the diagnosis of RA. However, long-term study is required to find out whether anti-MCV antibodies can be used as predictive test for incidence of RA.

Antibodies to mutated citrullinated vimentin in patients with chronic hepatitis C virus genotype IV infection-related arthropathy

One of the extra-hepatic manifestations of hepatitis C virus (HCV) infection is polyarthritis that mimics rheumatoid arthritis (RA). Anti-mutated citrullinated vimentin (MCV) was recently introduced in the diagnostic workup of RA, but its exact role in HCV infection and its related arthropathy is still unclear. The aim of the study is to determine the prevalence of anti-MCV antibodies in HCV-infected patients with or without articular involvement, and to investigate whether anti-MCV antibodies have an additional role to anticyclic citrullinated peptide (CCP) antibodies and rheumatoid factor (RF) in differentiating patients with RA from patients with HCV-related arthropathy. Fifty-five HCV-infected patients (HCV RNA positive) and 30 RA patients (fulfilling the American College of Rheumatology classification criteria for RA and negative for HCV) were included. Anti-MCV antibodies, anti-CCP antibodies, RF and cryoglobulins were measured. Articular involvement in hepatitis C patients was evaluated. Articular involvement was detected in 30/55 (54.5%) of HCV-infected patients. The most frequent pattern was symmetric polyarthralgias and the most frequent joints to be involved were the wrists, metacarpophalangeal joints, shoulders and knees. In HCV arthropathy, anti-MCV was positive in 9/30 (30%), anti-CCP in 0% and RF in 22/30 (73.3%). Whereas, in chronic HCV without arthropathy, anti-MCV was positive in 8 patients (32%), anti-CCP in one patient (4%) and RF in 23/25 (92.0%). There was no significant difference between the two HCV groups as regards the frequencies of anti-MCV (P = 0.89), anti-CCP (P = 0.93) and RF (P = 0.15). In RA, anti-MCV was positive in 93.3% anti-CCP in 96.7% and RF in 86.7%. There was no significant difference in RF between RA and HCV arthropathy (P = 0.33). Meanwhile, there was a highly significant difference between both groups regarding anti-MCV and anti-CCP (P < 0.0001 for each). The sensitivity of anti-MCV, anti-CCP and RF for RA was 93.3, 96.7 and 86.7%, respectively. Whereas their specificity was 69.1, 98.2 and 18.2%, respectively. In addition, the mean levels of anti-MCV and anti-CCP were significantly increased in RA than in all HCV patients (P = 0.038 and P < 0.0001, respectively). Meanwhile, there were no significant differences in mean levels of anti-MCV and anti-CCP between HCV patients with arthropathy and those without arthropathy (P = 0.11 and P = 0.73, respectively). Also, there were no differences in mean RF between both HCV groups. There was a significant positive correlation between anti-MCV and anti-CCP levels in patients with HCV-related arthropathy (r = 0.39, P = 0.032) and in those without arthropathy (r = 0.578, P = 0.002). Cryoglobulins were detected in 7/30 HCV-related arthropathy (23.3%) and were positively correlated with anti-MCV(r = 0.485, P = 0.007). Anti-CCP still attains the major role in differentiating RA from HCV arthropathy. Anti-MCV seems to play no additional role in this aspect. The role of mutation of vimentin in the pathogenesis of HCV arthropathy is not as clear as it is for RA and needs further investigation.

Mutated citrullinated vimentin antibodies in rheumatoid arthritis

Rheumatoid arthritis (RA) is the most common inflammatory systemic autoimmune disease, primarily affecting the peripheral joints. The past decade has been marked with revolutionary changes both in the therapeutic and diagnostic perspectives of RA. The discovery of an RA-specific citrullination-driven immune reaction gave a substantial contribution in the diagnostic approach to RA. Efforts directed towards the identification of the antigenic target specifically recognized by these autoantibodies resulted in the identification of vimentin in citrullinated form as the potential native antigen, among other proteins. Furthermore, it was found that the mutation of vimentin represents an independent trigger of antigenic properties, in addition to citrullination. As a result of this discovery, a commercial ELISA using mutated citrullinated vimentin (MCV) was developed. Increasingly, data now support the use of anti-MCV in RA diagnosis and prognosis for errosion. This review summarizes the research to date on the use of anti-MCV in RA diagnosis and prognosis and its potential use as a therapeutic marker. The pathologic role of these antibodies in RA disease is also discussed.

Anti-mutated citrullinated vimentin (anti-MCV) and anti-65 kDa heat shock protein (anti-hsp65): new biomarkers in ankylosing spondylitis

INTRODUCTION

Citrullination as well as anti-citrullinated protein/peptide antibodies (ACPA) have been implicated in the pathogenesis of rheumatoid arthritis (RA). While ACPAs are specific and sensitive markers for RA, there have been hardly any reports regarding ACPAs in ankylosing spondylitis (AS). The possible role of antibodies to Mycobacterial 65 kDa heat shock protein (hsp65) has not been characterized in AS. As new laboratory biomarkers of AS are needed, we investigated the prevalence of anti-mutated citrullinated vimentin (MCV) and anti-hsp65 antibodies in AS.

METHODS

Altogether 43 AS and 44 healthy controls were included in the study. Anti-MCV and anti-hsp65 were determined in sera by commercial and in-house ELISA, respectively. Serum autoantibody levels were correlated with ESR, CRP, HLA-B27 status, smoking habits, pain intensity, BASDAI, BASFI and BASMI indices.

RESULTS

Patients with AS had significantly higher serum anti-MCV levels (17.3 U/mL, range: 8.3-31.5 U/mL) in comparison to healthy subjects (8.9 U/mL, range: 5.4-13.3 U/mL) (p<0.01). Sixteen of the 43 AS patients (37%) and none of the 44 healthy controls (0%) were anti-MCV positive using the cut-off value recommended by the manufacturer (>20 U/mL). The mean anti-hsp65 concentration in AS sera was 124.8 AU/mL (range: 27.2-1000 AU/mL), while controls exerted significantly lower anti-hsp65 levels (mean: 51.8 AU/mL; range: 22.5-88.5 AU/mL) (p<0.001). Correlation analysis revealed that both anti-MCV positivity (r=0.613; p=0.012) and absolute serum anti-MCV levels (r=0.553; p=0.021) correlated with anti-hsp65 levels. Anti-MCV positivity also correlated with ESR (r=0.437; p=0.03).

CONCLUSIONS

Anti-MCV and anti-hsp65 may be novel biomarkers in AS.

Role of anti-citrullinated protein antibodies in diagnosis and prognosis of rheumatoid arthritis

Antibodies to citrullinated proteins/peptides (ACPAs) are the second serological marker to have recently been included in the 2010 ACR/EULAR Rheumatoid Arthritis (RA) Classification Criteria, which are focused on early diagnosis and therapy. This review discusses their history and some clinical aspects of ACPAs, focusing on the diagnostic utility of anti-cyclic citrullinated peptide (anti-CCP) antibodies as a marker of RA as compared to the widely used rheumatoid factor (RF). Simultaneously, this review aims to raise physician awareness and interest in anti-citrullinated vimentin antibody (anti-Sa/anti-MCV), another member of the ACPA family, which appears to have a better predictive value as a marker of RA than anti-CCP or RF and correlates closely with disease activity and therapeutic response among patients with RA.

The relevance of citrullinated vimentin in the production of antibodies against citrullinated proteins and the pathogenesis of rheumatoid arthritis

Antibodies against citrullinated proteins (ACPAs) are highly specific for RA. Since the discovery of these antibodies, several of studies that focused on the presence and identity of citrullinated proteins in the joints of RA patients have been carried out. The best-known antigens that bind ACPAs are citrullinated filaggrin, Type II collagen (CII), α-enolase, fibrinogen and vimentin. This review compares citrullinated filaggrin, CII, α-enolase and fibrinogen with vimentin in their contribution to ACPA triggering, and gives an overview of the literature in which the role of citrullinated and non-citrullinated vimentin in the onset of ACPA production and the pathogenesis of RA is discussed.

Immediate determination of ACPA and rheumatoid factor--a novel point of care test for detection of anti-MCV antibodies and rheumatoid factor using a lateral-flow immunoassay

Introduction

Autoantibodies against mutated and citrullinated vimentin (MCV) represent a novel diagnostic marker for rheumatoid arthritis (RA). Recently, an increased sensitivity for anti-MCV compared to autoantibodies against cyclic citrullinated peptides (anti-CCP2) was shown in cohorts of patients with early RA and established disease.

The aim of this study was to develop and evaluate a point of care test (POCT) for detection of anti-MCV antibodies immediately at the first visit or at the bed side.

Methods

A lateral-flow immunoassay was developed for simultaneous detection of anti-MCV antibodies and rheumatoid factor (RF-IgG) and evaluated in a prospective setting. Analyses were performed from whole blood samples of patients with seropositive RA (n = 108), seronegative RA as well as other rheumatic disorders (n = 122), and healthy blood donors (n = 200) and compared to detection via ELISA.

Results

Using the POCT, anti-MCV antibodies were detected in 54.6% and RF-IgG in 56.5% of patients with RA. Specificity was 99.1% for anti-MCV antibodies and 91.2% for RF-IgG. Compared to ELISA's results, POCT sensitivity was 69.3% for anti-MCV and 55.6% for RF-IgG, specificity was 99.7% and 97.2%, respectively.

Conclusions

This POCT for detection of anti-MCV antibodies and RF-IgG provides high specificity for the diagnosis of RA and is useful in clinical practice due to its simplicity and its reliable performance. This test can greatly improve a timely management of RA and may help in screening patients with suspected RA in non-specialized settings prompting early referrals.

Meta-analysis: diagnostic value of serum anti-mutated citrullinated vimentin antibodies in patients with rheumatoid arthritis

Conventional tests are not always helpful in making a diagnosis of rheumatoid arthritis (RA). This study aimed to comprehensively and quantitatively summarize the evidence on the accuracy of anti-mutated citrullinated vimentin (MCV) assay in the diagnosis of RA. A comprehensive meta-review of data on the accuracy of MCV concentrations in the diagnosis of RA were carried out from 16 published studies. Furthermore, receiver operating characteristic curves were used to summarize the overall test performance. The summary estimates for MCV in the diagnosis of RA were: sensitivity 0.77 [95% confidence interval (CI) 0.75-0.78], specificity 0.89 (95% CI 0.87-0.90), positive likelihood ratio (LR+) 7.24 (95% CI 5.60-9.36), negative likelihood ratio (LR-) 0.28 (95% CI 0.23-0.34) and diagnostic odds ratio 29.66 (95% CI 21.09-41.71). The area under the summary receiver operating characteristic curves was 0.92. Data from meta-analysis suggest the accuracy of MCV assay in the diagnosis of RA is high, but ultimately clinician must consider the results of MCV tests combing with other conventional examinations and the clinical feature.

The use of citrullinated peptides and proteins for the diagnosis of rheumatoid arthritis

The presence or absence of antibodies to citrullinated peptides/proteins (ACPA) is an important parameter that helps a clinician set a diagnosis of early rheumatoid arthritis and, hence, initiate treatment. There are several commercial tests available to measure ACPA levels, although it can be difficult to decide what the best test for a given clinical question is. We analyzed literature data in which the diagnostic and other properties of various ACPA tests are compared. The results show that for diagnostic purposes the CCP2 test has the highest specificity, the highest sensitivity in stratified studies and the highest positive predictive value. For the prediction of future joint destruction the CCP2, MCV, and CCP3 tests may be used. The ability to predict the likelihood of not achieving sustained disease-modifying antirheumatic drug-free remission was highest for the CCP2 test. Finally, the levels of anti-CCP2 and anti-CCP3 (and possibly anti-mutated citrullinated vimentin) in rheumatoid arthritis patients are not significantly influenced by TNFalpha blocking agents.

Antibodies to mutated citrullinated vimentin and antibodies to cyclic citrullinated peptides in juvenile idiopathic arthritis

BACKGROUND

The goal of the study was to assess the presence of antibodies to mutated citrullinated vimentin (anti-MCV) and cyclic citrullinated peptides (anti-CCP) in patients with juvenile idiopathic arthritis (JIA) compared with patients with other juvenile onset rheumatic diseases.

METHODS

The study included 56 patients who fulfilled the International League of Associations for Rheumatology (ILAR) classification criteria for JIA, and 17 control patients with other juvenile onset rheumatic diseases. Data on six core outcome variables and the Sharp score were collected for patients with JIA. Sera and synovial fluid, if available, were tested for anti-CCP and anti-MCV antibodies using a commercial enzyme-linked immunosorbent assay (ELISA).

RESULTS

Anti-MCV antibodies were positive in 3/56 (5.4%) and anti-CCP in 1/56 (1.8%) of patients with JIA. Two out of three anti-MCV positive patients (one of them also anti-CCP positive) were found to be rheumatoid factor (RF)-positive with polyarticular disease. Within the control group, anti-MCV was positive in 4/17 (23.5%) patients, while anti-CCP positivity was not observed. No correlation between anti-MCV with anti-CCP antibody levels was found for any of the six core outcome variables or for the adapted Sharp score.

CONCLUSIONS

Our results show that antibodies targeting citrullinated proteins are not a useful diagnostic marker for JIA, but can indicate severe patterns of disease in JIA.

Differentiation of Rheumatoid Arthritis From HCV Infection: Rheumatoid Factor, Anti-Cyclic Citrullinated Peptide or Anti-Mutated Citrullinated Vimentin?

Objective: Differentiation of rheumatoid arthritis (RA) from other diseases with joint involvement such as hepatitis-C virus (HCV) infection represents a diagnostic problem. In addition to the rheumatoid factor (RF), more specific and sensitive auto-antibodies are under evaluation in recent years with conflicting results. In this study, we tested the diagnostic value of rheumatoid factor, anti-cyclic citrullinated peptide (anti-CCP) and anti-mutated citrullinated vimentin (anti-MCV) in distinguishing RA from hepatitis C patients.

Materials and Methods: Sera of 34 RA patients and 30 hepatitis C patients were tested for RF, anti-CCP anti-MCV. Disease activity was determined by disease activity score (DAS-28) 28 in RA and by modified Knodell score in hepatitis C patients. Extra-articular involvement in RA and rheumatologic involvement in hepatitis C patients were documented.

Results: In roc analysis, area under curve (AUC) was the highest in anti-CCP. Sensitivity and specificity was 82% and 53%, 79%, and 96% and 70%, and 73% for RF, anti-CCP and anti-MCV respectively. DAS-28 has a weak correlation with RF (r=0.406), anti-CCP (r=0.433), and anti-MCV (r=0.453). There was no difference between the patients in autoantibody levels regarding extra-articular involvement and DAS-28 in RA, and joint involvement in hepatitis C patients.

Conclusion: Anti-MCV antibodies may be useful in distinguishing RA however it seems to have no additional value over anti-CCP or RF in hepatitis C patients. Anti-CCP antibodies are more reliable in diagnosis of RA due to their high specificity. (Turk J Rheumatol 2010; 25: 19-23)

Whither autoimmunity: the lessons of anti-CCP and B cell depletion

The most difficult component to understand in autoimmune disease has been the issue of causation. In contrast, there have been enormous gains in improved diagnostics as well as improved therapy. Indeed, the use of biologics have changed the profile of numerous autoimmune diseases. In this issue, we discuss two such aspects. Firstly, we place in perspective the use of anti-citrullinated protein antibodies in rheumatoid arthritis. Second, we discuss the increasing use of B cell depletion in the treatment of autoimmunity. Clinical Reviews in Allergy and Immunology is a unique venue for these themes because it covers the spectrum of allergy through autoimmunity. Indeed, we also present a special paper on the relationships of the hepatitis B virus and autoimmunity. Although the Th1 to Th2 dichotomy is well known to both murine and human immunologists, it is really in the study of specific inflammatory responses that they are correctly placed in the perspective of the continuum of immunopathology.

Profile of autoantibodies in Jaccoud's arthropathy

OBJECTIVE

To compare the frequency of different autoantibodies in a group of patients with Jaccoud's arthropathy (JA) secondary to systemic lupus erythematosus (SLE) with those without JA.

METHODS

A group of SLE patients with JA was compared with another group of SLE patients without this complication, matched by age and gender, regarding the presence of autoantibodies. Antibodies to cyclical citrullinated peptides (anti-CCP) and to mutated citrullinated vimentin (anti-MCV) as well as anti-SSA/Ro, anti-SSB/La, anti-Sm and anti-RNP and anticardiolipin (aCL) antibodies were searched by ELISA, using commercial kits. Rheumatoid factor was determined by nephelometry and antinuclear and anti-dsDNA antibodies by IIF.

RESULTS

Forty-eight individuals were included in the study, being 24 patients with JA and 24 without JA, matched by gender and age. The frequency of anti-CCP antibodies in the whole population was 12.5% (6 cases), with no difference between the 2 groups. Anti-MCV antibodies were detected in 10.4% (5 cases), being found only in those with JA (p=0.05). There was no association between the presence of JA and aCL, anti-Sm, anti-RNP and anti-SSB/La antibodies. On the other hand, a statistically significant association between the presence of anti-dsDNA antibodies and JA was observed (p=0.04) as well as a marginal association with a decrease in serum levels of C3 (p=0.06).

CONCLUSION

In the present study, there was an association between the presence of JA and anti-dsDNA antibodies, and anti-MCV antibodies were found only in those SLE patients with JA. Whether these antibodies have an etiopathogenic role in JA is entirely unknown.

The role of anti-mutated citrullinated vimentin antibodies in the diagnosis of early rheumatoid arthritis

OBJECTIVE

Anti-mutated citrullinated vimentin (MCV) antibodies have been reported as a fairly sensitive serological marker of rheumatoid arthritis (RA). We evaluated the diagnostic value of anti-MCV in a large cohort of Chinese patients with early RA.

METHODS

One hundred seventy patients with early RA (<1 yr duration), 66 with other rheumatic diseases, 10 with infectious diseases, and 60 healthy individuals were included in our study. Serum anti-MCV and second-generation anti-cyclic citrullinated peptide antibodies (anti-CCP2) were measured by ELISA, and rheumatoid factor (RF) was measured by rate nephelometry. The associated clinical data of patients with early RA were also evaluated. Then disease activity was scored by the formula for Disease Activity Score (DAS)28, and the degree of radiological changes was assessed by Sharp score.

RESULTS

The prevalence of serum anti-MCV in patients with early RA (78.2%, 133/170) was significantly higher than that of other rheumatologic patients and patients with infectious diseases. It was 12% (3/25) in systemic lupus erythematosus, 9.5% (2/21) in primary Sjögren's syndrome, 10% (1/10) in systemic sclerosis, 20% (2/10) in ankylosing spondylitis, 12.5% (1/8) in viral hepatitis type B, and 0% (0/2) in tuberculosis. Anti-MCV was not found in the serum of healthy subjects. The sensitivities of anti-MCV, anti-CCP2, and RF tests for early RA were 78.2%, 61.8%, and 72.4%, respectively, and the specificities were 93.4%, 96.3%, and 80.1%. The combination of anti-MCV and anti-CCP2 positivity showed a very high specificity (97.8%) and positive predictive value (97.1%), but a low sensitivity (58.8%). The sensitivity reached 81.2% when the union of anti-MCV and anti-CCP2 positivities was used as one combined criterion. Statistically, anti-MCV had significant correlation with anti-CCP2 (r=0.587, p=0.01, 2-tailed) and RF (r=0.389, p=0.01, 2-tailed). In addition, it had an interesting correlation with radiological assessment (r=0.349, p=0.05, 2-tailed). The anti-MCV had no significant correlation with other factors, such as erythrocyte sedimentation rate, C-reactive protein, antikeratin antibody, antiperinuclear factor, global visual analog scale score for joint pain, IgA, IgG, IgM, C3, C4, hidden rheumatoid factor for IgA (HRFIgA), HRFIgG, and DAS28.

CONCLUSION

Anti-MCV is a novel diagnostic marker for early RA. It may be more useful if the anti-CCP2 assay is performed concomitantly to diagnose patients with early RA.

Rheumatoid arthritis diagnosis with antimutated citrullinated vimentin ELISA by Orgentec Diagnostika

BACKGROUND

There is a need for highly sensitive and specific laboratory tests for the early diagnosis of rheumatoid arthritis (RA). Anticitrullinated protein/peptide antibodies are produced in the sera of RA patients.

OBJECTIVE

To assess and discuss the diagnostic value of Orgentec antimutated citrullinated vimentin (anti-MCV) ELISA and to compare this diagnostic to commercially available anticyclic citrullinated peptide (anti-CCP) tests.

METHODS

The evaluation is based on our recently published study on the comparison of anti-MCV and anti-CCP2 tests, as well as on published studies.

RESULTS/CONCLUSION

In established RA, the anti-MCV ELISA exerts a specificity comparable with anti-CCP2. Numerous recent studies suggest that anti-MCV may have higher sensitivity, however there are also some publications stating the opposite. In early RA, anti-MCV may be a better predictor of disease activity and radiological progression than anti-CCP tests.