Diagnostic accuracy of anti-MCV and anti-CCP antibodies in rheumatoid arthritis: A meta-analysis

Recent Advances in Biosensors for Diagnosis of Autoimmune Diseases

Over the last decade, autoimmune diseases (ADs) have undergone a significant increase because of genetic and/or environmental factors; therefore, their simple and fast diagnosis is of high importance. The conventional diagnostic techniques for ADs require tedious sample preparation, sophisticated instruments, a dedicated laboratory, and qualified personnel. For these reasons, biosensors could represent a useful alternative to these methods. Biosensors are considered to be promising tools that can be used in clinical analysis for an early diagnosis due to their high sensitivity, simplicity, low cost, possible miniaturization (POCT), and potential ability for real-time analysis. In this review, recently developed biosensors for the detection of autoimmune disease biomarkers are discussed. In the first part, we focus on the main AD biomarkers and the current methods of their detection. Then, we discuss the principles and different types of biosensors. Finally, we overview the characteristics of biosensors based on different bioreceptors reported in the literature.

Osteoimmunology: The Crosstalk between T Cells, B Cells, and Osteoclasts in Rheumatoid Arthritis

Rheumatoid arthritis (RA) is an ongoing inflammatory condition that affects the joints and can lead to severe damage to cartilage and bones, resulting in significant disability. This condition occurs when the immune system becomes overactive, causing osteoclasts, cells responsible for breaking down bone, to become more active than necessary, leading to bone breakdown. RA disrupts the equilibrium between osteoclasts and osteoblasts, resulting in serious complications such as localized bone erosion, weakened bones surrounding the joints, and even widespread osteoporosis. Antibodies against the receptor activator of nuclear factor-κB ligand (RANKL), a crucial stimulator of osteoclast differentiation, have shown great effectiveness both in laboratory settings and actual patient cases. Researchers are increasingly focusing on osteoclasts as significant contributors to bone erosion in RA. Given that RA involves an overactive immune system, T cells and B cells play a pivotal role by intensifying the immune response. The imbalance between Th17 cells and Treg cells, premature aging of T cells, and excessive production of antibodies by B cells not only exacerbate inflammation but also accelerate bone destruction. Understanding the connection between the immune system and osteoclasts is crucial for comprehending the impact of RA on bone health. By delving into the immune mechanisms that lead to joint damage, exploring the interactions between the immune system and osteoclasts, and investigating new biomarkers for RA, we can significantly improve early diagnosis, treatment, and prognosis of this condition.

Clinical significance of anti-mutated citrullinated vimentin antibodies in rheumatoid arthritis patients

BACKGROUND

Anti-mutated citrullinated vimentin (MCV) antibodies have recently been recommended as a better arthritis diagnostic marker.

OBJECTIVES

To investigate the association between anti-MCV antibodies and the clinical, functional, and radiographic characteristics of rheumatoid arthritis (RA) patients.

METHODS

This case-control study was conducted on 40 RA patients and 40 healthy subjects. All patients were subjected to an assessment of disease using the 28-joint DAS (DAS28) and Clinical Disease Activity Index (CDAI), function by HAQ-DI, physical activity by International Physical Activity Questionnaire (IPAQ), fatigue by Functional Assessment of Chronic Illness Therapy (FACIT), serological tests as well as anti-MCV Abs measurement. A plain X-ray of both hands and wrists was done.

RESULTS

The anti-MCV Abs level was significantly higher in RA patients than in healthy controls (P< 0.001). The anti-MCV Abs had a significant positive correlation with DAS, CDAI, HAQ, RF, Anti-CCP, and CRP (P= 0.006, 0.013, 0.005, < 0.001, < 0.001and 0.041 respectively) and a significant negative correlation with FACIT (p= 0.007). Positive anti-MCV RA patients had significantly higher erosions, JSN, and a total sharp score.

CONCLUSIONS

Anti-MCV Abs may contribute to poor physical activity and more fatigue in RA patients beyond their established role in disease activity and erosion.

Clinical Value of Detecting Anti-Mutated Citrullinated Vimentin, Anti-Cyclic Citrullinated Peptide, Red Cell Distribution Width and 25-Hydroxyvitamin D in the Diagnosis of Rheumatoid Arthritis

OBJECTIVES

To investigate the clinical value of detecting anti-mutated citrullinated vimentin (anti-MCV), anti-citrullinated peptide (anti-CCP), red-blood-cell distribution width (RDW), and 25-hydroxyvitamin D (25-[OH]D) in the diagnosis of rheumatoid arthritis (RA).

METHODS

We enrolled 119 patients with RA, 114 control individuals without RA (disease controls), and 40 healthy controls in our study (Han Chinese). Anti-CCP and anti-MCV were detected by enzyme-linked immunosorbent assay (ELISA), 25-(OH)D was detected by electrochemical luminescence, and RDW was calculated by erythrocyte parameters detected via the electric resistance method.

RESULTS

The serum levels of anti-CCP and anti-MCV in RA were higher than those in disease controls and healthy controls (P <.01). The areas under the curve (AUCs) of anti-MCV, anti-CCP, RDW, and 25-(OH)D were 0.857, 0.890, 0.611, and 0.569 respectively (P <.05). In various combinations of indicators, when RDW, 25-(OH)D, and anti-CCP; or RDW, 25-(OH)D, anti-CCP, and anti-MCV were connected in parallel, the sensitivity was the highest (all 94.1%). Also, when RDW, 25-(OH)D, anti-CCP, and anti-MCV were connected in series, the sensitivity was the lowest (13.4%).

CONCLUSIONS

Anti-CCP and anti-MCV are ideal indices for RA diagnosis. Also, in combination with RDW and 25-(OH)D, the diagnostic level will be improved, as well as the sensitivity and specificity, which is significant for the differential diagnosis of RA.

Advances in the diagnosis of autoimmune diseases based on citrullinated peptides/proteins

Introduction: Autoimmune diseases are still one of the hard obstacles associated with humanity. There are many exogenous and endogenous etiological factors behind autoimmune diseases, which may be combined or dispersed to stimulate the autoimmune responses. Protein citrullination represents one of these factors. Harnessing specific citrullinated proteins/peptides could early predict and/or diagnose some of the autoimmune diseases. Many generations of diagnostic tools based on citrullinated peptides with comparable specificity/sensitivity are available worldwide.Areas covered: In this review, we discuss the deimination reaction behind the citrullination of most known autoantigens targeted, different generations of diagnostic tools based on citrullinated probes with specificity/sensitivity of each as well as newly developed assays. Furthermore, the most advanced molecular analytical tools to detect the citrullinated residues in the biological fluid and their performance are also evaluated, providing new avenues to early detect autoimmune diseases with high accuracy.Expert opinion: With the current specificity/sensitivity tools available for autoimmune disease detection, emphasis must be placed on developing more advance and effective, early, rapid, and simple diagnostic devices for autoimmune disease monitoring (similar to a portable device for sugar test at home). The molecular analytical devices with dual and/or multiplexe functions should be more simplified and invested in clinical laboratories.

Biomarkers in Rheumatoid Arthritis

The utilization and identification of biomarkers in rheumatoid arthritis (RA) to facilitate timely diagnosis and the optimal management of the disease is an area of active investigation. This review focuses on biomarkers available for routine clinical use, details potential investigational biomarkers, and raises outstanding clinical questions.

Elevated Expression of the Long Noncoding RNA IFNG-AS1 in the Peripheral Blood from Patients with Rheumatoid Arthritis

Long noncoding RNAs (lncRNAs) have been increasingly recognized as key immune molecules that participate in the pathogenesis of autoimmune diseases. Previous studies have demonstrated that the lncRNA Ifng-AS1, a key scaffold that contributes to the transcription of IFN-γ, depends on T-bet for active transcription in Th1 cells. However, the effect of its human ortholog, IFNG-AS1, on the pathogenesis of rheumatoid arthritis (RA) remains unclear. In this study, we found that the transcript level of lncRNA IFNG-AS1 was increased in the peripheral blood of RA patients. IFNG, as a target gene of IFNG-AS1, was overexpressed and positively correlated with the transcript level of IFNG-AS1 in the RA patients. Our data also showed that the transcript level of T-bet was upregulated and positively correlated with IFNG-AS1 expression. T-bet regulated the transcription of IFNG-AS1 in human CD4⁺ T cells in vitro. Furthermore, strong positive correlations were observed between the increased transcript level of IFNG-AS1 and the serum level of rheumatoid factor, the erythrocyte sedimentation rate, and the C-reactive protein in RA patients, and patients positive for anticyclic citrullinated peptide antibodies had increased levels of IFNG-AS1. Finally, receiver operating characteristic (ROC) curve analysis suggested that IFNG-AS1 might be a potential biomarker of RA. Taken together, our findings indicated that IFNG-AS1, guided by T-bet, is augmented in the peripheral blood of RA patients and may play a critical role in the pathogenesis of RA by regulating the expression of IFNG.

An Overview of the Intrinsic Role of Citrullination in Autoimmune Disorders

A protein undergoes many types of posttranslation modification. Citrullination is one of these modifications, where an arginine amino acid is converted to a citrulline amino acid. This process depends on catalytic enzymes such as peptidylarginine deiminase enzymes (PADs). This modification leads to a charge shift, which affects the protein structure, protein-protein interactions, and hydrogen bond formation, and it may cause protein denaturation. The irreversible citrullination reaction is not limited to a specific protein, cell, or tissue. It can target a wide range of proteins in the cell membrane, cytoplasm, nucleus, and mitochondria. Citrullination is a normal reaction during cell death. Apoptosis is normally accompanied with a clearance process via scavenger cells. A defect in the clearance system either in terms of efficiency or capacity may occur due to massive cell death, which may result in the accumulation and leakage of PAD enzymes and the citrullinated peptide from the necrotized cell which could be recognized by the immune system, where the immunological tolerance will be avoided and the autoimmune disorders will be subsequently triggered. The induction of autoimmune responses, autoantibody production, and cytokines involved in the major autoimmune diseases will be discussed.

The B side of rheumatoid arthritis pathogenesis

In the last years, a dramatic amount of research has been performedincreasing the knowledge about the biological mechanism underpinning Rheumatoid Arthritis (RA) inflammation, putting B lymphocytes in the center of RA pathogenesis. Nowadays, B cell phenotypes and autoantibodies positivity arose as important biomarkers in early and long-standing disease. Moreover, comparative analysis of peripheral blood and synovial tissue compartments enables the identification of novel physiopathological mechanisms promoting inflammation. In this narrative review we will discuss the biological relevance of B cell derived autoimmunity and in RA course, from disease onset to remission achievement.

Cytokines (IL-15, IL-21, and IFN-γ) in rheumatoid arthritis: association with positivity to autoantibodies (RF, anti-CCP, anti-MCV, and anti-PADI4) and clinical activity

INTRODUCTION

Rheumatoid arthritis (RA) is an autoimmune disease characterized by synovial membrane damage and autoantibody production. RA is a heterogeneous disease, where cytokines such as IL-15, IL-21, and IFN-γ have been associated. However, their association with the autoantibodies has not been clearly described. The aim of this study was to evaluate the relationship between the cytokines IL-15, IL-21, and IFN-γ with the autoantibodies (RF, anti-CCP, anti-MCV, and anti-PADI4) in RA and disease activity.

METHODOLOGY

This study included 153 RA patients and 80 control subjects (CS). The levels of IL-15, IL-21, IFN-γ, anti-CCP, anti-MCV, and anti-PADI4 were quantified by ELISA, whereas RF was quantified by turbidimetry. The disease activity was evaluated by the indices disease activity score 28-erythrocyte sedimentation rate (DAS28-ESR), clinical disease activity index (CDAI), and simple disease activity index (SDAI).

RESULTS

The serum levels of IL-15, IL-21, and IFN-γ, and autoantibodies were increased in RA patients, compared with CS (p < 0.05). A correlation was found between IL-21 and anti-CCP and anti-MCV (p < 0.05). According to RA evolution, RF, anti-CCP, and anti-MCV had higher levels in early RA. In addition, increased levels of IL-21 were observed in RA seropositive patients (RF/anti-CCP/anti-MCV). The higher levels of both cytokines and autoantibodies were observed in moderate activity, evaluated by the three indices.

CONCLUSIONS

Our results suggest that the increased soluble levels of IL-15, IL-21, and IFN-γ are involved in the inflammatory network in RA. However, IL-21 serum levels are associated with higher titers of autoantibodies (RF, anti-CCP, and anti-MCV) and IL-15 with moderate activity. Key Points • IL-15, IL-21, and IFN-y are associated with the immunopathology of RA, but not significantly with the evolution of the disease. • RF, anti-CCP, and anti-MCV had higher levels in early than established RA. • IL-21 has an association with RF, anti-CCP, and anti-MCVand, for this reason, could be proposed as a disease biomarker. • Patients with activity moderate of disease showed higher levels of RF, anti-CCP, anti-MCV, and IL-15.

Meta-analysis: compared with anti-CCP and rheumatoid factor, could anti-MCV be the next biomarker in the rheumatoid arthritis classification criteria?

Background

Previous reviews of the diagnosis for rheumatoid arthritis (RA) have not compared anti-mutated citrullinated vimentin (MCV) with anti-cyclic citrullinated peptide (CCP) and rheumatoid factor (RF) in respect of sensitivity, specificity and the area under the curve (AUC) against disease controls for differential diagnosis. This meta-analysis aims to evaluate the value of anti-MCV in the diagnosis for RA, the combined sensitivity of anti-MCV and anti-CCP, and certain clinical characteristics related to the performance of anti-MCV.

Methods

Medline, Embase, Cochrane Library and Web of Science were searched for articles published up to 25 August 2018. A total of 33 studies including 6044 RA patients and 5094 healthy or disease controls achieved inclusive criteria. QUADAS-2 was applied to evaluate the quality of the included studies. The bivariate random effects model was employed in primary data synthesis to evaluate the diagnostic performance.

Results

The sensitivity of anti-MCV, anti-CCP and RF in RA diagnosis against a disease control group was 0.71, 0.71, 0.77, with the specificity of 0.89, 0.95, 0.73, and the AUC of the SROC of 0.89, 0.95, 0.82, respectively. The predesign of the primary study and diagnostic criteria were statistically significant as sources of heterogeneity. Anti-MCV and anti-CCP tests demonstrated a sensitivity of 0.77 when performed in parallel, with a sensitivity of 0.60 when performed in series; whereas, the combination of anti-MCV and RF presented a sensitivity of 0.64 when used in series.

Conclusions

Anti-MCV demonstrates comparable diagnostic value to anti-CCP and RF, thus it can be an effective diagnostic marker for RA and may be written into the next authoritative criteria.

When the plot thickens: a rare complication of rheumatoid arthritis

Introduction: Rheumatoid arthritis (RA) is a common illness with many extraarticular manifestations. Rheumatoid pachymeningitis is a rare neurologic complication of this common disease. Here in we present a patient with longstanding RA who developed this uncommon complication.

Case description: A 75-year-old woman with longstanding RA presented to the clinic with multiple seizure-like spells per day. Upon admission to the hospital, brain MRI showed enhancement of the meninges. After an extensive workup for possible other infectious or inflammatory causes, the patient was diagnosed with rheumatoid pachymeningitis.

Conclusion: Rheumatoid pachymeningitis is a rare complication of RA that usually occurs late in the disease course. It may have many neurologic manifestations include mimicking seizure or stroke and must be considered in patients with RA presenting with neurologic symptoms. Pachymeningitis is treated distinctly from articular RA, so early recognition can lead to appropriate treatment.

Laboratory and Clinical Performance of the ADVIA Centaur Anticyclic Citrullinated Peptide Assay for Rheumatoid Arthritis Diagnosis

CONTEXT.—

Anticyclic citrullinated peptide antibodies are important serologic markers for the diagnosis of rheumatoid arthritis. Several kinds of test reagents for automated immunoassay systems have been developed and used in recent years.

OBJECTIVE.—

To evaluate the analytic and diagnostic performance of the new ADVIA Centaur anticyclic citrullinated peptide assay (Siemens Healthineers, Erlangen, Germany) compared with the Elecsys assay (Roche Diagnostics, Mannheim, Germany).

DESIGN.—

A total of 576 serum samples were collected from subjects, including 156 patients (27%) with rheumatoid arthritis. Precision performance and analytical measurement range for the ADVIA assay were evaluated. Diagnostic performance of the 2 assays was compared based on sensitivity, specificity, and area under the receiver operating characteristic curves.

RESULTS.—

The ADVIA assay showed a within-laboratory imprecision of 3.4% coefficient of variation for levels of 3.36 and 24.99 U/mL. This assay was demonstrated to be linear from 0.4 to 180.0 U/mL. With default cutoff values, sensitivity and specificity for diagnosing rheumatoid arthritis were 71.2% and 97.9%, respectively, for the ADVIA assay and 73.1% and 96.9%, respectively, for the Elecsys assay. With the best cutoff values from the analyses of the receiver operating characteristic curve, the sensitivity of the 2 assays was the same at 75.6%. However, the specificity of the ADVIA assay was 96.4%, whereas that of the Elecsys assay was 94.3%. The area under the receiver operating characteristic curve value for the ADVIA assay was 0.867, which was not significantly different from that of the Elecsys assay (0.865).

CONCLUSIONS.—

The ADVIA Centaur anticyclic citrullinated peptide assay showed good analytic and diagnostic performance in diagnosing rheumatoid arthritis.

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.

Anti-streptavidin IgG antibody interference in anti-cyclic citrullinated peptide (CCP) IgG antibody assays is a rare but important cause of false-positive anti-CCP results

Background:

The detection of anti-cyclic citrullinated peptide (anti-CCP) IgG antibodies in blood is mainly used for the diagnosis of rheumatoid arthritis. Falsely elevated anti-CCP IgG antibodies due to anti-streptavidin IgG antibodies were suspected in our laboratory.

Methods:

In this study, we evaluated, in a standardized approach, the prevalence of anti-streptavidin IgG antibodies in a primary care setting and the effect of anti-streptavidin IgG antibodies on anti-CCP IgG assays from three different important commercial manufacturers (Abbott, Roche Diagnostics, Thermo Fisher Scientific). Three different populations were consecutively and prospectively studied: serum samples from 1000 ambulatory patients, 286 serum samples from patients for which anti-CCP was requested and 89 serum samples from patients which had previously given a positive anti-CCP result on Architect® i2000.

Results:

The frequency of confirmed anti-streptavidin IgG-positive samples detected in this study was 0.6% (8/1375). Anti-CCP IgG was determined on the eight samples with confirmed anti-streptavidin IgG antibodies: with the Cobas® method, seven positive anti-CCP results were observed and five positive anti-CCP results with the Architect® method. No positive anti-CCP IgG results were obtained with the EliA™ method. Rheumatoid factor was negative in these eight samples.

Conclusions:

Anti-streptavidin IgG antibodies rarely cause false-positive results in some anti-CCP assays. However, despite being an infrequent assay problem, it could possibly lead to diagnostic confusion or even an incorrect diagnosis of rheumatoid arthritis.

Clinical significance of detecting HLA-DR, 14-3-3η protein and d-dimer in the diagnosis of rheumatoid arthritis

AIM

To investigate the clinical significance of detecting several biomarkers collectively in the diagnosis of rheumatoid arthritis (RA).

METHODS

128 RA patients, 174 non-RA patients and 80 healthy controls were enrolled. HLA-DR4 and HLA-DR53 were detected by the PCR-SSP method, 14-3-3η protein, anti-CCP and anti-Sa were detected by ELISA and DD was detected by latex immunoturbidimetric assay.

RESULTS

The positive rates of HLA-DR4, HLA-DR53, 14-3-3η protein, anti-CCP and anti-Sa were obviously higher in the RA group (43.8, 38.3, 51.6, 80 and 40.6%, respectively); anti-CCP was of highest sensitivity (79.68%), highest specificity (97.5%) and Youden index (0.77). The AUC of 14-3-3η protein, DD, anti-CCP, anti-Sa were 0.813, 0.859, 0.930, 0.861, respectively.

CONCLUSION

All biomarkers were strongly correlated risk factors for RA; the combination of multiple biomarkers might be of help for diagnostic and therapeutic strategies in RA of recent onset.

Inflammatory arthritis and crystal arthropathy: Current concepts of skin and systemic manifestations

Systemic inflammatory disorders frequently involve the skin, and when cutaneous disease develops, such dermatologic manifestations may represent the initial sign of disease and may also provide valuable prognostic information about the underlying disorder. Familiarity with the various skin manifestations of systemic disease is therefore paramount and increases the likelihood of accurate diagnosis, which may facilitate the implementation of an appropriate treatment strategy. An improvement in quality of life and a reduction in the degree of morbidity may also be a realized benefit of accurate recognition of these skin signs. With this context in mind, this review highlights the salient clinical features and unique dermatologic manifestations of rheumatoid arthritis, adult-onset Still's disease, and the crystal arthropathy, gout.

Role of Serum cartilage oligomeric matrix protein (COMP) in the diagnosis of rheumatoid arthritis (RA): A case-control study

Objective

To analyse the role of serum cartilage oligomeric matrix protein (COMP) levels in the differential diagnosis of rheumatoid arthritis (RA).

Methods

This case–control study analysed the clinical and laboratory characteristics of patients with RA and healthy control subjects. The diagnostic ability of COMP for RA was evaluated by comparing it with anti-cyclic citrullinated peptide antibody levels. The sensitivity, specificity, positive and negative predictive values were calculated.

Results

The study enrolled 82 patients with RA and 34 healthy control subjects. The serum COMP level was significantly higher in patients with RA compared with control subjects (mean ± SD 29.51 ± 9.21 ng/ml versus 17.85 ± 5.55 ng/ml, respectively). The serum COMP level was significantly higher in patients with active RA compared with patients with RA in remission (mean ± SD 33.08 ± 8.80 ng/ml versus 24.94 ± 7.65 ng/ml, respectively). The cut-off value for COMP to discriminate patients with RA from healthy individuals was 21.51 ng/ml (sensitivity 0.817, specificity 0.882, positive predictive value 0.944, negative predictive value 0.667, and accuracy 0.836).

Conclusion

The serum COMP level has the potential to be used as a biological marker for differentiating between patients with RA and healthy individuals.