A new strategy for the early diagnosis of rheumatoid arthritis: A combined approach

Prediction of diagnosis results of rheumatoid arthritis patients based on autoantibodies and cost-sensitive neural network

OBJECTIVES

To analyze and evaluate the effectiveness of the detection of single autoantibody and combined autoantibodies in patients with rheumatoid arthritis (RA) and related autoimmune diseases and establish a machine learning model to predict the disease of RA.

METHODS

A total of 309 patients with joint pain as the first symptom were retrieved from the database. The effectiveness of single and combined antibodies tests was analyzed and evaluated in patients with RA, a cost-sensitive neural network (CSNN) model was used to integrate multiple autoantibodies and patient symptoms to predict the diagnosis of RA, and the ROC curve was used to analyze the diagnosis performance and calculate the optimal cutoff value.

RESULTS

There are differences in the seropositive rate of autoimmune diseases, the sensitivity and specificity of single or multiple autoantibody tests were insufficient, and anti-CCP performed best in RA diagnosis and had high diagnostic value. The cost-sensitive neural network prediction model had a sensitivity of up to 0.90 and specificity of up to 0.86, which was better than a single antibody and combined multiple antibody detection.

CONCLUSION

In-depth analysis of autoantibodies and reliable early diagnosis based on the neural network could guide specialized physicians to develop different treatment plans to prevent deterioration and enable early treatment with antirheumatic drugs for remission. Key Points • There are differences in the seropositive rate of autoimmune diseases. • This is the first study to use a cost-sensitive neural network model to diagnose RA disease in patients. • The diagnosis effect of the cost-sensitive neural network model is better than a single antibody and combined multiple antibody detection.

A new tool for early diagnosis of rheumatoid arthritis using combined biomarkers; synovial MAGE-1 mRNA and serum anti-CCP and RF

Introduction

rheumatoid arthritis (RA) is a common autoimmune disease with unknown etiology and pathogenesis. Biomarkers have the potential to aid in the clinical diagnosis of the disease, or to provide means of detecting early signs of the disease. Evaluating Melanoma associated antigen genes (MAGE-1) mRNA expression rate in synovial fluid cells and serum levels of anti-cyclic citrullinated peptides (anti-CCP) and rheumatoid factor (RF) for RA early diagnosis.

Methods

a total of 213 subjects were enrolled in the study, 135 RA patients and 78 normal subjects with traumatic knee joints (control group). Serum RF and anti-CCP were estimated quantitatively using ELISA. MAGE-1 mRNA expression rate was analyzed by RT-PCR.

Results

a significant increase in serum levels of RF IgM and anti-CCP in RA patients compared to the controls. A positively significant correlation was found between serum anti-CCP and RF IgM. The expression rate of MAGE-1 mRNA was 100% in RA patients versus the controls (0%). The specificity and the sensitivity of the three biomarkers was 100%.

Conclusion

the high expression rate of MAGE-1 in synovial fluid cells of RA patients is encouraging its utilization as a diagnostic biomarker for RA. The combined use of MAGE-1 transcript in synovial fluid cells, serum RF and anti-CCP is recommended for improving early diagnostic ability of RA.

Association of the polymorphisms of TRAF1 (rs10818488) and TNFAIP3 (rs2230926) with rheumatoid arthritis and systemic lupus erythematosus and their relationship to disease activity among Egyptian patients

Aim of the study

Recent studies demonstrated the association of tumor necrosis factor α-induced protein 3 (TNFAIP3) (rs2230926) and tumor necrosis factor receptor associated factor 1 (TRAF1) (rs10818488) with rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE) in different populations. We aimed at determining whether they confer susceptibility to SLE and RA in Egyptian population and if there is any relation to disease activity and auto-antibodies profile.

Material and methods

A case-control study involving 105 individuals with RA, 90 with SLE and 75 healthy controls was performed using TaqMan genotyping assay for two SNPs that showed the best evidence of association in the previous Caucasian studies.

Results

We detected significant differences in G allele frequency of TNFAIP3 (rs2230926) with SLE (p = 0.017^*) and RA (OR = 2.333; 95% CI: 1.103-4.935, p = 0.023^*) and association with RA disease activity (< 0.001). The A allele of TRAF1 was significantly increased in RA compared to controls(p = 0.049) and with RA activity (p = 0.001), while TRAF1 polymorphism did not exhibit any significant difference in the frequencies of genotypes or alleles in SLE and control (p = 0.280).

Conclusions

TNFAIP3 is a susceptibility gene to SLE and RA in the Egyptian population and is correlated to disease activity and the presence of autoantibodies while TRAF1 polymorphisms increase the risk of RA but not to SLE in Egyptian populations.

Relation between bone mineral density and IL-17 serum levels in Serbian patients with early Rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic inflammatory disease characterized by synovial inflammation and destruction of joint cartilage and bone. Different cytokines play important role in the processes that cause articular destruction and extra-articular manifestations in RA. The contribution of cytokines representing the Th1 (INF-γ), Th2 (IL-4) and IL-17A to the pathogenesis of early RA and bone mineral density (BMD) loss in still poorly understood. Serum samples of 38 early RA patients were evaluated for erythrocyte sedimentation rate (ESR), rheumatoid factor (RF), C-reactive protein (CRP), anti-cyclic citrullinated peptide antibodies (anti-CCP) and for the tested cytokines (IL-17A, IL-4 and INF-γ). BMD was evaluated by dualenergy X-ray absorptiometry (DXA). Disease activity score (DAS28) calculation was assessed for all patients. Control serum samples were obtained from 34 healthy volunteers. The levels of tested cytokines were significantly higher (IL-17A, p<0.001; INF-γ, P<0.001; IL-4, P<0.01) in patients with early RA, compared to the healthy controls. In early RA patients, strong correlation of serum IL-17A was found with DAS28, ESR and CRP. Also, a significant negative correlation was found between serum INF-γ levels and the DAS28 score. Significantly positive correlation of BMD values and CRP, DAS28 IL-17A were also demonstrated. DXA analysis revealed that the most common site for osteoporosis was the lumbar spine followed by the femoral neck. BMD values significantly correlated with CRP, DAS28 score and IL-17A serum levels. The mean serum IL-17A levels, in patients with early RA, corresponded with disease activity, severity and BMD loss, indicating the potential usefulness of serum IL-17A in defining the disease activity and bone remodeling.

Biomarkers of cartilage and surrounding joint tissue

The identification and clinical demonstration of efficacy and safety of osteo- and chondro-protective drugs are met with certain difficulties. During the last few decades, the pharmaceutical industry has, in the field of rheumatology, experienced disappointments associated with the development of disease modification. Today, the vast amount of patients suffering from serious, chronic joint diseases can only be offered treatments aimed at improving symptoms, such as pain and acute inflammation, and are not aimed at protecting the joint tissue. This huge, unmet medical need has been the driver behind the development of improved analytical techniques allowing better and more efficient clinical trial design, implementation and analysis. With this review, we aim to provide a brief and general overview of biochemical markers of joint tissue, with special focus on neoepitopes. Furthermore, we highlight recent studies applying biochemical markers in joint degenerative diseases. These disorders, including osteoarthritis, rheumatoid arthritis and spondyloarthropathies, are the most predominant disorders in Europe and the USA, and have enormous socioeconomical impact.

A systematic review of serum biomarkers anti-cyclic citrullinated Peptide and rheumatoid factor as tests for rheumatoid arthritis

This systematic review assesses the current status of anti-cyclic citrullinated peptide (anti-CCP) and rheumatoid factor (RF) tests in the diagnosis and prognosis of rheumatoid arthritis (RA). We reviewed publications on tests and biomarkers for early diagnosis of RA from English-language MEDLINE-indexed journals and non-MEDLINE-indexed sources. 85 publications were identified and reviewed, including 68 studies from MEDLINE and 17 non-MEDLINE sources. Anti-CCP2 assays provide improved sensitivity over anti-CCP assays and RF, but anti-CCP2 and RF assays in combination demonstrate a positive predictive value (PPV) nearing 100%, greater than the PPV of either of the tests alone. The combination also appears to be able to distinguish between patients whose disease course is expected to be more severe and both tests are incorporated in the 2010 ACR Rheumatoid Arthritis Classification Criteria. While the clinical value of anti-CCP tests has been established, differences in cut-off values, sensitivities and specificities exist between first-, second- and third-generation tests and harmonization efforts are under way. Anti-CCP and RF are clinically valuable biomarkers for the diagnosis and prognosis of RA patients. The combination of the two biomarkers in conjunction with other clinical measures is an important tool for the diagnosis and management of RA patients.

Serum and synovial fluid levels of interleukin-17 in correlation with disease activity in patients with RA

The aim of this study was to evaluate serum and synovial levels of IL-17A by ELISA in rheumatoid arthritis (RA) and find out the correlations between IL-17A levels and various clinical, laboratory parameters and RA disease activity and severity indices. Group I consists of 30 adult active RA patients fulfilling the ARA 1987 revised criteria, with knee effusion and receiving basic therapy, and with a mean age of 41.47±11.49 years and mean disease duration of 9.5±4.16 years. Group II consisted of 13 healthy volunteers, age- and sex-matched, with a mean age of 39.08±14.19 years. RA patients showed significantly higher mean serum IL-17A levels than controls (11.25±9.67 vs. 0.6±1.4 pg/mL, respectively, p=0.0002). Synovial IL-17A levels showed a significant positive correlation with serum IL-17A levels (r=0.5 and p=0.005). RA patients with negative rheumatoid factor (RF) had non-significantly higher mean serum IL-17A levels (12±9.86 pg/mL) compared to those with positive RF (10.82±9.81 pg/mL); however, the mean synovial IL-17A levels were nearly the same. Significant positive correlations were found between both serum and synovial IL-17A levels and DAS-28 scores (r=0.556, 0.392 and p=0.001, 0.032, respectively). RA patients with class III functional status showed significantly higher mean serum IL-17A levels (17.53±13.43 pg/mL) than classes I and II (8.97±6.97 pg/mL, p=0.009). These led us to conclude that the elevated serum and synovial IL-17A levels in RA patients parallel the degree of disease activity and severity. This may highlight the usefulness of IL-17 (especially serum level) as a possible marker for more aggressive joint involvement and damage.

Pearls in autoimmunity

This manuscript does a review of the more frequent issues published at Autoimmunity Reviews, Journal of Autoimmunity and Autoimmunity in the period of January–December 2009. The following topics were commented: (1) multiple sclerosis (MS) and its relationships with Epstein Barr infection, with vitamin D polymorphism and the new modalities of MS treatment. (2) Type 1 diabetes and genetic discovers, studies with GAD 65 and IA-2 autoantigen and the association T1D and autoimmune organ-specific diseases. (3) Autoimmune thyroid disorders and its association with susceptibility genes and polymorphisms. (4) Multiplex autoantibody profiling approaches in MS and rheumatoid arthritis. (5) Th17 cytokine in primary biliary cirrhosis, experimental autoimmune encephalomyelitis and celiac disease. (6) Vitamin D and experimental autoimmune prostatitis and pulmonary alveolar proteinosis.

Association of anti-modified citrullinated vimentin with subclinical atherosclerosis in early rheumatoid arthritis compared with anti-cyclic citrullinated peptide

OBJECTIVE

To investigate anti-modified citrullinated vimentin (anti-MCV) in early rheumatoid arthritis (RA), including correlation with disease activity and cardiovascular risk factors, compared with anti-cyclic citrullinated peptides (anti-CCP3).

METHODS

Anti-MCV and anti-CCP3 concentrations were measured in 100 patients with early RA and 100 healthy controls at baseline to determine sensitivity and specificity. Patients received methotrexate (MTX) 0.2 mg/kg/week plus prednisone 10 mg/day. Anti-MCV, anti-CCP3, rheumatoid factor (RF), Disease Activity Score for 28 joints (DAS-28), lipid profile, erythrocyte sedimentation rate (ESR), high-sensitivity C-reactive protein assay (hsCRP), homeostasis model assessment for insulin resistance (HOMA-IR) index, tumor necrosis factor-α (TNF-α), interleukin 6 (IL-6), and carotid intima-media thickness (cIMT) were measured before and after 12 months of treatment.

RESULTS

The sensitivity and specificity for anti-MCV antibody were 75% and 90%, respectively, and for anti-CCP3 antibody 71% and 96%. Serum anti-MCV and serum anti-CCP3 levels at baseline were positively correlated with hsCRP, IL-6, HOMA-IR index, serum RF levels (p < 0.001), and cIMT (p < 0.05). Serum anti-MCV was positively correlated with serum anti-CCP3 levels. There were significant positive correlations between the percentage of changes of anti-MCV levels versus changes in DAS-28, ESR, hsCRP, atherogenic ratios (TC/HDL-C and LDL-C/HDL-C), apolipoprotein A-I, IL-6, TNF-α, HOMA-IR index, and cIMT. These correlations were not found between changes in anti-CCP3 levels compared to clinical, laboratory, and radiological variables.

CONCLUSION

Anti-MCV was as sensitive as anti-CCP3 in diagnosing early RA. Anti-MCV testing appears to be useful for monitoring associated subclinical atherosclerosis in early RA.

Development and validation of gene therapies in autoimmune diseases: Epidemiology to animal models

Recent advancement in immunology, molecular biology, and bioinformatics has yielded extensive information on the pathophysiological mechanisms of autoimmunity, which has greatly facilitated the identification of potential therapeutic targets and the development of gene therapy in the treatment of autoimmune disease. Preclinical studies were carried out in animal models. This phenomenon is well illustrated in two prototypic animal models of autoimmune disease: the autoimmune encephalomyelitis (EAE) model of multiple sclerosis (MS) and collagen-induced arthritis (CIA) model in rheumatoid arthritis (RA). Here we discuss the current data on the development and validation of gene therapy in autoimmunity in these two models. The success in preclinical animal model studies provides the proof-of-concept of gene therapy for potential future applications in the treatment of autoimmune diseases. Furthermore, the identification of risk factors from epidemiological studies reveals further potential therapeutic targets to be examined in animal models.

Rheumatoid arthritis, Proteus, anti-CCP antibodies and Karl Popper

Rheumatoid arthritis (RA) is a crippling joint disease affecting over 20 million people worldwide. The cause of RA is most probably linked to the triad of microbial trigger, genetic association and autoimmunity and can be explained using the philosophical method of Karl Popper or Popperian sequences. Ten "Popper sequences" have been identified which point to the urinary microbe Proteus mirabilis as the cause of RA: Popper sequence 1 establishes that HLA-DR4 lymphocytes injected into a rabbit evoke specific antibodies against Proteus bacteria. Popper sequence 2 establishes that antibodies to Proteus bacteria are present in RA patients from 14 different countries. Popper sequence 3 establishes that antibodies to Proteus bacteria in RA patients are disease specific since no such antibodies are found in other conditions. Popper sequence 4 establishes that when RA patients have high titres of antibodies to Proteus such bacteria are found in urinary cultures. Popper sequence 5 establishes that only Proteus bacteria and no other microbes evoke significantly elevated antibodies in RA patients. Popper sequence 6 establishes that the "shared epitope" EQR(K)RAA shows "molecular mimicry" with the sequence ESRRAL found in Proteus haemolysin. Popper sequence 7 establishes that Proteus urease contains a sequence IRRET which has "molecular mimicry" with LRREI found in collagen XI of hyaline cartilage. Popper sequence 8 establishes that sera obtained from RA patients have cytopathic properties against sheep red cells coated with the cross-reacting EQR(K)RAA and LRREI self-antigen peptides. Popper sequence 9 establishes that Proteus sequences in haemolysin and urease as well as the self antigens, HLA-DR1/4 and collagen XI, each contain an arginine doublet, thereby providing a substrate for peptidyl arginine deiminase (PAD) to give rise to citrulline, which is the main antigenic component of CCP, antibodies to which are found in early cases of RA. Popper sequence 10 establishes that antibodies to Proteus come not only from sequences crossreacting to self antigens but also from non-crossreacting sequences, thereby indicating that active RA patients have been exposed to infection by Proteus. The ten Popper sequences establish that RA is most probably caused by Proteus upper urinary tract infections, which can possibly be treated with anti-Proteus therapy.