Antibodies against cyclic citrullinated peptide are associated with the DRB1 shared epitope and predict joint erosion in rheumatoid arthritis

The peculiar features, diversity and impact of citrulline-reactive autoantibodies

Since entering the stage 25 years ago as a highly specific serological biomarker for rheumatoid arthritis, anti-citrullinated protein antibodies (ACPAs) have been a topic of extensive research. This hallmark B cell response arises years before disease onset, displays interpatient autoantigen variability, and is associated with poor clinical outcomes. Technological and scientific advances have revealed broad clonal diversity and intriguing features including high levels of somatic hypermutation, variable-domain N-linked glycosylation, hapten-like peptide interactions, and clone-specific multireactivity to citrullinated, carbamylated and acetylated epitopes. ACPAs have been found in different isotypes and subclasses, in both circulation and tissue, and are secreted by both plasmablasts and long-lived plasma cells. Notably, although some disease-promoting features have been reported, results now demonstrate that certain monoclonal ACPAs therapeutically block arthritis and inflammation in mouse models. A wealth of functional studies using patient-derived polyclonal and monoclonal antibodies have provided evidence for pathogenic and protective effects of ACPAs in the context of arthritis. To understand the roles of ACPAs, one needs to consider their immunological properties by incorporating different facets such as rheumatoid arthritis B cell biology, environmental triggers and chronic antigen exposure. The emerging picture points to a complex role of citrulline-reactive autoantibodies, in which the diversity and dynamics of antibody clones could determine clinical progression and manifestations.

Unique autoantibody prevalence in long-term recovered SARS-CoV-2-infected individuals

The variability in resolution of SARS-CoV-2-infections between individuals neither is comprehended, nor are the long-term immunological consequences. To assess the long-term impact of a SARS-CoV-2-infection on the immune system, we conducted a prospective study of 80 acute and former SARS-CoV-2 infected individuals and 39 unexposed donors to evaluate autoantibody responses and immune composition. Autoantibody levels against cyclic citrullinated peptide (CCP), a specific predictor for rheumatoid arthritis (RA), were significantly (p = 0.035) elevated in convalescents only, whereas both acute COVID-19 patients and long-term convalescents showed critically increased levels of anti-tissue transglutaminase (TG), a specific predictor of celiac disease (CD) (p = 0.002). Both, anti-CCP and anti-TG antibody levels were still detectable after 4–8 months post infection. Anti-TG antibodies occurred predominantly in aged patients in a context of a post-SARS-CoV-2-specific immune composition (R² = 0.31; p = 0.044). This study shows that increased anti-CCP and anti-TG autoantibody levels can remain long-term after recovering even from mildly experienced COVID-19. The inter-relationship of the lung as viral entry side and RA- and CD-associated autoimmunity indicates that a SARS-CoV-2-infection could be a relevant environmental factor in their pathogenesis.

Vitamin D and rheumatoid arthritis: an ongoing mystery

PURPOSE OF REVIEW

In recent years, there has been a growing interest in the value of vitamin D and its effects on autoimmunity. The aim of this review is to summarize the current knowledge on the association between vitamin D and rheumatoid arthritis (RA) in terms of prevalence, disease activity, clinical expression, serology and gene polymorphisms of vitamin D receptors.

RECENT FINDINGS

Studies have shown contrasting findings concerning the association between vitamin D levels and RA. Vitamin D seems to have immunomodulatory properties. Therefore, low vitamin D levels could contribute to increased immune activation. However, the potential role of vitamin D supplementation in preventing RA manifestation and its beneficial role as a component of RA treatment remain controversial. The relationship between RA susceptibility and vitamin D polymorphisms is also unclear.

SUMMARY

Despite advancements synthesized by some recent meta-analyses, the relationship between vitamin D and RA requires further evaluation. Further research is needed to confirm the relationship between RA susceptibility and vitamin D polymorphisms and to determine whether vitamin D plays a role in preventing the manifestation of RA. Finally, additional studies are required to determine the impact and optimal amount of vitamin D supplementation in the treatment of RA patients.

[Structural and morphological changes in the eyes of arterial hypertensive patients with and without anti-CCP-positive rheumatoid arthritis]

INTRODUCTION

To investigate the additive systemic inflammatory process of rheumatoid arthritis (RA) in arterial hypertension patients, structural and morphological changes of the retina and optic nerve head were assessed by modern topographic technologies. Similarities of underlying vascular mechanisms between RA and arterial hypertension are interesting and have not been researched in depth. The aim of this study is to evaluate changes of RA and arterial hypertension with the optic coherence topography (OCT) and Heidelberg retina tomography (HRT III), to validate RA changes in comparison to arterial hypertension only patients and, finally, if these methods are useful to detect the chronic inflammatory influence of the RA on the eye.

METHODS

In this prospective study design, data of 18 patients with RA and arterial hypertension (55.3 ± 4.31 years old), positive for antibodies against cyclic citrullinated peptides, 21 patients with arterial hypertension (54.2 ± 4.18 years old) and 19 healthy subjects (53.1 ± 3.25 years old) were included. Intensive ophthalmologic and internistic screening tests were carried out in all subjects. All participants were investigated for the retinal nerve fiber layer (RNFL) and macula thickness with the OCT (Carl Zeiss AG Germany) and for stereometric parameters of the optic nerve head with the Heidelberg Retina Tomograph III (Heidelberg Engineering Germany). The pachymetry was conducted by the Orbscan II system (Bausch & Lomb). Statistical data were assessed by SPSS, v20.0.

RESULTS

No significant differences were found in visual function, diastolic and systolic blood pressure. RNFL, and macular thickness (Stratus-OCT) were almost consistent between the groups and even the main stereometric parameters measured with HRT III showed no significant differences.

CONCLUSION

Contrary to our study hypothesis no structural and morphological changes could be detected in patients with arterial hypertension without RA compared to healthy subjects. Furthermore, no RA-specific effects could be shown in comparison with the hypertension group. Thus, the used examination techniques are not suitable to prove the systemic inflammatory influence of RA on the eye.

Have radiographic progression rates in early rheumatoid arthritis changed? A systematic review and meta-analysis of long-term cohorts

OBJECTIVE

To evaluate, firstly, all published data on baseline and annual progression rates of radiographic damage from all longitudinal observational cohorts, and secondly, the association of standard clinical and laboratory parameters with long-term radiographic joint damage.

METHODS

A comprehensive search of the literature from 1975 to 2014, using PubMed, SCOPUS and Cochrane databases, identified a total of 28 studies that investigated long-term radiographic progression, and 41 studies investigating predictors of long-term radiographic progression. This was submitted and approved by PROSPERO in February 2014 (Registration Number: CRD42014007589).

RESULTS

Meta-analysis indicated an overall baseline rate of 2.02%, and a yearly increase of 1.08% of maximum damage. Stratified analysis found that baseline radiographic scores did not differ significantly between cohorts recruiting patients pre- and post-1990 (2.01% vs 2.03%; P > 0.01); however, the annual rate of progression was significantly reduced in the post-1990 cohorts (0.68% vs 1.50%; P < 0.05). High levels of acute phase markers, baseline radiographic damage, anti-CCP and RF positivity remain consistently predictive of long-term radiographic joint damage.

CONCLUSION

Critical changes in treatment practices over the last three decades are likely to explain the reduction in the long-term progression of structural joint damage. Acute phase markers and presence of RF/anti-CCP are strongly associated with increased radiographic progression.

Anti-CCP antibodies are not a marker of severity in established rheumatoid arthritis: a magnetic resonance imaging study

INTRODUCTION

The presence of anti-CCP is an important prognostic tool of rheumatoid arthritis (RA). But research is still ongoing on its relationship with disease activity and functional capacity.

OBJECTIVES

To study the relationship between anti-CCP and disease activity, functional capacity and structural damage indexes, by means of conventional radiography (CR) and magnetic resonance imaging (MRI), in cases of established RA.

METHODS

Cross-sectional study with RA patients with 1-10 disease duration. Participants underwent clinical evaluation with anti-CCP. Disease activity was assessed using the Clinical Disease Activity Index (CDAI), and functional capacity through the Health Assessment Questionnaire (HAQ). CR analysis was carried out by the Sharp van der Heijde index (SvdH), and MRI analysis by RAMRIS (Rheumatoid Arthritis Magnetic Resonance Image Scoring).

RESULTS

We evaluated 56 patients, with a median (IqR) age of 55 (47.5-60) years; 50 (89.3%) participants were female and 37 (66.1%) were positive for anti-CCP. Medians (IqR) of CDAI, HAQ, SvdH and RAMRIS were 14.75 (5.42-24.97) 1.06 (0.28-1.75), 2 (0-8) and 15 (7-35), respectively. There was no association between anti-CCP and CDAI, HAQ and SvdH and RAMRIS scores.

CONCLUSION

Our results have not established an association of anti-CCP with the severity of disease. To date, we cannot corroborate anti-CCP as a prognostic tool in patients with established RA.

Anti-CCP antibodies are not a marker of severity in established rheumatoid arthritis: a magnetic resonance imaging study

INTRODUCTION

The presence of anti-CCP is an important prognostic tool of rheumatoid arthritis (RA). But research is still ongoing on its relationship with disease activity and functional capacity.

OBJECTIVES

To study the relationship between anti-CCP and disease activity, functional capacity and structural damage indexes, by means of conventional radiography (CR) and magnetic resonance imaging (MRI), in cases of established RA.

METHODS

Cross-sectional study with RA patients with 1-10 years of disease duration. Participants underwent clinical evaluation with anti-CCP. Disease activity was assessed using the Clinical Disease Activity Index (CDAI), and functional capacity through the Health Assessment Questionnaire (HAQ). CR analysis was carried out by the Sharp van der Heijde index (SvdH), and MRI analysis by RAMRIS (Rheumatoid Arthritis Magnetic Resonance Image Scoring).

RESULTS

We evaluated 56 patients, with a median (IqR) age of 55 (47.5-60.0) years; 50 (89.3%) participants were female and 37 (66.1%) were positive for anti-CCP. Medians (IqR) of CDAI, HAQ, SvdH and RAMRIS were 14.75 (5.42-24.97) 1.06 (0.28-1.75), 2 (0-8) and 15 (7-35), respectively. There was no association between anti-CCP and CDAI, HAQ and SvdH and RAMRIS scores.

CONCLUSION

Our results have not established an association of anti-CCP with the severity of disease. To date, we cannot corroborate anti-CCP as a prognostic tool in patients with established RA.

The role of citrullinated protein antibodies in predicting erosive disease in rheumatoid arthritis: a systematic literature review and meta-analysis

Background. Autoantibodies to citrullinated peptides have been shown to be valuable in the diagnosis of rheumatoid arthritis (RA). The expanding repertoire of antibodies to citrullinated peptide antigens (ACPA) has been a topic of great interest in recent reviews and research studies, as has the ability of these autoantibodies to predict disease outcome. Objectives. The aim of this review was to provide an update on the relevance of ACPA as prognostic markers in RA. The ability to identify patients predisposed to an aggressive outcome at the time of initial diagnosis greatly facilitates the selection of appropriate and cost-effective treatment. Methods. A systematic review of the literature was carried out. Studies from 1967 up to June 2014 with data on prognostic value of ACPA were included. Quality assessment was done by using the modified Hayden list for prognostic studies. Meta-analysis was performed using BioStat software. Results. The results of 25 studies were selected for the final review. A total of 6421 patients with RA were included, mainly in inception cohorts, with follow-up duration ranging from one year to ten years. All studies carried prognostic data on all available isotypes of anticyclic citrullinated protein (CCP), while four had data on antimutated citrullinated vimentin (MCV). There was a single relevant study each on anticitrullinated enolase peptide 1 (CEP1) and antichimaeric fibrin/filaggrin citrullinated peptide 1 (CFFCP1). All studies showed ACPA to be strong predictors of joint erosions in RA. Other factors, particularly baseline erosions, showed an additive effect. Anti-MCV appeared to be a marker of a more aggressive form of disease. Ten studies had data on which a meta-analysis could be performed. This gave an overall odds ratio of 4.85 for ACPA (anti-CCP/MCV) positivity being predictive for the development of joint erosions. Two studies with data on anti-CEP1 and anti-CFFCP1 also showed this positive predictive role of ACPA for joint erosions. Conclusions. ACPA are strong predictors of severity in RA. Their use should be part of routine rheumatology practice.

Decline in hand bone mineral density indicates increased risk of erosive change in early rheumatoid arthritis

OBJECTIVE

Despite better disease suppression with combination disease-modifying antirheumatic drugs (DMARDs), some patients with rheumatoid arthritis (RA) have progressive erosive disease. The objective of this study was to determine whether hand bone mineral density (BMD) loss in the first 6 months of treatment indicates increased risk of erosions at 12 months.

METHODS

Patients with DMARD-naive early RA receiving treat-to-target therapy were studied (n = 106). Hand BMD was measured at baseline and 6 months by dual x-ray absorptiometry. Hand and feet radiographs were performed at baseline and 12 months and scored using the van der Heijde modification of the Sharp method. A K-means clustering algorithm was used to divide patients into 2 groups: the BMD loss group or the no loss group, according to their absolute change in BMD from baseline to 6 months. Multiple regression analysis (hurdle model) was performed to determine the risk factors for both erosive disease and erosion scores.

RESULTS

Hand BMD loss at 6 months was associated with erosion scores at 12 months (P = 0.021). In a multiple regression analysis, hand BMD loss (P = 0.046) and older age at onset (≥50 years; P = 0.014) were associated with erosive disease, whereas baseline erosion scores (P = 0.001) and anti-cyclic citrullinated peptide (P = 0.024) were correlated with erosion severity/progression.

CONCLUSION

In RA patients receiving treat-to-target therapy, early hand BMD loss could identify patients who are at risk of developing erosive disease at 12 months, potentially allowing intensification of treatment to prevent erosive damage.

Trajectory of intensive treat-to-target disease modifying drug regimen in an observational study of an early rheumatoid arthritis cohort

OBJECTIVES

Studies of early rheumatoid arthritis (RA) cohorts have analysed treatment response and prognostic factors at fixed time points. However, in treat-to-target protocols, therapeutic decision-making is dynamic and responsive to disease activity over time. To determine when a minimal residual disease response target should be expected, our primary objective was to identify the time-dependent therapeutic response to combination disease modifying antirheumatic drugs (DMARDs) for 12 months. Our secondary objective determined factors affecting this response trajectory.

DESIGN

Observational cohort.

SETTING

Treat-to-target early RA clinic in Australian tertiary referral hospital.

PARTICIPANTS

We enrolled consecutive patients attending an early arthritis clinic with symptom duration less than 12 months, who were diagnosed with RA for the first time between 2004 and 2008. 101 met these eligibility criteria and data were available at baseline through 12 months.

INTERVENTIONS

intensive DMARDs according to a treat-to-target protocol.

PRIMARY AND SECONDARY OUTCOME MEASURES

We measured disease activity scores (DAS) at each visit, then analysed therapeutic response and associated factors in a time-dependent fashion over 12 months.

RESULTS

The median DAS4vESR of 4.46 at baseline decreased 12 weeks later by 24%, while the proportion with DAS4v ≤ 2.6 increased (p<0.01). DAS4v continued to decrease over 52 weeks. DAS4v reduction of at least -0.45 at 4 weeks was predictive of DAS4v at 28 and 52 weeks. Female gender, current smoking, primary education and an interaction between baseline weight and C reactive protein (CRP) negatively impacted DAS4v reduction over 4 and 52 weeks. Time-varying effects of blood pressure, neutrophils, erythrocyte sedimentation rate and CRP also significantly influenced DAS4v over 52 weeks.

CONCLUSIONS

Time-dependent data suggest that the largest reduction of DAS4v to combination DMARDs occurs in the first month of therapy, and this predicts subsequent response. Variables known to impact long-term treatment response in RA also impacted early DAS4v response to combination DMARDs.

A citrullinated fibrinogen-specific T cell line enhances autoimmune arthritis in a mouse model of rheumatoid arthritis

Citrullinated proteins, derived from the conversion of peptidyl-arginine to peptidyl-citrulline, are present in the joints of patients with rheumatoid arthritis (RA), who also uniquely produce high levels of anti-citrullinated protein Abs. Citrullinated fibrinogen (CF) is abundant in rheumatoid synovial tissue, and anti-citrullinated protein Ab-positive RA patients exhibit circulating immune complexes containing CF. Thus, CF is a potential major target of pathogenic autoimmunity in RA. T cells are believed to be involved in this process by initiating, controlling, and driving Ag-specific immune responses in RA. In this study, we isolated a CD4 T cell line specific for CF that produces inflammatory cytokines. When transferred into mice with collagen-induced arthritis (CIA), this T cell line specifically enhanced the severity of autoimmune arthritis. Additionally, pathogenic IgG2a autoantibody levels to mouse type II collagen were increased in mice that received the T cells in CIA, and levels of these T cells were increased in the synovium, suggesting the T cells may have had systemic effects on the B cell response as well as local effects on the inflammatory environment. This work demonstrates that CD4 T cells specific for CF can amplify disease severity after onset of CIA.

Associations between six classical HLA loci and rheumatoid arthritis: a comprehensive analysis

Although the HLA region contributes to one-third of the genetic factors affecting rheumatoid arthritis (RA), there are few reports on the association of the disease with any of the HLA loci other than the DRB1. In this study we examined the association between RA and the alleles of the six classical HLA loci including DRB1. Six HLA loci (HLA-A, -B, -C, -DRB1, -DQB1 and -DPB1) of 1659 Japanese subjects (622 cases; 488 anti-cyclic citrullinated peptides (CCP) antibody (Ab) positive (82.6%); 103 anti-CCP Ab negative (17.4%); 31 not known and 1037 controls) were genotyped. Disease types and positivity/negativity for CCP autoantibodies were used to stratify the cases. Statistical and genetic assessments were performed by Fisher's exact tests, odds ratio, trend tests and haplotype estimation. None of the HLA loci were significantly associated with CCP sero-negative cases after Bonferroni correction and we therefore limited further analyses to using only the anti CCP-positive RA cases and both anti-CCP positive and anti-CCP negative controls. Some alleles of the non-DRB1 HLA loci showed significant association with RA, which could be explained by linkage disequilibrium with DRB1 alleles. However, DPB1*02:01, DPB1*04:01 and DPB1*09:01 conferred RA risk/protection independently from DRB1. DPB1*02:01 was significantly associated with the highly erosive disease type. The odds ratio of the four HLA-loci haplotypes with DRB1*04:05 and DQB1*04:01, which were the high-risk HLA alleles in Japanese, varied from 1.01 to 5.58. C*07:04, and B*15:18 showed similar P-values and odds ratios to DRB1*04:01, which was located on the same haplotype. This haplotype analysis showed that the DRB1 gene as well as five other HLA loci is required for a more comprehensive understanding of the genetic association between HLA and RA than analyzing DRB1 alone.

Anti-citrullinated peptide antibodies in the serum of heavy smokers without rheumatoid arthritis. A differential effect of chronic obstructive pulmonary disease?

The objective of this study is to analyse the frequency and levels of anti-citrullinated peptide/protein antibodies (ACPA) in the serum of non-rheumatoid arthritis (RA) heavy smokers with and without chronic obstructive pulmonary disease (COPD) and compare them with healthy never smokers and patients with RA. Serum samples of 110 heavy smokers without RA, 209 healthy never smokers and 134 patients with RA were tested for ACPA using a commercial anti-cyclic citrullinated peptide antibodies (CCP2) test and a homemade chimeric fibrin/filaggrin citrullinated synthetic peptide (anti-CFFCP) ELISA test. The frequency of positive results and autoantibody levels were compared between groups. The prevalence of the two types of ACPA was slightly higher in heavy smokers than in never smokers, although the difference was not significant, and significantly lower than in RA patients. The highest prevalence of positive ACPA in heavy smokers was found in subjects with COPD (7.4% of positive anti-CFFCP in patients with COPD in comparison with 2.4% in never smokers: OR 3.26; 95% CI 0.85-12.6, p = 0.089). Mean serum levels of ACPA in heavy smokers were not significantly different from those of never smokers. Heavy smokers with COPD had significantly higher levels of anti-CFFCP than those without COPD, although almost all patients had serum levels below the cut-off values. The prevalence of ACPA in heavy smokers without RA is low, but seems to be higher in heavy smokers with COPD. Larger studies are necessary to confirm these findings and determine the relationship between ACPA and lung disease.

Relationship between time-integrated disease activity estimated by DAS28-CRP and radiographic progression of anatomical damage in patients with early rheumatoid arthritis

Background

The main aim of the study was to investigate the relationship between persistent disease activity and radiographic progression of joint damage in early rheumatoid arthritis (ERA).

Methods

Forty-eight patients with active ERA was assessed every 3 months for disease activity for 3 years. Radiographic damage was measured by the Sharp/van der Heijde method (SHS). The cumulative inflammatory burden was estimated by the time-integrated values (area under the curve-AUC) of Disease Activity Score 28 joint based on C-reactive protein (DAS28-CRP) in rapid progressors versus non-progressors. Bland and Altman's 95% limits of agreement method were used to estimate the smallest detectable difference (SDD) of radiographic progression. The relationship between clinical and laboratory predictors of radiographic progression and their interactions with time was analysed by logistic regression model.

Results

After 3-years of follow-up, radiographic progression was observed in 54.2% (95%CI: 39.8% to 67.5%) of patients and SDD was 9.5 for total SHS. The percentage of patients with erosive disease increased from 33.3% at baseline to 76% at 36 months. The total SHS of the progressors worsened from a median (interquartile range) of 18.5 (15-20) at baseline to 38.5 (34-42) after 3 years (p < 0.0001) whereas non-progressors worsened from a median of 14.5 (13-20) at baseline to 22.5 (20-30) after 3 years (p < 0.001). In the regression model, time-integrated values of DAS28-CRP and anti-CCP positivity have the highest positive predictive value for progression (both at level of p < 0.0001). Radiographic progression was also predicted by a positive IgM-RF (p0.0009), and a high baseline joint damage (p = 0.0044).

Conclusions

These data indicate that the level of disease activity, as measured by time-integrated DAS28-CRP, anti-CCP and IgM-RF positivity and a high baseline joint damage, affects subsequent progression of radiographic damage in ERA.

Homeostasis 6: nurses as external control agents in rheumatoid arthritis

All disorders involve a disturbance of cellular and hence chemical function in the body. Rheumatoid arthritis (RA) is a chronic, systemic, inflammatory disease that usually attacks synovial joints and surrounding ligaments, muscles and their tendons and blood vessels. This article applies the concept of health professionals operating as external agents of homeostatic control (Clancy and McVicar, 20011a; 2011b) to RA and to the care of affected patients, using a case scenario to illustrate attempts to minimize homeostatic imbalances. After reading the article, nurses should be able to understand: how the principles of homeostatic theory apply to skeletomuscular function, in particular to synovial joint function; the skeletomuscular homeostatic role in movement; and that homeostatic failure of reduced mobility, as in RA, is a result of nature-nurture interaction; that illness arises from a cellular, hence chemical, homeostatic imbalance(s) (Clancy and McVicar, 2011a; 2011b; 2011c; 2011d; 2011e). RA is considered a cellular (B-lymphocyte) hence chemical (autoantibody) imbalance that causes the homeostatic imbalances (inflammatory pain, reduced mobility, reduced activities of daily living) associated with the condition. Health professionals are able at act as external agents of homeostatic control to only a limited extent when caring for people with RA because, as with any progressive disorder, they will only be managing signs and symptoms to improve patients' quality of life.

[Genetics of rheumatoid arthritis]

Genetic influences on susceptibility to and clinical course of rheumatoid arthritis have been known for a long time, but have so far eluded systematic, genome-wide analysis. In recent years, the availability of new typing techniques and international consortia with large patient cohorts has generated a wealth of new information on the genetic basis of this autoimmune disease. Newly described associations between immunologically relevant gene polymorphisms and RA susceptibility have already been replicated with great statistical power, and are currently incorporated into new, pathogenetically relevant functional pathways. The resulting new concepts identify cell populations of great potential relevance for the pathogenesis of the disease, and ultimately might lead to new diagnostic and therapeutic approaches in RA.

Antibodies against β-fibrin synthetic peptides: a study of their association with the immunogenetic background and disease course of rheumatoid arthritis patients

Preliminary studies have shown the potential application for the diagnosis of Rheumatoid Arthritis (RA) patients with a severe disease course of an epitopic domain of β-fibrin. The aim of the present work was the analysis of the presence of antibodies against several β-fibrin synthetic peptides in relation to the immunogenetic background and disease course in a clinically well-defined RA patient cohort. Our results indicated that positive patients against anti-β-fibrin synthetic peptides have a higher percentage of HLA-DRB1 shared epitope (SE) than negative patients. We also observed that the presence of SE alleles was significantly associated with a higher level of anti-[Cit(376)]βfib(365-383) antibodies. When analyzing the effect of different SE alleles, we found a significant positive association between carriers of QRRAA allele and [Cit(376)]βfib(365-383) (Odds ratio 3.77; CI95%: 1.41-10.08). These results suggest that the anti-β-fibrin status is associated with the immunogenetic background of RA patients.

Serum IgA rheumatoid factor and pyridinoline in very early arthritis as predictors of erosion(s) at two years: a simple model of prediction from a conservatively treated community-based inception cohort

OBJECTIVE

To identify, in conservatively treated, very early arthritis patients, predictors of ≥1 erosion(s) at 2 years, and to construct a prediction model.

METHODS

Community-based adults (n=310) who had never taken disease-modifying antirheumatic drugs (DMARDs) or steroids with swelling of ≥2 joints persisting for >4 weeks and lasting <6 months were recruited. Erosion status was assessed at 0, 6, 12, and 24 months; evaluations were comprised of clinical criteria (Disease Activity Score, Health Assessment Questionnaire), C-reactive protein level, erythrocyte sedimentation rate, autoantibodies, bone and cartilage markers, hand densitometry, and HLA class II shared epitopes. Patients meeting American College of Rheumatology rheumatoid arthritis (RA) criteria or with undifferentiated arthritis (UA) were followed and treated conservatively: one-third of RA patients and three-fourths of UA patients received no DMARDs during 2 years; a biologic agent was given to 1.8% of the patients during the first year. The main judgment criterion was ≥1 erosion(s) at 2 years.

RESULTS

At 2 years, 219 patients were assessed; 31.3% with RA and 10.6% with UA had ≥1 erosion(s). Logistic regression analysis at that time showed erosion(s) strongly associated with serum IgA rheumatoid factor (IgA-RF) and pyridinoline levels for the 190 patients with no baseline erosions, with the corresponding receiver operating characteristic curve having an area under the curve of 0.77 (95% confidence interval 0.64-0.86). A prediction model was constructed with IgA-RF thresholds of 5 and 25 IU/ml and a pyridinoline threshold of 10 nM/liter; odds ratios ranged from 1 for IgA-RF<5 IU/ml and pyridinoline <10 nM/liter to 50.75 for the association of IgA-RF≥5 IU/ml and pyridinoline≥10 nM/liter.

CONCLUSION

This model, using serum IgA-RF and pyridinoline concentrations, was able to predict≥1 erosion(s) at 2 years in very early arthritis patients.

[How do T-cells become activated in joints?]

Activated CD4+ T-cells are found in joints of patients with rheumatoid arthritis and are involved in the joint destroying autoimmune response. Besides proinflammatory cytokine production T-cells are indispensable for the activation of B-cells, the so-called T-cell help for B-cells. However, the recognition of autoantigens by T-cells seems of utmost importance for the pathogenesis of rheumatoid arthritis. Selective inhibition of this process is therefore one of the most interesting therapeutic targets for the future.

MicroRNAs as biomarkers in rheumatic diseases

MicroRNAs (miRNAs) are endogenous, noncoding, single-stranded RNAs of 19-25 nucleotides in length. They regulate gene expression and are important in a wide range of physiological and pathological processes. MiRNAs are attractive as potential biomarkers because their expression pattern is reflective of underlying pathophysiologic processes and they are specific to various disease states. Moreover, miRNAs can be detected in a variety of sources, including tissue, blood and body fluids; they are reasonably stable and appear to be resistant to differences in sample handling, which increases their appeal as practical biomarkers. The clinical utility of miRNAs as diagnostic or prognostic biomarkers has been demonstrated in various malignancies and a few nonmalignant diseases. There is accumulating evidence that miRNAs have an important role in systemic rheumatic diseases and that various diseases or different stages of the same disease are associated with distinct miRNA expression profiles. Preliminary data suggest that miRNAs are promising as candidate biomarkers of diagnosis, prognosis, disease activity and severity in autoimmune diseases. MiRNAs identified as potential biomarkers in pilot studies should be validated in larger studies designed specifically for biomarker validation.

Contribution of HLA-DRB1*04 alleles and anti-cyclic citrullinated antibodies to development of resistance to disease-modifying antirheumatic drugs in early rheumatoid arthritis

This study was intended to evaluate HLA-DRB1 alleles and antibodies against anti-cyclic citrullinated peptides (anti-CCP Abs) for their value in predicting patient responses to treatment with disease-modifying antirheumatic drugs (DMARDs) in early rheumatoid arthritis (RA). The subjects were 124 Japanese patients who had received their first treatment with DMARDs, usually methotrexate, within 1 year of disease onset and who had been followed-up for 2 years subsequently. Approximately 40% of patients developed DMARD resistance and accordingly required anti-tumor necrosis factor α (TNFα) therapy during the 2-year period. DMARD resistance was strongly associated with the carriage of SE-positive HLA-DRB1*04 alleles, especially the *0405 allele (OR, 3.92; 95%CI, 1.83-8.41; p = 0.0003). In contrast, the SE-positive allele HLA-DRB1*0101 was less potent in contributing to DMARD resistance. The rate of anti-CCP Ab-positive patients was significantly higher in the DMARD-resistant group (OR, 6.62; 95%CI, 1.45-30.24; p = 0.008). Multivariate logistic regression analysis confirmed the strong association of DMARD resistance with the presence of SE-positive *04 alleles (OR, 2.89; 95%CI, 1.28-6.53; p = 0.011) and anti-CCP Abs (OR, 6.31; 95%CI, 1.23-32.34; p = 0.027), yielding an area under the receiver operating characteristic curve of 0.76 (95% CI, 0.68-0.84; p = 0.000). After stratification, the highest rate of DMARD resistance was observed in patients having both SE-positive *04 alleles and anti-CCP Abs. These observations show that the presence of SE-positive *04 alleles in combination with anti-CCP Abs is the strongest predictor for development of DMARD resistance and eventual need of anti-TNFα agents in patients with early RA.

Effect of the human leukocyte antigen HLA-DRB1 and anti-cyclic citrullinated peptide on the outcome of rheumatoid arthritis patients

Our objective was to determine whether the presence of the human leukocyte antigen HLA-DRB1 locus is associated with production of anti-cyclic citrullinated peptide antibodies (anti-CCP Abs) and to what extent they are associated with increased susceptibility to and severity of rheumatoid arthritis (RA) in Egyptian patients. Twenty-nine RA patients gave informed consent to participate in a case-control study that was approved by the Ain Shams University Medical Ethics Committee. RA disease activity and severity were determined using the simplified disease activity index and Larsen scores, respectively. We used a wide scale national study on the pattern of HLA typing in normal Egyptians as a control study. Anti-CCP Abs and HLA-DRB1 typing were determined for all subjects. The alleles most strongly associated with RA were HLA-DRB1 [*01 , *04 and *06] (41.4%). RA patients with serum anti-CCP Ab titers above 60 U/mL had a significantly higher frequency of HLA-DRB1*01 (58.3%) and HLA-DRB1*04 alleles (83.3%). Significant positive correlations were found between serum and synovial anti-CCP Ab titer, RA disease activity, and severity (r = 0.87, 0.66 and 0.63, respectively; P < 0.05). HLA-DRB1 SE+ alleles [*01 and *04] were highly expressed among Egyptian RA patients. The presence of these alleles was associated with higher anti-CCP Ab titer, active and severe RA disease. Early determination of HLA-DRB1 SE+ alleles and serum anti-CCP Ab could facilitate the prediction of the clinical course and prognosis of RA when first evaluated leading to better disease control.

Autoantibodies in rheumatoid arthritis: rheumatoid factors and anticitrullinated protein antibodies

Rheumatoid arthritis (RA) is a systemic inflammatory autoimmune disease, characterized by chronic, erosive polyarthritis and by the presence of various autoantibodies in serum and synovial fluid. Since rheumatoid factor (RF) was first described, a number of other autoantibodies have been discovered in RA patients. The autoantigens recognized by these autoantibodies include cartilage components, chaperones, enzymes, nuclear proteins and citrullinated proteins. However, the clinical significances and pathogenic roles of these antibodies are largely unknown except for RF and anticitrullinated protein antibodies (ACPAs), whose clinical usefulness has been acknowledged due to their acceptable sensitivities and specificities, and prognostic values. This review presents and discusses the current state of the art regarding RF and ACPA in RA.

Equivalent responses to disease-modifying antirheumatic drugs initiated at any time during the first 15 months after symptom onset in patients with seropositive rheumatoid arthritis

OBJECTIVE

To evaluate responses by time to initiation of nonbiologic disease-modifying antirheumatic drugs (DMARD) in a DMARD-naive cohort of patients with early seropositive rheumatoid arthritis (RA).

METHODS

Subjects were categorized by the time from symptom onset to the first DMARD use (median 5.7 months, range 0.6-15.9). Subjects who started their first DMARD within 5 months of symptom onset were compared to subjects who started after 5 months. Disease Activity Scores (DAS-44) and total Sharp Score (TSS) progression rates were analyzed using Wilcoxon rank-sum and chi-square tests; multiple linear regression analysis adjusted for potential covariates. The slope of the least-squares regression line was calculated to estimate the annualized TSS progression rates.

RESULTS

Of 233 RA patients, 76% were female and mean age was 50 (SD 13) years. At DMARD start, DAS-44 was similar in all subsets within the 0.6 to 15 months' duration between symptom onset and DMARD initiation. Erosion scores tended to be higher in those who started DMARD later, but Health Assessment Questionnaire-Disability Index (HAQ-DI) scores were higher in those who started DMARD earlier. During the 2 years after DMARD initiation, improvements in HAQ-DI and DAS-44 were similar in the various duration subsets, with about 25% ever achieving DAS remission (DAS < 1.6). Radiographic progression tended to be numerically but not statistically more rapid in the earlier subsets.

CONCLUSION

Following initiation of nonbiologic DMARD therapy at various times within 15 months of symptom onset, improvements of DAS-44, HAQ-DI, remission rate, and radiographic progression rate were similar, although higher baseline erosion scores were present in those with later initiation of DMARD.

Relationship Between Cyclic Citrullinated Peptide Antibodies Positivity and HLA-DRB1 Shared Epitope Alleles in Patients with Rheumatoid Arthritis in Turkey

Objective: The most characteristic genetic risk factors for rheumatoid arthritis (RA), the HLA-DRB1 shared epitope (SE) alleles, encode for a common amino acid sequence in the peptide-presenting part of the HLA class II molecule. These SE alleles have been described recently to be a risk factor for the development of antibodies against citrullinated proteins in RA. The current study was performed to investigate the association between the cyclic citrullinated peptide antibodies (anti-CCP) and HLA-DR1 HLA-DRB1 shared epitope alleles in patients with RA in Turkey.

Materials and Methods: Sixty patients with RA who were newly diagnosed or under conventional treatment in our clinic and 60 healthy volunteers as controls were enrolled in the study. In patients with RA anti-CCP levels were investigated with enzyme-linked immunosorbent assay and HLA-DRB1 subtyping and SE was assessed by polymerase chain reaction. Only anti-CCP was measured in healthy volunteers.

Results: SE was positive in 50% of the patients with RA. Amongst the SE carriers, 30% of them were carrying double copy of SE. While anti-CCP was positive in 73,3% of patients with RA, this ratio was 0% in healthy volunteers. We determined that the existence of SE increases the positivity of anti-CCP (OR=4,3, 95% [CI], P=0.04 ), and a significant relationship was found between the anti-CCP positivity and the RF positivity. (OR=5,3, 95% [CI] P<0.05).

Conclusion: The results of the present study revealed that Turkish patients with RA carrying SE with HLA-DRB1 genes is significantly related with the production of anti-CCP. The diagnostic sensitivity and specificity of anti-CCP for RA is determined as 73,3% and 100% respectively. (Turk J Rheumatol 2010; 25: 12-8)

[Familial clustering, genetic roots and insights into the pathogenesis of autoimmune diseases]

Genome-wide association studies have dramatically increased our knowledge about the genetic contribution to autoimmune diseases. The identified genes are indicators for signal transduction pathways involved in disease pathogenesis and could contribute to potential new therapeutic approaches.

The Value of HLA-DRB1 Shared Epitope, −308 Tumor Necrosis Factor-α Gene Promoter Polymorphism, Rheumatoid Factor, Anti-Citrullinated Peptide Antibodies, and Early Erosions for Predicting Radiological Outcome in Recent-Onset Rheumatoid Arthritis

Objective.

To study the value of HLA-DRB1 shared epitope (SE), −308 tumor necrosis factor-α (TNF-α) gene promoter polymorphism, rheumatoid factor (RF), anti-citrullinated peptide antibodies (anti-CCP), and baseline erosions for predicting radiological outcome at 1 year in patients with recent-onset rheumatoid arthritis (RA).

Methods.

Radiological damage was assessed by radiographs at baseline and at 1 year in an inception cohort of 134 RA patients with disease duration ≤ 1 year at study entry. Radiographs were scored with the modified Sharp/van der Heijde (SvdH) erosion score for hands, wrists, and feet. The predictive value of the variables was studied by multiple linear regression analysis, using immunogenetic factors, baseline SvdH erosion score, and type of treatment during the followup period as independent variables, and SvdH erosion score at 1 year as the dependent variable.

Results.

The SvdH erosion score increased from the baseline visit to the 1-year visit in 49 patients (36.6%). In multiple linear regression analysis, radiological outcome was significantly predicted by SE homozygosity (ß coefficient 1.75; 95% CI 1.54, 2.96; p = 0.005) and baseline SvdH erosion score (ß coefficient 1.56; 95% CI 1.4, 1.71; p < 0.001). This model explained 78% of the variability of the dependent variable (R2 = 0.779).

Conclusion.

Erosive damage at 1 year in patients with recent-onset RA is significantly influenced by SE homozygosity and the presence of baseline erosions, but not by RF status, anti-CCP status, or −308 TNF-α genotype.

[Diagnostic utility of anti-cyclic citrullinated peptide antibody in early rheumatoid arthritis]

Current therapeutic strategies against rheumatoid arthritis (RA) employ increasingly aggressive regimens from an early stage of the disease ; thus, serological markers more specific than IgM-rheumatoid factor (IgM-RF) are desirable. Anti-cyclic citrullinated peptide (anti-CCP) antibody has been reported as a useful and highly specificity marker for the diagnosis of RA. To clarify the diagnostic utility of anti-CCP antibody in early RA, we measured serum concentrations of anti-CCP antibody, IgM-RF, anti-agalactosyl IgG antibody and matrix metalloproteinase (MMP)-3 in 184 polyarthritis patients who showed onset symptoms within the previous 2 years. The diagnostic sensitivity of anti-CCP antibody in early RA was 60.0%, equivalent to IgM-RF (66.3%) and anti-agalactosyl IgG antibody (66.0%). Specificity, positive predictive values and diagnostic accuracy of anti-CCP antibody were the best among the four tested makers. In 38 patients who initially did not meet the ACR criteria for RA, but were diagnosed with RA during the course, the diagnostic sensitivity of anti-CCP antibody was 55.3%. On the other hand, the disease activity score (DAS) 28 of anti-CCP antibody positive and the negative patients was 5.16 and 5.34, respectively. Our data indicated that determination of anti-CCP antibody was useful for early diagnosis of RA.

Serum levels of anti-cyclic citrullinated peptide antibodies are associated with a beneficial response to traditional herbal medicine (Kampo) in rheumatoid arthritis

This study investigated the usefulness of biomarkers indicating beneficial response to traditional herbal medicine (THM) among patients with rheumatoid arthritis (RA). We assessed 34 RA patients who received keishinieppiittokaryojutsubu (KER), one of the representative THM. The observational term was 12 months, and we calculated the disease activity score of 28 joints every 3 months and evaluated the response to KER using European League Against Rheumatism (EULAR) response criteria. Additionally, serum levels of anti-cyclic citrullinated peptide antibody (ACPA) were measured by enzyme-linked immunosorbent assay at the baseline and after 6 and 12 months of the treatment with KER. As a result, 14 (41.2%) of the 34 patients were defined as responders, 13 as non-responders and 7 as out of assessment after 6 months, respectively. Pretreatment levels of serum ACPA were lower in KER responders than in non-responders (P = 0.042), although other univariate analysis did not show any significant differences in baseline clinical measures between the two groups. Furthermore, responders to KER showed a significant decrease in the serum levels of ACPA. These findings suggest that pretreatment serum levels of ACPA are a useful predictor of a good response to treatment with KER. Furthermore, a decrease in serum levels of ACPA may be an adjunctive indicator in predicting the efficacy of this kind of treatment.

Using SELDI-TOF MS to identify serum biomarkers of rheumatoid arthritis

OBJECTIVES

No satisfactory biomarkers are currently available to screen for rheumatoid arthritis (RA). We have developed and evaluated surface-enhanced laser desorption/ionization time-of-flight mass spectrometry (SELDI-TOF MS) for detection and analysis of multiple proteins for distinguishing individuals with RA from control individuals.

METHODS

A total of 156 serum samples from 90 RA patients, 30 patients with ankylosing spondylitis (AS), and 36 healthy individuals were examined by SELDI technology. Spectral data were analysed by the support vector machine (SVM) approach and potential biomarkers were chosen for system training and were used to construct a diagnostic model.

RESULTS

Pattern 1, consisting of four protein peaks with m/z values of 3899, 4594, 7566, and 13,842, distinguished RA from the healthy samples with sensitivity of 90.0% and a specificity of 91.7%. Pattern 2, consisting of m/z peaks 4287 and 6471, distinguished RA from AS with a sensitivity of 86.7% and a specificity of 85.0%.

CONCLUSION

The combination of SELDI-TOF MS and SVM could facilitate the discovery of better biomarkers for RA and also provide a useful tool for molecular diagnosis in the future.

Clinical and radiological features of rheumatoid arthritis in British black Africans

The objective of this study was to determine whether radiographic damage is different in British black African patients with rheumatoid arthritis compared to Caucasian patients. Data on demographics, disease- and disability-related variables were obtained from all black African patients and their age-, gender- and disease-duration-matched Caucasian controls. After all features identifying the patients were concealed, X-rays of hands and feet were scored by using the Sharp/van der Heijde method. Data were analysed using Mann-Whitney U test, t test and chi (2) test. Sixty-four patients (32 in each ethnic group) were studied. The median age was 52 years and median disease duration 6 years. Seventy-two percent of patients were female. Black Africans and Caucasians did not differ significantly in rheumatoid factor positivity, disease-modifying anti-rheumatic drugs and biological treatment use. British black African patients had significantly more tender joints and disability. Joint space narrowing was significantly greater in Caucasian patients [48 (27-85) vs 56 (34-107), p = 0.01]. Caucasian patients had more number of erosions (172 vs 220) and higher erosion score; however, the difference in the erosion scores was not statistically significant [2 (0-48) vs 4.5 (0-46), p = 0.17]. Radiographic damage was less severe in black African patients with rheumatoid arthritis compared to their age-, gender- and disease-duration-matched Caucasian controls. A large prospective study is required to confirm the findings of this study and to establish the factors which might be accountable for any differences in the expression of rheumatoid arthritis in this ethnic group.