Is Anti-Citrullinated Protein Antibody-Positive Rheumatoid Arthritis Still a More Severe Disease Than Anti-Citrullinated Protein Antibody-Negative Rheumatoid Arthritis? A Longitudinal Cohort Study in Rheumatoid Arthritis Patients Diagnosed From 2000 Onward

Clinical Features of ACPA-Negative and ACPA-Positive Variants of Rheumatoid Arthritis

The aim of the study was to investigate the features of the clinical picture of the disease in patients with ACPA-negative and ACPA-positive variants of rheumatoid arthritis.

MATERIALS AND METHODS

: The study included patients with a reliable diagnosis of rheumatoid arthritis (RA) according to the criteria of ACR/EULAR 2010. Depending on the ACPA values, two groups of patients were recruited: ACPA-positive and ACPA-negative, comparable in gender, age, duration of the disease, and therapy. The nature of the onset and course of the disease and the activity of RA were evaluated (according to the DAS28, SDAI, CDAI indices).

RESULTS AND DISCUSSION

: The study involved 79 patients with ACPA-negative variant of RA and 79 ACPA-positive patients. The age of patients (Me [IR] (in years)) with the ACPA(-) variant was 52 [39; 62]; with the ACPA(+) variant, 54 [42; 62]; the duration of the disease (in months) was 59 [23; 122] and 48 [17; 84], respectively. In ACPA(+) patients, a higher disease activity was determined (by the indices DAS 28crp, DAS28esr, SDAI, CDAI), higher values of C-reactive protein and erythrocyte sedimentation rate, and a greater number of painful and swollen joints (p < 0.05). According to the localization of the involved joints, arthritis of the proximal interphalangeal, metacarpal, wrist and shoulder joints was more often determined in ACPA(+) patients. Systemic manifestations of RA at the time of examination and in the anamnesis were statistically significantly more common in ACPA(+) (32.9%) than in ACPA(-) (17.7%) patients. Of the systemic manifestations, rheumatoid nodules were more common in ACPA(+) patients, whereas a tendency to a higher frequency of neuropathy, sclerites, and episcleritis was revealed in ACPA(-) patients.

CONCLUSIONS

. In patients with ACPA(-) subtype, clinical signs of joint damage and the inflammatory component are less pronounced compared to ACPA(+). However, the mixed picture of manifestation, the less "bright" course of the disease, the absence of characteristic immunological biomarkers necessitate long-term and careful monitoring of this group of patients. At the same time, the subjective severity of the disease and dysfunction due to ankylosing joints do not differ from the ACPA(+) variant of RA.

Early identification of rheumatoid arthritis: does it induce treatment-related cost savings?

OBJECTIVE

Early diagnosis and treatment-start is key for rheumatoid arthritis (RA), but the economic effect of an early versus a later diagnosis has never been investigated. We aimed to investigate whether early diagnosis of RA is associated with lower treatment-related costs compared with later diagnosis.

METHODS

Patients with RA consecutively included in the Leiden Early Arthritis Clinic between 2011 and 2017 were studied (n=431). Symptom duration was defined as the time between symptom onset and first presentation at the outpatient clinic; early treatment start was defined as symptom duration <12 weeks. Information on disease-modifying anti-rheumatic drug use per patient over 5 years was obtained from prescription data from patient records. Prices were used from 2022 and 2012 (proxy of time of prescription) to study the impact of changes in drug costs. Autoantibody-positive and autoantibody-negative RA were studied separately because differences in disease severity may influence costs.

RESULTS

Within autoantibody-negative RA, costs were 316% higher in the late compared with the early group (β=4.16 (95% CI 1.57 to 11.1); €4856 vs €1159). When using 2012 prices, results were similar. For autoantibody-positive RA, costs were 19% higher in the late group (€9418 vs €7934, β=1.19, 0.57 to 2.47). This effect was present but smaller when using 2012 prices. Within patients with autoantibody-positive RA using biologicals, late treatment start was associated with 46% higher costs (β=1.46 (0.91 to 2.33)); higher costs were also seen when using 2012 prices.

CONCLUSION

When RA is detected within 12 weeks after symptom onset, treatment-related costs were lower in both autoantibody-negative and autoantibody-positive RA. This study is the first to report how early diagnosis and treatment start impact treatment-related costs.

Gut microbiome-immune interactions and their role in rheumatoid arthritis development

Objective

The primary objective is to study the impact of gut microbiota and their interactions with diverse immunological markers on the development of rheumatoid arthritis.

Methods

This study was performed in Astana, Kazakhstan, and included 77 Kazakh female patients older than 18 years, who met the American College of Rheumatology 2010 classification criteria for rheumatoid arthritis (RA), and 113 healthy controls. The DNA was extracted from fecal samples obtained from all study participants for subsequent sequencing at the 16S rRNA gene V1-V3 locus, facilitating the analysis of the gut microbiome. The Multiplex immunoassay was employed to measure the concentrations of inflammatory cytokines, chemokines, and immunoglobulins in both fecal and plasma samples.

Results

Our taxonomic analysis revealed significant differences in the composition of the gut microbiota between the healthy control cohort and the cohort with rheumatoid arthritis RA. Alpha diversity was significantly lower in the RA group. Lachnospiraceae were the most abundant taxon and found to be crucial, showing correlations with immunological markers such as IL5. Additionally, Lachnospiraceae and Oscillospiraceae exhibited the most predictable power and distinguished the composition of both study groups.

Conclusion

Our study identifies key differences in the gut microbiome of RA patients, revealing distinct microbial patterns and specific taxa abundance. We highlight potential biomarkers in immunological and bacterial pathways, offering insights into RA development and indicating possibilities for personalized treatment.

Polyautoimmunity in Patients With Anticyclic Citrullinated Peptide Antibody-Positive and -Negative Rheumatoid Arthritis: a Nationwide Cohort Study From Denmark

OBJECTIVE

This study aimed to compare the prevalence and incidence of polyautoimmunity between anticyclic citrullinated peptide antibody (anti-CCP)-positive and anti-CCP-negative patients with rheumatoid arthritis (RA).

METHODS

In a nationwide register-based cohort study, patients with RA (disease duration ≤ 2 yrs) in the DANBIO rheumatology register with an available anti-CCP test in the Register of Laboratory Results for Research were identified. The polyautoimmunity outcome included 21 nonrheumatic autoimmune diseases identified by linkage between the Danish Patient Registry and Prescription Registry. The age- and sex-adjusted prevalence ratio (PR) was calculated by modified Poisson regression to estimate the prevalence at diagnosis in anti-CCP-positive vs anti-CCP-negative patients. The hazard ratio (HR) of polyautoimmunity within 5 years of entry into DANBIO was estimated in cause-specific Cox regression models.

RESULTS

The study included 5839 anti-CCP-positive and 3799 anti-CCP-negative patients with RA. At first visit, the prevalence of prespecified polyautoimmune diseases in the Danish registers was 11.1% and 11.9% in anti-CCP-positive and anti-CCP-negative patients, respectively (PR 0.93, 95% CI 0.84-1.05). The most frequent autoimmune diseases were autoimmune thyroid disease, inflammatory bowel disease, and type 1 diabetes mellitus. During a mean follow-up of 3.5 years, only a few (n = 210) patients developed polyautoimmunity (HR 0.6, 95% CI 0.46-0.79).

CONCLUSION

Polyautoimmunity as captured through the Danish National Patient Registry occurred in approximately 1 in 10 patients with RA at time of diagnosis regardless of anti-CCP status. In the years subsequent to the RA diagnosis, only a few and mainly anti-CCP-negative patients developed autoimmune disease.

Patient burden and joint-inflammation during development of RA from arthralgia: is it similar in ACPA-positive and ACPA-negative disease?

OBJECTIVES

Anti-citrullinated protein antibody(ACPA)-positive and ACPA-negative rheumatoid arthritis(RA) differ in underlying risk factors but have a similar clinical presentation at RA-diagnosis. It is unknown what the ACPA-associated differences or similarities are during the symptomatic at-risk stage of RA, clinically suspect arthralgia(CSA). To deepen insights into these differences/similarities, we compared the course of symptoms/impairments and subclinical joint-inflammation in the CSA-phase during progression to inflammatory arthritis(IA) or to CSA-resolution.

METHODS

845 CSA-patients were followed for median 24 months; 136 patients developed IA and additional 355/505 patients had resolution of CSA according to rheumatologists. Patient burden (pain/morning stiffness/fatigue/functional disabilities/presenteeism) was assessed at baseline, 4/12/24 months and IA-development. Subclinical joint-inflammation in hands/feet was assessed over time with 1.5 T-MRI. Linear/Poisson mixed models were used.

RESULTS

Both in ACPA-positive and ACPA-negative patients, patient burden increased towards IA-development and decreased towards CSA-resolution. However, patient burden was lower in ACPA-positive than ACPA-negative disease on all timepoints. Conversely, subclinical joint-inflammation tended to increase more rapidly during development of ACPA-positive IA (IRR = 1.52,95%CI = 0.94-2.47, p= 0.089), and remained higher over time in ACPA-positive CSA-patients achieving resolution compared with ACPA-negative patients (IRR = 1.52,95%CI = 1.07-2.15, p= 0.018). Although correlation coefficients between changes in patient burden and subclinical joint-inflammation during progression to IA were weak, they were consistently higher in ACPA-positive than ACPA-negative disease, e.g. ρ = 0.29 vs ρ = 0.12 for functional disabilities.

CONCLUSION

During RA-development and CSA-resolution, ACPA-positive CSA-patients have lower patient burden, but more subclinical joint-inflammation than ACPA-negative CSA-patients. These data strengthen the notion that the development of ACPA-positive and ACPA-negative RA is pathophysiologically different, and encourage further research on these differences.

The universal presence of poor prognostic factors based on EULAR recommendations: A real-world study in 1164 Chinese RA patients

INTRODUCTION

Poor prognostic factors (PPFs) have been used in assisting therapeutic decision-making in rheumatoid arthritis (RA). There are no standard lists of PPFs for RA, and whether PPFs can guide RA treatment remains controversial.

OBJECTIVES

To analyze the profile of PPF based on EULAR recommendations in RA patients and explore the necessity of considering these PPFs in adjusting therapy.

METHODS

Prognostic factors including erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP), rheumatoid factor (RF), anti-citrullinated protein antibody (ACPA), swollen joint count (SJC), early erosions, and response to first conventional synthetic disease-modifying anti-rheumatic drugs (csDMARD) therapy in 1164 RA patients were collected. The profile of PPFs was graphically displayed. The correlation between different PPFs was analyzed.

RESULTS

Elevated ESR/CRP was presented in 746 (64%) patients, and positive RF/ACPA in 1021 (88%) patients. Two hundred and sixty-eight (23%) patients had≥4 swollen joints. Three hundred (26%) patients had moderate or high disease activity (MDA/HDA) despite csDMARD therapy. Failure of≥2 csDMARDs was found in 30% (224/740) of patients. One hundred and fifty-three out of 459 (33%) patients had early bone erosions, usually coexisted with other PPFs. Ninety-seven percent of RA patients had≥1 PPF. Being MDA/HDA≥3 months was significantly correlated with elevated ESR/CRP or high SJC, however uncorrelated with RF/ACPA positivity or early erosions.

CONCLUSIONS

PPFs are universally present in RA patients. The reasonability of guiding treatment strategies just based on the presence or absence of PPFs requires further investigation. The categories of PPFs can be simplified and the role of different PPFs combinations in guiding treatment needs to be explored.

Influence of anti-carbamylated protein antibodies on disease activity and joint erosions in seronegative and seropositive rheumatoid arthritis

Anti-carbamylated protein (anti-CarP) antibodies are promising biomarkers in rheumatoid arthritis (RA), although their significance in seronegative disease (SNRA) remains uncertain. To assess the influence of anti-CarP antibodies on disease activity and erosive joint damage in SNRA patients. In RA patients, rheumatoid factor (RF), anti-citrullinated protein antibodies, and anti-CarP antibodies were measured. Disease activity was assessed using DAS28-CRP and SDAI indices, while musculoskeletal ultrasound identified bone erosions. A total of 77 patients were enrolled, comprising 49 with seropositive RA (SPRA) and 28 with SNRA. Notably, 28% of SPRA and 10% of SNRA patients were positive to anti-CarP antibodies. Anti-CarP-positive patients exhibited elevated C-reactive protein (median 10.6, interquartile range 4.6-20.0 vs. 3.4, 1.7-9.9 mg/L; p = 0.005), erythrocyte sedimentation rate (34, 19-46 vs. 16, 7-25 mm/h; p = 0.002), DAS28-CRP (3.2, 2.6-4.2 vs. 2.6, 1.9-3.5; p = 0.048), and SDAI (19.9, 6.3-32.1 vs. 10.9, 5.5-18.1; p = 0.034) indices. Multivariate analysis revealed RF positivity as the sole predictor for anti-CarP antibodies (odds ratio [OR] = 5.9). Musculoskeletal ultrasound revealed bone erosions in 36% of RA patients; 35% among anti-CarP-negative patients and 40% among anti-CarP-positive patients. Notably, RF presence (OR = 44.3) and DAS28-CRP index (OR = 2.4) emerged as predictors of musculoskeletal ultrasound-confirmed erosive joint disease. Anti-CarP antibodies are detected at similar frequencies among both SPRA and SNRA patients. While associated with increased disease activity, these antibodies did not correlate with increased erosive joint damage.

Autoantibody-negative rheumatoid arthritis: still a challenge for the rheumatologist

Increased research over the past 30 years has greatly improved the understanding of the pathophysiological mechanisms and clinical aspects of autoantibody-positive rheumatoid arthritis, resulting in improved management and outcomes. In contrast, the subset of rheumatoid arthritis that does not have autoantibodies (such as rheumatoid factor and anti-citrullinated protein autoantibodies) remains less well defined in its pathogenic mechanisms. Autoantibody-negative rheumatoid arthritis continues to pose diagnostic challenges, might respond differently to therapies, and appears to be burdened with different comorbidities and outcomes. The clear separation of rheumatoid arthritis according to serotypes is still a subject of uncertainty and controversy, and studies specifically focused on comparing rheumatoid arthritis and rheumatoid arthritis-like arthritides that do not have autoantibodies remain scarce. The purpose of this Review is to summarise the peculiarities that make autoantibody-negative rheumatoid arthritis different from its autoantibody-positive counterpart, with the aim of generating debate and stimulating further research on this challenging condition.

Preventive interventions in individuals at risk for Rheumatoid Arthritis: State of the art and perspectives

During the last decade, the outlook for patients with rheumatoid arthritis (RA) has improved greatly, especially for patients with autoantibody-positive RA. To further improve long-term disease outcomes, the field has turned to investigating the efficacy of treatment initiated in the pre-arthritic phase of RA, based on the adage "the sooner the better." In this review, the concept of prevention is evaluated and different risk stages are being examined for their pre-test risks of RA development. These risks affect the post-test risk of biomarkers used at these stages and, consequently, the accuracy with which the risk of RA can be estimated. Furthermore, through their effect on accurate risk stratification, these pre-test risks ultimately also associate with the likelihood of false-negative trial results (the so-called "clinicostatistical tragedy"). Outcome measures to assess preventive effects are evaluated and relate to either the occurrence of disease itself or to the severity of risk factors for RA development. Results of recently completed prevention studies are discussed in the light of these theoretical considerations. The results vary, but clear prevention of RA has not been demonstrated. While some treatments (e.g. methotrexate) persistently reduced symptom severity, physical disability, and the severity of imaging joint inflammation, other treatments were not reported to produce long-lasting effects (hydroxychloroquine, rituximab, atorvastatin). The review concludes with future perspectives regarding the design of new prevention studies and considerations and requirements before findings can be implemented in daily practice in individuals at risk of RA attending rheumatology practices.

The course of fatigue during the development of rheumatoid arthritis and its relation with inflammation: a longitudinal study

OBJECTIVE

Fatigue is a prominent and disabling symptom in patients with rheumatoid arthritis (RA), that is only partially explained by inflammation and responds poorly to DMARD-therapy. We hypothesized that inflammation explains fatigue to a larger extent in the phase of clinically suspect arthralgia (CSA), when persistent clinical arthritis is still absent and fatigue has not yet become chronic. We therefore studied the course of fatigue in CSA during progression to RA and the association with inflammation at CSA-onset and at RA-diagnosis.

METHODS

600 consecutive CSA-patients were followed for RA-development. Additionally, 710 early RA-patients were studied at diagnosis. Fatigue was assessed every study visit and expressed on a 0-100 scale. Inflammation was measured with the DAS44-CRP, with and without including subclinical inflammation. The course of fatigue over time was studied with linear mixed models. Associations between fatigue and inflammation were studied with linear regression. Analyses were stratified by ACPA-status.

RESULTS

In 88 CSA-patients who developed RA, pre-arthritis fatigue-levels increased gradually with 7 points/year, towards 48 (95%CI=41-55) at RA-development (P=ns). Fatigue decreased in CSA-patients who did not develop RA (4 points/year, P<0.001). At CSA-onset, inflammation was associated with fatigue (β=18, meaning 18 points more fatigue per point increase DAS-score, P<0.01). This association was stronger than at RA-diagnosis (β=5, P<0.001). Fatigue-levels were lower in ACPA-positive pre-RA, but its association with inflammation was stronger compared to ACPA-negative pre-RA.

CONCLUSION

Fatigue increased gradually during progression from arthralgia to clinical arthritis, and fatigue was better explained by inflammation in CSA than in RA. This implies a 'phase-dependent relation' between inflammation and fatigue.

The association of serum RANKL levels with disease activity and hematological parameters in Syrian patients with rheumatoid arthritis

Our study aims to detect whether the serum RANKL could be a novel potential biomarker for activity and diagnosis of rheumatoid arthritis (RA). It included fifty-eight of RA patients and thirty of equal age and sex matched controls. Disease activity was determined by using DAS28-ESR. Serum Levels of RANKL were assayed by ELISA and compared with parameters such as ESR, CRP, Rheumatoid factor (RF) and anti-cyclic citrullinated peptide antibodies (ACPA). The serum RANKL levels were higher in RA patients compared to controls. There was an increase in its levels mean among post-menopausal patients compared to post-menopausal healthy group. RANKL levels were also higher in ACPA positive patients than ACPA negative. Our study found a correlation between RANKL levels and some parameters: DAS28, ACPA, CRP, and symptom duration. There was a moderate inverse correlation between RANKL levels and BMD. By ROC curve, our results displayed that the best cut-off value of RANKL was 178.99 pg/ml (sensitivity 79.31%; specificity 90%) to differentiate between RA patients and controls. In conclusion, elevated serum RANKL can be used as an indicator of disease activity and a diagnostic new biomarker in patients with early RA.

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Rheumatoid arthritis (RA) is categorized by chronic synovitis leads to cartilage degradation, and bone erosions.

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RANKL/RANK/OPG pathway stimulates osteoclasts and bone resorption.

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ACPA are associated with bone erosions.

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Serum RANKL correlates disease activity of Rheumatoid Arthritis.

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Serum RANKL is an innovative indicator in of Rheumatoid Arthritis patients.

Anti-Protein-Arginine Deiminase 4 IgG and IgA Delineate Severe Rheumatoid Arthritis

There is a strong need for biomarkers of rheumatoid arthritis (RA) in all phases of the patient’s journey and to enable the implementation of precision medicine strategies to improve patient care. The objective of this study was to evaluate the presence of anti-protein-arginine deiminase (PAD) 4 IgG and IgA in the sera of RA patients and disease controls, and to investigate their association with joint erosion and biological treatment use. Sera from 104 RA and 155 controls were tested for the presence of anti-PAD4 IgG and IgA using a new particle-based multi-analyte technology (PMAT). Information on the erosive disease and biological treatment use was available for 54 of the RA patients, who were also tested for anti-citrullinated protein antibodies (ACPA). An association between the autoantibodies and these clinical features was investigated. Anti-PAD4 showed sensitivity and specificity values of 25.0% and 94.2% for IgG and of 21.2% and 94.8% for IgA for RA, respectively. The levels of these antibodies were also significantly higher in RA patients vs. controls, in erosive RA vs. non-erosive disease, and in patients under biologics vs. patients that were not on this treatment regimen. The anti-PAD4 IgG and IgA levels were correlated (rho = 0.60, p < 0.0001), but individuals that were positive for only one of the two isotypes were also observed. Anti-PAD4 IgG and IgA are associated with severe RA, and they represent valuable biomarkers for prognosis prediction and patient stratification.

Disease mechanisms in preclinical rheumatoid arthritis: A narrative review

In the last decades, the concept of preclinical rheumatoid arthritis (RA) has become established. In fact, the discovery that disease mechanisms start years before the onset of clinical RA has been one of the major recent insights in the understanding of RA pathogenesis. In accordance with the complex nature of the disease, preclinical events extend over several sequential phases. In a genetically predisposed host, environmental factors will further increase susceptibility for incident RA. In the initial steps of preclinical disease, immune disturbance mechanisms take place outside the joint compartment, namely in mucosal surfaces, such as the lung, gums or gut. Herein, the persistent immunologic response to altered antigens will lead to breach of tolerance and trigger autoimmunity. In a second phase, the immune response matures and is amplified at a systemic level, with epitope spreading and widening of the autoantibody repertoire. Finally, the synovial and bone compartment are targeted by specific autoantibodies against modified antigens, initiating a local inflammatory response that will eventually culminate in clinically evident synovitis. In this review, we discuss the elaborate disease mechanisms in place during preclinical RA, providing a broad perspective in the light of current evidence.

Intervention with methotrexate in patients with arthralgia at risk of rheumatoid arthritis to reduce the development of persistent arthritis and its disease burden (TREAT EARLIER): a randomised, double-blind, placebo-controlled, proof-of-concept trial

BACKGROUND

Rheumatoid arthritis is the most common autoimmune disease worldwide and requires long-term treatment to suppress inflammation. Currently, treatment is started when arthritis is clinically apparent. We aimed to evaluate whether earlier intervention, in the preceding phase of arthralgia and subclinical joint inflammation, could prevent the development of clinical arthritis or reduce the disease burden.

METHODS

We conducted a randomised, double-blind, placebo-controlled, proof-of-concept-trial at the Leiden University Medical Centre, Leiden, Netherlands. Adults aged 18 years or older with arthralgia clinically suspected of progressing to rheumatoid arthritis and MRI-detected subclinical joint inflammation were eligible for enrolment across 13 rheumatology outpatient clinics in the southwest region of the Netherlands and randomly assigned (1:1) to a single intramuscular glucocorticoid injection (120 mg) and a 1-year course of oral methotrexate (up to 25 mg/week), or placebo (single injection and tablets for 1 year). Participants and investigators were masked to group assignment. Follow-up continued for 1 year after the end of the 1-year treatment period. The primary endpoint was development of clinical arthritis (fulfilling the 2010 rheumatoid arthritis classification criteria or involving two or more joints) that persisted for at least 2 weeks. Patient-reported physical functioning, symptoms, and work productivity were secondary endpoints, which were measured every 4 months. Additionally, the course of MRI-detected inflammation was studied. All participants entered the intention-to-treat analysis. This trial is registered with EudraCT, 2014-004472-35, and the Netherlands Trial Register, NTR4853-trial-NL4599.

FINDINGS

Between April 16, 2015, and Sept 11, 2019, 901 patients were assessed for eligibility and 236 were enrolled and randomly assigned to active treatment (n=119) or placebo (n=117). At 2 years, the frequency of the primary endpoint was similar between the groups (23 [19%] of 119 participants in the treatment group vs 21 [18%] of 117 in the placebo group; hazard ratio 0·81, 95% CI 0·45 to 1·48). Physical functioning improved more in the treatment group during the first 4 months and remained better than in the placebo group (mean between-group difference in Health Assessment Questionnaire disability index over 2 years: -0·09, 95% CI -0·16 to -0·03; p=0·0042). Similarly, pain (on scale 0-100, mean between-group difference: -8, 95% CI -12 to -4; p<0·0001), morning stiffness of joints (-12, -16 to -8; p<0·0001), presenteeism (-8%, -13 to -3; p=0·0007), and MRI-detected joint inflammation (-1·4 points, -2·0 to -0·9; p<0·0001) showed sustained improvement in the treatment group compared with the placebo group. The number of serious adverse events was equal in both groups; adverse events were consistent with the known safety profile for methotrexate.

INTERPRETATION

Methotrexate, the cornerstone treatment of rheumatoid arthritis, initiated at the pre-arthritis stage of symptoms and subclinical inflammation, did not prevent the development of clinical arthritis, but modified the disease course as shown by sustained improvement in MRI-detected inflammation, related symptoms, and impairments compared with placebo.

FUNDING

Dutch Research Council (NWO; Dutch Arthritis Society).

Presence of Autoantibodies in Males and Females With Rheumatoid Arthritis: A Systematic Review and Metaanalysis

OBJECTIVE

Rheumatoid arthritis (RA) is more common in females, and although the cause of RA is unknown, it is characterized by the production of autoantibodies. The aims of this study were to determine whether RA-associated autoantibodies are more often found in females than males and to identify factors that influence the relationship between sex and seropositivity.

METHODS

Databases were searched and studies of RA (N ≥ 100) were included if they reported proportion of seropositive patients with RA by sex. Metaanalyses and metaregression were conducted using the random-effects model. Covariates regressed were smoking, age, BMI, Health Assessment Questionnaire-Disability Index (HAQ-DI), and the Disease Activity Score in 28 joints (DAS28).

RESULTS

Eighty-four studies with a total of 141,381 subjects with rheumatoid factor (RF) seropositivity and 95,749 subjects with anticitrullinated protein antibody (ACPA) seropositivity met inclusion criteria. The mean age of participants ranged from 37 to 68 years and the proportion of female subjects ranged from 9% to 92%. Results indicated that females were less likely than males to be seropositive: odds ratio (OR) 0.84 [95% CI 0.77-0.91] for RF and OR 0.88 [95% CI 0.81-0.95] for ACPA. BMI, smoking, mean age, DAS28, and HAQ-DI did not affect the relationship between sex and seropositivity.

CONCLUSION

Although studies report that females have higher RA disease activity than males and that seropositivity predicts worse outcomes, females were less likely to be seropositive than males.

Cyclic Citrullinated Peptide Aptamer Treatment Attenuates Collagen-Induced Arthritis

We describe the study of a novel aptamer-based candidate for treatment of seropositive rheumatoid arthritis. The candidate is a nanoparticle-formulated cyclic citrullinated peptide aptamer, which targets autoantibodies and/or the immune reactions leading to antibody production. Due to its specificity, the peptide aptamer nanoparticles might not interfere with normal immune functions as seen with other disease-modifying antirheumatic drugs. Over a 3-week course of treatment, joint swelling and arthritis score in collagen-induced rats were significantly decreased compared with animals treated with phosphate-buffered saline, unloaded nanoparticles, or nanoparticles with a noncitrullinated control peptide. The reduction in joint swelling was associated with decreased anticitrullinated peptide autoantibody levels in the blood. Treatment with aptamer nanoparticles also increased interleukin-10 levels. The effect seen with the proposed treatment candidate could be mediated by upregulation of anti-inflammatory mediators and decreased levels of anticitrullinated peptide antibodies.

Anti-citrullinated Protein Antibody Generation, Pathogenesis, Clinical Application, and Prospects

Anti-citrullinated protein antibodies (ACPAs) are autoantibodies commonly observed in patients with rheumatoid arthritis (RA). Currently, most of the mechanisms of ACPA formation and bone destruction are well-understood, however, some unknown mechanisms still exist. There have been many new advances in ACPA-related clinical applications and targeted therapies. However, the existence of different ACPA subtypes is a limitation of targeted therapy. Herein, we present an overview of the process of ACPA generation, the underlying pathogenesis, and relevant clinical application and prospects.

Migraine in patients with rheumatoid arthritis and its relation to disease activity

Background

The comorbidity between rheumatoid arthritis (RA) and migraine is complex and not completely understood.

Objective

This study aimed to evaluate migraine frequency in patients with RA and its relation to disease activity.

Methods

A cross-sectional study was carried out on 210 consecutive RA Egyptian patients fulfilling the 2010 EULAR/ACR criteria (joint distribution, serology, symptom duration and acute phase reaction).

Results

Prevalence of migraine in RA was 28.2%. Disease activity, fibromyalgia and functional losses were significantly higher in migraine group with RA versus non-migraine group (P < 0.001). Disease Activity Score (DAS-28) was independently significant predictor as increasing DAS-28 score was associated with an increased likelihood of exhibiting migraine (5.5-times higher odds per one-unit increase in DAS-28 score). Prevalence of brain MRI white matter hyper-intensities (WMHs) in RA with migraine was 54.8%. WMHs were significantly higher in migraine patients with aura than migraine patients without aura, especially in older patients, longer migraine duration, longer rheumatoid duration and elevated ESR (p < 0.047, p < 0.034, P < 0.004, P < 0.015 and P < 0.22, respectively).

Conclusions

Migraine is highly frequent in RA patients, especially migraine with aura. The presence of rheumatoid activity, fibromyalgia and secondary Sjogren’s syndrome, elevated ESR and CRP are associated with functional losses in RA patients with migraine, especially migraine with aura. MR imaging of brain is a mandatory tool for detection of white matter hyper-intensities in RA patients with migraine, especially migraine with aura.

Presence of anti-acetylated peptide antibodies (AAPA) in inflammatory arthritis and other rheumatic diseases suggests discriminative diagnostic capacity towards early rheumatoid arthritis

Aims:

To determine the diagnostic value of anti-acetylated peptide antibodies (AAPA) in patients with rheumatoid arthritis (RA).

Methods:

Three acetylated peptides (ac-lysine, ac-lysine.inv and ac-ornithine) derived from vimentin were employed to measure AAPA by enzyme-linked immunosorbent assay (ELISA) in sera of 120 patients with early RA (eRA), 195 patients with established RA (est RA), 99 healthy controls (HC), and 216 patients with other inflammatory rheumatic diseases. A carbamylated and a citrullinated version of the vimentin peptide were used additionally. Receiver operating characteristics and logistic regression analyses were used to assess the discriminative capacity of AAPA.

Results:

AAPA were detected in 60% of eRA and 68.7% of estRA patients, 22.2% of HC, and 7.1– 30.6% of patients with other rheumatic diseases. Importantly, AAPA were also present in 40% of seronegative RA patients, while antibodies to the carbamylated peptide were detected less frequently. Diagnostic sensitivity of individual peptides for eRA was 28.3%, 35.8%, and 34% for ac-lysine, ac-ornithine, and ac-lysine.inv, respectively. Positive likelihood ratios (LR+) for eRA versus HC were 14.0, 7.1, and 2.1. While the presence of a single AAPA showed varying specificity (range: 84–98%), the presence of two AAPA increased specificity considerably since 26.7% of eRA, as compared with 6% of disease controls, were double positive. Thus, double positivity discriminated eRA from axial spondyloarthritis with a LR+ of 18.3. Remarkably, triple positivity was 100% specific for RA, being observed in 10% of eRA and 21.5% of estRA patients, even in the absence of RF and ACPA.

Conclusion:

AAPA are highly prevalent in early RA and occur also independently of RF and ACPA, thereby reducing the gap of seronegativity. Furthermore, multiple AAPA reactivity increased the specificity for RA, suggesting high diagnostic value of AAPA testing.

Methodological aspects of design, analysis and reporting of studies with work participation as an outcome domain in patients with inflammatory arthritis: results of two systematic literature reviews informing EULAR points to consider

Objective

To summarise the methodological aspects in studies with work participation (WP) as outcome domain in inflammatory arthritis (IA) and other chronic diseases.

Methods

Two systematic literature reviews (SLRs) were conducted in key electronic databases (2014–2019): search 1 focused on longitudinal prospective studies in IA and search 2 on SLRs in other chronic diseases. Two reviewers independently identified eligible studies and extracted data covering pre-defined methodological areas.

Results

In total, 58 studies in IA (22 randomised controlled trials, 36 longitudinal observational studies) and 24 SLRs in other chronic diseases were included. WP was the primary outcome in 26/58 (45%) studies. The methodological aspects least accounted for in IA studies were as follows (proportions of studies positively adhering to the topic are shown): aligning the studied population (16/58 (28%)) and sample size calculation (8/58 (14%)) with the work-related study objective; attribution of WP to overall health (28/58 (48%)); accounting for skewness of presenteeism/sick leave (10/52 (19%)); accounting for work-related contextual factors (25/58 (43%)); reporting attrition and its reasons (1/58 (2%)); reporting both aggregated results and proportions of individuals reaching predefined meaningful change or state (11/58 (16%)). SLRs in other chronic diseases confirmed heterogeneity and methodological flaws identified in IA studies without identifying new issues.

Conclusion

High methodological heterogeneity was observed in studies with WP as outcome domain. Consensus around various methodological aspects specific to WP studies is needed to improve quality of future studies. This review informs the EULAR Points to Consider for conducting and reporting studies with WP as an outcome in IA.

The impact of different (rheumatoid) arthritis phenotypes on patients' lives

Objectives

To compare patient-reported outcome (PRO) domains between three arthritis phenotypes [undifferentiated arthritis (UA), autoantibody-negative RA (RA⁻) and autoantibody-positive RA (RA⁺)] at diagnosis, after 2 years and over time.

Methods

All UA (n = 130), RA⁻ (n = 176) and RA⁺ (n = 331) patients from the tREACH trial, a stratified single-blinded trial with a treat-to-target approach, were used. PRO comparisons between phenotypes at baseline and after 2 years were performed with analysis of variance, while a linear mixed model compared them over time. Effect sizes were weighted against the minimal clinically important differences (MCIDs) for each PRO.

Results

RA⁻ patients had a higher disease burden compared with RA⁺ and UA. At baseline and after 2 years, RA⁻ patients had more functional impairment and a poorer Physical Component Summary (PCS) compared with the other phenotypes, while they only scored worse for general health and morning stiffness duration at baseline. The MCIDs were exceeded at baseline, except for functional ability between RA⁺ and UA, while after 2 years only the MCID of the PCS was exceeded by RA⁻ compared with UA and RA. After 2 years the PROs of all phenotypes improved, but PROs measuring functioning were still worse compared with the general population, even when patients had low disease activity.

Conclusion

RA⁻ patients had the highest disease burden of all phenotypes. Although most patients have low disease activity after treatment, all clinical phenotypes still have a similar significant impact on patients’ lives, which is mainly physical. Therefore it is important to assess and address PROs in daily practice because of persistent disease burden despite low disease activity.

Trial registration

ISRCTN26791028.

The number of risk factors for persistent disease determines the clinical course of early arthritis

Objectives

Management of early arthritis is based upon early recognition of individuals at high risk of developing persistent arthritis. Therefore, this study investigates whether the number of risk factors for persistent disease or treatment determines the clinical course of early arthritis by comparing the chance at (sustained) DMARD-free remission ((S)DFR) after 2 years follow-up.

Methods

Data from the tREACH trial, a stratified single-blinded multicentre strategy trial with a treat-to-target approach were used. We selected all patients with ≥1 swollen joint who did not fulfil 1987 and/or 2010 criteria for RA. The number of risk factors present; autoantibody-positivity, polyarthritis (>4), erosive disease and elevated acute phase reactants, determined risk group stratification. Multivariate logistic regression analyses were performed with (S)DFR as dependent variables and baseline disease activity score (DAS), treatment, symptom duration and number of risk factors present as independent variables.

Results

In total, 130 early arthritis patients were included and respectively 31, 66 and 33 had 0, 1 and ≥2 risk factors present. DFR rates were respectively 74%, 48% and 45% for early arthritis patients with 0, 1 and ≥2 risk factors present. In accordance SDFR rates were 61%, 32% and 30%. In our logistic model (S)DFR was not influenced by the initial treatment strategies when stratified for risk groups.

Conclusion

The chance at (S)DFR in early arthritis diminishes when more risk factors are present, which is irrespective of the given initial treatment. Our data point out to a stratified management approach in early arthritis based on their risk profile, but validation is needed.

Trial registration

ISRCTN registry: ISRCTN26791028 (http://www.isrctn.com/ISRCTN26791028).

Predictive value of anti-CarP and anti-PAD3 antibodies alone or in combination with RF and ACPA for the severity of rheumatoid arthritis

OBJECTIVES

The objective of this study was to analyse the predictive value of anti-carbamylated protein (anti-CarP) and anti-peptidyl-arginine deiminase type-3 (anti-PAD3) antibodies, alone or in combination with RF and ACPA, to identify patients at high risk of developing severe RA outcomes.

METHODS

Patients within the Swiss Clinical Quality Management registry with a biobank sample were tested for RF, ACPA, anti-CarP, and anti-PAD3 antibodies. We examined the association of each autoantibody with DAS28, HAQ and radiographic damage (Ratingen) at baseline and longitudinally.

RESULTS

Analyses included 851 established RA patients and 516 disease controls [axial spondyloarthritis (axSpA = 320) and PsA (196)]. Anti-CarP and anti-PAD3 antibodies were, respectively, present in 22.4% and 10.7% of the whole RA population, and in 13.2% and 3.8% of the RF and ACPA double seronegative patients. At baseline, RA patients with anti-PAD3 had higher DAS28 (4.2 vs 3.7; P= 0.005) and significantly more radiographic damage (14.9 vs 8.8; P= 0.02) than anti-PAD3-negative patients. In the ACPA-negative subgroup, baseline Ratingen scores were significantly higher in anti-PAD3-positive patients (P= 0.01). The combination of anti-PAD3, RF IgM, and ACPA was associated with significantly higher baseline radiographic scores than the double seropositive group (P= 0.04). The presence of any two of the previous autoantibodies was associated with significantly greater radiographic progression over 10 years than if all were absent (P= 0.02). There were no differences in RA outcome measures with regards to anti-CarP.

CONCLUSIONS

Anti-PAD3 antibodies are associated with higher disease activity and joint damage scores in RA patients.

Early DAS response after DMARD-start increases probability of achieving sustained DMARD-free remission in rheumatoid arthritis

Background

Sustained DMARD-free remission (SDFR) is increasingly achievable. The pathogenesis underlying SDFR development is unknown and patient characteristics at diagnosis poorly explain whether SDFR will be achieved. To increase the understanding, we studied the course of disease activity scores (DAS) over time in relation to SDFR development. Subsequently, we explored whether DAS course could be helpful identifying RA patients likely to achieve SDFR.

Methods

772 consecutive RA patients, promptly treated with csDMARDs (mostly methotrexate and treat-to-target treatment adjustments), were studied for SDFR development (absence of synovitis, persisting minimally 12 months after DMARD stop). The course of disease activity scores (DAS) was compared between RA patients with and without SDFR development within 7 years, using linear mixed models, stratified for ACPA. The relation between 4-month DAS and the probability of SDFR development was studied with logistic regression. Cumulative incidence of SDFR within DAS categories (< 1.6, 1.6–2.4, 2.4–3.6, ≥ 3.6) at 4 months was visualized using Kaplan-Meier curves.

Results

In ACPA-negative RA patients, those achieving SDFR showed a remarkably stronger DAS decline within the first 4 months, compared to RA patients without SDFR; − 1.73 units (95%CI, 1.28–2.18) versus − 1.07 units (95%CI, 0.90–1.23) (p < 0.001). In APCA-positive RA patients, such an effect was not observed, yet SDFR prevalence in this group was low. In ACPA-negative RA, DAS decline in the first 4 months and absolute DAS levels at 4 months (DAS_4 months) were equally predictive for SDFR development. Incidence of SDFR in ACPA-negative RA patients was high (70.2%) when DAS_4 months was < 1.6, whilst SDFR was rare (7.1%) when DAS_4 months was ≥ 3.6.

Conclusions

In ACPA-negative RA, an early response to treatment, i.e., a strong DAS decline within the first 4 months, is associated with a higher probability of SDFR development. DAS values at 4 months could be useful for later decisions to stop DMARDs.

TREAT Early Arthralgia to Reverse or Limit Impending Exacerbation to Rheumatoid arthritis (TREAT EARLIER): a randomized, double-blind, placebo-controlled clinical trial protocol

BACKGROUND

We present a study protocol for a randomized, double-blind, placebo-controlled trial that investigates the hypothesis if intervention in the symptomatic phase preceding clinical arthritis (clinically suspect arthralgia (CSA)) is effective in preventing progression from subclinical inflammation to clinically apparent persistent arthritis. Currently, rheumatoid arthritis (RA) can be recognized and diagnosed when arthritis (joint swelling) has become detectable at physical examination. Importantly, at this time, the immune processes have already matured, chronicity is established, and patients require long-standing treatment with disease-modifying anti-rheumatic drugs. The TREAT EARLIER trial studies the hypothesis that intervention in the symptomatic phase preceding clinical arthritis is more often successful in permanent disease modification because of less matured underlying disease processes.

METHODS

A two-level definition to identify patients that are prone to develop RA is used. First, patients should have CSA and recent-onset arthralgia (< 1 year) that is suspect to progress to RA according to the expertise of the treating rheumatologist. Second, patients need to have subclinical inflammation of the hand or foot joints at 1.5 T MRI. The trial aims to recruit 230 participants from secondary care hospital settings across the south-west region of The Netherlands. Intervention will be randomly assigned and includes a single-dose of intramuscular 120 mg methylprednisolon followed by methotrexate (increasing dose to 25 mg/week orally) or placebo (both; injection and tablets) over the course of 1 year. Thereafter, participants are followed for another year. The primary endpoint is the development of clinically detectable arthritis, either fulfilling the 2010 criteria for RA or unclassified clinical arthritis of ≥ 2 joints, which persists for at least 2 weeks. DMARD-free status is a co-primary endpoint. The patient-reported outcomes functioning, along with workability and symptoms, are key secondary endpoints. Participants, caregivers (including those assessing the endpoints), and scientific staff are all blinded to the group assignment.

DISCUSSION

This proof-of-concept study is the logical consequence of pre-work on the identification of patients with CSA with MRI-detected subclinical joint inflammation. It will test the hypothesis whether intervention in patients in this early phase with the cornerstone treatment of classified RA (methotrexate) hampers the development of persistent RA and reduce the disease burden of RA.

TRIAL REGISTRATION

Dutch Trial Register NL4599 (NTR4853). Registered on 20 October 2014.

Enhanced treatment strategies and distinct disease outcomes among autoantibody-positive and -negative rheumatoid arthritis patients over 25 years: A longitudinal cohort study in the Netherlands

BACKGROUND

Based on different genetic and environmental risk factors and histology, it has been proposed that rheumatoid arthritis (RA) consists of 2 types: autoantibody-positive and autoantibody-negative RA. However, until now, this remained hypothetical. To assess this hypothesis, we studied whether the long-term outcomes differed for these 2 groups of RA patients.

METHODS AND FINDINGS

In the Leiden Early Arthritis Clinic cohort, 1,285 consecutive RA patients were included between 1993 and 2016 and followed yearly. Treatment protocols in routine care improved over time, irrespective of autoantibody status, and 5 inclusion periods were used as instrumental variables: 1993-1996, delayed mild disease-modifying antirheumatic drug (DMARD) initiation (reference period); 1997-2000, early mild DMARDs; 2001-2005, early methotrexate; 2006-2010, early methotrexate followed by treat-to-target adjustments; 2011-2016, similar to 2006-2010 plus additional efforts for very early referral. Three long-term outcomes were studied: sustained DMARD-free remission (SDFR) (persistent absence of clinical synovitis after DMARD cessation), mortality, and functional disability measured by yearly Health Assessment Questionnaire (HAQ). Treatment response in the short term (disease activity) was measured by Disease Activity Score-28 with erythrocyte sedimentation rate (DAS28-ESR). Linear mixed models and Cox regression were used, stratified for autoantibody positivity, defined as IgG anti-CCP2 and/or IgM rheumatoid factor positivity. In total, 823 patients had autoantibody-positive RA (mean age 55 years, 67% female); 462 patients had autoantibody-negative RA (age 60 years, 64% female). Age, gender, and percentage of autoantibody-positive patients were stable throughout the inclusion periods. Disease activity significantly decreased over time within both groups. SDFR rates increased after introduction of treat-to-target (hazard ratio [HR] 2006-2010 relative to 1993-1996: 3.35 [95% CI 1.46 to 7.72; p = 0.004]; HR 2011-2016: 4.57 [95% CI 1.80 to 11.6; p = 0.001]) in autoantibody-positive RA, but not in autoantibody-negative RA. In autoantibody-positive RA, mortality decreased significantly after the introduction of treat-to-target treatment adjustments (HR 2006-2010: 0.56 [95% CI 0.34 to 0.92; p = 0.023]; HR 2011-2016: 0.33 [95% CI 0.14 to 0.77; p = 0.010]), but not in autoantibody-negative RA (HR 2006-2010: 0.79 [95% CI 0.40 to 1.56; p = 0.50]; HR 2011-2016: 0.36 [95% CI 0.10 to 1.34; p = 0.13]). Similarly, functional disability improved in autoantibody-positive RA for the periods after 2000 relative to 1993-1996 (range -0.16 [95% CI -0.29 to -0.03; p = 0.043] to -0.32 [95% CI -0.44 to -0.20; p < 0.001] units of improvement), but not in autoantibody-negative RA (range 0.10 [95% CI -0.12 to 0.31; p = 0.38] to -0.13 [95% CI -0.34 to 0.07; p = 0.20] units of improvement). Limitations to note were that treatment was not randomized-but it was protocolized and instrumental variable analysis was used to obtain comparable groups-and that a limited spread of ethnicities was included.

CONCLUSIONS

Although disease activity has improved in both autoantibody-positive and autoantibody-negative RA in recent decades, the response in long-term outcomes differed. We propose that it is time to subdivide RA into autoantibody-positive RA (type 1) and autoantibody-negative RA (type 2), in the hope that this leads to stratified treatment in RA.

Anti-cyclic citrullinated peptide antibodies are associated with radiographic damage but not disease activity in early rheumatoid arthritis diagnosed in 2006-2011

Objective: The discovery of anti-citrullinated protein antibodies (ACPAs) and the introduction of new therapeutic options have had profound impacts on early rheumatoid arthritis (RA) care. Since ACPA status, most widely assessed as reactivity to cyclic citrullinated peptides (CCPs), influences treatment decisions in early RA, we aimed to determine whether anti-CCP remains a predictor of disease activity and radiographic joint damage in more recent 'real-world' early RA. Method: Two observational early RA cohorts from Sweden enrolled patients in 1996-1999 (TIRA-1, n = 239) and 2006-2009 (TIRA-2, n = 444). Clinical and radiographic data and ongoing treatment were prospectively collected up to 3 years. Two other cohorts served as confirmation cohorts (TRAM-1, with enrolment 1996-2000, n = 249; and TRAM-2, 2006-2011, n = 528). Baseline anti-CCP status was related to disease activity, pharmacotherapy, and radiographic joint damage according to Larsen score. Results: In the TIRA-1 cohort, anti-CCP-positive patients had significantly higher 28-joint Disease Activity Score, swollen joint count, C-reactive protein level, and erythrocyte sedimentation rate during follow-up compared with anti-CCP-negative patients. In TIRA-2, no such differences were found, but baseline anti-CCP positivity was associated with higher 3 year Larsen score (5.4 vs 3.5, p = 0.039). In TRAM-2, anti-CCP also predicted radiographic damage (8.9 vs 6.7, p = 0.027), with no significant differences in disease activity. Conclusion: In the early RA cohorts recruiting patients in 2006-2011, baseline anti-CCP positivity was not associated with disease activity over time, but was associated with increased radiographic damage at follow-up. Hence, close radiographic monitoring is warranted in early anti-CCP-positive RA regardless of disease activity.

Presence of anti-citrullinated protein antibodies and costs and disease activity in early rheumatoid arthritis - a 3-year follow-up

Objective: To analyse healthcare utilization, loss of productivity, and disease activity in relation to presence of anti-citrullinated protein antibodies (ACPAs). Method: In total, 447 ACPA-positive and 224 ACPA-negative patients from two early rheumatoid arthritis cohorts, recruited 1996-1998 (cohort 1) and 2006-2009 (cohort 2), were followed during 3 years. Data on disease activity were collected, and patients reported healthcare utilization and days lost from work. Disease activity, healthcare costs, and loss of productivity were compared between ACPA groups. Linear regression was performed, controlling for confounders. Results: Healthcare costs did not differ significantly by ACPA status (EUR 3214 for vs EUR 2174 for ACPA-positive vs ACPA-negative patients in cohort 1, ns; EUR 4150 vs EUR 3820 in cohort 2, ns). Corresponding values for loss of productivity were EUR 9148 vs EUR 7916 (ns) and EUR 5857 vs EUR 5995 (ns). Total prescription of traditional disease-modifying anti-rheumatic drugs was higher in cohort 2 than in cohort 1. Methotrexate prescription was higher in ACPA-positive patients, but biologics did not differ significantly between ACPA groups. Disease activity was significantly more improved in cohort 2, but there was no difference in achieving remission in relation to ACPA status. In cohort 1, 25% of ACPA-positive patients were in remission vs 31% of ACPA-negative (ns) and in cohort 2, 55% vs 60% (ns). Conclusions: With increasing drug treatment for both ACPA-positive and ACPA-negative patients, outcome in ACPA-positive was no more severe than in ACPA-negative patients. Healthcare costs and loss of productivity were similar in the two groups.

An overview of autoantibodies in rheumatoid arthritis

Rheumatoid arthritis (RA) is a systemic auto-immune disease principally effecting synovial joints. RA is characterized by immune cell infiltration in the joint. The presence of autoantibodies is a hallmark for the disease, among these are rheumatoid factor and antibodies against post-translational modified proteins like citrullination (ACPA) and carbamylation (anti-CarP antibodies). These autoantibodies may form immune complexes in the joint, leading to the attraction of immune cells. Based on the presence of these autoantibodies, RA patients can be subdivided in autoantibody positive and negative disease. Both subsets can be associated with genetic and environmental risk factors for RA, like the human leukocyte antigen (HLA) allele and smoking. Autoantibodies can already be detected years before disease onset in a subgroup of patients and at symptom onset a broad isotype spectrum is observed. This suggests that various events occur prior to the development of RA in which the first autoantibodies develop in predisposed individuals. Therefore, the presence of these autoantibodies can be useful in predicting future RA patients. Research on the characteristics and effector function of these autoantibodies is ongoing and will give more knowledge in the inflammatory responses underlying RA. This will give insight in the pathogenic role of autoantibodies in RA. Recent data are suggestive of a role for mucosal surfaces in the development of auto-immune responses associated with (the development of) RA. In conclusion, investigating the potential pathogenic effector functions of autoantibody isotypes and their molecular- and physicochemical-compositions might improve understanding of the disease origin and its underlying immunological processes. This may lead to the development of new therapeutic targets and strategies.

Impact of the combined presence of erosions and ACPA on rheumatoid arthritis disease activity over time: results from the METEOR registry

Objective

To investigate associations between baseline presence of erosions and/or anti-citrullinated protein antibodies (ACPA) on functional ability, disease activity and treatment survival over time.

Methods

Real life data from newly diagnosed rheumatoid arthritis patients were identified in the international METEOR registry. Patients were grouped according to presence/absence of ACPA and/or erosions at baseline. Associations between the presence of ACPA and/or erosions (four groups) with the change of Disease Activity Score (DAS) and Health Assessment Questionnaire (HAQ) over time were assessed using linear mixed models during maximum 6 or maximum 12 months from baseline. Treatment survival was assessed using multiple failure-times Cox regression.

Results

Data were included from 701 ACPA‒/erosions‒, 334 ACPA‒/erosions+, 1585 ACPA+/erosions‒ and 1993 ACPA+/erosions+ patients. We found statistically significant differences in DAS and HAQ change over time between the four groups, both after maximum follow-up durations of 6 and of 12 months, but after stratification differences proved small and not clinically meaningful. Patients in the ACPA‒/erosions‒ group were less likely to switch treatment compared with the ACPA+/erosions‒ reference group (p<0.001). The other two ACPA/erosions groups did not differ from the reference group.

Conclusions

In this analysis of worldwide real life data, we found statistically significant, but clinically irrelevant differences in treatment response to initial disease modifying anti-rheumatic drug therapies as measured by DAS and HAQ in ACPA‒/erosions‒, ACPA‒/erosions+, ACPA+/erosions‒ and ACPA+/erosions+ rheumatoid arthritis patients. However, after maximum follow-up durations of 6 and 12 months all groups had a similar response to initial treatment, but with a lower likelihood to switch treatment for ACPA‒/erosions‒ patients during the first year of follow-up.

What is the additional value of MRI of the foot to the hand in undifferentiated arthritis to predict rheumatoid arthritis development?

Background

MRI-detected subclinical joint inflammation in the hand joints of patients with undifferentiated arthritis (UA) predicts progression to rheumatoid arthritis (RA). It is unknown if adding MRI of the foot increases predictive accuracy compared to the hand alone.

Methods

1.5-T contrast-enhanced MRI of the unilateral foot (MTP-1-5) and hand (MCP-2-5 and wrist) was performed in 123 patients presenting with UA (not fulfilling the 2010 RA criteria) and scored for bone marrow edema (BME), synovitis and tenosynovitis. Symptom-free controls (n = 193) served as a reference for defining an abnormal MRI. Patients were followed for RA development ≤ 1 year, defined as fulfilling the classification criteria or initiation of disease-modifying antirheumatic drugs because of the expert opinion of RA. The added predictive value of foot MRI to hand MRI was evaluated.

Results

Fifty-two percent developed RA. Foot tenosynovitis was predictive (OR 2.55, 95% CI 1.01–6.43), independent of BME and synovitis (OR 3.29, 95% CI 1.03–10.53), but not independent of CRP and number of swollen joints (OR 2.14, 95% CI 0.77–5.95). Hand tenosynovitis was also predictive independent of BME and synovitis (OR 3.99, 95% CI 1.64–9.69) and independent of CRP and swollen joints (OR 2.36, 95% CI 1.04–5.38). Adding foot tenosynovitis to hand tenosynovitis changed the sensitivity from 72 to 73%, specificity from 59 to 54% and AUC from 0.66 to 0.64; the net reclassification index was − 3.5.

Conclusion

MRI-detected tenosynovitis of the foot predicts progression to RA. However, adding MRI of the foot does not improve the predictive accuracy compared to MRI of the hand alone. In view of cost reduction, the performance of foot MRI for prognostic purposes in UA can be omitted.

Electronic supplementary material

The online version of this article (10.1186/s13075-019-1845-7) contains supplementary material, which is available to authorized users.

The Clinical Value of Autoantibodies in Rheumatoid Arthritis

Rheumatoid arthritis (RA) is a highly heterogeneous syndrome in terms of clinical presentation, progression, and response to therapy. In such a complicated context, the identification of disease-related biomarkers would be undoubtedly helpful in assisting tailored approaches for every patient. Despite remarkable efforts, however, progress in new biomarker development and validation is dramatically slow. At present, none of the candidate genetic, cellular, or molecular biomarker has yet surpassed the clinical value of RA-specific autoantibodies, including rheumatoid factor (RF) and anti-citrullinated protein autoantibodies (ACPA). Rather, recent years have witnessed significant advancements in our understanding of the multiple roles that RF and ACPA play in RA pathophysiology. This has helped clarifying the mechanistic basis of the clinical associations of autoantibodies in RA. In this short review, we will briefly summarize the effector functions of RF and ACPA, and analyse how autoantibodies may help subclassifying RA patients in terms of clinical presentation and response to therapy.