Ultrasound is not associated with the presence of systemic autoimmunity or symptoms in individuals at risk for rheumatoid arthritis

Rheumatoid Arthritis: The Continuum of Disease and Strategies for Prediction, Early Intervention, and Prevention

Rheumatoid arthritis (RA) is known to include a pre-RA stage that can be defined as the presence of familial or genetic risk factors, biomarker abnormalities (eg, anticitrullinated protein antibodies [ACPA]), symptoms, and even abnormal imaging findings prior to the development of the onset of clinical RA with inflammatory arthritis that is apparent on physical examination. Indeed, there are multiple completed or ongoing retrospective case-control as well as prospective observational studies to identify the key biologic drivers of disease. Further, building on the predictive ability of combinations of biomarkers, symptoms, and imaging for future RA, there are multiple clinical trials completed, underway, or in development to identify approaches that may prevent, delay, or ameliorate future clinical RA in at-risk individuals. Importantly, however, although an effective preventive intervention has not yet been identified, at-risk individuals are being increasingly identified in clinical care; this presents a challenge of how to manage these individuals in clinical practice. This review will discuss the current understanding of the biology and natural history of RA development, nomenclature, and current models for prediction of future RA, as well as evaluate the current and ongoing clinical prevention trials with the overall goal to provide insights into the challenges and opportunities in the field of RA prevention. Moreover, this review will provide up-to-date options for clinical management of individuals at risk for RA.

A potential role for chlamydial infection in rheumatoid arthritis development

OBJECTIVES

To assess the relationship between self-reported and serologic evidence of prior chlamydial infection, rheumatoid arthritis (RA)-related autoantibodies and risk of RA-development.

METHODS

This is a nested study within a prospective Swiss-based cohort including all first-degree relatives of RA patients (RA-FDR) who answered a question on past chlamydial infections. Primary outcome was systemic autoimmunity associated with RA (RA-autoimmunity) defined as positivity for anti-citrullinated peptide antibodies (ACPA) and/or rheumatoid factor (RF). Secondary outcomes were high levels of RA-autoimmunity, RA-associated symptoms and RA-autoimmunity, and subsequent seropositive RA diagnosis. We conducted a nested case-control analysis by measuring the serological status against Chlamydia trachomatis' major outer membrane protein. We replicated our analysis in an independent United States-based RA-FDR cohort.

RESULTS

Among 1231 RA-FDRs, 168 (13.6%) developed RA-autoimmunity. Prevalence of self-reported chlamydial infection was significantly higher in individuals with RA-autoimmunity compared with controls (17.9% vs 9.8%, OR = 2.00, 95%CI: 1.27-3.09, p < 0.01). This association remained significant after adjustments (OR = 1.91, 95%CI: 1.20-2.95). Stronger effect sizes were observed in later stages of RA development. There was a similar trend between a positive C. trachomatis serology and high levels of RA-autoimmunity (OR = 3.05, 95% CI: 1.10-8.46, p= 0.032). In the replication cohort, there were significant associations between chlamydial infection and RF positivity and incident RA, but not anti-CCP positivity.

CONCLUSIONS

Self-reported chlamydial infections are associated with elevated RA-autoimmunity in at risk individuals. The differing association of chlamydial infections and ACPA/RF between cohorts will need to be explored in future studies but is consistent with a role of mucosal origin of RA-related autoimmunity.

The role of ultrasound synovitis scores for patients who are at risk of rheumatoid arthritis

OBJECTIVES

The development of rheumatoid arthritis (RA) has been classified into 6 phases A-F according to the present risk factors in sequence of genes, environments, autoimmunity, arthralgia and joint swelling. To clarify the ultrasound synovitis scores in at-risk patients (phases C-E) and RA (phase F).

METHODS

Patients who had been experiencing hand joint symptoms for at least 6 weeks and asymptomatic patients with positive rheumatoid factor and/or anti-cyclic citrullinated peptide antibodies were enrolled. A 40-joint ultrasonography with semiquantitative synovitis scoring for gray scale (GS) and power Doppler (PD) images was performed.

RESULTS

A total of 139 patients were enrolled and classified into non-RA, phase C, phase D, phase E and phase F. Total GS scores in phases C (17.4 ± 7.0), D (16.0 ± 5.4), E (18.5 ± 7.7) and F (21.8 ± 9.1) were higher than those in non-RA (9.8 ± 4.0, P < 0.001). The total PD score in phase F (3.1 ± 4.6) was higher than that in phases C (0.2 ± 0.5), D (0.1 ± 0.4), and E (0.1 ± 0.3), as well as in non-RA (0.0 ± 0.0, P < 0.01). A total GS score ≥14 differentiated patients at risk for RA from patients with non-RA (area under curve [AUC] 0.82), while a total PD score ≥2 differentiated patients with RA from patients at risk for RA (AUC 0.71).

CONCLUSION

Total GS score may differentiate patients at risk for RA from non-RA patients, while total PD score may differentiate patients with RA from those who are at risk for RA.

When and how should we use imaging in individuals at risk of rheumatoid arthritis?

In recent years rheumatologists have begun to shift focus from early rheumatoid arthritis (RA) to studying individuals at risk of developing the disease. It is now possible to use blood, clinical and imaging biomarkers to identify those at risk of progression before the onset of clinical synovitis. The use of imaging, in particular ultrasound (US) and magnetic resonance imaging (MRI), has become much more widespread in individuals at-risk of RA. Numerous studies have demonstrated that imaging can help us understand RA pathogenesis as well as identifying individuals at high risk of progression. In addition, imaging techniques are becoming more sophisticated with newer imaging modalities such as high-resolution peripheral quantitative computed tomography (HR-pQRCT), nuclear imaging and whole body-MRI (WB-MRI) starting to emerge. Imaging studies in at risk individuals are heterogeneous in nature due to the different at-risk populations, imaging modalities and protocols used. This review will explore the available imaging modalities and the rationale for their use in the main populations at risk of RA.

Pre-RA: Can early diagnosis lead to prevention?

Rheumatoid arthritis (RA) is currently diagnosed and treated once an individual displays the clinical findings of inflammatory arthritis (IA). However, growing evidence supports that there is a 'pre-RA' stage that can be identified through factors such as autoantibodies in absence of clinically apparent IA. In particular, biomarkers, including antibodies to citrullinated protein antigens (ACPA), demonstrate a high risk for future IA/RA, and multiple clinical trials have been developed to intervene in individuals in pre-RA to prevent or delay clinically apparent disease. Herein, we will discuss in more depth what is currently known about the natural history of RA, and the emerging possibility that early 'diagnosis' of RA-related autoimmunity followed by an intervention can lead to the delay or prevention of the first onset of clinically apparent RA.

EULAR points to consider for conducting clinical trials and observational studies in individuals at risk of rheumatoid arthritis

BACKGROUND

Despite growing interest, there is no guidance or consensus on how to conduct clinical trials and observational studies in populations at risk of rheumatoid arthritis (RA).

METHODS

An European League Against Rheumatism (EULAR) task force formulated four research questions to be addressed by systematic literature review (SLR). The SLR results informed consensus statements. One overarching principle, 10 points to consider (PTC) and a research agenda were proposed. Task force members rated their level of agreement (1-10) for each PTC.

RESULTS

Epidemiological and demographic characteristics should be measured in all clinical trials and studies in at-risk individuals. Different at-risk populations, identified according to clinical presentation, were defined: asymptomatic, musculoskeletal symptoms without arthritis and early clinical arthritis. Study end-points should include the development of subclinical inflammation on imaging, clinical arthritis, RA and subsequent achievement of arthritis remission. Risk factors should be assessed at baseline and re-evaluated where appropriate; they include genetic markers and autoantibody profiling and additionally clinical symptoms and subclinical inflammation on imaging in those with symptoms and/or clinical arthritis. Trials should address the effect of the intervention on risk factors, as well as progression to clinical arthritis or RA. In patients with early clinical arthritis, pharmacological intervention has the potential to prevent RA development. Participants' knowledge of their RA risk may inform their decision to participate; information should be provided using an individually tailored approach.

CONCLUSION

These consensus statements provide data-driven guidance for rheumatologists, health professionals and investigators conducting clinical trials and observational studies in individuals at risk of RA.

Cohort profile: SCREEN-RA: design, methods and perspectives of a Swiss cohort study of first-degree relatives of patients with rheumatoid arthritis

PURPOSE

Rheumatoid arthritis (RA) is an insidious autoimmune disease, with an immunological onset years before diagnosis. Early interventions in preclinical stages could prevent or minimise the progression towards irreversible joint damage. The SCREEN-RA cohort (Evaluation of a SCREENing strategy for Rheumatoid Arthritis) aims to characterise the preclinical stages of the disease, to identify environmental risk factors, and to discover or validate novel biomarkers predictive for RA development.

PARTICIPANTS

SCREEN-RA includes an at-risk population for RA, namely first-degree relatives of patients with established RA.

FINDINGS TO DATE

The cohort started in 2009 is composed of mostly asymptomatic healthy individuals (total n=1458, 7262 person-years), with a mean age of 44 years at enrolment, 74% female and 91% Caucasian ethnicity. During the study period, 16 participants have developed RA. All participants provide baseline serum, DNA and RNA samples, and in a subset, stool samples and oral examination are performed for microbiota assessment. At enrolment, 10% of participants had asymptomatic autoimmunity associated with RA (n=147), 10% presented 'clinically suspect arthralgias' (n=143) and 3% reported arthralgias in conjunction with autoimmunity or high genetic risk (n=51). Studies with this cohort have uncovered risk factors for RA development, such as female hormonal factors, poor oral health or intestinal dysbiosis.

FUTURE PLANS

Future directions include immunological and 'multiomics' approaches to discover new biological markers of progression towards RA, as well as testing preventive interventions in 'high-risk' population.

Rheumatoid Arthritis Pathogenesis, Prediction, and Prevention: An Emerging Paradigm Shift

Rheumatoid arthritis (RA) is currently diagnosed and treated when an individual presents with signs and symptoms of inflammatory arthritis (IA) as well as other features, such as autoantibodies and/or imaging findings, that provide sufficient confidence that the individual has RA-like IA (e.g., meeting established classification criteria) that warrants therapeutic intervention. However, it is now known that there is a stage of seropositive RA during which circulating biomarkers and other factors (e.g., joint symptoms) can be used to predict if and when an individual who does not currently have IA may develop future clinically apparent IA and classifiable RA. Indeed, the discovery of the "pre-RA" stage of seropositive disease has led to the development of several clinical trials in which individuals are studied to identify ways to delay or prevent the onset of clinically apparent IA/RA. This review focuses on several issues pertinent to understanding the prevention of RA. These include discussion of the pathogenesis of pre-RA development, prediction of the likelihood and timing of future classifiable RA, and a review of completed and ongoing clinical trials in RA prevention. Furthermore, this review discusses challenges and opportunities to be addressed to effect a paradigm shift in RA, where in the near future, proactive risk assessment focused on prevention of RA will become a public health strategy in much the same manner as cardiovascular disease is managed today.

The Role of Ultrasound Across the Inflammatory Arthritis Continuum: Focus on "At-Risk" Individuals

In individuals at-risk of developing inflammatory arthritis, the value of an ultrasound (US) scan assessment to predict progression has been demonstrated repeatedly. However, depending on recruitment criteria, these individuals may be at different stages in the arthritis development continuum, therefore representing a heterogeneous population. As a consequence, the predictive value of ultrasound results may differ between cohorts. As other reviews have focused on the challenges in population recruitment or have combined biomarkers predicting value according to one recruitment pathway, we wanted to focus on the sole use of ultrasound assessment and its variation according to population recruitment criteria. In this review, we discuss the use of ultrasound in the different at-risk populations across the inflammatory arthritis disease continuum. This review demonstrates that although some sub-population data is scarce, ultrasound is best predictive in three at-risk populations: those with a positive ACPA test in the context of non-specific MSK symptoms, those with clinically suspect arthralgia and those with palindromic rheumatism. We consider that ultrasound assessment will be a cornerstone in prediction risk modeling and prevention studies of the preclinical phases of IA in the future.

Contemporary imaging of rheumatoid arthritis: Clinical role of ultrasound and MRI

Magnetic resonance imaging (MRI) and musculoskeletal ultrasound (MSUS) are sensitive imaging modalities used by clinicians to assist in decision-making in the management of rheumatoid arthritis (RA). This review will examine the utility of MRI and MSUS in diagnosing RA, predicting RA flares, tapering therapy, assessing remission, and examining difficult periarticular features. We will also outline the strengths and weaknesses of utilizing MRI and MSUS as outcome measures in the management of RA.

The Role of Musculoskeletal Ultrasound in the Rheumatoid Arthritis Continuum

PURPOSE OF REVIEW

Rheumatoid arthritis (RA) is no longer considered a fixed phenotype but rather a disease continuum. This review outlines the current and potential value of applying ultrasound (US) along this continuum: from the prediction of progression to RA in at-risk individuals, to confirmation of the early diagnosis of RA, as well as the consideration of differential diagnoses, and the use in disease monitoring and defining remission.

RECENT FINDINGS

In individuals at-risk of RA (i.e., positive autoantibodies with symptoms but without synovitis), US has shown a promising predictive value for the development of clinical arthritis, providing the opportunity to improve risk stratification (and disease prevention) of these individuals. The detection of inflammation on US in patients with early undifferentiated arthritis, in which a definite diagnosis cannot be reached, could predict evolution to persistent arthritis, mostly RA. This, in addition to the US potential ability to identify disease specific patterns for different rheumatic conditions, might facilitate early diagnosis and, therefore, improve the management of patients with RA, or other types of inflammatory arthritides. US has also demonstrated the capability to predict radiographic progression, and relapse risk after treatment discontinuation, in RA patients in remission according to the clinical instruments, raising implications in the management, including therapy discontinuation, of these patients. US has an undeniable value in the management of patients at different stages along the RA continuum. Further research is needed to identify which groups of patients benefit the most from US imaging.

Future use of musculoskeletal ultrasonography and magnetic resonance imaging in rheumatoid arthritis

PURPOSE OF REVIEW

Musculoskeletal ultrasonography (MSUS) and magnetic resonance imaging (MRI) play important roles in diagnosis, monitoring, and prognostication of rheumatoid arthritis. This review highlights recent literature in this field and aims to provide insight into the future use in clinical practice.

RECENT FINDINGS

Recent studies concerning the use of MSUS and MRI in clinical practice show how MSUS and MRI can improve diagnosis and monitoring of rheumatoid arthritis and how they can predict both radiographic progression and clinical outcome (e.g., successful tapering of medical treatment). Moreover, novel technical developments of the two imaging modalities, such as 3D ultrasonography, ultrasound image reading with convolutional neural network, image fusion (MSUS and MRI) and whole-body MRI show promising results. Further validation of these novel techniques is required prior to implementation.

SUMMARY

MSUS and MRI will be important parts of the future management of rheumatoid arthritis patients, mostly because of their ability to detect rheumatoid arthritis changes at a very early stage and to predict the course of disease. However, the exact role in routine clinical practice is still to be defined.

Measuring ACPA in the general population or primary care: is it useful?

Rheumatoid arthritis (RA) is associated with a significant disease burden and high costs for society. Because the disease has identifiable preclinical stages, screening and prevention have become a possibility in RA. Anticitrullinated peptide antibodies (ACPAs) are arguably the most likely candidate biomarker to screen for RA. This paper reviews the evidence for the use of ACPAs as a screening test in the broader general population, to identify individuals at high risk of subsequent onset of RA. We will review the diagnostic properties of the test and its positive and negative predictive value in different settings. We will discuss how ACPA testing could effectively be integrated in a broader screening strategy for RA.