Prevalence and predictive value of anti-cyclic citrullinated protein antibodies for future development of rheumatoid arthritis in early undifferentiated arthritis

Diagnosis, prognosis and classification of early arthritis: results of a systematic review informing the 2016 update of the EULAR recommendations for the management of early arthritis

OBJECTIVE

To update the evidence pertaining to the diagnosis, prognosis and classification of patients with early arthritis (EA), and to inform the 2016 European League Against Rheumatism (EULAR) recommendations for the management of patients with EA.

METHODS

MEDLINE, EMBASE and Cochrane databases were searched up to October 2015. The first part of the systematic literature review (SLR) involved a search for studies investigating the recognition and referral of EA. The second part involved a search for studies to identify the place of laboratory and imaging tests in establishing a diagnosis and a prognosis in patients with EA.

RESULTS

Regarding the issue of referral of patients with EA (1643 hits), 4 studies were included. These studies were in support of early referral for patients with EA. Regarding the issue of diagnosis and prognosis of patients with EA (11 435 hits), 88 studies were included, evaluating mainly the value of rheumatoid factor (RF) and anticitrullinated-peptide antibodies (ACPAs). Sensitivity of these antibodies for a RA diagnosis in patients with EA was moderate (40-80%). Specificity was higher, notably for ACPAs (frequently >80%). ACPAs also showed better prognostic performance than RF (negative predictive values around 80%). We confirmed that structural damage on baseline X-rays is predictive of further radiographic progression in patients with EA. Regarding other imaging modalities, data are sparse.

CONCLUSIONS

This SLR highlights the importance of early referral for patients with EA and confirms that RF and mainly ACPAs as well as a search for structural X-rays changes may help in the diagnosis and prognosis of patients with EA.

Anti-citrullinated peptide antibodies and their value for predicting responses to biologic agents: a review

Anti-citrullinated peptide antibodies (ACPAs) play an important pathogenic role both at the onset and during the disease course. These antibodies precede the clinical appearance of rheumatoid arthritis (RA) and are associated with a less favorable prognosis, both clinically and radiologically. The objective of this work was to conduct a comprehensive review of studies published through September 2015 of ACPAs' role as a predictor of the therapeutic response to the biological agents in RA patients. The review also includes summary of the biology and detection of ACPAs as well as ACPAs in relation to joint disease and CV disease and the possible role of seroconversion. The reviews of studies examining TNF inhibitors and tocilizumab yielded negative results. In the case of rituximab, the data indicated a greater probability of clinical benefit in ACPA(+) patients versus ACPA(-) patients, as has been previously described for rheumatoid factor. Nonetheless, the effect is discreet and heterogeneous. Another drug that may have greater effectiveness in ACPA(+) patients is abatacept. Some studies have suggested that the drug is more efficient in ACPA(+) patients and that those patients show greater drug retention. In a subanalysis of the AMPLE trial, patients with very high ACPA titers who were treated with abatacept had a statistically significant response compared to patients with lower titers. In summary, the available studies suggest that the presence of or high titers of ACPA may predict a better response to rituximab and/or abatacept. Evidence regarding TNFi and tocilizumab is lacking. However, there is a lack of studies with appropriate designs to demonstrate that some drugs are superior to others for ACPA(+) patients.

Anti-cyclic citrullinated peptide antibody titer predicts time to rheumatoid arthritis onset in patients with undifferentiated arthritis: results from a 2-year prospective study

Introduction

The diagnostic, predictive and prognostic role of anti-cyclic citrullinated peptide (CCP) antibodies in rheumatoid arthritis (RA) patients is widely accepted. Moreover, detection of these antibodies in subjects presenting with undifferentiated arthritis (UA) is associated with a significant risk to develop the disease. On the other hand, clinical and prognostic significance of evaluating anti-CCP levels in subjects with inflammatory arthritis at disease onset has not been fully clarified. The goal of this prospective study is to analyze the value and prognostic significance of anti-CCP titer quantification in UA subjects.

Methods

Serial anti-CCP assays were measured in 192 consecutive patients presenting with UA lasting less than 12 weeks. Clinical and serological data and arthritis outcome were evaluated every 6 months until two years of follow-up.

Results

Anti-CCP positivity, at both low and high titer, and arthritis of hand joints significantly predicted RA at two years, risk increasing in subjects with high anti-CCP titers at baseline. Moreover, time to RA diagnosis was shorter in patients with high anti-CCP2 titers at enrollment with respect to those with low antibody concentration.

Conclusions

Presence of anti-CCP antibodies, at both low and high concentration, is significantly associated with RA development in subjects with recent onset UA. However, time interval from the onset of the first symptoms to the fulfilment of the classification criteria appears to be directly related to the initial anti-CCP level.

Goals for rheumatoid arthritis: treating to target or treating to prevent?

Although treat-to-target goals for rheumatoid arthritis (RA) have been well-established through several guidelines in recent years, concerns regarding treat-to-prevent goals for RA remain unclear. RA patients are typically subjected to over- or under-treatment because it is difficult for clinicians to determine the prognosis of RA patients. This typically results in failure to select and identify patient subsets that should receive monotherapy or combination therapy to treat early RA. Understanding treat-to-prevent goals, as well as unfavorable prognoses, risk factors, and prediction methods for RA, is therefore critical for making treatment decisions. Rapid radiographic progression plays a central role in contributing to other composite RA indices, so this may be the best method for defining treat-to-prevent goals for RA. Accordingly, risk factors of rapid radiographic progression have been defined and two prediction models were retrospectively derived based on clinical trial data. Additional studies are required to develop risk models that can be used for accurate predictions.

Bone edema on magnetic resonance imaging is an independent predictor of rheumatoid arthritis development in patients with early undifferentiated arthritis

OBJECTIVE

To study magnetic resonance imaging (MRI) as a tool for early diagnosis of rheumatoid arthritis (RA) in patients with early undifferentiated arthritis (UA).

METHODS

Patients (n = 116) without a specific rheumatologic diagnosis, but with ≥2 tender joints and/or ≥2 swollen joints among the metacarpophalangeal, proximal interphalangeal, wrist, or metatarsophalangeal (MTP) joints for >6 weeks but <24 months, underwent clinical, biochemical, conventional radiographic, and MRI examinations and were followed up for >12 months for the final diagnosis of RA or non-RA. Based on univariate analyses, clinical, biochemical, and imaging parameters were selected for inclusion as explanatory variables in multiple logistic regression analysis, with development of RA as the dependent variable. A prediction model was developed, and its performance was tested and compared with that of a previous model developed by van der Helm-van Mil et al (the vdHvM model).

RESULTS

Of the 116 patients with early UA, 27 (23.3%) developed RA. When the prediction model was applied, which included as explanatory variables presence of hand arthritis, positivity for rheumatoid factor (RF), morning stiffness lasting >1 hour, and the Outcome Measures in Rheumatology Clinical Trials MRI summary score for bone edema in the MTP and wrist joints, the outcome of RA or non-RA was correctly identified in 82% of the patients (sensitivity 81%, specificity 82%). Another cutoff value for the prediction index in the model would allow a higher specificity (98%) and higher accuracy (83%), but lower sensitivity (36%). With the vdHvM model, RA/non-RA was predicted in 60.2% of the population.

CONCLUSION

MRI evidence of bone edema in the MTP and wrist joints is an independent predictor of future RA in patients with early UA. A prediction model that includes the variables clinical hand arthritis, morning stiffness, positivity for RF, and bone edema on MRI in the MTP and wrist joints correctly identified the development or lack of development of RA in 82% of patients.