The use of MRI-detected synovitis to determine the number of involved joints for the 2010 ACR/EULAR classification criteria for Rheumatoid Arthritis - is it of additional benefit?

Changes in peripheral blood T lymphocyte subsets predict disease progression in patients with rheumatoid arthritis

OBJECTIVE

To explore the correlation between abnormal changes in peripheral blood T lymphocyte subsets and disease progression in patients with active rheumatoid arthritis (RA).

METHODS

This is a retrospective study, in which 53 patients with active RA were selected as the study subjects and 50 healthy people were selected as the control group. Lymphocyte subsets were determined in both arms. According to whether CD4/CD8 ratio increased, RA patients were subdivided into an elevated CD4/CD8 group and a non-elevated CD4/CD8 group, and compared to the control group. The risk factors affecting the disease progression of patients with active RA were analyzed.

RESULTS

CD4⁺ T lymphocyte subsets in patients with increased CD4/CD8 were significantly higher than those in healthy controls. In addition, the elevated CD4/CD8 group showed significantly CD8⁺ T lymphocyte subsets than the non-elevated CD4/CD8 group and the control group (P<0.05). The CD4⁺ T lymphocyte subsets in the elevated CD4/CD8 group were not significantly higher than those in the non-elevated CD4/CD8 group (P>0.05). The CD3⁺ T lymphocyte subsets as well as CD19⁺ B and NK lymphocyte subsets showed no significant difference among the three arms (P>0.05). In addition, CD4, CD8 and CD4/CD8 were identified to be the risk factors affecting disease progression in patients with active RA.

CONCLUSIONS

When an autoimmune disorder occurs in patients with active RA, CD8⁺ T lymphocyte subsets are significantly suppressed, while CD4⁺ T lymphocyte subsets show different manifestations, with some patients presenting no obvious increase. In addition, CD4, CD8 and CD4/CD8 can help to indicate the risk of disease progression in patients with active RA.

Reappraisal of bone scintigraphy as a new tool for the evaluation of disease activity in patients with rheumatoid arthritis

We aimed to compare the reliability of bone scintigraphy (BS) and fluorine-18-fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography (PET)-derived parameters in the detection of active arthritis in 28-joint areas and evaluate the reliability of joint counts between BS and clinical assessment in patients with rheumatoid arthritis (RA). We enrolled 106 patients (67 in the development group and 39 in the validation groups) with active RA who underwent BS, ¹⁸F-FDG PET/computed tomography (CT), and clinical evaluation of disease activity. We compared the results of BS-derived joint assessment with those of PET-derived and clinical joint assessments. Subsequently we developed a disease activity score (DAS) using BS-positive joints and validated it in an independent group. The number of BS-positive joints in 28-joint areas significantly correlated with the swollen /tender joint counts (SJC/TJC) and PET-derived joint counts. A BS uptake score of 2 (strong positive) was significantly more sensitive compared with a BS uptake score of 1 (weak positive) in detecting a PET-positive joint among the 28-joints. After conducting multivariate analyses including erythrocyte sediment rate (ESR) and patient global assessment (PGA) in addition to BS-derived parameters, BS/DAS was obtained as follows: 0.056 × number of BS-positive joints in 28 joints + 0.012 × ESR + 0.030 × PGA. A significant correlation between BS/DAS and DAS28-ESR was confirmed in the validation group. Strong positive uptake of BS is sensitive and reproducible for the detection of active joints, and can complement the clinical assessment of disease activity in RA.

Subclinical synovitis in arthralgia: how often does it result in clinical arthritis? Reflecting on starting points for disease-modifying anti-rheumatic drug treatment

Objectives

According to guidelines, clinical arthritis is mandatory for diagnosing RA. However, in the absence of clinical synovitis, imaging-detected subclinical synovitis is increasingly used instead and is considered as a starting point for DMARD therapy. To search for evidence we studied the natural course of arthralgia patients with subclinical synovitis from three longitudinal cohorts and determined the frequencies of non-progression to clinically apparent inflammatory arthritis (IA) (i.e. ‘false positives’).

Methods

Subclinical synovitis in the hands or feet of arthralgia patients was visualized with US (two cohorts; definition: greyscale ≥2 and/or power Doppler ≥1) or MRI (one cohort; definition: synovitis score ≥1 by two readers). Patients were followed for 1  year on for IA development; two cohorts also had 3  year data. Analyses were stratified for ACPA.

Results

Subclinical synovitis at presentation was present in 36%, 41% and 31% in the three cohorts. Of the ACPA-positive arthralgia patients with subclinical synovitis, 54%, 44% and 68%, respectively, did not develop IA. These percentages were even higher in the ACPA-negative arthralgia patients: 66%, 85% and 89%, respectively. Similar results were seen after 3 years of follow-up.

Conclusion

Replacing clinical arthritis with subclinical synovitis to identify RA introduces a high false-positive rate (44–89%). These data suggest an overestimation regarding the value of ACPA positivity in combination with the presence of subclinical synovitis in patients with arthralgia, which harbours the risk of overtreatment if DMARDs are initiated in the absence of clinical arthritis.