Major reduction of ultrasound-detected synovitis during subcutaneous tocilizumab treatment: results from a multicentre 24 week study of patients with rheumatoid arthritis

Calprotectin, a sensitive marker of inflammation, is robustly assessed in plasma from patients with early or established rheumatoid arthritis by use of different laboratory methods

Calprotectin (S100A8/S100A9, MRP8/MRP14) is a major leukocyte protein found to be more sensitive than C-Reactive Protein (CRP) and Erythrocyte Sedimentation Rate (ESR) as a marker of inflammation in patients with rheumatoid arthritis (RA). The present objective was to explore the robustness of calprotectin assessments by comparing two different laboratory methods assessing calprotectin in plasma samples from patients with early or established RA. A total of 212 patients with early RA (mean (SD) age 52(13.3) years, disease duration 0.6(0.5) years) and 177 patients with established RA (mean (SD) age 52.9(13.0) years, disease duration 10.0(8.8) years) were assessed by clinical, laboratory, and ultrasound examinations. Frozen plasma samples (-80 °C) were analysed for calprotectin levels at baseline, 1, 2, 3, 6 and 12 months by use of either enzyme-linked immunosorbent assay (ELISA) or fluoroenzyme immunoassay (FEIA). The ELISA technique used kits from Calpro AS and the FEIA technology was assessed on an automated Thermo Fisher Scientific instrument. The results showed high correlations between the two methods at baseline and during follow-up, with Spearman correlation at baseline 0.93 (p < 0.001) in the early and 0.96 (p < 0.001) in the established RA cohorts. The correlations between each of the two calprotectin assessments and clinical examinations had similar range. Calprotectin correlated well with clinical examinations, with at least as high correlations as CRP and ESR. The present study showed similar results for the two analytical methods, supporting the robustness of calprotectin analyses, and suggest calprotectin in plasma to be included in the assessments offered by clinical routine laboratories.

Correlation between ultrasonographic scores and American college of rheumatology recommended rheumatoid arthritis disease activity measures: a systematic review and network meta-analysis

BACKGROUND

To validate and facilitate ultrasound examinations on rheumatoid arthritis (RA) disease activity measurements in routine clinical practice.

METHODS

A systematic review and network meta-analysis (NMA) of ultrasound examinations on joints and its correlation with clinical RA disease activity was performed. PubMed, Embase and Cochrane library were searched for literatures published up to May 01st 2021. Bayesian random-effect NMA was conducted to pool the correlations of ultrasonographic assessment scores with composite RA disease activity measurements.

RESULTS

Fifteen studies evaluating twelve different existing ultrasonographic measurements on joints evaluation for RA disease activity scoring were included in this NMA. For comparisons with clinical disease activity index and simplified disease activity index, synovitis gray scale ultrasound 7 joints (GSUS7) demonstrated modest correlation of 0.30[- 0.74, 1.23] and 0.46[- 0.45, 1.15] respectively, followed by synovitis power Doppler ultrasound 7 joints (PDUS7) (0.25[- 0.57, 1.14], 0.31[- 0.46, 1.24]) and power Doppler ultrasound 12 joints (PDUS12) (0.23[- 1.36, 0.83], 0.25[- 1.18, 0.88]). As for disease activity score using 28 joint counts, PDUS12 showed the biggest correlation of 0.53[- 0.09, 1.11], followed by ultrasound 7 joints (US7) (0.50[0.06, 0.93]), PDUS7 (0.49[- 0.24, 1.12]), power Doppler ultrasound 6 joints (PDUS6) (0.42[- 0.29, 1.21]), synovitis PDUS7 (0.47[- 0.09, 1.27]) and synovitis GSUS7 (0.40[0.01, 0.86]).

CONCLUSION

Comparative validity was observed on fewer joints ultrasonic evaluation for RA disease activity measurements, such as synovitis GSUS7 and synovitis PDUS7. Ultrasonographic measurements can be complementary for clinical RA disease activity measures with clinical efficiency, and technical guidelines were in need for clinical routine practice.

Controversies in rheumatology: Ultrasound for monitoring of RA - do we need it?

Clinical joint examination is the cornerstone for evaluation of patients with rheumatoid arthritis (RA). However, since large discrepancies have been shown even between experienced rheumatologists in evaluation of joint inflammation, and tender joints may have limited value in reflecting inflammation, ultrasound has in the last decennials been introduced in the clinical assessments of RA patients. Ultrasound has high accordance with other imaging modalities and enables detection of clinically difficult pathologies and contributes to assessments of joints difficult to evaluate clinically. However, there is no general agreement on the optimal use of ultrasound in rheumatology and the prevalence of machines as well as the level of experience is highly different across the countries. In addition, standardized use of ultrasound in treat-to-target follow-up of RA patients was found not to have any added value. Thus, how to use ultrasound in monitoring of RA patients is open for debate. The present article will discuss the pros and cons for using ultrasound in the clinical setting.

Serum etanercept concentrations in relation to disease activity and treatment response assessed by ultrasound, biomarkers and clinical disease activity scores: results from a prospective observational study of patients with rheumatoid arthritis

Objectives

To identify the therapeutic range for etanercept and to assess the incidence of anti-etanercept antibody formation.

Methods

Associations between etanercept serum concentration and disease activity as well as treatment response were examined in a longitudinal observational study of rheumatoid arthritis patients starting etanercept. Disease activity was assessed by ultrasound (grey scale and power Doppler), 28-joint Disease Activity Score (DAS28), Simplified Disease Activity Index, plasma calprotectin and C reactive protein. Etanercept concentration and anti-etanercept antibodies were analysed using automated in-house fluorescence assays.

Results

A total of 89 patients were included, whereof 66% were biological disease-modifying antirheumatic drug (DMARD) naïve and 91% used concomitant synthetic DMARD. At 3 months, the median etanercept concentration was 1.8 (IQR 1.1–2.5) mg/L. Longitudinal associations were found between etanercept concentration and disease activity assessed by plasma calprotectin, C reactive protein and DAS28, but not between etanercept concentration and improvement in disease activity by any of the parameters at 3, 6 or 12 months of treatment. Etanercept concentrations were not significantly different among patients who achieved response or remission, compared with non-response or non-remission. Hence, no therapeutic range could be identified. None of the patients developed anti-etanercept antibodies.

Conclusion

Despite the use of sensitive and objective markers of inflammation, a therapeutic range could not be identified for etanercept. Hence, this study suggests that proactive therapeutic drug monitoring is unlikely to benefit rheumatoid arthritis patients treated with etanercept, but a potential benefit in certain clinical situations cannot be excluded.

Fatigue Is Not Associated With Objective Assessments of Inflammation During Tocilizumab Treatment of Patients With Rheumatoid Arthritis

Objective

In patients with rheumatoid arthritis (RA), the relation between fatigue and disease activity is not established, and our objective was to explore in post hoc analyses the associations between fatigue and subjective as well as objective assessments of inflammation during follow‐up of patients with RA initiating biologic treatment.

Methods

In a Nordic multicenter study, patients with RA starting tocilizumab were examined for fatigue (Functional Assessment of Chronic Illness Therapy–Fatigue sum score) as well as patient‐reported outcome measures (PROMs) (patient's global disease activity, joint pain, and Health Assessment Questionnaire Disability Index), clinical examinations (examiner's global disease activity, 28 tender/swollen joint counts), laboratory variables (erythrocyte sedimentation rate, C‐reactive protein), and ultrasound assessments (semiquantitative scoring [0‐3]) of gray scale and Doppler of 36 joints and 4 tendons) at baseline and 4, 12, and 24 weeks. The associations were explored by using nonparametric tests, including the Wilcoxon rank test, the Mann–Whitney U test, Spearman correlations, and a linear regression and linear mixed model.

Results

One hundred ten patients were included (83% female, mean [SD] age 55.6 [12.1] years, mean [SD] RA duration 8.7 [9.5] years, 81% anti–cyclic citrullinated peptide positive). Fatigue, PROMs, and clinical, laboratory, and ultrasound variables all decreased significantly during follow‐up, already at 4 weeks (P < 0.001). Fatigue was both cross‐sectionally and longitudinally associated with PROMs, whereas there were no or low associations with clinical, laboratory, or ultrasound assessments of inflammation. Baseline fatigue was predictive of PROMs at 12 and 24 weeks (P < 0.05 and P < 0.001, respectively) but not of any objective assessments.

Conclusion

Fatigue was primarily associated with subjective assessments of disease activity. Thus, the present study supports fatigue to reflect other aspects of RA disease activity than inflammation.

Doppler ultrasound impacts response to intravenous tocilizumab in rheumatoid arthritis patients

OBJECTIVE

Within rheumatoid arthritis (RA) patients treated with intravenous tocilizumab (IV-TCZ), it is unclear if power Doppler ultrasonography (PDUS) can predict future clinical response. This study sought to determine if baseline PDUS or its early changes can predict 12-week and 24-week disease activity outcomes, and quantify the need for dose escalation (4 to 8 mg/kg).

METHODS

Fifty-four RA patients starting IV-TCZ were evaluated at baseline, 4, 6, 12, 16, and 24 weeks using 34-joint PDUS (US34-PDUS), clinical disease activity index (CDAI), 28-joint disease activity score using erythrocyte sedimentation rate (DAS28-ESR), ACR 20/50/70, health assessment questionnaire-disability index (HAQ-DI), and PDUS 20/50/70, a novel measure. Logistic regression models evaluated the predictive utility of US34-PDUS of DAS28-ESR response after adjusting for covariates.

RESULTS

Ninety-four percent of patients required dose escalation to 8 mg/kg. US34-PDUS, CDAI, and DAS28-ESR improved significantly over 24 weeks (p < 0.001). Baseline PDUS and 12-week PDUS change correlated with CDAI at 24 weeks (p < 0.05). Logistic regression demonstrated baseline US34-PDUS was independently associated with DAS28-ESR ≥ 1.2 response, even after adjusting for baseline DAS28-ESR (p = 0.03). CDAI, DAS28-ESR, and their components increased across PDUS 20/50/70 categories; however, HAQ-DI did not.

CONCLUSION

RA patients treated with IV-TCZ for 24 weeks demonstrated significant improvement, and baseline/early changes in PDUS were predictive of later clinical response. The PDUS 20/50/70 measure is a novel metric of response. This study suggests that IV-TCZ 4 mg/kg may not be sufficient to attain low RA disease activity at 12 weeks, in RA patients with moderate to severe disease (DAS28 ≥ 4.4 and US34-PDUS ≥ 10).

TRIAL REGISTRATION

ClinicalTrials.gov NCT01717859 Key Points • Over 90% of RA patients with baseline DAS28-ESR ≥ 4.4 and PDUS34 ≥ 10 required intravenous tocilizumab dose escalation from 4 to 8 mg/kg at 12 weeks. • Reduction in power Doppler ultrasonography (US34-PDUS) scores correlate with DAS28-ESR and CDAI over 24 weeks in rheumatoid arthritis patients with moderate to severe disease activity. • Baseline US34-PDUS predicts future improvements in clinical disease activity outcomes, independent of baseline DAS28-ESR. • Clinical response measures, DAS28-ESR and CDAI, improved across US34-PDUS 20/50/70 categories, while patient-reported outcomes did not.

Rheumatoid arthritis patients with predominantly tender joints rarely achieve clinical remission despite being in ultrasound remission

Objectives

Given that subjective variables might reduce remission by composite DAS (CDAS), the main objectives were to explore whether RA patients with mainly tender vs mainly swollen joints had differences in patient-reported outcome measures (PROMs), clinical or US assessments or in achieving remission defined by CDAS or US.

Methods

In a Nordic multicentre study, RA patients initiating tocilizumab were assessed by PROMs, clinical, laboratory and US assessments (36 joints and 4 tendons) at baseline, 4, 12 and 24 weeks. Remission was defined according to clinical disease activity index (CDAI)/Boolean or no Doppler activity present. Tender-swollen joint differences (TSJDs) were calculated. Statistics exploring changes over time/differences between groups included Wilcoxon, Mann-Whitney, Kruskal-Wallis and Spearman tests.

Results

One hundred and ten patients were included [mean (s.d.) age 55.6 (12.1) years, RA duration 8.7 (9.5) years]. All PROMs, clinical, laboratory and US scores decreased during follow-up (P < 0.001). During follow-up, tender joint counts were correlated primarily with PROMs [r = 0.24-0.56 (P < 0.05-0.001)] and swollen joint counts with US synovitis scores [r = 0.33-0.72 (P < 0.05-0.001)]. At 24 weeks, patients with TSJD > 0 had higher PROMs and CDAI (P < 0.05-0.001) but lower US synovitis scores (P < 0.05). Remission by CDAI/Boolean was seen in 26-34% and by Doppler 53%, but only 2-3% of patients with TSJD > 0 achieved CDAI/Boolean remission.

Conclusion

Patients with more tender than swollen joints scored higher on subjective assessments but had less US synovitis. They seldom achieved CDAS remission despite many being in Doppler remission. If patients with predominantly tender joints do not reach CDAS remission, objective assessments of inflammation should be performed.

Trial registration

ClinicalTrials.gov, https://clinicaltrials.gov/, NCT02046616.

Pain: A Review of Interleukin-6 and Its Roles in the Pain of Rheumatoid Arthritis

Pain is a major and common symptom reported as a top priority in patients with rheumatoid arthritis (RA). Intuitively, RA-related pain is often considered to be a natural consequence of peripheral inflammation, so treatment of RA is expected to manage pain concurrently as part of inflammation control. However, pain in patients with RA can be poorly correlated with objective measures of inflammation, for example, in patients who are otherwise in remission. Joint damage appears to account for only a fraction of this residual pain. Emerging evidence suggests that alteration of peripheral and central pain processing contributes to RA-related pain; this is parallel to, but somewhat independent of, joint inflammation. Interleukin (IL)-6 is a proinflammatory cytokine that contributes to the pathogenesis of RA. It exerts systemic effects via signaling through soluble forms of the IL-6 receptor (“trans-signaling”). Evidence from preclinical studies demonstrates that intra-articular IL-6 can produce long-lasting peripheral sensitization to mechanical stimulation and suggests an important role for IL-6 in central pain sensitization. This may be partly explained by its ability to activate neurons through trans-signaling, affecting nociceptive plasticity and nerve fiber regrowth. Local activity at neuron endings may culminate in altered pain processing in the central nervous system because of persistent signaling from sensitized peripheral neurons. Peripheral and central sensitization can promote the development of chronic pain, which can have a significant impact on patients’ health and quality of life. A proportion of pain in RA may be more appropriately managed as an entity separate from inflammation. Both the peripheral and central nervous systems should be recognized as important potential systems targeted by RA. The substantial burden of RA-related chronic pain suggests that pain should be a key focus in RA management and should be assessed and addressed early and separately from the inflammatory component.