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Hammer HB, Pedersen SL, Jonsson MK, Mathsson-Alm L, Gehring I, Sexton J, Haavardsholm EA, Askling J. 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. Scand J Clin Lab Invest 2023; 83:330-335. [PMID: 37343245 DOI: 10.1080/00365513.2023.2225223] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2023] [Revised: 05/01/2023] [Accepted: 06/11/2023] [Indexed: 06/23/2023]
Abstract
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.
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Affiliation(s)
- Hilde Berner Hammer
- Center for treatment of Rheumatic and Musculoskeletal Diseases (REMEDY), Diakonhjemmet Hospital, Oslo, Norway
- Faculty of Medicine, University of Oslo, Oslo, Norway
| | | | - Maria K Jonsson
- Broegelmann Research Laboratory, Department of Clinical Science, University of Bergen, Bergen, Norway
- Department of Paediatrics, Haukeland University Hospital, Bergen, Norway
| | | | | | - Joe Sexton
- Center for treatment of Rheumatic and Musculoskeletal Diseases (REMEDY), Diakonhjemmet Hospital, Oslo, Norway
| | - Espen A Haavardsholm
- Center for treatment of Rheumatic and Musculoskeletal Diseases (REMEDY), Diakonhjemmet Hospital, Oslo, Norway
- Faculty of Medicine, University of Oslo, Oslo, Norway
| | - Johan Askling
- Department of Medicine, Karolinska Institutet, Solna, Sweden
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Zhu J, Wang J, Dong Y, Song Y, Huang P. Correlation between ultrasonographic scores and American college of rheumatology recommended rheumatoid arthritis disease activity measures: a systematic review and network meta-analysis. J Ultrasound 2023; 26:39-47. [PMID: 36633809 PMCID: PMC10063773 DOI: 10.1007/s40477-022-00749-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Accepted: 10/19/2022] [Indexed: 01/13/2023] Open
Abstract
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.
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Affiliation(s)
- Jianing Zhu
- Department of Ultrasound in Medicine, The Second Affiliated Hospital of Zhejiang University School of Medicine, Zhejiang University, Hangzhou, 310009 China
- Research Center of Ultrasound in Medicine and Biomedical Engineering, The Second Affiliated Hospital of Zhejiang University School of Medicine, Zhejiang University, Hangzhou, 310009 China
| | - Jing Wang
- Department of Ultrasound in Medicine, The Second Affiliated Hospital of Zhejiang University School of Medicine, Zhejiang University, Hangzhou, 310009 China
- Research Center of Ultrasound in Medicine and Biomedical Engineering, The Second Affiliated Hospital of Zhejiang University School of Medicine, Zhejiang University, Hangzhou, 310009 China
| | - Yiping Dong
- Department of Ultrasound in Medicine, The Second Affiliated Hospital of Zhejiang University School of Medicine, Zhejiang University, Hangzhou, 310009 China
- Research Center of Ultrasound in Medicine and Biomedical Engineering, The Second Affiliated Hospital of Zhejiang University School of Medicine, Zhejiang University, Hangzhou, 310009 China
| | - Yue Song
- Department of Ultrasound in Medicine, The Second Affiliated Hospital of Zhejiang University School of Medicine, Zhejiang University, Hangzhou, 310009 China
- Research Center of Ultrasound in Medicine and Biomedical Engineering, The Second Affiliated Hospital of Zhejiang University School of Medicine, Zhejiang University, Hangzhou, 310009 China
| | - Pintong Huang
- Department of Ultrasound in Medicine, The Second Affiliated Hospital of Zhejiang University School of Medicine, Zhejiang University, Hangzhou, 310009 China
- Research Center of Ultrasound in Medicine and Biomedical Engineering, The Second Affiliated Hospital of Zhejiang University School of Medicine, Zhejiang University, Hangzhou, 310009 China
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Hammer HB, Caporali R. Controversies in rheumatology: Ultrasound for monitoring of RA - do we need it? Rheumatology (Oxford) 2022; 61:4245-4251. [PMID: 35394009 DOI: 10.1093/rheumatology/keac228] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Revised: 03/10/2022] [Accepted: 04/03/2022] [Indexed: 11/14/2022] Open
Abstract
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.
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Affiliation(s)
- Hilde Berner Hammer
- Department of Rheumatology, Diakonhjemmet Hospital, Oslo, Norway.,Faculty of medicine, University of Oslo, Norway
| | - Roberto Caporali
- Department of Clinical Sciences and Community Health, University of Milan, Milan, Italy.,Department of Rheumatology and Medical Sciences, ASST Pini-CTO, Milan, Italy
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Gehin JE, Syversen SW, Warren DJ, Goll GL, Sexton J, Bolstad N, Hammer HB. 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. RMD Open 2021; 7:rmdopen-2021-001985. [PMID: 34911811 PMCID: PMC8679136 DOI: 10.1136/rmdopen-2021-001985] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Accepted: 11/16/2021] [Indexed: 12/21/2022] Open
Abstract
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.
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Affiliation(s)
- Johanna Elin Gehin
- Department of Medical Biochemistry, Oslo University Hospital, Oslo, Norway .,Faculty of Medicine, University of Oslo, Oslo, Norway
| | | | - David John Warren
- Department of Medical Biochemistry, Oslo University Hospital, Oslo, Norway
| | - Guro Løvik Goll
- Division of Rheumatology and Research, Diakonhjemmet Hospital, Oslo, Norway
| | - Joseph Sexton
- Division of Rheumatology and Research, Diakonhjemmet Hospital, Oslo, Norway
| | - Nils Bolstad
- Department of Medical Biochemistry, Oslo University Hospital, Oslo, Norway
| | - Hilde Berner Hammer
- Faculty of Medicine, University of Oslo, Oslo, Norway.,Division of Rheumatology and Research, Diakonhjemmet Hospital, Oslo, Norway
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Hammer HB, Agular B, Terslev L. Fatigue Is Not Associated With Objective Assessments of Inflammation During Tocilizumab Treatment of Patients With Rheumatoid Arthritis. ACR Open Rheumatol 2021; 4:202-208. [PMID: 34806341 PMCID: PMC8916557 DOI: 10.1002/acr2.11379] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2021] [Accepted: 10/15/2021] [Indexed: 11/06/2022] Open
Abstract
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.
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Morris NT, Brook J, Ben-Artzi A, Martin W, Kermani TA, Avedikian-Tatosyan L, Karpouzas G, Nagam H, Navarro G, Choi S, Taylor MB, Elashoff D, Kaeley GS, Ranganath VK. Doppler ultrasound impacts response to intravenous tocilizumab in rheumatoid arthritis patients. Clin Rheumatol 2021; 40:5055-5065. [PMID: 34269927 DOI: 10.1007/s10067-021-05857-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Revised: 06/29/2021] [Accepted: 07/01/2021] [Indexed: 11/28/2022]
Abstract
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.
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Affiliation(s)
- Nicolette T Morris
- Division of Rheumatology, David Geffen School of Medicine, University of California, Los Angeles, 1000 Veteran Avenue, Box 32-59, Los Angeles, CA, 90024, USA
| | - Jenny Brook
- Department of Medicine Statistics Core, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Ami Ben-Artzi
- Division of Rheumatology, Cedars Sinai Medical Center, Los Angeles, CA, USA
| | - William Martin
- Division of Rheumatology, David Geffen School of Medicine, University of California, Los Angeles, 1000 Veteran Avenue, Box 32-59, Los Angeles, CA, 90024, USA
| | - Tanaz A Kermani
- Division of Rheumatology, David Geffen School of Medicine, University of California, Los Angeles, 1000 Veteran Avenue, Box 32-59, Los Angeles, CA, 90024, USA
| | | | - George Karpouzas
- Division of Rheumatology, Harbor-UCLA Medical Center, Los Angeles, CA, USA
| | - Himakar Nagam
- University of California, Irvine, School of Medicine, Irvine, CA, USA
| | - Geraldine Navarro
- Division of Rheumatology, David Geffen School of Medicine, University of California, Los Angeles, 1000 Veteran Avenue, Box 32-59, Los Angeles, CA, 90024, USA
| | - Soo Choi
- Division of Rheumatology, School of Medicine, University of California, San Diego, San Diego, CA, USA
| | - Mihaela B Taylor
- Division of Rheumatology, David Geffen School of Medicine, University of California, Los Angeles, 1000 Veteran Avenue, Box 32-59, Los Angeles, CA, 90024, USA
| | - David Elashoff
- Department of Medicine Statistics Core, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Gurjit S Kaeley
- Division of Rheumatology and Clinical Immunology, College of Medicine, University of Florida, Jacksonville, Jacksonville, FL, USA
| | - Veena K Ranganath
- Division of Rheumatology, David Geffen School of Medicine, University of California, Los Angeles, 1000 Veteran Avenue, Box 32-59, Los Angeles, CA, 90024, USA.
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Hammer HB, Jensen Hansen IM, Järvinen P, Leirisalo-Repo M, Ziegelasch M, Agular B, Terslev L. Rheumatoid arthritis patients with predominantly tender joints rarely achieve clinical remission despite being in ultrasound remission. Rheumatol Adv Pract 2021; 5:rkab030. [PMID: 34131623 PMCID: PMC8195913 DOI: 10.1093/rap/rkab030] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Accepted: 02/17/2021] [Indexed: 01/04/2023] Open
Abstract
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.
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Affiliation(s)
- Hilde Berner Hammer
- Department of Rheumatology, Diakonhjemmet Hospital.,Faculty of Medicine, University of Oslo, Oslo, Norway
| | | | - Pentti Järvinen
- Department of Rheumatology, Kiljava Medical Research, Hyvinkää
| | - Marjatta Leirisalo-Repo
- Department of Rheumatology, Helsinki University Hospital, University of Helsinki, Helsinki, Finland
| | | | | | - Lene Terslev
- Centre for Rheumatology and Spine Diseases, Rigshospitalet Glostrup, Copenhagen, Denmark
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Sebba A. Pain: A Review of Interleukin-6 and Its Roles in the Pain of Rheumatoid Arthritis. Open Access Rheumatol 2021; 13:31-43. [PMID: 33707975 PMCID: PMC7943546 DOI: 10.2147/oarrr.s291388] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2020] [Accepted: 01/22/2021] [Indexed: 12/29/2022] Open
Abstract
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.
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Affiliation(s)
- Anthony Sebba
- Division of Rheumatology, University of South Florida, Tampa, FL, USA
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