Serum interleukin 6 levels in rheumatoid arthritis: correlations with clinical and laboratory indices of disease activity
Open accessAbstract
In rheumatoid synovium interleukin 6 (IL-6) is the most abundantly expressed cytokine. Increased serum levels have been previously reported in patients with rheumatoid arthritis (RA). In this study serum IL-6 levels were measured in a well defined cohort using a bioassay (B9 cells) and levels were correlated with conventional clinical and laboratory indices of disease activity. Levels were significantly higher in serum from patients with RA (median 55 IU/ml; interquartile range 28-139) compared with serum from disease (median 7 IU/ml; 1-23) and normal controls (median 10 IU/ml; 7-12). No difference was observed between men and women. Levels did not correlate with disease duration. Significant associations were observed between IL-6 and C reactive protein and between the Ritchie articular index and duration of morning stiffness. No other correlations were observed. The value of these findings in the monitoring of RA and as an indicator of response to second line treatment needs to be established.
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Serum IL-6 levels in rheumatoid arthritis patients correlate with clinical and laboratory indices of the disease.
“and serum IL-6 levels in RA patients correlate with clinical and laboratory indices of the disease (234).”
From IL-6 in inflammation, autoimmunity and cancer (2021) · cites this paper as [234]
The Abstract reports a significant correlation between serum IL-6 and C-reactive protein, a laboratory index. It does not report a significant correlation between IL-6 and a clinical index: the other association named is between the Ritchie articular index and morning stiffness, and it says no other correlations were observed. (LLM, conf=0.86)
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“In addition, it was found that synovial fluid obtained from patients with RA contains high amounts of IL-6 (44, 45), and serum IL-6 levels in RA patients correlate with clinical and laboratory indices of the disease (234).”
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- Authors
- Madhok, R., Crilly, A., Watson, J., & Capell, H. A.
- Affiliations
- Western Infirmary (GB)
- Venue
- Annals of the Rheumatic Diseases
- Publisher
- Elsevier BV
- Published
- 1993-03
- Volume
- 52
- Issue
- 3
- Pages
- 232-234
- ISSN
- 0003-4967 (ISSN-L)
- PMC
- PMC1005024
- OpenAlex
- W2012942026
- Cited by
- 340
- References
- 0
- Citations by year
- 2026: 3 · 2025: 8 · 2024: 9 · 2023: 10 · 2022: 15 · 2021: 13 · 2020: 9 · 2019: 10 · 2018: 14 · 2017: 16 · 2016: 17 · 2015: 18 · 2014: 14 · 2013: 9 · 2012: 17
- FWCI
- 5.49
- Type
- journal article
- Language
- en
- Open access
- bronze
- doi.org
- Locations
- Annals of the Rheumatic Diseases (publishedVersion)
- PubMed Central (publishedVersion)
- Europe PMC (PubMed Central) (publishedVersion)
- PubMed (publishedVersion)
- HighWire Press Open Archive (submittedVersion)
- Topics
- Health Sciences › Medicine › Rheumatology › Rheumatoid Arthritis Research and Therapies
- Health Sciences › Medicine › Hematology › Autoimmune and Inflammatory Disorders Research
- Health Sciences › Medicine › Oncology › Cytokine Signaling Pathways and Interactions
- Keywords
- interleukin-6, rheumatoid arthritis, serum cytokines, disease activity, C-reactive protein, Ritchie articular index, morning stiffness, disease duration, synovial cytokines, treatment response monitoring
- MeSH terms
- Aged, Arthritis, Rheumatoid, C-Reactive Protein, Female, Humans, Male, Middle Aged, Osteoarthritis, Severity of Illness Index, Cohort Studies, Interleukin-6
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