Interleukin-6, soluble interleukin-2-receptor and soluble interleukin-6-receptor in sera of patients with rheumatoid arthritis: influences of disease activity and drug therapy

Eur J Med Res. 1997 Sep 29;2(9):401-6.


Cytokines and their receptors play a fundamental role in the development and maintenance of the inflammatory process in rheumatoid arthritis (RA). The purpose of this study was to evaluate sIL-2R, sIL-6R and IL-6 levels in the sera of 48 RA patients and to correlate them with disease activity, indicators of inflammatory process as ESR and CRP, and drug treatment modalities. IL-6 and sIL-2R levels were positively correlated with disease activity, ESR and CRP. No correlation between sIL-6R levels and these markers were observed. Our results suggest that different drug therapies have a decisive influence on the levels of selected cytokines. All investigated disease-modifying antirheumatic drugs (DMARDs) were able to reduce the IL-6 level significantly. Non-immunosuppressive DMARDs decreased the amount of circulating sIL-2R more than immunosuppressive drugs. Treatment with methotrexate resulted in a significant reduction of circulating levels of sIL-6R compared to azathioprine therapy. Under low dose glucocorticoid therapy, significantly lower levels of sIL-6R were found than in patients without glucocorticoids. In conclusion, the results provide some arguments in favour of combined drug therapies, which might possibly enhance the effectiveness of RA therapy.

MeSH terms

  • Adult
  • Aged
  • Antirheumatic Agents / administration & dosage
  • Antirheumatic Agents / therapeutic use
  • Arthritis, Rheumatoid / drug therapy*
  • Arthritis, Rheumatoid / immunology*
  • Blood Sedimentation
  • C-Reactive Protein / metabolism
  • Drug Interactions
  • Drug Therapy, Combination
  • Female
  • Glucocorticoids / administration & dosage
  • Glucocorticoids / therapeutic use
  • Humans
  • Immunosuppressive Agents / administration & dosage
  • Immunosuppressive Agents / therapeutic use
  • Interleukin-6 / blood*
  • Male
  • Middle Aged
  • Receptors, Interleukin-2 / blood*
  • Receptors, Interleukin-6 / blood*
  • Solubility


  • Antirheumatic Agents
  • Glucocorticoids
  • Immunosuppressive Agents
  • Interleukin-6
  • Receptors, Interleukin-2
  • Receptors, Interleukin-6
  • C-Reactive Protein