Relationship of soluble interleukin-2-receptor and interleukin-6 with class-specific rheumatoid factors during low-dose methotrexate treatment in rheumatoid arthritis

Rev Rhum Engl Ed. 1997 Feb;64(2):89-94.


We studied the effect of a 6-month treatment with low-dose MTX in 22 RA patients, with the purpose of investigating the relationship of sIL-2R and IL-6 serum changes with those of class specific RFs. The patients with RA had higher serum levels of sIL-2R (p < 0.0001), and IL-6 (p < 0.0005) than healthy volunteers. We found that the levels of IgM-RF (p < 0.0004), IgA-RF (p < 0.002), IgG-RF (p < 0.025), sIL-2R (p < 0.017) and IL-6 (p < 0.044) as well as the main clinical and laboratory variables, were significantly reduced in RA patients treated with low dose MTX for six months. The changes from baseline of IgM-RF correlated with those of IL-6 (p < 0.023), suggesting that MTX may affect IL-6 and IgM-RF production in part by a common mechanism. In conclusion our results show that there is a relationship between IL-6 and IgM-RF changes from baseline during MTX therapy, but the hypothesis of a link between the effects of this drug on cytokine network and RF production needs further investigation.

Publication types

  • Clinical Trial

MeSH terms

  • Adult
  • Aged
  • Antirheumatic Agents / administration & dosage*
  • Antirheumatic Agents / therapeutic use
  • Arthritis, Rheumatoid / blood*
  • Arthritis, Rheumatoid / drug therapy*
  • Female
  • Humans
  • Immunoglobulin A / blood
  • Immunoglobulin G / blood
  • Immunoglobulin M / blood
  • Interleukin-6 / blood*
  • Male
  • Methotrexate / administration & dosage*
  • Methotrexate / therapeutic use
  • Middle Aged
  • Receptors, Interleukin-2 / blood*
  • Rheumatoid Factor / blood*
  • Solubility


  • Antirheumatic Agents
  • Immunoglobulin A
  • Immunoglobulin G
  • Immunoglobulin M
  • Interleukin-6
  • Receptors, Interleukin-2
  • Rheumatoid Factor
  • Methotrexate