One year treatment with low dose methotrexate in rheumatoid arthritis: effect on class specific rheumatoid factors

Clin Rheumatol. 1993 Sep;12(3):357-60. doi: 10.1007/BF02231579.


We evaluated the effect of a one-year treatment of low dose methotrexate (MTX) on class specific rheumatoid factors in 27 patients with rheumatoid arthritis (RA). Enzyme-linked immunosorbent assay (ELISA) showed after 6 and 12 months a significant reduction of IgM-RF, IgA-RF and IgG-RF levels from the baseline values. During MTX treatment, changes of each RF isotype were not correlated with any other isotype and its corresponding immunoglobulin changes. Moreover, immunological changes were not related to the improvement of clinical parameters. Our results showed that low dose MTX can specifically affect levels of RF isotypes, which are involved in the immune pathogenesis of RA.

MeSH terms

  • Adult
  • Aged
  • Arthritis, Rheumatoid / drug therapy*
  • Arthritis, Rheumatoid / immunology*
  • Arthritis, Rheumatoid / physiopathology
  • Drug Administration Schedule
  • Female
  • Humans
  • Immunoglobulin A / analysis
  • Immunoglobulin G / analysis
  • Immunoglobulin M / analysis
  • Male
  • Methotrexate / administration & dosage*
  • Methotrexate / therapeutic use
  • Middle Aged
  • Rheumatoid Factor / analysis*
  • Severity of Illness Index


  • Immunoglobulin A
  • Immunoglobulin G
  • Immunoglobulin M
  • Rheumatoid Factor
  • Methotrexate