IgM, IgA, and IgG rheumatoid factors in early rheumatoid arthritis predictive of radiological progression?

Scand J Rheumatol. 1995;24(3):146-53. doi: 10.3109/03009749509099303.


The significance of IgM, IgA and IgG rheumatoid factors (RF) for the prediction of radiological progression, and as process variables during follow-up, was evaluated in a three-year prospective study of 149 patients with early rheumatoid arthritis (symptoms < 1 year at study entry). The occurrence of IgA-RF and IgG-RF at study entry without simultaneous occurrence of IgM-RF, and the seroconversion from RF-negative at entry to RF-positive during follow-up appeared to be unusual. A significant correlation was found between each of the RF-isotype levels at entry and radiological progression after three years. However, no significant prognostic value of IgA-RF and IgG-RF could be demonstrated if analysed in combination with IgM-RF, initial disease activity (as measured by C-reactive protein level), initial radiologic score, HLA-DR4 and HLA-DR2. Although IgM-RF levels generally reflected the course of disease activity and did so better than IgA-RF and IgG-RF levels, their clinical significance as process variables appeared to be limited compared to C-reactive protein.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Arthritis, Rheumatoid / diagnostic imaging*
  • Arthritis, Rheumatoid / immunology*
  • Enzyme-Linked Immunosorbent Assay
  • Female
  • Follow-Up Studies
  • Humans
  • Immunoglobulin A / blood
  • Immunoglobulin G / blood
  • Immunoglobulin M / blood
  • Male
  • Middle Aged
  • Predictive Value of Tests
  • Prognosis
  • Prospective Studies
  • Radiography
  • Regression Analysis
  • Rheumatoid Factor / blood*


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