PT - JOURNAL ARTICLE AU - D van Zeben AU - J M Hazes AU - A H Zwinderman AU - A Cats AU - E A van der Voort AU - F C Breedveld TI - Clinical significance of rheumatoid factors in early rheumatoid arthritis: results of a follow up study. AID - 10.1136/ard.51.9.1029 DP - 1992 Sep 01 TA - Annals of the Rheumatic Diseases PG - 1029--1035 VI - 51 IP - 9 4099 - http://ard.bmj.com/content/51/9/1029.short 4100 - http://ard.bmj.com/content/51/9/1029.full SO - Ann Rheum Dis1992 Sep 01; 51 AB - Serum rheumatoid factors (RF) were measured yearly in 135 women with rheumatoid arthritis by the Waaler-Rose and latex fixation tests and IgM, IgA, and IgG RF were measured by enzyme linked immunosorbent assays (ELISAs). The patients were followed up from an early phase of the disease for a mean duration of six years. Patients with a persistently positive RF test, irrespective of the type of test used, had more radiological abnormalities, more disease activity, worse functional ability, more extra-articular manifestations, and needed more treatment with second line drugs than patients with persistently negative or variably positive and negative test results during the follow up. Increased RF levels, especially a high level of IgA RF within three years of the onset of symptoms, was prognostic for a more severe disease outcome six years after the onset of symptoms.