Antiperinuclear factors are present in polyarthritis before ACR criteria for rheumatoid arthritis are fulfilled

Abstract

Objective: To show that antiperinuclear factor (APF) may be useful for the diagnosis of rheumatoid arthritis at a time when the American College of Rheumatology (ACR) criteria are not yet fulfilled. Methods: Testing for APF-IgG (1:100 threshold) and rheumatoid factors (RF) was done in 60 patients with polyarthritis of recent onset during a three year follow up. Results: At the end of the study, 21/40 rheumatoid arthritis were positive for RF and 31/40 for APF, including 18/40 cases (45%) in which ACR criteria were not yet fulfilled. Conclusions: APF are useful in the diagnosis of early rheumatoid arthritis.