Diagnostic Signification of Antiperinuclear Factor(APF) in Rheumatoid Arthritis

Choi, Il Yong; Lee, Kwang Hyun; Kim, Shin Kyoo; Lim, Byeong Goo

Abstract

In systemic rheumatic disease, marker antibodies such as anti-Sm, anti Scl-70 and anti Jo-1 are helpful in the diagnosis of disease, but in rheumatoid arthritis, the diagnosis is difficult due to the low sensitivity and specificity of the rheumatoid factor(RF). So, a new maker antibody with high sensitivity and specificity was needed. Recently, the antiperi- nuclear factor(APF) has gained particular attention. The results of the APF and RF test in 165 patients with rheumatoid arthritis, 77 patients with osteoarthritis, and 109 normal healthy persons, which were taken between January, 1994 through December 1994 were as follows; 1. The sensitivity, specificity, and predictive value of positivity of the RF test in patients with rheumatoid arthritis were 58.2%, 93.5%, and 95.0%, and that of the APF test were 72.1%, 94.6% and 92.2%, respectively. 2. The sensitivity, specificity and predictive value of positivity when combining the APF with the RF were 83.0%, 85.7%, and 92.6%, respectively. 3. The disease status of the patients correlated with intensity of the APF test, that is, the more severe the disease status, the higher intensity. In conclusion, the APF was useful in the diagnosis of rheumatoid arthritis, and may be used as an indicator of disease status. When combining test the APF with RF, the incidence of sero-negative rheumatoid arthritis decreased.