PT  - JOURNAL ARTICLE
AU  - YAN-FENG HOU
AU  - GUANG-ZHI SUN
AU  - HONG-SHENG SUN
AU  - WEN-PING PAN
AU  - WEN-BO LIU
AU  - CHENG-QI ZHANG
TI  - Diagnostic Value of Anti-Sa and Anticitrullinated Protein Antibodies in Rheumatoid Arthritis
AID  - 10.3899/jrheum.111523
DP  - 2012 Aug 01
TA  - The Journal of Rheumatology
PG  - 1506--1508
VI  - 39
IP  - 8
4099  - http://www.jrheum.org/content/39/8/1506.short
4100  - http://www.jrheum.org/content/39/8/1506.full
SO  - J Rheumatol2012 Aug 01; 39
AB  - Objective. To determine the diagnostic value of anticitrullinated protein antibodies, second generation (ACPA2), by electrochemiluminescent immunoassay (ECLIA) and anti-Sa by ELISA in a large cohort of Chinese patients with early rheumatoid arthritis (RA). Methods. One hundred ninety-eight patients with early RA (< 1 yr duration), 112 with other rheumatic diseases, and 60 healthy individuals were studied. Results. The combination of anti-Sa and ACPA2 positivity had the highest specificity (99.42%), but it had a rather low sensitivity (50.0%). The combination of anti-rheumatoid factor (RF) and ACPA2 showed the highest sensitivity (80.30%), with specificity of 95.93%. The mean titer of ACPA2 and RF was significantly higher in the anti-Sa-positive group compared to the negative group (ACPA2, p <0.001; RF, p = 0.007). The 28-joint Disease Activity Scores of the anti-Sa-positive patients were significantly higher than those of the negative group (p = 0.01). The anti-Sa had no significant correlation with age, sex, antinuclear antibody, SSA, SSB, erythrocyte sedimentation rate, C-reactive protein, immunoglobulin A (IgA), IgG, IgM, C3, and C4. Conclusion. Our results come from a newly developed ECLIA for detection of ACPA2 and the anti-Sa-antibody-based ELISA system. The combined application of ACPA2 and anti-Sa tests can improve the laboratory diagnosis of early RA.