Table 1 Average levels of antibodies to arginine (A)- and citrulline (C)-containing telopeptides of type I and II collagens, the corresponding C/A ratios and anti-CCP antibodies in future patients with rheumatoid arthritis (RA) and their controls
Baseline variableRF-positive RARF-negative RARA in total
Case mean (SD)Control mean (SD)pCase mean (SD)Control mean (SD)pCase mean (SD)Control mean (SD)p
No. of females (%)58 (65.2)27 (77.1)85 (68.5)253 (68.8)
Age (years)45.6 (13.1)45.6 (13.0)0.4145.6 (10.2)45.6 (10.2)0.5245.6 (12.3)45.6 (12.3)0.55
A (I) (unit)10.4 (6.6)9.8 (3.4)0.4311.3 (5.7)12.1 (1.0)0.6810.7 (6.3)10.4 (6.0)0.77
C (I) (unit)19.3 (42.1)8.8 (2.8)0.039.7 (4.2)9.4 (7.8)0.8716.6 (36.0)8.9 (4.7)0.03
C/A (I) (ratio)1.9 (4.4)0.9 (0.1)0.040.9 (0.3)0.9 (0.1)0.421.7 (3.8)0.9 (0.1)0.04
A (II) (unit)10.4 (5.3)10.0 (2.9)0.4710.1 (3.4)10.5 (6.9)0.7710.3 (4.9)10.1 (4.4)0.71
C (II) (unit)15.2 (28.0)9.0 (2.5)0.049.3 (2.9)9.5 (6.9)0.8913.6 (23.9)9.1 (4.2)0.04
C/A (II) (ratio)1.6 (3.3)0.9 (0.1)0.060.9 (0.1)0.9 (0.1)0.451.4 (2.8)0.9 (0.1)0.06
Anti-CCP (unit)219.1 (489.1)16.0 (1.5)0.000254.7 (141.7)16.5 (3.5)0.12172.7 (426.8)16.1 (2.3)0.00008