Introduction
Methods
Patients and control subjects
Autoantibody measurements
Statistics
Results
Diagnostic impact of RA-associated autoantibodies
Sensitivity (%) | AUC | 95% CI | IgA RF, p value | IgG RF, p value | IgM RF, p value | |
---|---|---|---|---|---|---|
Anti-CCP2 | 52 | 0.82 | 0.78 to 0.86 | 0.11 | 0.63 | 0.07 |
IgA RF | 56 | 0.85 | 0.82 to 0.89 | – | 0.042 | 0.0007 |
IgG RF | 49 | 0.80 | 0.76 to 0.85 | – | – | 0.24 |
IgM RF | 52 | 0.77 | 0.73 to 0.82 | – | – | – |
Prognostic impact of RA-associated autoantibodies
All patients (total number) or median (range): total number | Anti-CCP2 positive (total number) | Anti-CCP2 negative (total number) |
p
| IgA RF positive (total number) | IgA RF negative (total number) |
p
| IgG RF positive (total number) | IgG RF negative (total number) |
p
| IgM RF positive (total number) | IgM RF negative (total number) |
p
| |
---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Females/total number of patients | 251 (281) | 129 (137) | 105 (125) |
0.008
| 130 (139) | 90 (109) |
0.007
| 114(124) | 111 (129) | 0.14 | 119 (131) | 102(119) | 0.2 |
Age at diagnosis (years) | 49 (18–80): (281) | 48 (137) | 50 (125) |
0.019
| 49 (139) | 50 (114) | 0.33 | 47 (124) | 51 (133) |
0.003
| 48 (131) | 50 (123) | 0.17 |
Disease duration (months) | 36 (1–420): (275) | 60 (134) | 48 (124) | 0.25 | 60 (137) | 48 (108) | 0.43 | 60 (122) | 48 (128) | 0.38 | 60 (127) | 48 (119) | 0.17 |
Age at disease onset (years) | 43 (17.4–75): (273) | 41.5(133) | 46 (123) |
0.003
| 42 (137) | 45.7(106) |
0.014
| 40 (122) | 48 (127) |
< 0.0001
| 42 (127) | 45.3 (118) |
0.029
|
Number of swollen and/or tender joints | 6 (1–27): (259) | 7 (133) | 5 (122) | 0.83 | 6 (137) | 5 (105) | 0.64 | 10 (121) | 5 (128) |
0.028
| 6 (127) | 5 (116) | 0.9 |
Erosions (X-ray) | 34 (61) | 16 (34) | 12 (27) | 0.8 | 19 (33) | 15 (26) | 0.99 | 16 (34) | 12 (27) | 0.83 | 15 (33) | 12 (27) | 0.93 |
Osteopenia (X-ray) | 43 (61) | 19 (43) | 9 (18) | 0.68 | 24 (41) | 10 (18) | 0.83 | 18 (43) | 10 (18) | 0.33 | 20 (43) | 7 (17) | 0.71 |
ZD | 68 (252) | 42 (132) | 25 (118) | 0.058 | 41 (135) | 22 (102) | 0.13 | 39 (117) | 28 (125) | 0.057 | 37 (126) | 27(114) | 0.32 |
UD | 81 (252) | 50 (132) | 31(118) | 0.05 | 50(135) | 27(102) | 0.09 | 45(117) | 36(125) | 0.11 | 49(126) | 28(114) |
0.018
|
SND | 38 (252) | 26(132) | 11 (118) |
0.021
| 26 (135) | 8 (102) |
0.013
| 28 (117) | 9 (125) |
0.0003
| 23 (126) | 12 (114) | 0.09 |
BD | 25 (252) | 17 (132) | 8 (118) | 0.11 | 18 (135) | 6 (102) | 0.059 | 17 (117) | 6 (125) |
0.009
| 16 (126) | 8 (114) | 0.14 |
Any hand deformity (ZD, UD, SWN, BTN) | 107 (252) | 64 (132) | 42 (118) |
0.039
| 63 (135) | 39 (102) | 0.19 | 58 (117) | 46 (125) |
0.044
| 62 (126) | 41 (114) |
0.039
|
Any finger deformity (ZD, SWN, BTN) | 82 (252) | 52 (132) | 29 (118) |
0.012
| 50 (135) | 27 (102) | 0.88 | 47 (117) | 32 (125) |
0.016
| 47 (126) | 31 (114) | 0.09 |
ESR (mm/1 h) | 56 (10–140): (170) | 65 (89) | 55 (76) | 0.32 | 61.5 (92) | 55 (65) | 0.21 | 65 (85) | 55 (77) | 0.23 | 55 (83) | 56 (74) | 0.98 |
Hb (mg/dl) | 12 (8–16.7): (178) | 12 (87) | 12 (88) | 0.67 | 12 (93) | 12 (75) | 0.44 | 12 (79) | 12.05 (94) | 0.19 | 12 (85) | 12 (83) | 0.54 |
WBC × 1000/μl | 5.8 (3–20): (175) | 5.9 (86) | 5.6 (87) | 0.34 | 5.8 (93) | 5.7 (73) | 0.74 | 5.9 (78) | 5.5 (93) | 0.12 | 5.7 (84) | 6 (80) | 0.64 |
Mean age of arthritis onset for antibody negative patients (n) | Mean age of arthritis onset for antibody-positive patients (n) | p Value (t test) | Median age of arthritis onset for antibody-negative patients (n) | Median age of arthritis onset for antibody-positive patients (n) | p Value (MW test) | |
---|---|---|---|---|---|---|
IgG RF positive vs. negative, all patients (n = 253) | 46.7 (127) | 39.7 (122) |
< 0.0001
| 48 (127) | 40 (122) |
< 0.0001
|
IgG RF positive vs. negative, anti-CCP2-positive patients only (n = 132) | 44.1 (38) | 39.6 (91) | 0.061 | 45 (38) | 40 (91) |
0.041
|
IgG RF positive vs. negative, anti-CCP2-negative patients only (n = 121) | 47.8 (89) | 40.1 (31) |
0.011
| 48 (89) | 36 (31) |
0.002
|
Anti-CCP2 positive vs. negative, all patients (n = 253) | 45.8 (120) | 40.9 (129) |
0.0019
| 46 (120) | 42 (129) |
0.0041
|
Anti-CCP2 positive vs. negative, IgG RF-positive patients only (n = 124) | 40.1 (31) | 39.6 (91) | 0.85 | 36 (31) | 40 (91) | 0.62 |
Anti-CCP2 positive vs. negative, IgG RF-negative patients only (n = 129) | 47.8 (89) | 44.1 (38) | 0.13 | 48 (89) | 45 (38) | 0.13 |