Clinical characteristics of ACPA-negative and ACPA-positive patients in the symptomatic phase preceding clinical arthritis
| All patients | |||
| ACPA negative (n=37) | ACPA positive (n=30) | p Value | |
| Symptoms at symptom onset | |||
| Symptom onset | |||
| Acute (<1 week) | 8 (22) | 8 (27) | 0.53 |
| Gradual | 26 (70) | 16 (55) | |
| Intermittent | 3 (8) | 5 (17) | |
| Symptoms started with* | |||
| Pain | 34 (92) | 29 (97) | 0.41 |
| Stiffness | 26 (70) | 17 (57) | 0.25 |
| Loss of function | 16 (43) | 10 (33) | 0.41 |
| Localisation affected joints | |||
| Small joints hand/feet | 27 (73) | 21 (70) | 0.18 |
| Large joints | 5 (14) | 1 (3) | |
| Both | 5 (14) | 8 (27) | |
| Localisation affected joints | |||
| Upper extremities | 29 (78) | 15 (50) | 0.014 |
| Lower extremities | 5 (14) | 4 (13) | |
| Both | 3 (8) | 11 (37) | |
| Localisation affected joints | |||
| Symmetric | 22 (60) | 22 (73) | 0.23 |
| Presentation with arthralgia | |||
| Family history of RA | 13 (35) | 11 (37) | 0.90 |
| Symptoms determining inclusion in the cohort | |||
| Inflammatory type of symptoms | 14 (39) | 18 (60) | 0.089 |
| Morning stiffness ≥60 min | 9 (25) | 2 (7) | |
| Both | 13 (36) | 10 (33) | |
| Physical examination | |||
| 68 TJC, mean±SD | 9±8 | 5±3 | 0.007† |
| Difficulties making a fist | 16 (43) | 3 (11) | 0.004† |
| Squeeze test | |||
| Positive for both MTP and MCP joints | 8 (22) | 4 (14) | 0.48 |
| Positive for MCP joints only | 11 (31) | 7 (24) | |
| Positive for MTP joints only | 4 (11) | 2 (7) | |
| Negative for both | 13 (36) | 16 (55) | |
| HAQ score, mean±SD | 0.8±0.6 | 0.7±0.6 | 0.57 |
All values are indicated as n (%), unless indicated otherwise.
Missings were as follows: symptom onset (1), symptoms determining inclusion in the cohort (1), difficulties making a fist (1), squeeze test (2), HAQ score (2).
*Multiple answers could be given, so the percentages can add up to >100%.
†Significant after correction for multiple testing.
ACPA, anticitrullinated protein antibodies; HAQ, health assessment questionnaire; MCP, metacarpophalangeal; MTP, metatarsophalangeal; RA, rheumatoid arthritis; TJC, tender joint count.