All patients n=150* | No arthritis during follow-up (n=119) | Arthritis during follow-up (n=30) | |
---|---|---|---|
Clinical characteristics | |||
Age in years, mean (SD) | 43.2 (12.9) | 43.1 (12.8) | 43.9 (13.7) |
Female, n (%) | 109 (72.7) | 87 (73.1) | 22 (73.3) |
Family history positive for RA, n (%) | 51 (34.0) | 38 (31.9) | 12 (40.0) |
Symptom duration† in weeks, med (IQR) (n=141) | 18 (9–30) | 18 (10–31) | 17 (8–30) |
Gradual symptom onset (>1 week) (n=149) | 31 (20.8) | 95 (80.5) | 22 (73.3) |
Localisation of initial symptoms (n=149) | |||
Small joints, n (%) | 127 (85.2) | 107 (90.7) | 19 (63.3) |
Small and large joints, n (%) | 15 (10.1) | 6 (5.1) | 9 (30.0) |
Large joints, n (%) | 7 (4.7) | 5 (4.2) | 2 (6.7) |
Localisation of initial symptoms | |||
Upper extremities, n (%) | 108 (72.0) | 88 (73.9) | 20 (66.7) |
Upper and lower extremities, n (%) | 28 (18.7) | 21 (17.6) | 7 (23.3) |
Lower extremities, n (%) | 14 (9.3) | 10 (8.4) | 3 (10.0) |
Symmetrical localisation of initial symptoms, n (%) (n=149) | 110 (73.8) | 91 (77.1) | 19 (63.3) |
Morning stiffness ≥60 min at inclusion, n (%) (n=144) | 53 (36.8) | 38 (33.6) | 15 (50.0) |
68-TJC, med (IQR) (n=146) | 5 (3–10) | 6 (3–10) | 5 (3–7.5) |
BMI in kg/m2, mean (SD) (n=149) | 26.6 (5.2) | 26.5 (5.0) | 26.7 (6.1) |
Present smoker, n (%) | 38 (25.3) | 29 (24.4) | 9 (30.0) |
CRP level in mg/L, med (IQR) | 0 (0–4.6) | 0 (0–4) | 1.5 (0–14.5) |
CRP level >5 mg/L, n (%) | 31 (20.7) | 21 (17.6) | 10 (33.3) |
RF-positive (>3.5 IU/mL), n (%) | 33 (22.0) | 15 (12.6) | 18 (60.0) |
ACPA-positive (>7 U/mL), n (%) | 24 (16.0) | 8 (6.7) | 16 (53.3) |
MRI characteristics MRI categorised into positive or negative for any subclinical inflammation and for specific inflammatory features | |||
---|---|---|---|
All patients n=144* | No arthritis during follow-up (n=116) | Arthritis during follow-up (n=27) | |
Presence of any MRI-detected inflammation, n (%) | 66 (45.8) | 44 (37.9) | 22 (81.5) |
Only synovitis, n (%) | 9 (6.3) | 9 (7.8) | 0 (0) |
Only BME, n (%) | 12 (8.3) | 10 (8.6) | 2 (7.4) |
Only tenosynovitis, n (%) | 15 (10.4) | 7 (6.0) | 8 (29.6) |
Synovitis and BME, n (%) | 3 (2.1) | 2 (1.7) | 1 (3.7) |
Synovitis and tenosynovitis, n (%) | 18 (12.5) | 12 (10.3) | 6 (22.2) |
BME and tenosynovitis, n (%) | 2 (1.4) | 1 (0.9) | 1 (3.7) |
Synovitis, BME and tenosynovitis, n (%) | 7 (4.9) | 3 (2.6) | 4 (14.8) |
Presence of MRI-detected synovitis, n (%) | 37 (25.7) | 26 (22.4) | 11 (40.7) |
Presence of MRI-detected BME, n (%) | 24 (16.7) | 16 (13.8) | 8 (29.6) |
Presence of MRI-detected tenosynovitis, n (%) | 42 (29.2) | 23 (19.8) | 19 (70.4) |
38 patients (25.3%) were positive for ACPA and/or RF.
The median total RAMRIS inflammation score was 2 (IQR 1–5); the total RAMRIS scores for synovitis, BME and tenosynovitis were 1 (IQR 0–2.5), 0.5 (IQR 0–1.5) and 0 (IQR 0–1.5), respectively. Characteristics were not compared between the groups of patients that have and have not developed clinical arthritis during follow-up because the patients have different follow-up durations.
*One patient that developed gout during follow-up was excluded from further analyses as the patient did not belong to the non-arthritis group and the diagnosis was outside the spectrum of chronic arthritis/RA.
†Duration since the start of symptoms.
ACPA, anticitrullinated peptide antibodies; BME, bone marrow oedema; BMI, body mass index; med, median; CRP, C reactive protein; n, number; RA, rheumatoid arthritis; RAMRIS, RA MRI scoring system; RF, rheumatoid factor; TJC, tender joint count.