Table 1

Baseline characteristics

GroupsERALRAHCP values
Patients, n (%)20 (36)20 (36)16 (28)
Age64.5 (8.9)60.8 (8.5)43.8 (14.1)<0.01
Female, n (%)15 (75)12 (60)12 (71)0.58
Current/former/never smoker32%/32%/3616%/26%/58%0.37
Blood sample results
 CRP, mg/L20.4 (19.8)15.9 (18.9)1.8 (2.3)<0.01
 Monocytes, 109/L0.62 (0.3)0.65 (0.2)0.6 (0.2)0.73
 RF or CCP-positive, n (%)14 (64)15 (71)0 (0)<0.01
Pulmonary function test
 FEV1 (% predicted)111.5 (25)102.7 (17)0.21
 FVC (% predicted)122.5 (23)108.8 (16)0.04
 TLC (% predicted)112 (18)104.5 (17)0.30
 DLCOc (% predicted)90.8 (17)92.0 (10)0.79
Rheumatoid arthritis characteristics
 Disease duration (years)0.06 (0.14)13.58 (8.46)<0.01
 DAS28CRP5.45 (1.30)4.25 (0.85)<0.01
EULAR disease activity
 Remission, n (%)0 (0)0 (0)
 Low activity, n (%)0 (0)0 (0)
 Moderate activity, n (%)6 (30)18 (90)
 High activity, n (%)14 (70)2 (10)<0.01
 Erosive disease*3 (15.8)10 (50)0.02
Treatment
 Naive/Not in treatment, n (%)20 (100.0)2 (10.0)
 cDMARD, n (%)0 (0.0)17 (45.0)
 bDMARD, n (%)0 (0.0)2 (10.0)<0.01
 Peroral steroid, n (%)0 (0.0)1 (5.0)0.31
  • *Defined as erosions on hands or feet X-ray compatible with RA damage.

  • bDMARD, biological disease-modifying antirheumatic drug; CCP, cyclic citrullinated peptide; cDMARD, conventional disease-modifying antirheumatic drug; CRP, C-reactive protein; DAS28CRP, Disease Activity Score 28 joints combined with CRP value; DLCOc, diffusion capacity of the lung for carbon monoxide corrected for haemoglobin level; ERA, early untreated rheumatoid arthritis; FEV1, forced expiratory volume in 1 s; FVC, forced ventilatory capacity; HC, healthy control; LRA, long-standing rheumatoid arthritis; RF, rheumatoid factor; TLC, total lung capacity.