Demographic characteristic of patients with early RA (symptom duration less than 1 year) included in the study
| Demographics and disease characteristics | All patients | HRCT airway abnormalities | HRCT parenchymal abnormalities | ||||
|---|---|---|---|---|---|---|---|
| No | Yes | P value | No | Yes | P value | ||
| Number | 106 | 38 | 68 | 48 | 58 | ||
| Age, (mean years ± SD) | 57.5±14.1 | 52.9±16.0 | 60.0±12.3 | 0.02 | 53.2±15.6 | 61.0±11.7 | 0.005 |
| Women (n (%)) | 73 (68.9) | 23 (60.5) | 50 (73.5) | 0.17 | 36 (75.0) | 37 (63.8) | 0.22 |
| Ever smokers (n (%)) | 77 (72.6) | 30 (78.9) | 47 (69.1) | 0.28 | 30 (62.5) | 47 (81.0) | 0.03 |
| Current smokers (n (%)) | 31 (29.2) | 12 (31.6) | 19 (27.9) | 0.69 | 11 (22.9) | 20 (34.5) | 0.19 |
| Pack-years (median (IQR)) | 11.5 (0–24.1) | 9.1 (0.6–23.1) | 13.0 (0–24.1) | 0.74 | 3.0 (0–16.5) | 17.3 (4.0–35.5) | 0.0005 |
| Anti-CCP2 IgG-positive (n (%)) | 71 (67.0) | 25 (65.8) | 46 (67.6) | 0.85 | 26 (54.2) | 45 (77.6) | 0.01 |
| RF-positive (n (%)) | 73 (68.9) | 25 (65.8) | 48 (70.6) | 0.61 | 29 (60.4) | 44 (75.9) | 0.09 |
| ACPA and RF-negative (n (%)) | 26 (24.5) | 10 (26.3) | 16 (23.5) | 0.75 | 16 (33.3) | 10 (17.2) | 0.06 |
| Any HLA-DR SE (n (%)) | 73 (68.9) | 24 (63.2) | 49 (72.1) | 0.34 | 32 (66.7) | 41 (70.7) | 0.66 |
| Bone erosions (n (%)) | 23 (21.7) | 10 (26.3) | 13 (19.1) | 0.39 | 10 (20.8) | 13 (22.4) | 0.84 |
| Disease activity | |||||||
| DAS28 (mean±SD) | 5.5±1.1 | 5.3±0.9 | 5.6±1.2 | 0.19 | 5.5±1.0 | 5.5±1.2 | 0.96 |
| SJC (median (IQR)) | 9 (6–13) | 9.5 (6–12.25) | 9 (6–13.75) | 0.72 | 9.5 (7–14) | 9 (6–13) | 0.88 |
| TJC (median (IQR)) | 10 (6–13) | 9 (4–13) | 10 (6–14) | 0.25 | 10 (6–13) | 9 (4.75–14.25) | 0.96 |
| CRP (median (IQR)) | 10 (4–24) | 9.5 (3.5–18.25) | 10 (4.25–26.5) | 0.28 | 10 (4–24) | 9.5 (4–22.75) | 0.72 |
| ESR (median (IQR)) | 27.5 (17–46) | 26 (14.5–42) | 28 (18–52) | 0.10 | 24.5 (15.25–43.25) | 32 (18.75–48) | 0.55 |
| Pulmonary function test (median (IQR)) | |||||||
| VC (% of predicted) | 107 (95–119) | 112 (100–122.5) | 105 (92.25–115) | 0.11 | 108 (101.25–119) | 106 (93–120) | 0.29 |
| FVC (% of predicted) | 108 (95.5–117) | 112 (103.5–125.5) | 105 (91–114) | 0.01 | 109.5 (99.75–117.25) | 105 (91–117) | 0.17 |
| FEV1 (% of predicted) | 99 (85–110) | 100 (89.5–112) | 95 (81–109.75) | 0.04 | 103 (90.25–111.25) | 94 (81–104) | 0.006 |
| FEV1/FVC | 0.76 (0.65–0.80) | 0.74 (0.65–0.79) | 0.76 (0.65–0.81) | 0.46 | 0.77 (0.69–0.82) | 0.73 (0.63–0.77) | 0.003 |
| DLCO (% of predicted) | 78 (70–88) | 77 (66.5–86.5) | 79 (72–89.75) | 0.74 | 78.5 (71–85.25) | 78 (67–90) | 0.82 |
The data has been further stratified for the presence and absence of HRCT airway and parenchymal abnormalities. The bolded values represent statistically significant p values (p<0.05).
ACPA, anticitrullinated protein/peptide antibodies; CRP, C reactive protein; DAS28, Disease Activity Score in 28 joints; DLCO, diffusing capacity for carbon monoxide; ESR, erythrocyte sedimentation rate; FEV1, forced expiratory volume in 1s; FVC, forced vital capacity; HLA-DR SE, shared epitope risk allele; HRCT, high-resolution CT; SJC, swollen joint count; TJC, tender joint count; VC, vital capacity.