Table 4.
Comparison of clinical characteristics between pSS-ILD group and sSS-ILD group.
| Total (n = 316) | pSS-ILD (n = 240) | sSS-ILD (n = 76) | p | |
|---|---|---|---|---|
| Age at diagnosis (years) | 58 (23–84) | 59 (23–83) | 56.5 (35–84) | .281 |
| Duration of disease (years) | 2.0 (0.9–4.8) | 1.90 (0.9–2.8) | 2.05 (1.5–4.8) | .481 |
| Male | 40 (12.7%) | 32 (13.3%) | 8 (10.5%) | .521 |
| Sicca symptoms | 208 (65.8%) | 155 (64.6%) | 53 (69.7%) | .409 |
| Rampant caries | 64 (20.3%) | 46 (19.2%) | 18 (23.7%) | .393 |
| Arthralgia | 106 (33.5%) | 73 (30.4%) | 33 (43.4%) | .036 |
| Purpura | 10 (3.2%) | 7 (2.9%) | 3 (3.9%) | .942 |
| Raynaud's phenomenon | 59 (18.7%) | 41 (17.1%) | 18 (23.7%) | .198 |
| Respiratory symptoms | 212 (67.1%) | 153 (63.8%) | 59 (77.6%) | .025 |
| Digestive symptoms | 40 (12.7%) | 28 (11.7%) | 12 (15.8%) | .346 |
| Laboratory results | ||||
| Anti-SSA body | 245 (77.5%) | 180 (75.0%) | 65 (85.5%) | .055 |
| Anti-SSB body | 99 (31.3%) | 74 (30.8%) | 25 (32.9%) | .736 |
| Anti-Ro-52 body | 235 (74.4%) | 172 (71.7%) | 63 (82.9%) | .051 |
| Antinuclear antibodies | 221 (69.9%) | 170 (70.8%) | 51 (76.1%) | .394 |
| Rheumatoid factor | 92 (29.1%) | 35 (14.6%) | 57 (75.0%) | <.001 |
| Proteinuriaa | 80 (25.3%) | 46 (19.2%) | 34 (44.7%) | <.001 |
| Hypercreatinaemia, >133.0 µmol/L | 12 (3.8%) | 5 (2.1%) | 7 (9.2%) | .013 |
| Hyperglobulinaemia, >40.0 g/L | 74 (23.4%) | 51 (21.3%) | 23 (30.3%) | .106 |
| C3 (g/L) | 0.86 (0.08–1.7) | 0.88 (0.22–1.7) | 0.80 (0.08–1.42) | .013 |
| Albumin (g/L) | 34.8 (15.7–50.8) | 34.8 (15.7–50.8) | 34.6 (20.8–46.5) | .575 |
| Elevated ALT, >42 U/L | 16 (5.1%) | 10 (4.2%) | 6 (7.9%) | .229 |
| Elevated AST, >37 U/L | 15 (4.7%) | 8 (3.3%) | 7 (9.2%) | .057 |
| ESR (mm/h) | 41.4 (1–140) | 39.5 (1–140) | 53 (7–140) | .003 |
| CRP (mg/L) | 5.99 (0.08–165) | 5.87 (0.08–165) | 6.09 (0.08–99.7) | .459 |
| Haemoglobin (g/L) | 117 (57–200) | 118 (60–200) | 114 (57–171) | .072 |
| Leukocytes (×109/L) | 6.03 (1.56–20.01) | 6.43 (1.93–20.01) | 5.5 (1.56–17.71) | .024 |
| Lymphocytes (×109/L) | 1.37 (0.22–4.32) | 1.47 (0.33–4.32) | 1.19 (0.22–4.04) | .009 |
| Platelets (×109/L) | 191 (2–736) | 196 (3–526) | 179 (2–736) | .341 |
| Image abnormalities | ||||
| Irregular linear opacities | 135 (42.7%) | 105 (43.8%) | 30 (39.5%) | .511 |
| Grid shadow | 97 (30.7%) | 69 (28.8%) | 28 (36.8%) | .183 |
| Pleural thickening | 90 (28.5%) | 70 (29.2%) | 20 (26.3%) | .631 |
| Septal thickening | 84 (26.6%) | 64 (26.7%) | 20 (26.3%) | .952 |
| Ground-glass opacities | 77 (24.4%) | 58 (24.2%) | 19 (25.0%) | .883 |
| Honeycombing | 48 (15.2%) | 34 (14.2%) | 14 (18.4%) | .368 |
| HRCT patterns | ||||
| NSIP | 178 (56.3%) | 138 (57.5%) | 40 (52.6%) | .456 |
| UIP | 32 (10.1%) | 25 (10.4%) | 7 (9.2%) | .761 |
| COP | 14 (4.4%) | 9 (3.8%) | 5 (6.6%) | .337 |
| LIP | 10 (3.2%) | 7 (2.9%) | 3 (3.9%) | .708 |
| Mixed multiple patterns | 82 (25.9%) | 61 (25.4%) | 21 (27.6%) | .701 |
| Lung functions | ||||
| FVC (%Pred) | 78.5 (43–120) | 79.1 (43–113) | 78.5 (48–120) | .764 |
| FEV1/FVC | 83 (70–102) | 84 (70–102) | 82.5 (78–99) | .892 |
| DLCO (%Pred) | 69 (42–88) | 73 (43–88) | 65 (42–87) | .035 |
pSS-ILD: primary Sjögren’s syndrome patients with interstitial lung disease; sSS-ILD: secondary Sjögren’s syndrome patients with interstitial lung disease; C3: complements 3; ALT: alanine aminotransferase; AST: aspartate aminotransferase; ESR: erythrocyte sedimentation rate; CRP: C-reactive protein; HRCT: high-resolution CT; NSIP: non-specific interstitial pneumonitis; UIP: usual interstitial pneumonia; COP: cryptogenic organizing pneumonia; LIP: lymphocytic interstitial pneumonia.
Values are presented as number (%) or median (range).
a
The proteinuria is defined as the amount of protein in the urine beyond 150 mg/24 h.