Disease characteristics and demographics, signs, and symptoms evaluated by the ESSPRI and the SGRQ; results of the PFT and radiographic findings in the 27 never-smoking and the 24 ever-smoking patients with pSS. Clinically significant reversibility was defined as FEV1 improvement > 12% and > 200 ml. Radiographic signs of ILD represent traction bronchiectasis, ground glass attenuation, or honeycombing. Values are mean ± SD or % with abnormal findings unless otherwise specified.
| Characteristics | Never-smoking pSS, n = 27 | Ever-smoking pSS, n = 24 | p, Never- vs Ever-smoking pSS |
|---|---|---|---|
| Age, yrs | 58 ± 14 | 63 ± 10 | 0.227 |
| Disease duration, yrs | 19 ± 14 | 15 ± 10 | 0.321 |
| Anti-SSA antibody seropositives | 74 | 83 | 0.508 |
| Anti-SSB antibody seropositives | 33 | 63 | 0.037 |
| IgG, g/l | 13.5 ± 5.1 | 14.2 ± 5.2 | 0.624 |
| C3, g/l | 1.02 ± 0.26 | 1.04 ± 0.25 | 0.604 |
| C4, g/l | 0.17 ± 0.07 | 0.19 ± 0.07 | 0.395 |
| Lower lip biopsy, focus score ≥ 1 | 85 | 58 | 0.058 |
| ESSDAI total score | 7 ± 7 | 7 ± 5 | 0.499 |
| ESSPRI total score | 6 ± 2 | 6 ± 2 | 0.681 |
| SGRQ total score | 20 ± 16 | 24 ± 17 | 0.365 |
| PFT results | |||
| VC, l | 3.5 ± 0.9 | 3.1 ± 0.7 | 0.034 |
| TLC, l | 5.8 ± 1.2 | 5.4 ± 0.8 | 0.643 |
| RV, l | 2.2 ± 0.5 | 2.3 ± 0.4 | 0.389 |
| FEV1, l | 2.5 ± 0.6 | 2.1 ± 0.6 | 0.009 |
| FEV1/VC ratio | 0.72 ± 0.08 | 0.67 ± 0.08 | 0.026 |
| DLCO, mmol/min kPa | 7.1 ± 1.9 | 5.7 ± 1.6 | 0.013 |
| COPD, n (%) | 8 (30) | 13 (54) | 0.076 |
| Clinically significant reversibility, n (%) | 0 (0) | 2 (8) | 0.216 |
| Radiographic findings | |||
| Radiographic abnormalities, any of the below | 60 | 71 | 0.388 |
| Air trapping | 37 | 33 | 0.782 |
| Reticular pattern | 22 | 46 | 0.074 |
| Central bronchiectasis | 19 | 33 | 0.226 |
| Traction bronchiectasis | 15 | 0 | 0.113 |
| Cysts | 26 | 33 | 0.562 |
| Emphysema | 8 | 21 | 0.232 |
| Ground glass attenuation | 15 | 8 | 0.671 |
| Honeycombing | 0 | 0 | NA |
| ILD signs | 26 | 8 | 0.147 |
ESSPRI: EULAR Sjögren Patient Reported Index; SGRQ: St. George’s Respiratory Questionnaire; PFT: pulmonary function tests; pSS: primary Sjögren syndrome; FEV1: forced expiratory volume in 1 s; ILD: interstitial lung disease; IgG: immunoglobulin G; C3: complement factor 3; C4: complement factor 4; ESSDAI: EULAR Sjögren Disease Activity Index; VC: vital capacity; TLC: total lung capacity; RV: residual volume; COPD: chronic obstructive pulmonary disease; NA: not assessed; EULAR: European League Against Rheumatism.