Characteristics of secondary Sjögren’s syndrome by connective tissue disease in comparison with primary Sjögren’s syndrome.
| Characteristic | RA, n = 20 | p* | SLE, n = 15 | p* | Scleroderma, n = 30 | p* |
|---|---|---|---|---|---|---|
| Age, yrs ± SD | 52.5 ± 15 | 0.3 | 44.9 ± | 0.003 | 56.5 ± 13 | 0.8 |
| Female, n (%) | 20 (100) | 1 | 15 (100) | 1 | 30 (100) | 0.43 |
| Ocular symptoms, n (%) | 17 (85) | 0.3 | 13 (86) | 0.6 | 25 (83) | 0.2 |
| Oral symptoms, n (%) | 16 (80) | 0.02 | 15 (100) | 1 | 24 (80) | 0.01 |
| Parotid enlargement, n (%) | 0 | < 0.001 | 1 (6) | 0.001 | 5 (16) | 0.001 |
| Schirmer-positive, n (%) | 17 (85) | 0.6 | 12 (80) | 0.3 | 24 (80) | 0.3 |
| Wafer test, n (%) | 18 (90) | 0.6 | 13 (86) | 0.3 | 28 (93) | 1 |
| Fluorescein stain test, n (%) | 11 (55) | 0.9 | 10 (66) | 0.4 | 18 (60) | 0.6 |
| NSWSF, ml/5 min, median (range) | 0.3 (0–2.7) | 0.8 | 0.5 (0–1.6) | 0.8 | 0.25 (0–2.5) | 0.2 |
| NSWSF ≤ 0.1 ml/min, n (%) | 16 (80) | 0.7 | 13 (86) | 0.4 | 27 (90) | 0.08 |
| Anti–Ro/La antibodies, n (%) | 4 (20) | < 0.001 | 6 (40) | 0.003 | 14 (46) | 0.001 |
| Anti-Ro, U/ml, median (range) | 3.4 (1.2–139) | < 0.001 | 3.9 (1.6–36,908) | 0.02 | 4.6 (1.9–4840) | < 0.001 |
| Anti-La, U/ml, median (range) | 4.5 (2.1–70.5) | < 0.001 | 5.4 (2.1–146,300) | 0.27 | 4.6 (2.8–148) | < 0.001 |
| Nonerosive arthritis, n (%) | 0 | 0.003 | 14 (70) | < 0.001 | 7 (23) | 0.3 |
| Myositis, n (%) | 0 | — | 0 | — | 2 (6) | 0.04 |
| Neuropathy, n (%) | 0 | 0.04 | 3 (20) | 1 | 2 (6) | 0.19 |
| Renal involvement, n (%) | 0 | 0.5 | 4 (27) | 0.04 | 1 (3) | 1 |
| Raynaud phenomenon, n (%) | 0 | 0.09 | 4 (27) | 0.4 | 25 (83) | < 0.001 |
| Vasculitis, n (%) | 1 (5) | 0.4 | 1 (6) | 0.4 | 0 | 1 |
| Adenopathy, n (%) | 0 | 0.17 | 0 | 0.3 | 2 (6) | 0.7 |
| Immunosuppressant use, n (%) | 20 (100) | < 0.001 | 9 (60) | 0.02 | 8 (26) | 1 |
| Prednisone use, n (%) | 2 (1) | 0.1 | 5 (33) | 0.002 | 7 (23) | 0.004 |
NSWSF: nonstimulated whole salivary flow rate.
↵* For comparison with primary Sjögren’s syndrome.