Table 1.
Clinical characteristics of patients with primary Sjögren’s syndrome
| All patients | Anti-SSA/SSB positive | Anti-SSA/SSB negative | P-valuea | ||
|---|---|---|---|---|---|
| (n = 982) | (n = 717) | (n = 265) | |||
| Females, % | 93.1 | 92.1 | 95.8 | 0.037 | |
| Age, mean (s.d.), years | |||||
| At symptom onset | 46.2 (14.7) | 45.1 (15.1) | 49.0 (13.3) | 5.0 × 10−4 | |
| At diagnosis | 52.6 (13.7) | 51.3 (14.0) | 56.1 (12.1) | <1 × 10−4 | |
| Laboratory findings, % | |||||
| ANA | 74.8 | 85.8 | 44.9 | <1 × 10−4 | |
| Anti-SSA | 70.5 | 96.5 | 0.0 | ||
| Anti-SSB | 42.8 | 58.8 | 0.0 | ||
| Anti-SSA and/or anti-SSB | 73.0 | 100 | 0.0 | ||
| Anaemia Hb <120 g/l | 22.3 | 26.5 | 10.9 | <1 × 10−4 | |
| Leukopenia <4.0 × 109/l | 30.5 | 36.8 | 13.9 | <1 × 10−4 | |
| Thrombocytopenia <100 × 109/l | 3.7 | 4.3 | 2.0 | 0.15 | |
| P-IgG >15 g/l | 48.8 | 59.6 | 14.5 | <1 × 10−4 | |
| Minor salivary gland biopsies | |||||
| Focus score, mean (s.d.) | 2.4 (2.4) | 2.5 (2.6) | 2.2 (1.9) | 0.04 | |
| Germinal centre formations, % | 21.8 | 25.5 | 14.2 | 0.013 | |
| Extraglandular manifestations, % | |||||
| Raynaud | 29.1 | 29.1 | 29.0 | 0.98 | |
| Arthritis | 19.4 | 20.6 | 16.1 | 0.12 | |
| Purpura | 10.7 | 13.8 | 2.8 | <1 × 10−4 | |
| Major salivary gland swelling | 30.0 | 32.8 | 22.6 | 3.9 × 10−3 | |
| Lymphadenopathy | 9.1 | 10.5 | 5.3 | 0.014 | |
| Hypothyreoidism | 22.5 | 21.3 | 25.4 | 0.21 | |
| Myositis | 0.9 | 1.1 | 0.5 | 0.38 | |
| Interstitial lung disease | 6.8 | 7.6 | 4.3 | 0.12 | |
| Interstitial nephritis | 3.0 | 3.3 | 2.2 | 0.46 | |
| Lymphoma | 4.6 | 5.5 | 2.3 | 0.036 | |
| Age at lymphoma onset, mean (s.d.), years | 57.1 (13.7) | 54.5 (12.4) | 73.8 (9.0) | 8.8 × 10−4 | |
a
P-value for the comparison between anti-SSA/SSB (anti-SSA and/or anti-SSB) positive and anti-SSA/SSB negative patients. Continuous variables compared with Student’s unpaired t-test, frequencies with χ2 test.