Table 2.
Demographic and clinical characteristics of patients according to autoimmune disease status.
| Primary SS (n = 11) | Secondary SS (n = 7) | Other autoimmune disease (n = 21) | No known autoimmune disease (n = 97) | p value | |
|---|---|---|---|---|---|
| Demographics | |||||
| Age (years), mean (SD) | 58 (8.4) | 61 (15.5) | 58 (15.3) | 60 (10.9) | 0.82 |
| Female, n (%) | 11 (100%) | 7 (100%) | 18 (86%) | 79 (81%) | 0.26 |
| SS-related symptoms, n (%) | |||||
| Dry mouth | 3 (27%) | 2 (29%) | 8 (38%) | 30 (31%) | 0.91 |
| Joint/muscle pain | 2 (18%) | 0 | 2 (9%) | 20 (21%) | 0.38 |
| Fatigue | 2 (18%) | 1 (14%) | 1 (5%) | 13 (13%) | 0.67 |
| Diagnostic parameters, n (%) | |||||
| Anti-SSA | 9 (82%) | 4 (57%) | 0 | 0 | |
| Anti-SSB | 3 (27%) | 2 (29%) | 0 | 0 | |
| RF | 5 (46%) | 4 (57%) | 3 (14%) | 2 (2%) | |
| ANA ≥ 1 : 320 | 6 (55%) | 3 (42%) | 3 (14%) | 2 (2%) | |
| Positive biopsy | 2/3 (67%) | 0/1 (0%) | 0/2 (0%) | 0/7 (0%) | |
| Novel autoantibodies, n (%) | 8 (73%) | 1 (14%) | 10 (48%) | 37 (38%) | 0.06 |
| Anti-SP1 | 3 (27%) | 1 (14%) | 2 (9%) | 13 (13%) | 0.57 |
| Anti-CA6 | 3 (27%) | 0 | 5 (24%) | 21 (22%) | 0.53 |
| Anti-PSP | 6 (54%) | 0 | 4 (19%) | 10 (10%) | 0.001 |
| Dry eye measures, mean (SD) | |||||
| Tear osmolarity (mOsm/L) | 323 (33.7) | 308 (17.4) | 307 (17.7) | 307 (14.5) | 0.054 |
| Schirmer test (mm) | 9.0 (8.1) | 4.8 (3.6) | 7.7 (11.5) | 7.9 (6.7) | 0.79 |
| Schirmer test ≤ 5 mm, n (%) | 5 (71%) | 2 (67%) | 7 (78%) | 25 (43%) | 0.14 |
| Total OSS (0-12) | 8.3 (3.3) | 8.6 (1.8) | 7.2 (2.7) | 5.5 (3.5) | 0.003 |
| Corneal staining (0-6) | 3.3 (1.8) | 3.4 (1.5) | 2.9 (1.9) | 2.3 (1.8) | 0.15 |
| Conjunctival staining (0-6) | 5.0 (1.8) | 5.1 (1.2) | 4.4 (1.6) | 3.2 (2.3) | 0.002 |
| OSS ≥ 5, n (%) | 6 (60%) | 4 (67%) | 13 (68%) | 60 (72%) | 0.97 |
| Schirmer ≤ 5 mm or OSS ≥ 5, n (%) | 8 (73%) | 5 (83%) | 17 (85%) | 70 (75%) | 0.77 |
Results are represented as mean (standard deviation) for continuous variables and number (percentage) for binary variables. The one-way analysis of variance (ANOVA) was used for comparison of continuous variables and chi-squared testing for categorical variables between groups. SS: Sjögren's syndrome; SD: standard deviation; SSA: Sjögren's syndrome-related antigen A; SSB: Sjögren's syndrome-related antigen B; RF: rheumatoid factor; ANA: antinuclear antibody; SP1: salivary protein 1; CA6: carbonic anhydrase 6; PSP: parotid secretory antigen; OSS: ocular staining score.