Anti-SSA/SSB-negative primary Sjögren’s syndrome showing different clinical phenotypes: a retrospective study of 934 cases

Table 3 Factors associated with anti-SSA and anti-SSB antibody negativity in patients with pSS.

Variables	OR	95%CI	P-value*
Age (years)	1.03	1.01, 1.05	0.002
Sex (male)	1.86	1.05, 3.31	0.034
Disease duration (months)	1.00	0.99, 1.00	0.018
Nationality (Han)	1.18	0.47, 2.98	0.727
Arthralgia	1.37	0.90, 2.10	0.143
Palpable purpura	0.53	0.22, 1.28	0.160
Schirmer I test ≤ 5 mm/5 min	2.85	1.24, 6.53	0.013
ANA titers ≥ 1:320	0.76	0.46, 1.25	0.278
Positive anti-Ro52	0.13	0.09, 0.19	< 0.001
Positive anti-CENP-B	4.17	2.04, 8.53	< 0.001
Positive RF (> 20 IU/mL)	0.40	0.25, 0.63	< 0.001
Leucopenia (< 4 × 10⁹/L)	0.98	0.45, 2.14	0.953
Neutropenia (< 1.5 × 10⁹/L)	0.61	0.25, 1.48	0.274
Anemia (< 110 g/L)	0.68	0.38, 1.19	0.171
Thrombocytopenia (100 × 10⁹/L)	0.47	0.24, 0.96	0.037
Hyper-IgA (> 3.78 g/L)	0.71	0.43, 1.17	0.181
Hyper-IgG (> 16.2 g/L)	0.78	0.49, 1.26	0.315
Low C3 (< 0.7 g/L)	1.02	0.60, 1.75	0.935
Low C4 (< 0.16 g/L)	0.83	0.53, 1.30	0.408
Elevated ESR (> 20 mm/h)	0.87	0.54, 1.41	0.564
Interstitial lung disease	2.54	1.67, 3.85	< 0.001

* Multivariate logistic regression analysis
ANA, antinuclear antibodies; anti-CENP-B, anti-centromere protein B; RF, rheumatoid factor; IgA, immunoglobulin A; IgG, immunoglobulin G; C3, complement 3; C4, complement 4. ESR, erythrocyte sedimentation rate

ISSN: 2523-3106