Real-world Clinical and Diagnostic Features of Patients With Isolated Anti-SSB Antibodies Compared With Those With Combined Anti-SSA and Anti-SSB Antibodies

BACKGROUND/OBJECTIVE: Anti-SSA and/or anti-SSB antibodies are commonly seen in Sjögren disease but lack disease specificity. Isolated anti-SSB may have a limited association with Sjögren, while dual anti-SSA/SSB positivity may indicate more severe disease. This study compared clinical and serologic features of patients with isolated anti-SSB versus dual anti-SSA/SSB positivity in a real-world setting. METHODS: A retrospective medical records review study from January 1, 2018, to December 31, 2022, was conducted. Adults with positive serologic testing for anti-SSA and anti-SSB antibodies were included. Patients with isolated anti-SSA, negative repeat serology within 6 months, or insufficient data were excluded. Demographic data, clinical manifestations, autoantibody profiles, and diagnostic outcomes were compared. Continuous variables were analyzed using Student t test and categorical variables using χ2 test; logistic regression was applied for odds ratios. RESULTS: Three hundred fifteen patients were included: 109 with isolated anti-SSB and 206 with anti-SSA/SSB positivity. Compared with the dual-positive anti-SSA/anti-SSB, patients with isolated anti-SSB antibody were significantly less likely to exhibit anemia, leukopenia, proteinuria, or positive ANA. Other autoantibodies (anti-Smith, anti-RNP, RF, anti-CCP) were also less frequent in the isolated anti-SSB group. This group had lower rates of xerophthalmia and diagnoses of Sjögren disease, systemic lupus erythematosus, and rheumatoid arthritis, and were more often without a rheumatologic diagnosis. CONCLUSIONS: Isolated anti-SSB positivity is associated with a significantly lower likelihood of Sjögren disease, SLE, and RA. These findings suggest that isolated anti-SSB may lack diagnostic utility and could represent a clinically insignificant serologic finding in many patients.