Association Between Quantitative Sialoscintigraphy and Antibody Profiles in Patients With Sjögren or Sicca Syndrome

This study analyzed the association between anti-Ro/SSA and anti-La/SSB antibody levels with quantitative and visual sialoscintigraphy patterns in patients suspected of having Sjögren or sicca syndrome.

Medical records of patients who underwent sialoscintigraphy between April 2020 and May 2022 were reviewed. Associations between antibody levels and sialoscintigraphy parameters were evaluated using linear regression. Receiver operating characteristic curve analysis was used to identify antibody cutoff values for predicting flat-type patterns and the risk of Sjögren or sicca syndrome.

Of the 170 patients (mean age, 56.6 years; 78.8% female), 95.3% had dry mouth and eyes, 30% experienced polyarthralgia, and 66.5% were prescribed hydroxychloroquine. The most common sialoscintigraphy finding was the median-type time-activity curve (TAC) pattern. Anti-Ro/SSA and anti-La/SSB levels were significantly correlated with maximum accumulation or maximum secretion in the salivary glands. Receiver operating characteristic analysis for anti-Ro/SSA predicting a flat-type TAC pattern showed an area under the curve (AUC) of 0.659 to 0.780, with specificity between 82.1% and 86.3% for antibody levels greater than 85.2 units. Anti-Ro/SSA levels greater than 49.75 units predicted a higher risk of Sjögren or sicca syndrome, with an AUC of 0.622 and 83.9% specificity. Anti-La/SSB levels had no significant predictive value, with an AUC of 0.554.

Anti-Ro/SSA levels greater than 85.2 units were strong predictors of flat-type TAC patterns, indicating near-total salivary gland dysfunction and supporting their diagnostic utility in Sjögren or sicca syndrome.