Association between sialoscintigraphy parameters and rheumatoid factor seropositivity in patients with suspected...

To investigate the association between quantitative sialoscintigraphy parameters and rheumatoid factor (RF) seropositivity in patients with suspected autoimmune salivary gland dysfunction and to evaluate the diagnostic performance of functional imaging in relation to anti-Ro/SSA antibody (SSA) and anti-La/SSB antibody (SSB) profiles. We retrospectively reviewed the records of 100 patients who underwent sialoscintigraphy for sicca symptoms or suspected Sjögren's syndrome from April 2020 to May 2022. Quantitative parameters including time to maximum uptake(T_max)and time to onset of secretion(T_min)were extracted from time-activity curves. Serologic data for RF, SSA, and SSB antibodies were analyzed. Logistic regression and receiver operating characteristic (ROC) analyses were performed to assess associations and diagnostic performance. Of the 100 included patients, 22% were RF-positive, 52% were SSA positive, and 22% were SSB positive. Logistic regression analysis identified younger age (OR [odds ratio] = 0.955; 95% CI [confidence interval], 0.922-0.989;p = 0.009), prolonged submandibular gland T_min(OR = 1.309; 95% CI, 1.026-1.672;p= 0.031); and reduced T_maxin both the parotid (OR = 0.904; 95% CI, 0.820-0.997;p = 0.043) and submandibular glands (OR = 0.941; 95% CI, 0.891-0.993;p= 0.028) as significantly associated with RF seropositivity. Although group-wise comparisons showed no statistically significant differences, borderline trends were observed in submandibularT_maxand T_min.Taken together, these findings suggest that although the individual diagnostic performance of T_maxand T_minmay be limited, their combined assessment offers clinically meaningful insights into autoimmune-related salivary gland dysfunction. Quantitative sialoscintigraphy parameters, particularly prolonged submandibular T_minand reduced T_maxin submandibular and parotid glands, are associated with RF seropositivity and likely reflect early immune-mediated glandular dysfunction. Although their individual diagnostic performance is modest, these scintigraphic parameters may contribute valuable information when integrated with serologic markers and visual interpretation in assessing autoimmune salivary gland disease.