Dynamic salivary gland scintigraphy in rheumatoid arthritis: Association with disease activity

To evaluate salivary gland function in patients with rheumatoid arthritis (RA) and to assess its association with disease activity and systemic inflammatory markers.

In this retrospective study, 90 patients with RA and 50 age- and sex-matched healthy controls underwent ⁹⁹ᵐTcO₄^- dynamic planar salivary gland scintigraphy. No SPECT or CT acquisition was performed. Maximum accumulation rate (MAR) and maximum secretion rate (MSR) were calculated for the parotid and submandibular glands. Associations with DAS28-CRP, C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), rheumatoid factor (RF), and anti-cyclic citrullinated peptide antibodies (anti-CCP) were assessed using Spearman correlation analysis.

RA patients showed significantly lower MAR and MSR compared with healthy controls (both P < 0.001). Salivary gland function declined progressively with increasing disease activity. MAR and MSR were negatively correlated with CRP, ESR, RF, and anti-CCP levels.

Salivary gland dysfunction is common in RA patients without Sjögren's syndrome and is associated with disease activity and systemic inflammation. Dynamic planar salivary gland scintigraphy provides a non-invasive quantitative method for evaluating glandular function in RA. Prospective studies are warranted to further define its clinical role.