A Stratification Approach Based on Salivary Gland Ultrasonography for Assessing Secretory Function in Sjögren Disease

Our aim was to develop an ultrasonographic scoring model for staging hypofunction of salivary glands (SGs) in patients with Sjögren disease (SjD).

The assessment of SG secretory hypofunction was conducted by measuring whole salivary flows. B-mode ultrasonography was performed bilaterally on the parotid and submandibular glands to quantitatively evaluate the gland score and Outcome Measures in Rheumatology (OMERACT) score. The correlation between these scores and SG secretory function in patients with SjD was analyzed, leading to the development of an ultrasonographic scoring model for staging SG hypofunction.

A 1-center derivation cohort comprising 164 patients with SjD and a double-center validation cohort consisting of 107 patients with SjD were included. Both ultrasonographic scores demonstrated excellent discriminatory ability between patients with SjD with hypofunction and those with normal function (area under the curve > 0.8 for both; P < 0.001). A novel ultrasonographic scoring model revealed that low total OMERACT scores (< 5) indicated initial-stage SG hypofunction, whereas high scores (> 9) suggested end-stage hypofunction. Conversely, patients with moderate-level total OMERACT scores (5-9) required further stratification using total gland scores. The incidence of SG hypofunction among all 271 patients with SjD was found to be 18% in the initial stage, 58% in the progressive stage, and 100% in the end stage (P < 0.01). Further, the incidence of lacrimal gland involvement and hyperglobulinemia (IgG > 16 IU/mL) was significantly lower in the initial-stage patients compared to those at other stages (all P < 0.01).

The novel ultrasonographic scoring model incorporates precise definitions for each stage of SG hypofunction, providing a robust and clinically significant approach to stratification of SG secretory hypofunction in SjD.