Clinical and laboratory characteristics of salivary gland ultrasonography‐positive patients with primary Sjögren's syndrome

OBJECTIVE: This study aimed to investigate the clinical and laboratory characteristics of salivary gland ultrasonography (SGUS)-positive patients with primary Sjögren's syndrome (pSS) compared to SGUS-negative patients and to analyse the diagnostic value of SGUS and labial salivary gland biopsy (LSGB) grading in pSS. METHODS: A retrospective analysis of patients admitted to the Affiliated Hospital of Yangzhou University between May 2019 and November 2023 was conducted. According to the OMERACT scoring system, patients with pSS were divided into an SGUS-negative group (score <2) and an SGUS-positive group (score ≥2). The patient's age, gender, clinical symptoms, laboratory parameters and diagnostic examinations were compared and analysed, and Spearman correlation analysis was used to analyse the correlation between SGUS, LSGB and influencing factors. RESULTS: There was no significant difference in dry mouth, dry eyes, tooth loss, fever, joint pain, fatigue, interstitial lung disease or renal tubular acidosis between the two groups, although there were more patients with salivary gland enlargement in the SGUS-positive group (p < 0.05). In terms of high levels of immunoglobulin G (IgG), high levels of rheumatoid factor (RF), anti-nuclear antibody ≥1:320, anti-Sjögren's syndrome A-52KD and anti-Sjögren's syndrome B, the number of cases in the SGUS-positive group was greater than that in the SGUS-negative group (p < 0.05). LSGB samples were graded per the Chisholm-Mason system with significant differences between multiple groups. SGUS score negatively correlated with age and positively correlated with LSGB grade. CONCLUSION: This study showed that the SGUS score positively correlated with LSGB grade in pSS patients and negatively correlated with patient age. Thus, SGUS and LSGB are consistent in the diagnosis of pSS to reflect the degree of salivary gland involvement, and patients who are SGUS positive have high RF and IgG levels, a variety of autoantibodies positive and a tendency toward salivary gland enlargement.