Clinical characteristics of chronic sclerosing sialadenitis as a distinctive entity from primary Sjögren's syndrome.

Objective: This study aimed to elucidate the clinical and laboratory differences between chronic sclerosing sialadenitis (CSS) and primary Sjögren's syndrome (pSS), highlighting CSS as a distinct pathological entity within the spectrum of salivary gland pathology. Methods: This retrospective, single-center study was conducted at Seoul St. Mary's Hospital between January 2000 and December 2022. Patients diagnosed with CSS via salivary gland biopsy were included, and those with IgG4-related disease (IgG4-RD) or other confounding factors were excluded. Clinical and laboratory CSS profiles were compared with those of a control group of patients with typical pSS from the Korean Initiative of Primary Sjögren's Syndrome (KISS) prospective cohort study. Twenty-one with CSS and 501 patients with pSS from Seoul St. Mary's Hospital were retrospectively analyzed. Results: Patients with CSS were older at diagnosis, had a lower prevalence of ocular symptoms, and exhibited distinct immunological markers compared to those with pSS. Logistic regression analysis revealed that anti-Ro antibody positivity, elevated erythrocyte sedimentation rate levels, low serum complement 3 levels, and accompanying dry eye symptoms were factors distinguishing pSS from CSS. Conclusion: Even after excluding IgG4-RD, CSS was significantly different from pSS in terms of clinical and laboratory findings. Recognition of these differences is crucial for the accurate diagnosis and management of CSS, underscoring its status as a distinct pathological entity among salivary gland pathologies.