Blood stasis syndrome is a significant concurrent syndrome in primary Sjögren's syndrome (pSS). However, the quantitative characteristics and clinical correlations remain insufficiently explored.

To investigate the quantitative characteristics of blood stasis syndrome in pSS patients and the association with glandular secretory function, imaging features, serum indicators, and the risk of systemic involvement.

A total of 171 patients with suspected pSS who were diagnosed and treated at Yueyang Hospital of Integrated Traditional Chinese and Western Medicine, Shanghai University of Traditional Chinese Medicine between July 2022 and January 2024 were enrolled as study subjects. Based on the 2016 ACR/EULAR classification criteria, patients were divided into a pSS group (130 cases) and non-pSS group (41 cases). General information was collected, including gender, age, clinical manifestations, presence of other autoimmune diseases, other medical history, and medication history. Clinical indicators included unstimulated salivary flow rate, Visual Analog Scale (VAS) score for dry mouth, salivary gland ultrasound (SGUS), and labial gland biopsy results. Laboratory indicators included antinuclear antibodies (ANA), anti-SSA/Ro antibodies, IgG, erythrocyte sedimentation rate (ESR), rheumatoid factor, C3, C4, and systemic involvement. Blood stasis syndrome scores were calculated using the International Diagnostic Guidelines for blood stasis syndrome. Differences in general information, clinical indicators, and blood stasis syndrome scores between the two groups were compared. Grading of SGUS was performed according to the Outcome Measures in Rheumatology (OMERACT) grading system, and blood stasis syndrome scores were compared among patients with different grades. Spearman correlation analyses were used to evaluate the correlations between blood stasis scores and clinical indicators. The distribution of high-frequency blood stasis syndrome scores was also analyzed.

The rates of positive blood stasis syndrome, blood stasis syndrome scores, VAS scores for dry mouth, total SGUS grades for bilateral glands, positive rates of labial gland biopsy, positive rates of anti-SSA/Ro antibodies, ANA titers, ESR, and IgG levels of pSS group were higher than non-pSS group, and the unstimulated salivary flow rate was lower than non-pSS group, with a statistically significant difference (P<0.05). Correlation analysis revealed that blood stasis scores in the pSS group were positively correlated with VAS scores for dry mouth (r_s=0.520, P<0.05) and total SGUS grades for bilateral glands (r_s=0.492, P<0.05), negatively correlated with unstimulated salivary flow rate (r_s=-0.491, P<0.05). The rate of systemic involvement in the moderate to severe blood stasis group was higher than the mild group (P<0.05). Analysis of high-frequency blood stasis items showed that purple-dark tongue or sublingual venous engorgement, fixed pain, limb numbness/joint deformity, and pathological masses had higher positive rates in the blood stasis syndrome differentiation of pSS patients. In SGUS grading, the blood stasis scores in the grade 3 groups for both parotid and submandibular glands were higher than those in the lower-grade groups, with statistically significant differences (P<0.05).

Blood stasis syndrome is prevalent in pSS patients, and its severity is closely associated with glandular dysfunction, abnormalities in SGUS imaging, and the risk of systemic involvement. SGUS can serve as an objective assessment tool for blood stasis syndrome, supporting the TCM theory of blood stasis leading to dryness, and providing a theoretical basis and clinical reference for the personalized diagnosis and treatment of pSS.