Objective

Syndecan-1 (SDC-1), a transmembrane heparin sulphate proteoglycan predominantly expressed on epithelial cells, also exists in a soluble form through ectodomain shedding. SDC-1 expression and shedding may be modulated in the inflammatory milieu of primary Sjögren’s syndrome (SS). We investigated SDC-1 expression in minor salivary glands (MSGs) and analysed the association between salivary or plasma levels of SDC-1 and clinical parameters in SS.

Method

We measured salivary and plasma SDC-1 levels via an enzyme-linked immunosorbent assay and assessed the salivary flow rates (SFRs) in 70 patients with SS and 35 healthy subjects. Disease activity indices, serological markers, salivary gland scintigraphy, and MSG biopsy were evaluated in patients with SS.

Results

SDC-1 expression was upregulated on ductal epithelial cells in inflamed salivary glands. Salivary SDC-1 levels in patients significantly exceeded those in healthy subjects [median (interquartile range) 49.0 (20.7–79.1) vs 3.7 (1.7–6.3) ng/mL, p < 0.001] and inversely correlated with SFRs (r = −0.358, p = 0.032) and ejection fractions of the parotid (r = −0.363, p = 0.027) and submandibular (r = −0.485, p = 0.002) glands in salivary gland scintigraphy. Plasma SDC-1 levels were significantly correlated with the EULAR Sjögren’s Syndrome Disease Activity Index (r = 0.507, p < 0.001) and EULAR Sjögren’s Syndrome Patient Reported Index (r = 0.267, p = 0.033). Focus scores were correlated with salivary SDC-1 levels (r = 0.551, p = 0.004).

Conclusions

Salivary and plasma SDC-1 levels may constitute potential biomarkers for salivary gland function and disease activity, respectively, in SS.

中文翻译：

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唾液 syndecan-1 水平升高与干燥综合征患者的唾液腺功能和炎症有关

客观的

Syndecan-1 (SDC-1) 是一种主要在上皮细胞上表达的跨膜硫酸肝素蛋白多糖，也通过胞外域脱落以可溶形式存在。SDC-1 的表达和脱落可能在原发性干燥综合征 (SS) 的炎症环境中受到调节。我们研究了 SDC-1 在小唾液腺 (MSG) 中的表达，并分析了 SDC-1 的唾液或血浆水平与 SS 临床参数之间的关联。

方法

我们通过酶联免疫吸附试验测量唾液和血浆 SDC-1 水平，并评估了 70 名 SS 患者和 35 名健康受试者的唾液流速 (SFR)。对 SS 患者的疾病活动指数、血清学标志物、唾液腺闪烁显像和味精活检进行了评估。

结果

SDC-1 表达上调在发炎的唾液腺导管上皮细胞。患者唾液 SDC-1 水平显着超过健康受试者 [中位数（四分位距）49.0 (20.7–79.1) vs 3.7 (1.7–6.3) ng/mL, p < 0.001] 并且与 SFR 呈负相关（r = -0.358 , p = 0.032) 和唾液腺闪烁扫描中腮腺 (r = -0.363, p = 0.027) 和颌下腺 (r = -0.485, p = 0.002) 的射血分数。血浆 SDC-1 水平与 EULAR 干燥综合征疾病活动指数 (r = 0.507, p < 0.001) 和 EULAR 干燥综合征患者报告指数 (r = 0.267, p = 0.033) 显着相关。焦点得分与唾液 SDC-1 水平相关（r = 0.551，p = 0.004）。

结论

唾液和血浆 SDC-1 水平可能分别构成 SS 中唾液腺功能和疾病活动的潜在生物标志物。