Division of Clinical Immunology and Rheumatology, F4-105, Academic Medical Center/University of Amsterdam, Meibergdreef 9, Amsterdam, The Netherlands.
Rheumatology (Oxford). 2012 Sep;51(9):1557-62. doi: 10.1093/rheumatology/kes080. Epub 2012 May 4.
A proliferation-inducing ligand (APRIL) and B-cell activating factor (BAFF) are B-cell-related mediators and may play a role in the pathogenesis in SS. In this descriptive study we assessed the expression of APRIL and BAFF in the minor salivary gland and serum from SS patients.
Paraffin-embedded minor salivary gland sections from SS patients, non-SS controls and healthy volunteers were analysed by immunohistochemistry. Digital image quantification was performed to evaluate the expression of BAFF, APRIL and transmembrane activator and CAML interactor. Furthermore, serum was analysed for soluble BAFF and APRIL levels by ELISA. All the data were also analysed for subjects with decreased and normal stimulated salivary flow independent of the classification.
APRIL expression was lower in minor salivary gland biopsies from SS patients compared with healthy volunteers and to a lesser extent non-SS controls, whereas BAFF expression was similar in all groups. Soluble APRIL levels in serum were increased in SS patients and in subjects with decreased salivary flow independent of the classification.
APRIL salivary gland tissue levels are decreased, suggesting that targeting this cytokine locally in the salivary glands would not benefit SS patients. Moreover, the discrepancy between local and systemic levels is striking and future research should assess this in more detail.
增殖诱导配体 (APRIL) 和 B 细胞激活因子 (BAFF) 是与 B 细胞相关的介质，可能在 SS 的发病机制中发挥作用。在本描述性研究中，我们评估了 APRIL 和 BAFF 在 SS 患者的小唾液腺和血清中的表达。
通过免疫组织化学分析 SS 患者、非 SS 对照组和健康志愿者的石蜡包埋小唾液腺切片。通过数字图像定量来评估 BAFF、APRIL 和跨膜激活剂和 CAML 相互作用蛋白的表达。此外，通过 ELISA 分析血清中可溶性 BAFF 和 APRIL 水平。所有数据还针对唾液流量减少和正常刺激的受试者进行了分析，而与分类无关。
与健康志愿者和非 SS 对照组相比，SS 患者的小唾液腺活检中 APRIL 表达降低，而 BAFF 表达在所有组中相似。血清中可溶性 APRIL 水平在 SS 患者和分类无关的唾液流量减少的受试者中升高。
唾液腺组织中 APRIL 水平降低，表明局部靶向这种细胞因子对 SS 患者无益。此外，局部和全身水平之间的差异很明显，未来的研究应更详细地评估这一点。
