Background S100A4 is a member of calcium binding S100 protein family well known for its role in cancer progression and metastasis. Nevertheless, S100A4 also serves as a negative regulator of bone formation. Dickkopf-1 (DKK-1), marker of bone remodelling, is also implicated in the process of syndesmophyte formation in ankylosing spondylitis. The aim of our study was to evaluate plasma levels of S100A4 in patients with axial spondyloarthritis and to determine the potential association of S100A4 with disease severity, clinical manifestations and with bone changes in a cross-sectional study. Methods Fifty-eight patients with axial spondyloarthritis and 40 healthy controls were studied. Biological samples were analysed for S100A4 and Dickkopf-1. Disease activity was assessed according to the Bath Ankylosing Spondylitis Disease Activity Index. C-reactive protein (CRP) was used as a marker of inflammation. Radiographic damage was assessed using the modified Stoke Ankylosing Spondylitis Spinal Score (mSASSS). Results The plasma levels of S100A4 were significantly higher in patients with axial spondyloarthritis compared to heathy controls (p < 0.0001). The levels of S100A4 were higher in early stages of the disease and lower in patients with the presence of syndesmophytes (p = 0.009). Furthermore, we found weak but significant inverse correlation of plasma S100A4 with the mSASSS (r = - 0.363, p = 0.030). Levels of S100A4 were negatively associated with disease duration (r = - 0.404, p = 0.002) and positively with Dickkopf-1 binding capacity (r = 0.312, p = 0.023). Conclusions This is the first study showing elevated circulating levels of S100A4 in patients with axial spondyloarthritis, particularly in early stages of the disease prior to spinal involvement, and its significantly lower levels in patients with syndesmophytes. The role of S100A4 in the pathogenesis of axial spondyloarthritis can be suggested.

中文翻译：

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S100A4 在中轴型脊柱关节炎中升高：与疾病严重程度的潜在联系。

背景 S100A4 是钙结合 S100 蛋白家族的成员，因其在癌症进展和转移中的作用而广为人知。尽管如此，S100A4 也可作为骨形成的负调节剂。Dickkopf-1 (DKK-1) 是骨重塑的标志物，也与强直性脊柱炎中的联合腱鞘形成过程有关。我们研究的目的是评估中轴型脊柱关节炎患者的血浆 S100A4 水平，并在一项横断面研究中确定 S100A4 与疾病严重程度、临床表现和骨骼变化的潜在关联。方法对58例中轴型脊柱关节炎患者和40名健康对照者进行研究。分析生物样品的 S100A4 和 Dickkopf-1。根据巴斯强直性脊柱炎疾病活动指数评估疾病活动性。C反应蛋白（CRP）被用作炎症的标志物。使用改良的斯托克强直性脊柱炎脊柱评分 (mSASSS) 评估射线照相损伤。结果 与健康对照组相比，中轴型脊柱关节炎患者的血浆 S100A4 水平显着升高（p < 0.0001）。S100A4 的水平在疾病的早期阶段较高，而在存在联合真菌的患者中较低（p = 0.009）。此外，我们发现血浆 S100A4 与 mSASSS 呈弱但显着的负相关（r = - 0.363，p = 0.030）。S100A4 水平与疾病持续时间呈负相关（r = - 0.404，p = 0.002），与 Dickkopf-1 结合能力呈正相关（r = 0.312，p = 0.023）。结论 这是第一项研究显示 S100A4 在中轴型脊柱关节炎患者中的循环水平升高，特别是在脊柱受累之前的疾病早期阶段，而在联合腱鞘炎患者中 S100A4 水平显着降低。可以提出 S100A4 在中轴型脊柱关节炎发病机制中的作用。