Aschenberg Sophie, Finzel Stephanie, Schmidt Sarah, Kraus Sebastian, Engelke Klaus, Englbrecht Matthias, Rech Jürgen, Schett Georg
Arthritis Res Ther. 2013;15(3):R62. doi: 10.1186/ar4235.
The aim of this study was to determine the factors, including markers of bone resorption and bone formation, which determine catabolic and anabolic periarticular bone changes in patients with rheumatoid arthritis (RA).
Forty RA patients received high-resolution peripheral quantitative computed tomography (HR-pQCT) analysis of the metacarpophalangeal joints II and III of the dominantly affected hand at two sequential time points (baseline, one year follow-up). Erosion counts and scores as well as osteophyte counts and scores were recorded. Simultaneously, serum markers of bone resorption (C-terminal telopeptide of type I collagen (CTX I), tartrate-resistant acid phosphatase 5b (TRAP5b)), bone formation (bone alkaline phosphatase (BAP), osteocalcin (OC)) and calcium homeostasis (parathyroid hormone (PTH), 25-hydroxyvitamin D3 (Vit D)) were assessed. Bone biomarkers were correlated to imaging data by partial correlation adjusting for various demographic and disease-specific parameters. Additionally, imaging data were analyzed by mixed linear model regression.
Partial correlation analysis showed that TRAP5b levels correlate significantly with bone erosions, whereas BAP levels correlate with osteophytes at both time points. In the mixed linear model with erosions as the dependent variable, disease duration (P <0.001) was the key determinant for these catabolic bone changes. In contrast, BAP (P = 0.001) as well as age (P = 0.018), but not disease duration (P = 0.762), were the main determinants for the anabolic changes (osteophytes) of the periarticular bone in patients with RA.
This study shows that structural bone changes assessed with HR-pQCT are accompanied by alterations in systemic markers of bone resorption and bone formation. Besides, it can be shown that bone erosions in RA patients depend on disease duration, whereas osteophytes are associated with age as well as serum level of BAP. Therefore, these data not only suggest that different variables are involved in formation of bone erosions and osteophytes in RA patients, but also that periarticular bone changes correlate with alterations in systemic markers of bone metabolism, pointing out BAP as an important parameter.
本研究旨在确定包括骨吸收和骨形成标志物在内的因素，这些因素决定类风湿关节炎（RA）患者关节周围的分解代谢和合成代谢性骨变化。
40例RA患者在两个连续时间点（基线、一年随访）接受了对优势手第二和第三掌指关节的高分辨率外周定量计算机断层扫描（HR-pQCT）分析。记录侵蚀计数和评分以及骨赘计数和评分。同时，评估骨吸收（I型胶原C末端肽（CTX I）、抗酒石酸酸性磷酸酶5b（TRAP5b））、骨形成（骨碱性磷酸酶（BAP）、骨钙素（OC））和钙稳态（甲状旁腺激素（PTH）、25-羟基维生素D3（维生素D））的血清标志物。通过对各种人口统计学和疾病特异性参数进行偏相关分析，将骨生物标志物与影像学数据相关联。此外，通过混合线性模型回归分析影像学数据。
偏相关分析表明，TRAP5b水平与骨侵蚀显著相关，而BAP水平在两个时间点均与骨赘相关。在以侵蚀为因变量的混合线性模型中，病程（P<0.001）是这些分解代谢性骨变化的关键决定因素。相比之下，BAP（P = 0.001）以及年龄（P = 0.018），而非病程（P = 0.762），是RA患者关节周围骨合成代谢变化（骨赘）的主要决定因素。
本研究表明，HR-pQCT评估的结构性骨变化伴随着骨吸收和骨形成的全身标志物的改变。此外，可以表明RA患者的骨侵蚀取决于病程，而骨赘与年龄以及BAP的血清水平相关。因此，这些数据不仅表明不同变量参与了RA患者骨侵蚀和骨赘的形成，而且关节周围骨变化与骨代谢的全身标志物改变相关，指出BAP是一个重要参数。
