Vaziri-Sani Fariba, Brundin Charlotte, Agardh Daniel
Kristianstad University, Kristianstad, Sweden.
Diabetes and Celiac Disease Unit, Department of Clinical Sciences, Lund University, Malmö, Sweden.
Bone Rep. 2017 Oct 24;7:132-136. doi: 10.1016/j.bonr.2017.10.004. eCollection 2017 Dec.
Autoantibodies against osteoprotegerin (OPG) have been associated with osteoporosis. The aim was to develop an immunoassay for OPG autoantibodies and test their diagnostic usefulness of identifying women general population with low bone mineral density.
Included were 698 women at mean age 55.1 years (range 50.4-60.6) randomly selected from the general population. Measurement of wrist bone mineral density (g/cm) was performed of the non-dominant wrist by dual-energy X-ray absorptiometry (DXA). A T-score < - 2.5 was defined as having a low bone mineral density. Measurements of OPG autoantibodies were carried by radiobinding assays. Cut-off levels for a positive value were determined from the deviation from normality in the distribution of 398 healthy blood donors representing the 99.7th percentile.
Forty-five of the 698 (6.6%) women were IgG-OPG positive compared with 2 of 398 (0.5%) controls ( < 0.0001) and 35 of the 698 (5.0%) women had a T-score < - 2.5. There was no difference in bone mineral density between IgG-OPG positive (median 0.439 (range 0.315-0.547) g/cm) women and IgG-OPG negative (median 0.435 (range 0.176-0.652) g/cm) women ( = 0.3956). Furthermore, there was neither a correlation between IgG-OPG levels and bone mineral density (r = 0.1896; = 0.2068) nor T-score (r = 0.1889; = 0.2086). Diagnostic sensitivity and specificity of IgG-OPG for low bone mineral density were 5.7% and 92.9%, and positive and negative predictive values were 7.4% and 90.8%, respectively.
Elevated OPG autoantibody levels do not predict low bone mineral density in middle-aged women selected from the general population.
抗骨保护素（OPG）自身抗体与骨质疏松症相关。本研究旨在开发一种检测OPG自身抗体的免疫测定方法，并测试其在识别骨密度低的普通女性人群中的诊断价值。
纳入了698名平均年龄55.1岁（范围50.4 - 60.6岁）的女性，她们是从普通人群中随机选取的。通过双能X线吸收法（DXA）对非优势手腕的骨密度（g/cm）进行测量。T值< - 2.5被定义为骨密度低。通过放射结合试验检测OPG自身抗体。根据398名健康献血者（代表第99.7百分位数）分布的正态偏差确定阳性值的临界水平。
698名女性中有45名（6.6%）IgG - OPG呈阳性，而398名对照中有2名（0.5%）呈阳性（P < 0.0001），698名女性中有35名（5.0%）T值< - 2.5。IgG - OPG阳性女性（中位数0.439（范围0.315 - 0.547）g/cm）和IgG - OPG阴性女性（中位数0.435（范围0.176 - 0.652）g/cm）的骨密度无差异（P = 0.3956）。此外，IgG - OPG水平与骨密度（r = 0.1896；P = 0.2068）以及T值（r = 0.1889；P = 0.2086）均无相关性。IgG - OPG对低骨密度的诊断敏感性和特异性分别为5.7%和92.9%，阳性预测值和阴性预测值分别为7.4%和90.8%。
从普通人群中选取的中年女性中，OPG自身抗体水平升高并不能预测骨密度低。
