Kyd P A, Vooght K D, Kerkhoff F, Thomas E, Fairney A
Department of Metabolic Medicine, Imperial College School of Medicine & St Mary's NHS Trust, London, UK.
Ann Clin Biochem. 1998 Nov;35 ( Pt 6):717-25. doi: 10.1177/000456329803500603.
We have evaluated two commercial assays for serum bone specific alkaline phosphatase (bALP) as a marker of bone turnover in a group of 35 postmenopausal women with osteoporosis during their first year of treatment with the anti-resorptive drug, alendronate. The immunoradiometric assay (bALP-I) measured protein mass, whereas the immunocapture assay (bALP-E) measured activity. Before treatment, bALP values with both methods were within the postmenopausal reference ranges. Treatment with alendronate produced a decrease in bALP after 3 months, reaching a plateau after 6 months: for bALP-I a mean change of -34%, (P < 0.0001), bALP-E, -19% (P < 0.001), and total ALP, -19% (P < 0.0001). The decrease was significant in 53% (bALP-I) and 31% (bALP-E) of patients. The ratio of serum bALP-E/bALP-I in patients was not constant but rose after therapy with alendronate. Neither baseline bALP, nor the per cent change in bALP after 6 months, correlated with bone mineral density (BMD) change after 1 year at either lumbar spine or femoral neck. We conclude that bALP-I appeared to be a more sensitive marker of the suppression of bone turnover by alendronate than did bALP-E, but that neither was useful in the detection of osteoporosis, nor the prediction of individual BMD response to alendronate therapy.
我们评估了两种用于检测血清骨特异性碱性磷酸酶（bALP）的商业检测方法，以此作为骨转换标志物，检测对象为35名患有骨质疏松症的绝经后女性，她们在接受抗吸收药物阿仑膦酸钠治疗的第一年。免疫放射分析（bALP-I）检测蛋白质质量，而免疫捕获分析（bALP-E）检测活性。治疗前，两种方法测得的bALP值均在绝经后参考范围内。阿仑膦酸钠治疗3个月后bALP降低，6个月后达到平台期：bALP-I平均变化为-34%，（P<0.0001），bALP-E为-19%（P<0.001），总碱性磷酸酶为-19%（P<0.0001）。53%（bALP-I）和31%（bALP-E）的患者下降显著。患者血清bALP-E/bALP-I的比值并不恒定，在阿仑膦酸钠治疗后升高。基线bALP以及6个月后bALP的变化百分比，均与腰椎或股骨颈1年后的骨密度（BMD）变化无关。我们得出结论，bALP-I似乎比bALP-E更能敏感地反映阿仑膦酸钠对骨转换的抑制作用，但两者均无助于骨质疏松症的检测，也无法预测个体对阿仑膦酸钠治疗的BMD反应。
