Bone and Mineral Metabolic Unit, Division of Clinical Chemistry, Department of Clinical and Experimental Medicine, Faculty of Health Sciences at Linköping University, Linköping, Sweden.
Scand J Clin Lab Invest. 2010 Apr;70(2):128-35. doi: 10.3109/00365511003642527.
Alkaline phosphatase (ALP) is routinely used in the assessment of Paget's disease of bone (PDB); however, the individual bone ALP isoforms (B/I, B1, and B2) have not been investigated in this disorder.
Subjects comprised 37 patients (mean age 74 years) with symptomatic PDB confirmed by radiograph and stratified into high and low total ALP activity groups and 66 healthy individuals (mean age 64 years). Extracts of human cancellous and cortical bone tissues were also investigated. The bone ALP isoforms, measured by HPLC, were compared with two bone ALP immunoassays (Metra and Ostase), and the bone formation marker intact amino-terminal procollagen type I propeptide (iPINP).
All bone ALP isoforms were increased in high ALP activity PDB compared with the low ALP activity and control groups (p < 0.0001). The B2 isoform had the greater relative activity representing 36%, 50%, and 71%, of the total ALP activity in the control, low and high ALP activity groups, respectively. Compared with controls, B2 was increased in the low ALP activity PDB group (p < 0.05). ROC analysis showed a validity of approximately 80% for B2 to discriminate patients with PDB.
All bone ALP isoforms were increased in patients with high ALP activity PDB and the B2 isoform was even elevated in the low ALP activity PDB group. The bone ALP isoform B2 may be of use in the management of PDB but that has to be further elucidated in subsequent studies.
碱性磷酸酶（ALP）常用于评估佩吉特病（PDB）；然而，个体骨 ALP 同工酶（B/I、B1 和 B2）在这种疾病中尚未得到研究。
研究对象包括 37 名（平均年龄 74 岁）有症状的 PDB 患者（经 X 光证实），并按总 ALP 活性分为高活性组和低活性组，以及 66 名健康个体（平均年龄 64 岁）。还研究了人松质骨和皮质骨组织的提取物。通过 HPLC 测量的骨 ALP 同工酶与两种骨 ALP 免疫测定法（Metra 和 Ostase）以及骨形成标志物完整氨基末端原胶原 I 前肽（iPINP）进行比较。
与低 ALP 活性组和对照组相比，高 ALP 活性 PDB 患者的所有骨 ALP 同工酶均升高（p < 0.0001）。B2 同工酶具有更大的相对活性，分别占对照组、低 ALP 活性组和高 ALP 活性组总 ALP 活性的 36%、50%和 71%。与对照组相比，低 ALP 活性 PDB 组的 B2 同工酶升高（p < 0.05）。ROC 分析显示 B2 区分 PDB 患者的有效性约为 80%。
高 ALP 活性 PDB 患者的所有骨 ALP 同工酶均升高，低 ALP 活性 PDB 组的 B2 同工酶甚至升高。骨 ALP 同工酶 B2 可能对 PDB 的管理有用，但需要在后续研究中进一步阐明。
