Static and dynamic bone histomorphometry in children with osteogenesis imperfecta
Static and dynamic bone histomorphometry in children with osteogenesis imperfecta
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DOI：
10.1016/s8756-3282(00)00269-6
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发表时间：
2000-06-01
期刊：
影响因子：
4.1
通讯作者：
Glorieux, FH
中科院分区：
文献类型：
--
作者：
Rauch, F;Travers, R;Glorieux, FH
成骨不全（OI）是一种遗传性疾病，其特征是骨脆性增加和低骨量。四种临床类型通常被区分，示意性地，I型是最温和的表型，II型通常是致命的，III型是与出生后存活相容的最严重的形式，IV型是中度严重的。虽然影响I型胶原蛋白的突变是大多数患者的疾病原因，但遗传缺陷导致骨发育异常的机制尚未得到很好的表征。因此，我们评估了70例年龄在1.5 - 13.5岁的儿童的四环素标记髂骨活检的定量静态和动态组织形态计量学参数，这些儿童患有I型OI（n = 32）、III型OI（n = 11）和IV型OI（n = 27），并将结果与27例年龄匹配的无代谢性骨病的对照组进行比较。在所有OI类型中，活检核心宽度、皮质宽度和松质骨体积均明显减少。松质骨体积减少是由于骨小梁数量减少41%-57%和骨小梁厚度减少15%-27%。回归分析显示，对照组和OI患者的骨小梁数量不随年龄变化，表明没有骨小梁损失发生。对照组骨小梁厚度的年增长为5.8 μ m，I型OI为3.6 μ m，而在III型和IV型OI中没有明显的骨小梁增厚，反映重塑周期中形成的骨量的壁厚度在17名I型OI患者的亚组中减少了14%，但在其他类型的OI中没有确定。I型OI中的重塑平衡比对照组中的积极性低，在第三和第四类中可能接近于零。骨重建的表面参数在所有OI类型中均增加，表明重建单位的募集增加。未发现基质矿化缺陷。总之，有证据表明所有三种机制存在缺陷，这三种机制通常导致儿童时期骨量增加;即外部骨大小酸性形状的建模，软骨内骨化产生次级骨小梁，以及重塑增厚次级骨小梁。因此，OI可能被认为是一种疾病，其中成骨细胞中的单一遗传缺陷干扰了通常确保骨骼适应生长期间不断增加的机械需求的多种机制。(Bone 26：581-589; 2000）（C）2000由Elsevier Science Inc. All rights reserved.
Osteogenesis imperfecta (OI) is a genetic disorder characterized by increased bone fragility and low bone mass. Four clinical types are commonly distinguished, Schematically, type I is the mildest phenotype, type II is usually lethal, type III is the most severe form compatible with postnatal survival, and type IV is moderately severe. Although mutations affecting collagen type I are responsible for the disease in most patients, the mechanisms by which the genetic defects cause abnormal bone development have not been well characterized. Therefore, we evaluated quantitative static and dynamic histomorphometric parameters in tetracycline-labeled iliac bone biopsies from 70 children, aged 1.5 to 13.5 years, with OI types I (n = 32), III (n = 11), and IV (n = 27), Results were compared with those of 27 age-matched controls without metabolic bone disease. Biopsy core width, cortical width, and cancellous bone volume were clearly decreased in all OI types. Decreased cancellous bone volume was due to a 41%-57% reduction in trabecular number and a 15%-27% lower trabecular thickness, Regression analyses revealed that trabecular number did not vary with age in either controls or OI patients, indicating that no trabecular loss occurred, The annual increase in trabecular thickness was 5.8 mu m in controls and 3.6 mu m in type I OI, whereas no trabecular thickening was evident in type III and IV OI, Wall thickness, which reflects the amount of hone formed during a remodeling cycle, was decreased by 14% in a subgroup of 17 type I OI patients, but was not determined in the other OI types, The remodeling balance was less positive in type I OI than in controls, and probably close to zero in types III and IV. Surface-based parameters of bone remodeling were increased in all OI types, indicating increased recruitment of remodeling units. No defect in matrix mineralization was found. In conclusion, there was evidence of defects in all three mechanisms, which normally lead to an increase in bone mass during childhood; that is, modeling of external bone size acid shape, production of secondary trabeculae by endochondral ossification, and thickening of secondary trabeculae by remodeling. Thus, OI might be regarded as a disease in which a single genetic defect in the osteoblast interferes with multiple mechanisms that normally ensure adaptation of the skeleton to the increasing mechanical needs during growth. (Bone 26:581-589; 2000) (C) 2000 by Elsevier Science Inc. All rights reserved.