异体脱蛋白骨关节复合钙磷骨水泥与重组人血管内皮细胞生长因子和重组人骨形态发生蛋白2移植的免疫学研究*☆

背景：异体骨关节移植因难以克服的免疫排斥反应、与宿主骨愈合困难等问题在临床使用有一定局限性，如何降低其免疫原性、促进其再血管化及成骨是目前研究的重点。 目的：观察复合钙磷骨水泥与重组人血管内皮细胞生长因子及重组人骨形态发生蛋白2的异体脱蛋白骨关节移植材料（CPC/ DPOA /rhVEGF/rhBMP-2）的免疫原性、成骨及再血管化能力。 设计、时间及地点：随机对照体内动物实验，于2006-03/09在重庆医科大学临床学院骨科实验室完成。 材料：自制犬的股骨下端脱蛋白骨关节移植体、DPOA/rhVEGF/rhBMP-2移植体及CPC/ DPOA /rhVEGF/rhBMP-2移植体。 方法：取36只杂交犬，麻醉后距膝关节面30 mm 处用线锯切断股骨制备骨缺损模型，然后随机分成3组，分别植入CPC/rhVEGF/rhBMP-2/DPOA，rhVEGF/rhBMP-2/DPOA及单纯脱蛋白骨关节移植体。 主要观察指标：术后4，8，12，16周进行移植物X射线、组织学、股动脉新生血管分布及T淋巴细胞亚群分析。 结果：术后4~16周，CPC/rhVEGF/rhBMP-2/DPOA移植组新骨形成及再血管化明显好于其他2组(P < 0.01)，各时间点炎症反应较其他组轻(P < 0.01)，Ⅰ型胶原免疫组化的面积积分吸光度值高于其他2组(P < 0.01)。术后2，4周CPC/rhVEGF/ rhBMP-2/DPOA移植组CD4/CD8比值低于其他2组（P < 0.01），术后8，16周3组CD4/CD8比值均较前有所降低，组间差异无显著性意义(P > 0.05)。 结论：CPC/rhVEGF/rhBMP-2/ DPOA移植材料的免疫原性较低，可发生移植材料的早期再血管化和新骨的形成。

Deproteinized osteoarticular allografts integrated with calcium phosphate cement and recombinant human vascular endothelial cell growth factor plus recombinant human bone morphogenetic protein-2: An immunological study

BACKGROUND: Osteoarticular allograft has its invariable limit because of some problems such as immunological rejection hard to overcome and knitting to host difficultly. So it is the emphasis of current research to degrade its immunogenicity and promote its revascularization and bone formation. OBJECTIVE: To observe the immunogenicity and ability to ossify and revascularize of variant deproteinized osteoarticular grafts integrated of calcium phosphate cement (CPC) and recombinant human vascular endothelial cell growth factor (rhVEGF) + recombinant human bone morphogenetic protein-2 (rhBMP-2). DESIGN, TIME AND SETTING: Randomized contrast experiment in animals was completed at Orthopaedic Laboratory, College of Clinical Medicine of Chongqing Medical University from March to September in 2006. MATERIALS: Harvested from inferior femur of the dogs, deproteinized osteoarticular allografts, deproteinized osteoarticular allografts/rhVEGF/rhBMP-2 and CPC/deproteinized osteoarticular allograft/rhVEGF/rhBMP-2 were made. METHODS: Bone defect models were induced in 36 inbred dogs by cutting off femur by wire saw from articular surface with 30 mm, and they were randomly divided into three groups with 12 in each group. Animals were fixed with CPC/rhVEGF/rhBMP-2/deproteinized osteoarticular allograft, rhVEGF/rhBMP-2/deproteinized osteoarticular allograft or simple deproteinized osteoarticular allograft. MAIN OUTCOME MEASURES: At the 4th, 8th, 12th and 16th weeks after operation, the effects were partly assessed by X-ray film examination, histological examination, new vessels distribution examination of femoral artery and subgroup analysis of T lymphocytes. RESULTS: From the 4th to the 16th weeks after operation, the callus formation and revascularization in group fixed with CPC/rhVEGF/rhBMP-2/deproteinized osteoarticular allograft were obviously better than other two groups (P < 0.01). The inflammatory reaction in group fixed with CPC/rhVEGF/rhBMP-2/deproteinized osteoarticular allograft was weaker than that in other two groups (P < 0.01), while integral absorbance value was higher than other two groups by immunohistochemical staining of I-collagen (P < 0.01). At the 2nd and 4th weeks after operation, the ratios of CD4/CD8 in group fixed with CPC/rhVEGF/rhBMP-2/deproteinized osteoarticular allograft were obviously lower than those in other two groups (P < 0.01), and the ratios in three groups all decreased at the 8th and 16th weeks after operation. The difference had no statistical significance (P > 0.05). CONCLUSION: The grafting material of CPC/rhVEGF/rhBMP-2/deproteinized osteoarticular allograft has low immunogenicity, it can proceed revascularization and new bone formation early.