尿毒症患者血管中膜钙化和骨特异性蛋白的表达

目的研究尿毒症患者血管中骨特异性蛋白的表达和钙盐沉积的关系。方法88例尿毒症患者在接受肾移植手术时，留取其腹壁下动脉的近端2～3cm。钙盐沉积染色采用von Kossa法和茜素红染色方法。骨特异性蛋白，包括骨桥蛋白(OPN)、骨唾液酸桥蛋白(BSP)及碱性磷酸酶(AKP)的表达采用免疫组化染色法。测定血钙、磷、FrrH、甘油三酯(TG)、总胆固醇(Tch)、低密度脂蛋白(LDL)，计算体重指数(BMI)。结果88例腹壁下动脉标本中出现血管钙化的有23例，发生率为26．1％；轻中度钙化8例(9．1％)，重度钙化15例(17％)，均发生在血管中膜。出现明显钙化的腹壁下动脉的中膜均有OPN、BSP、AKP的阳性沉积；65例无明显钙化的标本中也有50例(76．9％)中膜有AKP、OPN、BSP的阳性沉积。腹壁下动脉重度钙化标本中膜OPN、BSP、AKP免疫组化的积分均显著高于无钙化标本，轻中度钙化标本AKP的积分也高于无钙化标本。年龄、BMI与OPN、AKP、BSP免疫组化阳性积分均成正相关，血磷与OPN(r=0．262，P=0．017)，AKP(r=0．23，P=0．036)成正相关。结论尿毒症患者腹壁下动脉的钙化与骨特异性蛋白的表达有关。在一些无显性钙化的患者腹壁下动脉也有骨特异性蛋白的表达，提示血管骨特异性蛋白的表达可能是血管壁钙化的早期表现．细胞介导的主动钙化过程参与了尿毒症患者血管中膜的钙化。

Medial artery calcification and deposition of bone matrix proteins in end-stage renal disease patients

Objective To study the relationship between the medial artery calcification and deposition of bone matrix proteins in uremic patients.Methods Pieces of inferior epigastric artery were taken from 88 ESRD patients at the time of renal transplantation. The vessels were examined for calcification by von Kossa stain and alizalin pH 4.2 red stain and for the presence of bone matrix proteins by immunohistochemistry. Other related factors including clinical and laboratory parameters were also determined. Results Sixty-five(73.9%) of the vessels had no evidence of calcification, eight (9.1%) vessels had mild/moderate calcification and fifteen(17%) had severe calcification. All calcification occurred in medial layer. Positive immunohistochemical staining of osteopontin, bone sialprotein and alkaline phosphatase was found in the smooth muscular cell plasma of medial layer in the vessels with present calcification. However, above positive staining was also observed in 76.9% of the vessels without overt calcification.Positive immunohistochemical staining score of OPN,BSP and AKP in the inferior epigastric artery with severe calcification was significantly higher than that in the inferior epigastric artery without calcification. Same findings were obtained as for AKP in the mild/moderate calcification. Increasing age and body mass index were positively correlated with immunohistochemical score of OPN,AKP and BSP. Serum phosphate was positively correlated with OPN(r=0.262, P=0.017), and AKP(r=0.23, P=0.036) respectively. Conclusions Vascular calcification is related to the deposition of the bone matrix proteins in the inferior epigastric artery of ESRD patients. It is also found that there are depositions of the bone matrix proteins in the inferior epigastric artery of ESRD patients without overt calcification. This implies that the deposition of the bone matrix proteins is probably an early sign of overt calcification.It also indicates that an active cell-mediated process is involved in the vascular calcification.