Oka K, Moriyama T, Takahara S, Naruse M, Namba Y, Ichimaru N, Kyo M, Kokado Y, Okuyama A, Ito T, Imai E, Aozasa K
Department of Pathology, Graduate School of Medicine, Osaka University, 2-2 Yamadaoka, Suita, Osaka 565-0871, Japan.
Transplant Proc. 2005 Jun;37(5):2131-4. doi: 10.1016/j.transproceed.2005.05.001.
Chronic allograft nephropathy (CAN) is the main cause of renal transplant failure in the first decade posttransplant. The precise pathogenetic mechanism for CAN is not completely understood. A possible role of renin-angiotensin system for CAN has been suggested through clinical observations that angiotensin-converting enzyme inhibition and angiotensin II receptor blockers prevent CAN.
Distribution of renin-positive cells in allograft biopsy specimens was examined immunohistochemically in 23 renal transplant recipients diagnosed with CAN Biopsy specimens obtained from seven recipients with stable renal function were examined as controls. Histologic evaluation was performed based on the Banff 97 classification.
Renin-positive cells were found in the juxtaglomerular apparatus (JGA) adjoining the afferent arterioles in both groups. When the number of renin-positive cells in JGA was defined as a renin index, it was significantly higher in the CAN than the control group (P = .007). There was no significant difference in age, interval between transplantation and biopsy, and blood pressure between groups. Only a significantly higher serum creatinine was found in the CAN group.
The increased renin-positive cells in JGA suggest a significant role of the intrarenal renin-angiotensin system activation in the development of CAN.
慢性移植肾肾病（CAN）是肾移植术后首个十年内移植肾失功的主要原因。CAN的确切发病机制尚未完全明确。通过临床观察发现血管紧张素转换酶抑制剂和血管紧张素II受体阻滞剂可预防CAN，提示肾素-血管紧张素系统在CAN中可能发挥作用。
对23例诊断为CAN的肾移植受者的移植肾活检标本进行免疫组化检查，以检测肾素阳性细胞的分布情况。选取7例肾功能稳定的受者的活检标本作为对照。根据Banff 97分类法进行组织学评估。
两组入球小动脉旁的肾小球旁器（JGA）中均发现有肾素阳性细胞。将JGA中肾素阳性细胞数量定义为肾素指数，CAN组肾素指数显著高于对照组（P = .007）。两组受者的年龄、移植与活检间隔时间及血压无显著差异。仅CAN组血清肌酐显著升高。
JGA中肾素阳性细胞增多提示肾内肾素-血管紧张素系统激活在CAN发生发展中起重要作用。
