Supplementary Material for: Hypertension in living kidney donors has no effect on complement activation and fibrosis

Background: In the past, elevated blood pressure was considered an exclusion criterion for living kidney donation because of concerns about premature kidney failure. Hypertension leads to complement deposits and renal fibrosis in the kidney. Therefore, the aim of this study was to investigate whether increased complement deposits and fibrosis can be observed in grafts of hypertensive compared to normotensive living donors. Methods: Zero-time renal biopsies from 238 living donors (52 hypertensive) and the corresponding one-year protocol biopsies were examined for complement deposits of C1q, C3c, and MASP-2. Findings were compared to kidney biopsies from patients with hypertensive nephropathy. Further, renal fibrosis was visualized by Sirius Red staining, scored semiquantitatively and compared to biopsies from deceased donors and kidneys with hypertensive nephropathy. Additionally, zero-time biopsies from hypertensive (n = 6) and normotensive (n = 5) living donors were analyzed for expression of fibrosis-associated genes by multiplex mRNA analysis and compared to zero-time biopsies (n = 6) from deceased donors. Results: In all zero-time biopsies from living donors, complement deposits were minimal for C1q, C3c, and MASP-2 compared to samples with hypertensive nephropathy, regardless of whether the donor was hypertensive or normotensive. In one-year protocol biopsies, complement deposits were unchanged, while renal fibrosis was slightly but not significantly increased in hypertensive compared to normotensive living donors. Gene expression data showed that the 11 zero-time biopsies from hypertensive and normotensive living donors clustered together, and were clearly separated from the deceased donor biopsies. Conclusion: The use of kidneys from hypertensive living donors appears to have no or little effect on renal complement deposits and fibrosis one year after transplantation.背景：既往由于担心供者会出现过早肾衰竭，血压升高曾被视为活体肾脏捐献（living kidney donation）的排除标准。高血压（Hypertension）可引发肾脏补体沉积（complement deposits）与肾纤维化（renal fibrosis）。因此本研究旨在探究，与血压正常（normotensive）的活体供肾者相比，高血压供者的移植肾（grafts）中是否可观察到补体沉积与纤维化程度升高。方法：本研究纳入238例活体供者（其中52例为高血压患者）的即刻肾活检（zero-time renal biopsies）标本，以及对应的术后1年方案规定活检标本，检测其中补体C1q（C1q）、C3c（C3c）及MASP-2（MASP-2）的沉积情况，并将检测结果与高血压性肾病（hypertensive nephropathy）患者的肾活检标本进行对比。此外，通过天狼星红染色（Sirius Red staining）可视化肾纤维化程度，采用半定量法进行评分，并与尸体供者（deceased donors）肾活检标本及高血压性肾病肾活检标本进行对比。另外，针对6例高血压活体供者与5例血压正常活体供者的即刻肾活检标本，采用多重mRNA分析（multiplex mRNA analysis）检测纤维化相关基因（fibrosis-associated genes）的表达水平，并与6例尸体供者的即刻肾活检标本进行对比。结果：无论供者为高血压患者还是血压正常者，与高血压性肾病标本相比，所有活体供者的即刻肾活检标本中，C1q、C3c及MASP-2的补体沉积水平均极低。在术后1年的方案规定活检标本中，补体沉积水平无明显变化；而与血压正常的供者相比，高血压供者的肾纤维化程度仅出现轻度升高，但该差异无统计学意义。基因表达数据显示，来自高血压与血压正常活体供者的11份即刻肾活检标本聚为一类，且与尸体供者的肾活检标本明显区分开来。结论：高血压活体供者的肾脏用于移植后，对移植术后1年的肾脏补体沉积与肾纤维化似乎无明显或仅存在极轻微影响。