Department of Medicine, and London Health Sciences Centre, Nephrology Division, The University of Western Ontario, London, Canada.
Clin J Am Soc Nephrol. 2009 Oct;4(10):1606-10. doi: 10.2215/CJN.02910509. Epub 2009 Aug 27.
Cystatin C, a low molecular weight protein, is produced by nucleated cells, filtered by glomeruli, and degraded by tubules at a constant rate. Its serum concentration has been proposed as a marker of GFR. Its size should make it dialyzable. It is hypothesized that serum cystatin C levels are influenced by the method and intensity of dialysis received.
This is a cross-sectional pilot study of cystatin C in functionally anephric dialysis patients. It was measured predialysis in 14 patients on conventional (3 to 5 h, 3 x wk) hemodialysis; eight on nocturnal hemodialysis (three to seven nights, 6 to 8 h); three on daily hemodialysis (6 d, 1(1/2) to 2(1/2) h); and 10 on automated peritoneal dialysis. All had urea kinetic studies and values for single pool Kt/V (Sp Kt/V), standard weekly Kt/V (Std Kt/V), and protein equivalent of nitrogen appearance (nPNA; g/kg/d). C reactive protein (CRP; mg/L) and thyroid stimulating hormone (TSH; mIU/L) were measured as factors known to influence cystatin C.
There was no correlation between cystatin C and Sp Kt/V, but there was a significant inverse linear correlation with Std Kt/V and there were significant differences between treatment modalities in cystatin C levels and in Std Kt/V. The estimation of cystatin C was reliable and stable over 3 to 6 wk and its levels uninfluenced by nPNA, CRP, or TSH.
Serum cystatin C levels are influenced by the method and intensity of dialysis and may have a role in treatment adequacy monitoring.
胱抑素 C 是一种低分子量蛋白质，由有核细胞产生，经肾小球滤过，在肾小管以恒定速率降解。其血清浓度已被提出作为 GFR 的标志物。由于其分子量较小，理论上应该可以被透析清除。因此，有人假设血清胱抑素 C 水平受到透析方式和强度的影响。
这是一项关于功能性无尿透析患者胱抑素 C 的横断面研究。共纳入 14 名患者，他们分别接受常规透析（3-5 小时，每周 3 次）、夜间透析（3-7 晚，6-8 小时）、每日透析（6 天，1.5-2.5 小时）和自动化腹膜透析治疗。所有患者均进行了尿素动力学研究，计算单室 Kt/V（Sp Kt/V）、标准每周 Kt/V（Std Kt/V）和蛋白分解率（nPNA；g/kg/d）。还测量了 C 反应蛋白（CRP；mg/L）和促甲状腺激素（TSH；mIU/L）作为已知影响胱抑素 C 的因素。
胱抑素 C 与 Sp Kt/V 之间无相关性，但与 Std Kt/V 呈显著负线性相关，不同透析方式之间的胱抑素 C 水平和 Std Kt/V 存在显著差异。胱抑素 C 的估计值在 3-6 周内是可靠且稳定的，其水平不受 nPNA、CRP 或 TSH 的影响。
血清胱抑素 C 水平受到透析方式和强度的影响，可能在评估治疗充分性方面具有一定作用。
