Steubl Dominik, Hettwer Stefan, Dahinden Pius, Luppa Peter, Rondak Ina-Christine, Regenbogen Claudia, Stock Konrad F, Renders Lutz, Heemann Uwe, Roos Marcel
Abteilung für Nephrologie, Klinikum rechts der Isar, Technische Universität München, Ismaninger Str. 22, 81675, Munich, Germany,
Int Urol Nephrol. 2015 Feb;47(2):391-6. doi: 10.1007/s11255-014-0852-5. Epub 2014 Oct 29.
C-terminal agrin fragment (CAF, size 22 kDa) is a promising new biomarker for kidney function. This study evaluated the usefulness of CAF as a serum biomarker for residual renal function (RRF) in patients undergoing automated peritoneal dialysis (APD).
Serum, urine and dialysate samples were obtained in 12 end-stage renal disease patients undergoing APD. Total, renal and peritoneal clearances were calculated for CAF, creatinine, blood urea nitrogen (BUN) and cystatin c. kt/V was computed, and RRF (in ml/min) was calculated as the arithmetic mean of creatinine and BUN clearance. Correlations between the biomarkers' serum concentrations, clearances, kt/V and RRF were computed.
Serum CAF concentrations were highly correlated with serum concentrations of creatinine (r = 0.806, p = 0.002), BUN (r = 0.727, p = 0.007), cystatin c (r = 0.839, p = 0.001) and inversely to 24-h urinary output (r = -0.669, p = 0.017). RRF was inversely correlated with serum concentrations of CAF, cystatin c and creatinine being highest for CAF (r = -0.734, p = 0.007) followed by cystatin c (r = -0.65, p = 0.022) and creatinine (r = -0.606, p = 0.037). Serum BUN was not significantly associated with RRF (r = -0.497, p = 0.101). Age, weight and gender did not significantly affect serum CAF concentrations.
Serum CAF provides a robust serum biomarker for RRF in peritoneal dialysis patients undergoing APD, possibly outperforming the value of conventional biomarkers.
C 端聚集蛋白聚糖片段（CAF，大小为 22 kDa）是一种很有前景的新型肾功能生物标志物。本研究评估了 CAF 作为接受自动化腹膜透析（APD）患者残余肾功能（RRF）血清生物标志物的实用性。
收集了 12 例接受 APD 的终末期肾病患者的血清、尿液和透析液样本。计算了 CAF、肌酐、血尿素氮（BUN）和胱抑素 c 的总清除率、肾清除率和腹膜清除率。计算了 kt/V，并将 RRF（以 ml/min 为单位）计算为肌酐和 BUN 清除率的算术平均值。计算了生物标志物的血清浓度、清除率、kt/V 与 RRF 之间的相关性。
血清 CAF 浓度与肌酐血清浓度（r = 0.806，p = 0.002）、BUN（r = 0.727，p = 0.007）、胱抑素 c（r = 0.839，p = 0.001）高度相关，与 24 小时尿量呈负相关（r = -0.669，p = 0.017）。RRF 与 CAF、胱抑素 c 和肌酐的血清浓度呈负相关，其中 CAF 相关性最高（r = -0.734，p = 0.007），其次是胱抑素 c（r = -0.65，p = 0.022）和肌酐（r = -0.606，p = 0.037）。血清 BUN 与 RRF 无显著相关性（r = -0.497，p = 0.101）。年龄、体重和性别对血清 CAF 浓度无显著影响。
血清 CAF 为接受 APD 的腹膜透析患者的 RRF 提供了一种可靠的血清生物标志物，可能优于传统生物标志物的价值。
