Characteristics of urinary and serum soluble Klotho protein in patients with different degrees of chronic kidney disease

BMC Nephrology

Research Article

Makoto Kuro-o¹  Kazuhiro Shiizaki¹  Yoshiyuki Morishita²  Yasuhiro Ando²  Tetsu Akimoto²  Naoko Otani²  Hiromichi Yoshizawa²  Takanori Komada²  Eiji Kusano²  Akihiko Numata²  Chiharu Ito²  Shigeaki Muto²  Eri Takeshima²  Tomoyuki Yamazaki²  Kana Iwazu²  Yuko Watanabe² 

[1] Department of Pathology, University of Texas Southwestern Medical Center, 6000 Harry Hines Blvd., 75390-9072, Dallas, TX, USA;Division of Nephrology, Department of Internal Medicine, Jichi Medical University, 3311-1 Yakushiji, 329-0498, Shimotsuke-Shi, TOCHIGI, Japan;

关键词: Klotho;    Chronic kidney disease;    Renal function;    Urinary protein;    Creatinine;   

DOI  :  10.1186/1471-2369-13-155

 received in 2012-05-08, accepted in 2012-11-18,  发布年份 2012

来源: Springer

【 摘 要 】

BackgroundKlotho is a single-pass transmembrane protein, which appears to be implicated in aging. The purpose of the present study was to characterize the relationship between the soluble Klotho level and renal function in patients with various degrees of chronic kidney disease (CKD).MethodsThe levels of soluble Klotho in the serum and urine obtained from one hundred thirty-one CKD patients were determined by a sandwich enzyme-linked immunosorbent assay system.ResultsThe amount of urinary excreted Klotho during the 24 hr period ranged from 1.6 to 5178 ng/day (median 427 ng/day; interquartile range [IR] 56.8-1293.1), and the serum Klotho concentration ranged from 163.9 to 2123.7 pg/ml (median 759.7 pg/ml; IR 579.5-1069.1). The estimated glomerular filtration rate (eGFR) was significantly correlated with the log-transformed values of the amount of 24 hr urinary excreted Klotho (r = 0.407, p < 0.01) and the serum Klotho levels (r = 0.232, p < 0.01). However, a stepwise multiple regression analysis identified eGFR to be a variable independently associated only with the log-transformed value of the amount of 24-hr urinary excreted Klotho but not with the log-transformed serum Klotho concentration. Despite the strong correlation between random urine protein-to-creatinine ratio and the 24 hr urinary protein excretion (r = 0.834, p < 0.01), a moderate linear association was observed between the log-transformed value of the amount of 24 hr urinary excreted Klotho and that of the urinary Klotho-to-creatinine ratio (Klotho/Cr) in random urine specimens (r = 0.726, p < 0.01).ConclusionsThe amount of urinary Klotho, rather than the serum Klotho levels, should be linked to the magnitude of the functioning nephrons in CKD patients. The use of random urine Klotho/Cr as a surrogate for the amount of 24-hr urinary excreted Klotho needs to be evaluated more carefully.

【 授权许可】

CC BY   
© Akimoto et al.; licensee BioMed Central Ltd. 2012