Urinary 8-oxoGuo as a potential novel evaluation index for patients with nephrotic syndrome

Abstract

Urinary 8-oxo-7,8-dihydroguanosine (8-oxoGuo) and 8-oxo-7,8-dihydro-2′- deoxyguanosine (8-oxodGuo) are considered biomarkers of oxidative stress, and patients with nephrotic syndrome have been reported to have increased oxidative stress levels. In this study, we aimed to assess the value of 8-oxoGuo and 8-oxodGuo as novel biomarkers to evaluate the severity of nephrotic syndrome. In total, 107 patients with nephrotic syndrome and 116 healthy controls were recruited for this study. The concentrations of urinary 8-oxoGuo and 8-oxodGuo were measured using isotope-labeled liquid chromatography with tandem mass spectrometry. Urinary creatinine was used to regulate 8-oxoGuo and 8-oxodGuo concentrations. Urinary 8-oxoGuo and 8-oxoGuo/Cr levels in patients with nephrotic syndrome were significantly higher than those in healthy control participants. 8-oxoGuo/Cr showed a positive correlation with the 24 h urinary total protein (UTP) and UTP levels and negative correlations with serum total protein and albumin levels. After treatment, urinary 8-oxoGuo and 8-oxoGuo/Cr levels were significantly lower in the group with a low 24 h-UTP value (<3.5 g/d) than in the high value group. 8-oxoGuo can be used as a feasible and reliable biomarker for the assessment of nephrotic syndrome.

Highlights

• Urinary 8-oxoGuo level was significantly increased in patients with nephrotic syndrome.

• Urinary 8-oxoGuo level increased with an increase in plasma protein and a decrease in urine protein.

• Urinary 8-oxoGuo level decreased with nephrotic syndrome remission when urinary microalbumin showed no significant change.

• Urinary 8-oxoGuo level can be used as novel biomarkers of nephrotic syndrome.

Keywords:

• 8-oxoGuo
• biomarker
• oxidative stress
• nephrotic syndrome

Author contributions

Conceptualization: Zhen Liu and Jian-Ping Cai; Methodology: Zhen Liu; Software: Zhen Liu; Validation: Zhen Liu and Jing-Jing Wang; Formal analysis; Zhen Liu and Qian Liu; Investigation: Zhen Liu and Jing-Jing Wang; Resources: Zhen Liu, Ya-Qing Ma, and Ya-Min Dang; Data curation: Zhen Liu and Jin Li; Writing—original draft preparation: Zhen Liu; Writing—review and editing: Zhen Liu, Shan Jiang and Jian-Ping Cai; Visualization; Zhen Liu; Supervision: Zhen Liu; Project administration: Zhen Liu and Jian-Ping Cai; Funding acquisition: Jian-Ping Cai. All authors have read and agreed to the published version of the manuscript. The authors declare that they have no competing interests.

Acknowledgments

The authors are grateful to the members of the Institute of Geriatrics of the Ministry of Health for their assistance and advice.

Institutional review board statement

The study was conducted in accordance with the Declaration of Helsinki, and approved by the institutional review board of Beijing Hospital (2019BJYYEC-054-02).

Informed consent statement

Informed consent was obtained from all subjects involved.

Disclosure statement

The authors declare that they have no competing interests.

Data availability statement

Data are available upon reasonable request to the corresponding author.

Additional information

Funding

This work was supported by the National Key R&D Program of China [2018YFC2000300], CAMS Innovation Fund for Medical Sciences [No. 2021-1-I2M-050] and the National Natural Science Foundation of China [No. 82170856].