Metabolomics profiling for diagnosis of acute renal failure after cardiopulmonary bypass

Acute renal failure (ARF) is one of the most serious complications of cardiopulmonary bypass (CPB) surgery. Serum creatinine level is a key compound examined to understand whether renal function is normal. However, its level may vary based on age, gender, race, muscle mass, nutrition, and drugs taken by an individual. In addition, it may not be detected without a 50% reduction in renal function and may lead to delays in treatment. New markers are needed for early diagnosis of ARF. They were determined for early diagnosis of ARF after CPB. Metabolic differences in plasma samples of individuals who developed and did not develop ARF after cardiopulmonary bypass were determined.

This study was the first to perform an untargeted metabolomics analysis for early diagnosis of ARF after CPB surgery. Plasma samples were taken from 105 patients (9 ARF patients) at five time points to identify the time at which a more accurate ARF diagnosis can be made. A total of 687 samples, including quality control samples, were analyzed.

Two hundred twenty-six metabolites were identified using retention index libraries. Based on the statistical evaluations, tryptophan, threonine, and methionine were found in lower concentrations in patients with ARF compared to the control group at all time points. Whereas gluconic acid, hypoxanthine, and lactic acid showed a decreasing trend over time, longitudinal analysis showed that cysteine, hippuric acid, and uric acid levels increased over time in the ARF group.

These metabolites are candidate biomarkers for early diagnosis of ARF as well as biomarkers for tracking the recovery of ARF patients.