Objective: To evaluate whether urinary phospholipids could be regarded as biomarkers of chronic kidney disease.
Materials and methods: Thirteen healthy volunteers and 26 consecutive chronic kidney disease patients were included. Urinary phospholipids were quantified by high-performance liquid chromatography coupled with electrospray ionization tandem mass spectrometry.
Results: Urinary phosphatidylcholines concentrations (PC 16:0/16:0, 16:0/22:3, 16:0/18:1 and 16:0/18:2) were significantly higher both in glomerulonephritis group (all p < 0.001) and in tubulointerstitial injury group (all p < 0.05) than in healthy control group. Meanwhile, sphingomyelin concentrations (SM 18:1/16:0 and 18:1/18:0) in glomerulonephritis group were significantly higher than those in healthy control group (all p < 0.001). Urinary PCs and SMs were positively correlated with proteinuria but negatively correlated with serum albumin. Meanwhile, PCs were positively correlated with serum creatinine.
Conclusion: Our work first demonstrated that urinary phospholipids might be biomarkers for the chronic kidney disease patients. Increased urinary phospholipids in chronic kidney disease patients might result from proteinuria, damaged kidney function or proteinuria induced hypoalbuminemia or lipotoxicity.