Correlation between plasma proprotein convertase subtilisin/kexin type 9 and blood lipids in patients with newly diagnosed primary nephrotic syndrome.

Background: Proprotein convertase subtilisin/kexin type 9 (PCSK9) is a major post-transcriptional regulator of low-density lipoprotein receptor degradation. Recently, PCSK9 was shown to be overexpressed by liver cells in rats with proteinuria. However, the levels of PCSK9 in newly diagnosed primary nephrotic syndrome (PNS) patients and correlations involving PCSK9 and blood lipids are not clearly understood. Methods: One hundred and sixteen patients who were newly diagnosed with PNS were enrolled in this study. Results: Plasma PCSK9 levels in PNS patients were significantly higher than those in healthy controls [310.86 (250.87, 390.25) ng/ml vs 255.67 (202.26, 320.26) ng/ml, p = 0.002]. Plasma PCSK9 in PNS patients was positively correlated with total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) (gamma = 0.246, p = 0.008, and gamma = 0.183, p = 0.049). When plasma PCSK9 was >267.60 ng/ml, the risk of developing hypercholesterolemia significantly increased in PNS patients (OR = 6.40, 95% CI 2.06-19.87, p = 0.001). When plasma PCSK9 was >255.05 ng/ml, the risk of developing higher levels of LDL-C significantly increased in PNS patients (OR = 3.83, 95%CI 1.25-11.68, p = 0.018). Conclusions: Plasma PCSK9 levels in newly diagnosed PNS patients were markedly increased, and elevated PCSK9 abundance was positively correlated with elevated serum TC and LDL-C levels, suggesting that PCSK9 may emerge as a novel therapeutic target in NS-associated hypercholesterolemia.