BACKGROUND AND AIMS: Lipoprotein-associated phospholipase A(2) (Lp-PLA(2)) is a 
pro-atherogenic phospholipase A(2), which is predominantly complexed to 
low-density lipoprotein (LDL) particles. Proprotein convertase subtilisin-kexin 
type 9 (PCSK9) provides a key step in LDL metabolism by stimulating LDL receptor 
degradation. We determined relationships between plasma PCSK9 and Lp-PLA(2) 
mass.
METHODS: Lp-PLA(2) mass (turbidimetric immunoassay), PCSK9 (enzyme-linked 
immunosorbent assay) and (apo) lipoproteins were measured in 53 nondiabetic 
subjects (27 women) with body mass index <30 kg/m(2).
RESULTS: Lp-PLA(2) and PCSK9 levels were both correlated positively with LDL 
cholesterol and non-high-density lipoprotein (HDL) cholesterol (r = 0.330 to r = 
0.382, p ≤0.02). Remarkably, Lp-PLA(2) was inversely related to PCSK9 (r = 
-0.388, p = 0.004). The Lp-PLA(2)/apolipoprotein B ratio, as a measure of the 
Lp-PLA(2) content in apolipoprotein B-containing lipoproteins, was also 
inversely correlated with PCSK9 (r = -0.575, p <0.001). The inverse 
relationships of Lp-PLA(2) (p = 0.023) and the Lp-PLA(2)/apolipoprotein B ratio 
(p = 0.001) with PCSK9 levels remained significant after controlling for age, 
gender, triglycerides and HDL cholesterol.
CONCLUSIONS: Despite increasing effects on LDL cholesterol, higher PCSK9 levels 
are unlikely to confer impaired Lp-PLA(2) metabolism. We propose to evaluate the 
possible influence of PCSK9 inhibiting strategies on Lp-PLA(2) regulation and 
vice versa to determine effects of Lp-PLA(2) inhibitors on the PCSK9 pathway.