Which of the following is described as a variant form of LDL associated with increased risk of atherosclerotic cardiovascular disease?

• A. Lp(a)
• B. HDL
• C. ApoA-I
• D. ApoA-II

Answer: (A)

Lp(a) is the LDL-like particle that carries an additional apolipoprotein, apo(a), attached to the LDL protein ApoB-100. This unique structure makes it more atherogenic and pro-thrombotic, contributing to higher risk of atherosclerotic cardiovascular disease beyond what typical LDL cholesterol levels predict. The apo(a) component also resembles plasminogen, which can interfere with fibrinolysis and promote thrombosis, further increasing vascular risk. Levels are largely genetically determined and not easily altered by lifestyle, so Lp(a) stands out as a distinct, risk-enhancing lipoprotein particle.

HDL and its apolipoproteins (ApoA-I, ApoA-II) are associated with reverse cholesterol transport and protective effects, not LDL-like particles with apo(a); they don’t represent the variant described.