ApoB and Lp(a) Tests: What Guidelines Say and What They Cost

The short answer: ApoB and Lp(a) are two blood tests that look beyond the standard cholesterol panel. ApoB counts atherogenic particles; Lp(a) is a mostly inherited particle that independently raises heart attack and stroke risk. The 2026 ACC/AHA guideline recommends measuring Lp(a) at least once in every adult, according to the ACC’s own summary, and gives ApoB a narrower role. On Quest’s site (2 Oct 2026) Lp(a) alone is $45 plus a $6 fee, and a panel including ApoB is $215. This page describes what the tests measure and what guidelines say; it is not medical advice, and results should be discussed with a clinician.

What each test measures

• ApoB (apolipoprotein B) is a protein on each atherogenic lipoprotein particle, so one ApoB roughly equals one particle. It is a particle count, where LDL-C is cholesterol mass. A 2026 comparison of the 2025 ESC/EAS and 2026 ACC/AHA guidelines says both frameworks share the premise that LDL-C and other ApoB-containing lipoproteins are causal drivers of atherosclerotic disease (Eur J Prev Cardiol 2026).
• Lp(a) is an LDL-like particle with an extra protein attached. The JAMA 2009 pooled analysis of 126,634 people in 36 prospective studies found Lp(a) highly consistent within a person over several years and modestly associated with coronary heart disease (adjusted risk ratio 1.13 per standard deviation, 95% CI 1.09 to 1.18) and ischaemic stroke (1.10). The 2022 European Atherosclerosis Society consensus calls the association causal and continuous.

What guidelines say

Differences to know: the European documents use mg/dL and nmol/L thresholds that are not interchangeable by one fixed factor (the 2025 ESC pairs 50 mg/dL with 105 nmol/L, while the ACC summary quotes thresholds in nmol/L), so check which unit your lab reports. We read the ACC’s summary, the publisher page of the 2025 ESC/EAS update and PubMed records; the full texts of the 2026 ACC/AHA guideline (AHA journals, 403) and the 2019 ESC/EAS guideline (OUP PDF, 403) were behind publisher blocks, so those two rows rest on the ACC summary and secondary sources, as labelled. Do not read the table as personal advice.

What the tests cost (direct to consumer, 2 Oct 2026)

Quest lists Lp(a) as usually a once-only test because levels are stable. Insurance or a clinician’s order can change what you pay; prices vary by lab and country and were read from each company’s page on the date shown.

What to do with this

A test measures a number; it does not tell you what to do. Ask a clinician whether and when testing makes sense for you, particularly with a family history of early heart disease or high Lp(a). The biomarkers guide puts ApoB among other markers, at-home blood tests compares services, and longevity labs covers ordering routes.

Method note

Researched from PubMed records, the ACC’s guideline summary, the OUP page for the 2025 update, and the Quest and Function pages, checked 2 Oct 2026. The 2026 ACC/AHA and 2019 ESC/EAS full texts were not readable by our tools; where a class of recommendation comes from a secondary summary, the table says so. We did not order any test. General information, not medical advice.