Cleveland HeartLab

The HDL Function Panel with HDLfx pCAD Score is a blood test that looks beyond “HDL cholesterol” (HDL-C) quantity to assess how well your HDL particles work. It measures a set of apolipoproteins carried on HDL-like particles and uses them to estimate HDL’s cholesterol efflux capacity (CEC)—the process by which HDL helps remove cholesterol from artery walls. The panel then reports a composite HDLfx pCAD Score that classifies relative risk for coronary atherosclerosis. Why HDL function matters While low HDL-C is linked to higher cardiovascular risk, raising HDL-C with drugs hasn’t consistently reduced events. That’s why researchers and clinicians focus on HDL function—especially CEC—as a more meaningful indicator of cardiovascular protection. What’s measured ApoA1-associated lipoprotein (AALP) apolipoproteins: ApoA1, ApoC1, ApoC2, ApoC3, ApoC4 (nmol/L), isolated using an ApoA-1 affinity method and quantified by LC-MS/MS. HDLfx pCEC: a predicted CEC derived from those proteins that correlates strongly with cell-based CEC (r = 0.86). HDLfx pCAD Score: a risk-classification algorithm reweighted from the pCEC model to improve CAD case identification. How to read the results (high level) HDLfx pCAD Score ≤ 71: lower relative risk classification > 71: higher relative risk classification (in the reference study, sensitivity ~76% and specificity ~75% for detecting coronary atherosclerosis defined as ≥50% stenosis). This score does not diagnose disease; it refines risk assessment and should be interpreted with your overall clinical picture. HDLfx pCEC (%) Sex-specific reference intervals are provided on the report (men ~8.9–14.2 % efflux/4 hr; women ~9.1–15.6 % efflux/4 hr). Higher CEC generally indicates better HDL function. AALP apolipoproteins (ApoA1, C1, C2, C3, C4) Reported with male/female reference ranges to help identify patterns associated with less favorable HDL functionality. Your clinician will interpret these in context of lipids, inflammation, diabetes status, medications, and family history. Who might consider this panel People with discordant lipid profiles (e.g., normal or high HDL-C but residual risk). Premature CAD in the family or personal history of atherosclerosis. Metabolic syndrome, insulin resistance, type 2 diabetes, chronic inflammatory conditions, or persistent risk despite statin therapy. (Clinical use should always be individualized.) Practical takeaways HDL-C is not the whole story; HDL function provides added insight. A higher pCAD Score (>71) suggests higher relative risk and may prompt more aggressive risk-factor management (lifestyle, LDL-lowering, glycemic control, blood pressure, inflammation). Use this panel to fine-tune prevention strategies alongside standard lipids, ApoB/LDL-C, inflammation markers, diabetes metrics, imaging, and clinical judgment.

The Lipoprotein Particles and Apolipoproteins category focuses on biomarkers related to cholesterol and fat transport in the body. These include various types of lipoproteins, like LDL and HDL, and apolipoproteins, which are protein components of lipoproteins. Analyzing these markers provides insights into cardiovascular risk, helping to assess the potential for heart disease and stroke. This category is key for understanding lipid metabolism and guiding interventions for heart health.