Apo-B is the main protein component of low-density lipoprotein (LDL), often called “bad cholesterol.”

Each LDL particle contains one Apo-B molecule, making Apo-B a direct measure of LDL particle number.

Clinical uses include:

Assessing cardiovascular risk more accurately than LDL cholesterol alone.

Monitoring patients with dyslipidemia, metabolic syndrome, or coronary artery disease.

Evaluating effectiveness of lipid-lowering therapy.

Supporting diagnosis of familial hypercholesterolemia and other genetic lipid disorders.

The test is performed using a blood sample.

Analyte: Apolipoprotein B concentration in serum.

Normal Range (approximate, varies by lab):

< 90 mg/dL → desirable

90 – 120 mg/dL → borderline

120 mg/dL → high cardiovascular risk

Abnormal Findings:

High Apo-B: Indicates increased LDL particle number and higher risk of atherosclerosis and heart disease.

Low Apo-B: May occur with effective lipid-lowering therapy or certain genetic lipid disorders.
Clinical Use:

Provides a sensitive marker of atherogenic lipoproteins.

Helps refine cardiovascular risk assessment beyond standard cholesterol tests.

Guides treatment and monitoring in patients with metabolic and cardiovascular conditions.