Lipids & ApoB
Lipoprotein(a)Lp(a)
Genetically determined LDL-like particle with prothrombotic kringle domain; an independent cardiovascular risk factor.
Sample
Serum
Clinical reference range
— to 50 mg/dL
Low risk · <75 nmol/L preferred where available.
Conv: —–50 mg/dL
Biology
What it measures
Apo(a) is covalently linked to apoB-100 on an LDL particle. Concentration is 80–90% genetically determined; lifestyle and statins barely move it.
Clinical use
Why we order it
Once-in-a-lifetime measurement to refine ASCVD risk; family screening.
Lens · Clinical
Interpretation by lens
Clinical interpretation
Elevated Lp(a) >50 mg/dL warrants more aggressive LDL/apoB targets and family cascade screening.
Differential
Causes of abnormal values
Causes of HIGH
- ↑Genetic (LPA gene)
- ↑Renal failure (modest)
Pitfalls
Pre-analytic & interpretation traps
- !Statins do not lower Lp(a); some raise it ~10%. PCSK9 inhibitors lower it 20–30%.
Evidence-graded claims
What the data says
A
Lp(a) is a causal, independent ASCVD risk factor
Mendelian randomization, multiple cohorts.
E
Niacin or aspirin lower Lp(a)-mediated CV risk
No outcome trial supports this.
C
Pelacarsen (antisense oligonucleotide) reduces Lp(a) ~80% — trial pending for events
HORIZON trial ongoing.
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