Testing
Switching Lp(a) assays at a Norwegian national lab changed who counted as high-risk: the Roche assay flagged 80% more patients above 180 mg/dL than Siemens (Am J Prev Cardiol 2024)
Original title: Real-world impact of transitioning from one lipoprotein(a) assay to another in a clinical setting
This study analysed nationwide Norwegian clinical laboratory data covering 185,493 unique individuals (47.7% women, aged 18-50) with 272,463 Lp(a) measurements, comparing results from the Roche assay used between 2000 and 2009 against the Siemens assay used from 2009 to 2019 at the same central laboratory. While most individuals (66-75%) had low Lp(a) below 30 mg/dL regardless of assay, the Roche assay detected 20% more individuals above 50 mg/dL, 40% more above 100 mg/dL, and 80% more above 180 mg/dL than the Siemens assay, a discrepancy attributed to calibration differences between the two immunoassays. Simply switching laboratory assay meaningfully changed how many patients crossed clinically actionable Lp(a) thresholds, particularly at higher, more clinically consequential levels, underscoring the practical importance of assay standardisation for consistent risk stratification.
Original abstract
Background And Aims: Different lipoprotein(a) [Lp(a)] assays may affect risk stratification of individuals and thus clinical decision-making. We aimed to investigate how transitioning between Lp(a) assays at a large central laboratory affected the proportion of individuals with Lp(a) result above clinical thresholds.
Methods: We studied nationwide clinical laboratory data including 185,493 unique individuals (47.7 % women) aged 18-50 years with 272,463 Lp(a) measurements using Roche (2000-2009) and Siemens Lp(a) assay (2009-2019).
Results: While the majority of individuals (66-75 %) had low levels of Lp(a) (<30 mg/dL) independent of the assay used, the Roche assay detected 20 % more individuals with Lp(a) >50 mg/dL, 40 % more individuals with Lp(a) >100 mg/dL and 80 % more individuals with Lp(a) > 180 mg/dL than the currently used Siemens assay, likely due to calibration differences.
Conclusion: Transitioning from one Lp(a) immunoassay to another had significant impact on Lp(a) results, particularly in individuals approaching clinically relevant Lp(a) thresholds.
Summary written by lp-a.org from the published abstract; figures as published. Page updated 18 August 2026. Methods.