LRL: Lipids Reference Laboratory

The CDC Lipids Reference Laboratory (LRL) performs reference measurement procedures for total cholesterol, total glycerides, HDL-Cholesterol and LDL-cholesterol. The performed procedures are highly accurate and precise and are well within analytical performance criteria established for CRMLN Member Laboratories. The type of reference procedure used by the LRL for each analyte are as follows:

• LDL-cholesterol: Ultracentrifugation
• HDL-cholesterol: Ultracentrifugation
• Total cholesterol: Abell Kendall
• Total glycerides: Mass spectrometry–based
• Total cholesterol: Mass spectrometry–based

Clinical decision points are derived from tests standardized to the reference methods listed above. Thus, CDC’s LRL ensures that measurement results obtained for the same analyte, but using different measurement procedures, can be compared to these same decision points.

To meet increasing demands for reference performed by mass spectrometry, the LRL maintains reference procedures based on isotope dilution gas chromatography for total cholesterol and total glycerides.

All LRL methods meet requirements necessary to avoid imprecision and bias, and are calibrated to the National Institute Standards and Technology (NIST) standard reference materials. The Joint Committee for Traceability in Laboratory medicine (JCTLM) recognizes and lists LRL reference methods in its database.

The LRL assigns target values to reference materials used in CRMLN and LSP Standardization Programs. CDC’s LRL collaborates with NIST and other domestic and international organizations to assign target values to reference materials and trueness controls. The LRL also provides reference measurement services to organizations and laboratories worldwide to improve the accuracy and reliability of cholesterol and other lipid measurements.

References

1. Edwards S, Stribling S, Pyatt S, Kimberly M. Reference measurement procedure for total glycerides by isotope dilution GC-MS. Clin Chem. 2012 58(4):768-776
2. Handbook of Lipoprotein Testing, 2nd Edition. Washington DC: AACC Press 2001
3. Edwards S, Kimberly M, Pyatt S, Stribling S, Dobbin K, Myers G. Proposed serum cholesterol reference measurement procedure by gas chromatography-isotope dilution mass spectrometry. Clin Chem. 2011 Apr; 57(4):614-22
4. Cooper G et al. Interlaboratory testing of the transferability of a candidate reference method for total cholesterol in serum. Clin. Chem., 1986, 32, 921-929