[Development of the HDL-C and LDL-C direct methods and the subsequent evolution].

Today, more than a decade after the development of direct methods for determining HDL-cholesterol (HDL-C) and LDL-cholesterol (LDL-C) concentrations, there are calls to review the reagents in response to discrepancies in patient samples with increased levels of atypical lipoproteins, such as apoE-rich HDL, IDL, Lp-X, and Lp-Y. Seven direct HDL-C assays showed different reactions toward apoE-rich HDL in sera from patients with CETP deficiency and cholestasis. On the other hand, the reactivity of the direct LDL-C assays to serum samples with elevated levels of IDL, Lp-X, and Lp-Y varied considerably between assay kits from each manufacturer.