Apolipoprotein E to B ratio: a marker for type III hyperlipoproteinaemia.

Apolipoproteins B and E were determined in 40 patients with type III hyperlipoproteinaemia (familial dysbetalipoproteinaemia) and in 48 patients with other types of hyperlipoproteinaemia matched for cholesterol and triacylglycerols. In type III patients, apolipoprotein E was increased and apolipoprotein B was lower than in other types of hyperlipoproteinaemia. The apolipoprotein E to apolipoprotein B ratio almost completely discriminated between type III and other types of hyperlipoproteinaemia. Assuming a cut-off value of 0.09 for the apolipoprotein E to apolipoprotein B ratio, diagnostic sensitivity was 95% and specificity was 88%. It is concluded that the apolipoprotein E to apolipoprotein B ratio represents the first-line screening quantity of choice for the identification of patients with type III hyperlipoproteinaemia in the clinical laboratory.