title: Analytical performance and clinical utility of a direct LDL-cholesterol assay in a hyperlipidemic pediatric population.
abstract: This study compares a new latex immunoseparation method for the direct determination of plasma low-density lipoprotein cholesterol (LDL-C) with the reference procedure for LDL-C (beta-quantification) in a pediatric hyperlipidemic population. The direct LDL-C assay has a mean bias of -98 mg/L in a fasting group (n = 96) of patients (mean triglycerides 1057 +/- 720 mg/L) and a bias of +177 mg/L in a nonfasting group (n = 42, mean triglycerides 4854 +/- 5457 mg/L). The mean total analytical error calculated from our data is 13.8%. The direct LDL-C assay and the commonly used Friedewald calculation respectively classified 81% and 84% of fasting patients correctly, according to the cutoffs of 1100 and 1300 mg/L for LDL-C set by the National Cholesterol Education Program for pediatric patients. Of combined fasting and nonfasting patients, 80% were correctly classified by the direct LDL-C assay. Therefore, despite several analytical shortcomings, the direct LDL-C assay may be useful in managing hyperlipidemic children without the need for a fasting specimen.
authors.affiliation: Department of Laboratory Medicine, Children's Hospital, Boston, MA 02115, USA.
authors.forename: N
authors.initials: N
authors.lastname: Harris
authors.forename: E J
authors.initials: EJ
authors.lastname: Neufeld
authors.forename: J W
authors.initials: JW
authors.lastname: Newburger
authors.forename: B
authors.initials: B
authors.lastname: Ticho
authors.forename: A
authors.initials: A
authors.lastname: Baker
authors.forename: G S
authors.initials: GS
authors.lastname: Ginsburg
authors.forename: E
authors.initials: E
authors.lastname: Rimm
authors.forename: N
authors.initials: N
authors.lastname: Rifai
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D008078:Cholesterol, LDL / Q000097:blood*; D005215:Fasting; D006801:Humans; D006949:Hyperlipidemias / Q000097:blood*; D007118:Immunoassay / Q000379:methods* / Q000706:statistics & numerical data*; D007223:Infant; D011786:Quality Control; D012680:Sensitivity and Specificity; D014280:Triglycerides / Q000097:blood
chemical_list: D008078:Cholesterol, LDL; D014280:Triglycerides