β-Lipoprotein quantitation in cord blood spotted on filter paper: A screening test

The authors describe an electroimmunodiffusion technique for measuring β-lipoprotein in cord blood spotted on filter paper. A series of cord-blood samples, taken from 916 consecutive live-birth infants, was spotted directly onto filter paper and assayed for β-lipoprotein. Eleven had above-normal β-lipoprotein. Of these 11, 7 were tested 2 to 6 mth later, along with their parents, for total cholesterol and triglyceride concentrations. Five infants had increased cholesterol values, and 4 parents of these infants had either increased cholesterol or triglyceride values. The authors also measured β-lipoprotein concentrations in 63 paired samples of dried cord-blood and 3-day post-delivery blood specimens, routinely collected for phenylketonuria screening. They saw a significant correlation between results for the specimens, but detected no cases of increased β-lipoprotein. β-Lipoprotein assay in dried specimens of cord blood is simple, inexpensive, and potentially is useful in mass screening of newborns for familial type II and combined hyperlipidemia.