OBJECTIVE: We aimed to prepare dried-blood spot (DBS) quality control (QC) materials for lysosomal storage disease (LSD) screening tests and to determine optimum blood and DBS storage conditions. METHODS: We compared enzyme activities of five LSD markers in adult blood, umbilical-cord blood, and leukocyte-reduced blood. We measured activities in liquid blood and DBSs after predetermined intervals at controlled temperatures and humidities. RESULTS: Lysosomal-enzyme activity levels in umbilical-cord blood mimicked those in newborn screening samples. Lysosomal-enzyme activities in leukocyte-reduced blood were lower than in LSD-positive patient samples. Enzyme activities were stable in refrigerated liquid blood for 32 days and in frozen DBSs stored at low humidity for a year. Activity losses from DBSs after 34 days at 37±1°C were 35%-66% in low humidity and 61%-100% in high humidity. CONCLUSIONS: Umbilical-cord blood is the preferred matrix for LSD-normal DBS QC materials. Leukocyte-reduced blood is lysosomal enzyme-deficient. Failure to control humidity during DBS storage results in loss of lysosomal-enzyme activities. Published by Elsevier Inc.
OBJECTIVE: We aimed to prepare dried-blood spot (DBS) quality control (QC) materials for lysosomal storage disease (LSD) screening tests and to determine optimum blood and DBS storage conditions. METHODS: We compared enzyme activities of five LSD markers in adult blood, umbilical-cord blood, and leukocyte-reduced blood. We measured activities in liquid blood and DBSs after predetermined intervals at controlled temperatures and humidities. RESULTS: Lysosomal-enzyme activity levels in umbilical-cord blood mimicked those in newborn screening samples. Lysosomal-enzyme activities in leukocyte-reduced blood were lower than in LSD-positive patient samples. Enzyme activities were stable in refrigerated liquid blood for 32 days and in frozen DBSs stored at low humidity for a year. Activity losses from DBSs after 34 days at 37±1°C were 35%-66% in low humidity and 61%-100% in high humidity. CONCLUSIONS: Umbilical-cord blood is the preferred matrix for LSD-normal DBS QC materials. Leukocyte-reduced blood is lysosomal enzyme-deficient. Failure to control humidity during DBS storage results in loss of lysosomal-enzyme activities. Published by Elsevier Inc.
Authors: Rebekah Nixon; Ting Hin Richard Ip; Benjamin Jenkins; Ping K Yip; Paul Clarke; Vennila Ponnusamy; Adina T Michael-Titus; Albert Koulman; Divyen K Shah Journal: Nutrients Date: 2021-11-28 Impact factor: 5.717
Authors: Joseph J Orsini; Denise M Kay; Carlos A Saavedra-Matiz; David A Wenger; Patricia K Duffner; Richard W Erbe; Chad Biski; Monica Martin; Lea M Krein; Matthew Nichols; Joanne Kurtzberg; Maria L Escolar; Darius J Adams; Georgianne L Arnold; Alejandro Iglesias; Patricia Galvin-Parton; David F Kronn; Jennifer M Kwon; Paul A Levy; Joan E Pellegrino; Natasha Shur; Melissa P Wasserstein; Michele Caggana Journal: Genet Med Date: 2016-01-21 Impact factor: 8.822