Newborn Screening Quality Assurance Program, 4770 Buford Highway NE, Centers for Disease Control and Prevention, Atlanta, GA 30341, USA.
Clin Biochem. 2011 Jun;44(8-9):704-10. doi: 10.1016/j.clinbiochem.2011.02.014. Epub 2011 Mar 4.
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.
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.
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.
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.
我们旨在制备用于溶酶体贮积病（LSD）筛查试验的干血斑（DBS）质量控制（QC）材料，并确定最佳的血液和 DBS 储存条件。
我们比较了成人血液、脐血和白细胞减少血液中五种 LSD 标志物的酶活性。我们在受控温度和湿度下，预先设定时间间隔，测量了液体血液和 DBS 中的活性。
脐血中的溶酶体酶活性水平与新生儿筛查样本相似。白细胞减少血液中的溶酶体酶活性低于 LSD 阳性患者样本。冷藏的液体血液中 32 天，低湿度下冷冻的 DBS 可稳定保存 1 年。在 37±1°C 下 34 天后，低湿度下 DBS 的活性损失为 35%-66%，高湿度下为 61%-100%。
脐血是 LSD 正常 DBS QC 材料的首选基质。白细胞减少血液缺乏溶酶体酶。DBS 储存过程中湿度控制不当会导致溶酶体酶活性丧失。
