Holtrop T G, Yee H Y, Simpson P M, Kauffman R E
Department of Pediatrics, Children's Hospital of Michigan, Wayne State University School of Medicine, Detroit 48201, USA.
Arch Pediatr Adolesc Med. 1998 May;152(5):455-8. doi: 10.1001/archpedi.152.5.455.
To test whether a method of fingerstick blood sample collection onto filter paper could be used as an alternative screening method in the field in settings where environmental lead contamination is a high risk.
Members of the Pediatric Mobile Team of Children's Hospital of Michigan, Detroit, collected paired venous and capillary blood samples from 120 children, aged 6 months to 6 years, who presented for services at any of 7 sites located in decaying neighborhoods of older sections of Detroit. All samples were analyzed for lead content by graphite furnace atomic absorption spectrometry.
When filter paper samples with blood lead levels of 0.48 micromol/L (10 microg/dL) or higher were compared with matched venous samples, the concordance coefficient was 0.96. The sensitivity and specificity of the filter paper samples relative to the venous samples for a cutoff of 0.48 micromol/L (10 microg/dL) or higher were 94% and 99%, respectively, with a positive predictive value of 97%. However, at a cutoff of 0.72 micromol/L (15 microg/dL), the sensitivity and specificity dropped to 75% and 98%, respectively, with filter paper samples underreporting blood lead values. At any cutoff point (0.48, 0.72, or 0.96 micromol/L [10, 15, or 20 microg/dL]), the filter paper method was highly specific for lead.
Capillary filter paper sampling is an accurate and practical alternative to venous sampling for blood lead screening using 0.48 micromol/L (10 microg/dL) as the cutoff. The filter paper method predicts levels of 0.72 micromol/L (15 microg/dL) or higher less well. The cause of divergent values above 0.72 micromol/L (15 microg/dL) is not clear. Environmental contamination of capillary filter paper, however, does not seem to be an explanation.
检测在环境铅污染风险较高的地区，将手指采血样本采集到滤纸上的方法能否用作现场替代筛查方法。
密歇根州底特律市儿童医院儿科流动团队的成员，从120名年龄在6个月至6岁的儿童中采集配对的静脉血和毛细血管血样本，这些儿童在底特律老城区衰败社区的7个地点中的任何一个地点接受服务。所有样本均采用石墨炉原子吸收光谱法分析铅含量。
将血铅水平为0.48微摩尔/升（10微克/分升）或更高的滤纸样本与匹配的静脉样本进行比较时，一致性系数为0.96。滤纸样本相对于静脉样本，血铅水平截止值为0.48微摩尔/升（10微克/分升）或更高时的灵敏度和特异性分别为94%和99%，阳性预测值为97%。然而，在截止值为0.72微摩尔/升（15微克/分升）时，灵敏度和特异性分别降至75%和98%，滤纸样本会漏报血铅值。在任何截止点（0.48、0.72或0.96微摩尔/升[10、15或20微克/分升]），滤纸法对铅的检测具有高度特异性。
以0.48微摩尔/升（10微克/分升）为截止值进行血铅筛查时，毛细血管滤纸采样是静脉采样的一种准确且实用的替代方法。滤纸法对0.72微摩尔/升（15微克/分升）或更高水平的预测效果较差。高于0.72微摩尔/升（15微克/分升）时出现差异值的原因尚不清楚。然而，毛细血管滤纸的环境污染似乎并不是一个解释。
