Rolfe P B, Marcinak J F, Nice A J, Williams R H
Department of Pediatrics, University of Illinois, Chicago 60612.
Am J Dis Child. 1993 Jan;147(1):66-8. doi: 10.1001/archpedi.1993.02160250068020.
To determine the usefulness of zinc protoporphyrin, as measured by the Helena Protofluor-Z hematofluorometer, for detecting elevated lead levels.
Observational, descriptive review of laboratory records from a university toxicology laboratory.
Inner-city university pediatric clinic and two affiliated community clinics in Chicago, Ill.
Seven hundred seventy-five children younger than 7 years with paired lead-zinc protoporphyrin results.
MEASUREMENTS/RESULTS: Fifty-six percent had lead levels of at least 0.48 mumol/L and 8% had lead levels of at least 1.21 mumol/L. The sensitivity, positive predictive value, and negative predictive value of a zinc protoporphyrin level of 70 mumol/mol of hemoglobin for detecting a lead level of 0.48 mumol/L were 42%, 66%, and 50%, respectively, and for a lead level of 1.21 mumol/L were 74%, 18%, and 97%, respectively. Receiver operating characteristic curves demonstrated that for detecting lead levels of 0.48 mumol/L with zinc protoporphyrin, the probability of a true-positive result is close to that of a false-positive one.
Zinc protoporphyrin is not a reliable screening test for detecting low blood lead levels.
通过海伦娜Protofluor-Z血液荧光计测量，确定锌原卟啉在检测铅水平升高方面的效用。
对一所大学毒理学实验室的实验室记录进行观察性、描述性回顾。
伊利诺伊州芝加哥市的市中心大学儿科诊所及两家附属社区诊所。
775名7岁以下儿童，其铅和锌原卟啉检测结果配对。
测量指标/结果：56%的儿童铅水平至少为0.48μmol/L，8%的儿童铅水平至少为1.21μmol/L。血红蛋白中锌原卟啉水平为70μmol/mol时，检测铅水平为0.48μmol/L的灵敏度、阳性预测值和阴性预测值分别为42%、66%和50%，检测铅水平为1.21μmol/L时分别为74%、18%和97%。受试者工作特征曲线表明，用锌原卟啉检测铅水平为0.48μmol/L时，真阳性结果的概率与假阳性结果相近。
锌原卟啉并非检测低血铅水平的可靠筛查试验。
