铅中毒筛选指标的再评价

Re-assessment of Indicators for Screening Lead Poisoning

目的评价铅中毒筛选指标的准确性。方法连续收集157名铅接触工人的血标本，同时测定血铅、红细胞游离原叶啉（FEP）、锌叶啉（ZPP）、尿铅、尿δ-氨基-酮戊酸（δ-ALA），红细胞嘧啶5’核苷酸酶（P5’N）的活性。以血铅≥1．93μmol／L、≥2.90μmol／L为金标准，用受试者工作特征（ROC）曲线下的面积评价上述指标在血铅≥1．93μmol／L、≥2．90μmol／L的准确性，用ROC曲线分析软件、EPINFOR统计软件对筛选血铅≥1．93μmol／L、≥2．90μmol／L时平行试验的准确性进行比较。结果血铅≥1．93μmol／L、≥2．90μmol／L时，根据ROC曲线下的面积（AUCROC），各指标的准确性分别为：ZPP0．978、红细胞P5’N0．973、FEP0．937、尿δ-ALA0．890、尿铅0845，尿δ-ALA和尿铅与ZPP比较，差异有显著性；血铅≥2．90μmol／L时，根据ROC曲线下的面积（AUCROC），各指标的准确性分别为：红细胞P5’N0．975、ZPP0.954、FEP0.96、尿δ-ALA0．900、尿铅0．750，FEP、尿δ-ALA和尿铅与红细胞P5’N比较，差异有显著性。筛选血铅≥1．93μmol／L和≥2．90μmol／L，联合红细胞P5’N和ZPP平行试验的敏感度显著高于联合尿铅和尿δ-AIA的平行试验。结论血铅≥1．93μmol／L及≥2．90μmol／L红细胞P5’N及ZPP的准确性较高?

Objective To determine the accuracy of the indicators for detechng lead poisoning. MethodsBlood and urire specimens in 157 wnrkers exposed to lead were cdsted. Their blwh levels of lead, free erythrocyte protoporphyrin (FEP), zinc protoporphyrin (ZPP), urine δ-aminolevulinic acid and arhvity of red cell pyrimithe 5'-nucleotidase were detendned, with ghd standaxds of blood lead levels of≥1. 93 μwL and ≥ 2.90μmol/L. Accuracy assessment of the indicators mentioned ahav for detecting lead poisoning was hased on the anunder the areiver opeheve characteristic (AUCROC) curve with a software specially for ROC curve ahalsis andsoftware of Epi-Info, after detendning tha oytimal cut-off ponts for the ahae mentioned indicators in deteetinghae with bled lead ≥3 l. 93 μmol/L and 3 2. 90μmol/L. The sensihvity of scmening in parallel for detechngthose with bIed lead ≥1 .93 μmol/L and ≥2.90μmol/L was calculated and compared. Results For detectingthose with blood lead level ≥ 1 .93μmol/L, the area under ROC curve (AUCROC) of ahave indicators was 0.978for ZPP, 0.973 for nd cell P5' N, 0.937 for FEP, 0. 890 for urine ALA (significantly different from that forZPP with P<0.05), and o.845 for urine lead level (sienificantly different from that for ZPP with P<0.05), respectively. For detecting those with blood lead level ≥ 2.90≥ μmol/L, the area under ROC curve (AUCROC) ofdrie indicaors was 0.975 for tal cell P5'N, 0.954 for ZPP, 0.906 for FEP (significantly different from that forred cell P5'N with P<0.05), 0.900 for urine δ-ALA (sigificantly different for tha for red cell P5'N with P<0.05), and 0.750 for urine lead level (significantly different from that for red cell P5'N with P<0.05). Sensitivity of screening in parallel with ZPP and P5'N was significantly higher than that with urine levels of lead and δALA. Conclusion Determinations of red cell P5'N and ZPP for detechng thase with blch lead ≥ 1 .93μmol/Land ≥ 2. 0μmol/L are more accurate.