Abstract: Objectives To improve the detection of bone alkaline phosphatase(BAP) for early diagnosis and prevention of rickets for reducing missed diagnosis and misdiagnosis. Methods Enzyme-linked immuno sorbent assay (ELISA) method was used to detect of BAP of rickets,suspected rickets and healthy infants quantitatively.The reference range was established to find the critical point of diagnosis and evaluated its diagnostic value using ROC curve analysis.Further more,the diagnostic performance of quantitative BAP was compared with qualitative BAP and ALP. Results The reference range of ELISA quantitative detection of infant BAP was 68~246 U/L.With more than 280 U/L as threshold value of rickets,the diagnostic specificity was 99.6%,the sensitivity was 91.2%,the accuracy percentage was 98.2%,and positive likelihood ratio was 227.9.By contrast,with more than 236 U/L quantitative ALP as the thershold value of rickets,the diagnostic specificity was 72.0%,the sensitivity was 79.4%,the accuracy percentage was 72.9%,and positive likelihood ratio was 2.8.The specificity of BAP qualitative to diagnosis of rickets was 84.8%,the sensitivity was 35.3%,the accuracy percentage was 78.9% and positive likelihood ratio was 2.3.For 23 cases with early signs of rickets,BAP ELISA quantitative hinted rickets in 16 cases (69.6%),BAP qualitative hinted rickets in 6 cases (26.1%),ALP quantitative hinted rickets in 11 cases (47.8%). Conclusions Compared with ALP quantitative and BAP qualitative,BAP quantitative with ELISA showed a better diagnostic capability of infant rickets.BAP ELISA can earlier find the change of the serum marker in infant with rickets,facilitate timely intervention.Therefore,it is recommended that detecting BAP with ELISA quantitative to reduce missed diagnosis and misdiagnosis of rickets.

Key words: rickets, bone alkaline phosphatase, enzyme-linked immuno sorbent assay, diagnostic performance, ROC analysis

摘要： 目的 改善骨碱性磷酸酶(BAP)检测方法 ,早期诊断和防控佝偻病,减少漏诊和误诊。方法 采用ELISA酶联免疫方法 ,对佝偻病、疑似佝偻病及正常保健婴幼儿血清标本进行BAP定量检测,建立参考区间,利用ROC曲线分析找到诊断临界点,评价其诊断价值,并与ALP定量和BAP定性的诊断性能比较。结果 ELISA定量检测婴幼儿BAP的参考区间为68~246 U/L,以>280 U/L 作为佝偻病诊断界限,则诊断特异性达到99.6%,敏感性91.2%,正确百分率98.2%,阳性似然比为227.9。与之相比,ALP定量以>236U/L作为佝偻症诊断界限,则诊断特异性72.0%,敏感性79.4%,正确百分率72.9%,阳性似然比为2.8;BAP定性诊断佝偻病的特异性为84.8%,敏感性为35.3%,正确百分率78.9%,阳性似然比为2.3。对23例佝偻病早期的病例,BAP ELISA定量提示佝偻病的有16例(69.6%),BAP定性提示佝偻病的有6例(26.1%),ALP定量提示佝偻病的有11例(47.8%)。结论 与ALP定量和BAP定性相比,BAP ELISA定量对婴幼儿佝偻病具有更好的诊断能力。BAP ELISA定量能更早地发现佝偻病早期血清标志物的改变,便于及时进行干预。因此,推荐采用ELISA定量方法 进行BAP检测,减少佝偻病漏诊和误诊。

关键词: 佝偻病, 骨碱性磷酸酶, 酶联免疫吸附实验, 诊断性能, ROC分析