A trial for reducing false-positives in screening for neuroblastoma by baby food developed for the screening

本研究旨在通过滤纸尿VMA的测定，阐明神经母细胞瘤筛查中假阳性的原因，通过研制筛查用的婴儿食品，减少假阳性的发生，为6个月大婴儿的母亲提供新的筛查指导。首先，在体内研究尿液检测和摄入禁忌食物之间的剂量效应和时间关系，已知在体外，当婴儿和母乳喂养的母亲服用时，会导致假阳性。第二，通过建议母亲给婴儿食品来减少假阳性的人群试验。第三，通过对筛查前食物摄入情况的调查，对筛查阴性和假阳性婴儿的差异进行了研究。婴儿口服橙子汁和香蕉引起很高的假阳性率。假阳性持续时间为摄入后1 ~数小时，20小时后未发现阳性结果，橙子汁摄入量无明显剂量-效应关系。橙子汁中导致假阳性的物质通过母乳传递给婴儿，并持续20多个小时。指导组与未指导组的假阳性率差异无统计学意义。在阴性组和假阳性组中，婴儿食用其他食物的比例分别为37%和47%，但差异无统计学意义。需要进一步分析这两组之间食物类型的差异。

An experimental and an epidemiologic studies were conducted with the aims of firstly clarifying the cause of false-positives in screening for neuroblastoma by measurement of urine VMA collected with filter paper, secondly reducing falsepositives by developing baby food for the screening, and thirdly establishing new guidance to mothers of 6-month-old babies, candidates for the screening.The research consisted of three phases. Firstly, investigation of the doseeffect and time relationsip in vivo between the urine test and intake of contraindicated food, known to cause false-positives in vitro, when taken by babies and when taken by mothers who breast feed. Secondly, a population trial to reduce false-positives by advising mothers to give baby food developed for the screening. Thirdly, investigation through a questionnair survey of the difference between negative and false-positive babies in foodstuffs taken before the screening.The result of the experimental study revealed the following. Orange juice and banana taken orally by infants induced a very high false-positive rate. The falsepositive results lasted from one to several hours after intake and after 20 hours no positive result was found. No apparent dose-effect relationship was observed for the intake of orange juice. Substances in orange juice causing false-positives passed to infants through breast milk and this lasted for more than 20 hours.The population trial yielded the following results. No difference was observed in the false-positive rate between those infants under the guidance and those without the guidance. Proportion of infants who took other food than was indicated was 37% in the negative group and 47% in the false-positive group, but the difference was not statistically significant. Further analysis of the difference in the types of food taken between the two groups is needed.