Rock M J, Mischler E H, Farrell P M, Wei L J, Bruns W T, Hassemer D J, Laessig R H
Department of Pediatrics, University of Wisconsin-Madison 53792.
Pediatrics. 1990 Jun;85(6):1001-7.
Detection of elevated levels of immunoreactive trypsinogen (IRT) in dried neonatal blood spots has been used as a screening test for cystic fibrosis. In other cystic fibrosis newborn-screening studies, a sweat chloride test is generally performed only if an infant has a persistent IRT level above a selected cutoff value on both the initial and subsequent specimens. Neither the timing of the second specimen nor the value of the cutoff point for the second specimen has been comprehensively evaluated. In this randomized, controlled study, 145,024 infants were screened in the neonatal period for cystic fibrosis using the 99.8 percentile (180 ng/mL) as the neonatal cutoff point. A total of 129 infants had elevated neonatal IRT levels and had negative results on sweat tests (false-positive by IRT screening). A total of 54 children with cystic fibrosis were identified in the screened and comparison groups. Excluding patients with meconium ileus, 4 infants with cystic fibrosis had neonatal IRT values less than 180 ng/mL, and an additional 9 infants with cystic fibrosis had values decline to less than 180 ng/mL within the first 2 1/2 months of age. The IRT values of infants with and without cystic fibrosis overlapped considerably beyond 30 days of age. These findings suggest that further refinement of cystic fibrosis screening methodology will be necessary to achieve an acceptable sensitivity and specificity.
检测干血斑中免疫反应性胰蛋白酶原（IRT）水平升高已被用作囊性纤维化的筛查试验。在其他囊性纤维化新生儿筛查研究中，通常仅当婴儿的初始样本和后续样本的IRT水平持续高于选定的临界值时才进行汗液氯化物试验。第二个样本的采集时间和第二个样本的临界值均未得到全面评估。在这项随机对照研究中，145,024名婴儿在新生儿期接受了囊性纤维化筛查，使用第99.8百分位数（180 ng/mL）作为新生儿临界值。共有129名婴儿的新生儿IRT水平升高，但汗液试验结果为阴性（IRT筛查假阳性）。在筛查组和对照组中总共识别出54名囊性纤维化患儿。排除胎粪性肠梗阻患者后，4名囊性纤维化婴儿的新生儿IRT值低于180 ng/mL，另外9名囊性纤维化婴儿在出生后头2个半月内IRT值降至低于180 ng/mL。30日龄以上患囊性纤维化和未患囊性纤维化婴儿的IRT值有相当大的重叠。这些发现表明，要实现可接受的敏感性和特异性，有必要进一步完善囊性纤维化筛查方法。
