Iovanna J L, Férec C, Sarles J, Dagorn J C
U. 315 INSERM, Marseille, France.
C R Acad Sci III. 1994 Jun;317(6):561-4.
Neonatal screening of cystic fibrosis (CF) is presently based on immunoreactive trypsin (IRT) assay in blood spots, whose low specificity is a matter of concern. Because the pancreatitis-associated protein (PAP) proved to be a better serum marker of pancreatic alteration than exocrine enzymes, it might be an interesting alternative for CF screening. We report here a preliminary evaluation of the PAP test, conducted in retrospect on blood spots from groups of neonates already screened for CF with the IRT. Neonates with elevated IRT were submitted to subsequent analysis of the Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) gene. Neonates with normal IRT (n = 990) or high IRT but normal genotype (n = 28) had normal PAP. Elevated PAP was observed in all CF neonates (n = 11). False-positives for the PAP test were found only among neonates with high IRT and heterozygotes for a mutation in the CFTR gene (6 out of 17 cases). That group represents less than 0.2% of newborns. These results therefore suggest that PAP discriminates CF neonates with a significantly better specificity than IRT.
目前，新生儿囊性纤维化（CF）筛查基于血斑中的免疫反应性胰蛋白酶（IRT）检测，但其低特异性令人担忧。由于胰腺炎相关蛋白（PAP）被证明是比外分泌酶更好的胰腺改变血清标志物，它可能是CF筛查的一个有趣替代方法。我们在此报告对PAP检测的初步评估，该评估是对已用IRT筛查CF的新生儿组血斑进行回顾性分析。IRT升高的新生儿随后接受囊性纤维化跨膜传导调节因子（CFTR）基因分析。IRT正常的新生儿（n = 990）或IRT高但基因型正常的新生儿（n = 28）PAP正常。在所有CF新生儿（n = 11）中均观察到PAP升高。PAP检测的假阳性仅在IRT高且CFTR基因突变杂合子的新生儿中发现（17例中有6例）。该组占新生儿的比例不到0.2%。因此，这些结果表明，与IRT相比，PAP对CF新生儿的鉴别特异性明显更好。
