Automated immunoprecipitation of meconium albumin for cystic fibrosis screening in the newborn.

Cystic fibrosis is the most frequent substantially lethal inherited disease in the 
United States. Newborn screening for cystic fibrosis has been suggested because 
early diagnosis permits genetic counselling of parents and improved treatment and 
prognosis for cystic fibrosis patients. The fact that cystic fibrosis newborns 
have abnormally high meconium albumin seems to offer the best screening 
approach. Because we have had equivocal and false positive results with 
meconium albumin test strips, we have developed a nephelometric automated immunoprecipitation 
method for the quantitative and specific analysis of meconium albumin. On 
a total of 3895 meconiums so far examined, eleven albumin elevations 
of undetermined origin have been detected. Nine of these were associated 
with prematurity. There have been, so far, no detected true positives 
and no known false negatives. The normal range for meconium albumin 
is in agreement with previously published ranges determined using manual immunochemical 
methods. This method is rapid and economic. The question of sensitivity, 
specificity and predictive value of this and other detection methods is 
discussed. 