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.