Amniotic fluid protease activity and the prenatal detection of cystic fibrosis

Changes in the protease activity in amniotic fluid has been proposed as a valid method for the prenatal detection of cystic fibrosis (CF). We have studied by quantitative and qualitative procedures, sixty four amniotic fluids: two of them from CF-affected fetuses. Interpretation of the benzoyl arginine ethyl ester (BAEE)-staining patterns after isoelectric focusing was often difficult, and repeated experiments gave variable results. In order to improve gel discrimination, we performed amniotic fluid electrofocusing in the presence of detergents: 0.1 per cent Triton X-100, 0.1 per cent DOC, or 0.1 per cent SDS. In these conditions, the pattern revealed by BAEE was modified, but no differences were observed between CF and normal amniotic fluids.