title: Reliable diagnosis of the major type of cystic fibrosis with fibroblast cultures. A double blind study.
abstract: A double blind study has been carried out to demonstrate that the most common type of cystic fibrosis (CF) can be reliably diagnosed with skin-derived fibroblast cultures. Alkaline phosphatase (AIP) activity has been measured in 6 normal controls, 12 CF-heterozygotes and 6 CF-homozygotes before and after stimulation with Tamm-Horsfall-glycoprotein (THP), isoproterenol and theophyline ("THP-induction test"). The mean AIP-activities after THP-induction were 8.8, 12.7 and 34.6 for the three different genotypes respectively. There was no overlap between the values of CF-homozygotes on the one hand, and the values of CF-heterozygotes and normal controls on the other hand. All 24 specimens were correctly diagnosed in the present double blind study, indicating the very high degree of reliability of the THP-induction test in the detection of the predominant type of cystic fibrosis with fibroblast cultures. Normal controls and CF-heterozygotes could not be discriminated on an individual basis, but as a group the CF-heterozygotes displayed higher AIP-values.
mesh_terms: D000293:Adolescent; D000328:Adult; D000469:Alkaline Phosphatase / Q000378:metabolism; D002478:Cells, Cultured; D002648:Child; D002675:Child, Preschool; D002986:Clinical Trials as Topic; D003550:Cystic Fibrosis / Q000175:diagnosis* / Q000201:enzymology; D004311:Double-Blind Method; D005260:Female; D005347:Fibroblasts / Q000201:enzymology*; D006023:Glycoproteins; D006579:Heterozygote; D006720:Homozygote; D006801:Humans; D007545:Isoproterenol; D008297:Male; D008875:Middle Aged; D012867:Skin / Q000201:enzymology; D013806:Theophylline
chemical_list: D006023:Glycoproteins; D013806:Theophylline; D000469:Alkaline Phosphatase; D007545:Isoproterenol