Microvillar peptidase activity in amniotic fluid: possible use in the prenatal diagnosis of cystic fibrosis

Lancet. 1983 Feb 12;1(8320):329-31. doi: 10.1016/s0140-6736(83)91630-6.


The activities of two microvillar peptidases, gamma-glutamyl transpeptidase (GGTP) and aminopeptidase M (APM), have been measured in 132 samples of mid-trimester amniotic fluid. These included samples from 16 pregnancies at risk for cystic fibrosis. The activities of both peptidases were significantly below the normal range in amniotic fluids from the 6 affected pregnancies. This points to early pathological changes in fetal tissues in which microvilli are prominent. In contrast, 4-methylumbelliferylguanidinobenzoate-reactive protease activity in amniotic fluid from the 6 affected pregnancies was normal. Correlation of individual values between GGTP and APM was close in all cases examined, so that when a further 7 samples from cases at risk became available they were tested for GGTP alone. Of these, the 3 affected pregnancies had significantly reduced GGTP activity, particularly in the early weeks of gestation. It is suggested that early amniocentesis and examination of gamma-glutamyl-transpeptidase isoenzyme constitution might make possible the reliable early diagnosis of cystic fibrosis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aminopeptidases / metabolism*
  • Amniocentesis
  • Amniotic Fluid / enzymology*
  • CD13 Antigens
  • Cystic Fibrosis / diagnosis*
  • Female
  • Gestational Age
  • Humans
  • Microvilli / enzymology
  • Pregnancy
  • gamma-Glutamyltransferase / metabolism*


  • gamma-Glutamyltransferase
  • Aminopeptidases
  • CD13 Antigens