Specific biochemical amniotic fluid pattern of fetal isolated esophageal atresia.
BACKGROUND
Perinatal care of esophageal atresia (EA) may be improved by prenatal diagnosis. Ultrasound findings (polyhydramnios and/or nonvisualization of fetal stomach) lead to a detection rate of ~50%. An amniotic fluid (AF) biochemical pattern characterized by high total protein, γ-glutamyl transpeptidase (GGTP), and normal l-leucine-aminopeptidase (AMP) leads to a 100% detection rate. The aim of this study was to explain this specific pattern.


METHODS
On the basis of enzyme activities assay, the following four objectives were sought: (i) comparing AF markers between EA and other digestive tract atresias, (ii) determining local GGTP synthesis in the esophagus (immunohistobiochemistry), (iii) determining the presence of a specific AF-AMP activity inhibitor, and (iv) comparing AF-AMP and AF-GGTP half-lives.


RESULTS
The AF-EA pattern was similar to that observed in upper duodenal atresia (above the Oddi sphincter). No local synthesis of GGTP was observed in the esophagus. No AF-AMP activity inhibitor was found. AF-GGTP had a longer half-life than AF-AMP.


CONCLUSIONS
Due to the swallowing anomaly observed in EA, GGTP and AMP values physiologically observed at 18 wk will decrease on the basis of the half-lives of markers, with a flat slope for GGTP and a sharp slope for AMP, therefore explaining the differences observed in the AF-EA pattern.
Department of Pediatric Surgery, Robert Debré Hospital, AP-HP, University of Paris VII, Paris, France.
Cécile
C
Muller
Isabelle
I
Czerkiewicz
Fabien
F
Guimiot
Sophie
S
Dreux
Laurent J
LJ
Salomon
Naziha
N
Khen-Dunlop
Arnaud
A
Bonnard
Thomas
T
Schmitz
Jean-François
JF
Oury
Françoise
F
Muller
D000653:Amniotic Fluid / Q000737:chemistry*; D015415:Biomarkers / Q000737:chemistry*; D004933:Esophageal Atresia / Q000175:diagnosis* / Q000378:metabolism / Q000473:pathology; D006207:Half-Life; D006801:Humans; D007150:Immunohistochemistry; D007621:Karyotyping; D007931:Leucyl Aminopeptidase / Q000032:analysis; D011296:Prenatal Diagnosis / Q000379:methods*; D011506:Proteins / Q000032:analysis; D012189:Retrospective Studies; D018709:Statistics, Nonparametric; D005723:gamma-Glutamyltransferase / Q000032:analysis
D015415:Biomarkers; D011506:Proteins; D005723:gamma-Glutamyltransferase; D007931:Leucyl Aminopeptidase