title: Clara cell protein 16 concentration in mid-trimester amniotic fluid: association with fetal gender, fetal G>A +38 CC16 gene polymorphism and pregnancy outcome.
abstract: Clara cell protein 16 (CC16) is a major immunomodulatory protein produced in the fetal lung. We hypothesized that the mid-trimester amniotic fluid concentration of CC16 would vary according to a +38 CC16 polymorphism in the fetal genome and that increased levels would be an early indicator of subsequent adverse pregnancy outcome. Mid-trimester singleton amniotic fluids from 244 women were assayed for CC16 by ELISA. DNA from fetal cells in 179 amniotic fluids were tested for the A>G polymorphism at position +38 in exon 1 by PCR. Outcome data were obtained from 233 women after completion of laboratory testing. Median CC16 levels were higher in amniotic fluids containing male fetuses than in those with females (p=0.0005). Median amniotic fluid CC16 levels were higher in Hispanics than in Whites and Asians (p<0.05). CC16*G homozygosity was associated with elevated amniotic fluid CC16 concentrations compared to CC16*A homozygotes (p=0.02). Intraamniotic CC16 levels were highest in pregnancies that subsequently resulted in preterm premature rupture of membranes (PPROM) (p=0.01). We conclude that mid-trimester intraamniotic CC16 concentrations vary by gender, ethnicity and fetal CC16 gene polymorphism. Elevated CC16 levels are predictive of subsequent development of PPROM.
authors.affiliation: Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, Weill Medical College of Cornell University, 525 East 68th Street, Box 35, NY 10021, USA.
authors.forename: Sriram C
authors.initials: SC
authors.lastname: Perni
authors.forename: Santosh
authors.initials: S
authors.lastname: Vardhana
authors.forename: Robin
authors.initials: R
authors.lastname: Kalish
authors.forename: Stephen
authors.initials: S
authors.lastname: Chasen
authors.forename: Steven S
authors.initials: SS
authors.lastname: Witkin
mesh_terms: D000328:Adult; D000653:Amniotic Fluid / Q000378:metabolism*; D015415:Biomarkers / Q000032:analysis; D016022:Case-Control Studies; D005260:Female; D005322:Premature Rupture of Fetal Membranes / Q000235:genetics* / Q000378:metabolism*; D006801:Humans; D020641:Polymorphism, Single Nucleotide; D011237:Predictive Value of Tests; D011247:Pregnancy; D011256:Pregnancy Outcome; D011262:Pregnancy Trimester, Second / Q000235:genetics / Q000378:metabolism*; D014598:Uteroglobin / Q000032:analysis* / Q000235:genetics*
chemical_list: D015415:Biomarkers; C556389:SCGB1A1 protein, human; D014598:Uteroglobin