PP13, maternal ABO blood groups and the risk assessment of pregnancy complications

PLoS One. 2011;6(7):e21564. doi: 10.1371/journal.pone.0021564. Epub 2011 Jul 25.


Background: Placental Protein 13 (PP13), an early biomarker of preeclampsia, is a placenta-specific galectin that binds beta-galactosides, building-blocks of ABO blood-group antigens, possibly affecting its bioavailability in blood.

Methods and findings: We studied PP13-binding to erythrocytes, maternal blood-group effect on serum PP13 and its performance as a predictor of preeclampsia and intrauterine growth restriction (IUGR). Datasets of maternal serum PP13 in Caucasian (n = 1078) and Hispanic (n = 242) women were analyzed according to blood groups. In vivo, in vitro and in silico PP13-binding to ABO blood-group antigens and erythrocytes were studied by PP13-immunostainings of placental tissue-microarrays, flow-cytometry of erythrocyte-bound PP13, and model-building of PP13--blood-group H antigen complex, respectively. Women with blood group AB had the lowest serum PP13 in the first trimester, while those with blood group B had the highest PP13 throughout pregnancy. In accordance, PP13-binding was the strongest to blood-group AB erythrocytes and weakest to blood-group B erythrocytes. PP13-staining of maternal and fetal erythrocytes was revealed, and a plausible molecular model of PP13 complexed with blood-group H antigen was built. Adjustment of PP13 MoMs to maternal ABO blood group improved the prediction accuracy of first trimester maternal serum PP13 MoMs for preeclampsia and IUGR.

Conclusions: ABO blood group can alter PP13-bioavailability in blood, and it may also be a key determinant for other lectins' bioavailability in the circulation. The adjustment of PP13 MoMs to ABO blood group improves the predictive accuracy of this test.

Publication types

  • Research Support, N.I.H., Intramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • ABO Blood-Group System / chemistry
  • ABO Blood-Group System / metabolism*
  • Amino Acid Sequence
  • Erythrocytes / metabolism
  • Female
  • Fetal Growth Retardation / blood
  • Fetal Growth Retardation / diagnosis
  • Galectins / blood*
  • Galectins / chemistry
  • Galectins / metabolism
  • Hispanic or Latino
  • Humans
  • Models, Molecular
  • Molecular Sequence Data
  • Mothers*
  • Pre-Eclampsia / blood
  • Pre-Eclampsia / diagnosis
  • Predictive Value of Tests
  • Pregnancy
  • Pregnancy Complications / blood*
  • Pregnancy Complications / diagnosis*
  • Pregnancy Complications / metabolism
  • Pregnancy Proteins / blood*
  • Pregnancy Proteins / chemistry
  • Pregnancy Proteins / metabolism
  • Protein Conformation
  • Risk Assessment
  • Substrate Specificity
  • White People


  • ABO Blood-Group System
  • Galectins
  • LGALS13 protein, human
  • Pregnancy Proteins