Lipopolysaccharide-binding protein in microbial invasion of the amniotic cavity and human parturition.
OBJECTIVE
Lipopolysaccharide-binding protein (LBP) is an acute-phase protein of predominantly hepatic origin, capable of binding the lipid A fraction of bacterial lipopolysaccharide (LPS). The complex LBP-LPS binds to CD14, and has been implicated in the host response to gram-negative infection. The purpose of this study was to determine whether microbial invasion of the amniotic cavity (MIAC) and parturition (term and preterm) are associated with changes in the amniotic fluid concentration of LBP.


METHODS
Amniotic fluid was retrieved by amniocentesis from 343 patients in the following groups: (1) those in mid-trimester with a subsequent normal pregnancy outcome (n = 84); (2) those in mid-trimester with a fetal loss after the procedure (n = 10); (3) those with preterm labor and intact membranes without MIAC who delivered at term (n = 36) or prematurely (n = 52), and those with preterm labor with MIAC (n = 26); (4) those with preterm premature rupture of membranes (PROM) with (n = 26) and without (n = 26) MIAC; and (5) those delivering at term with intact membranes in the absence of MIAC, in labor (n = 52) and not in labor (n = 31). The concentration of LBP in amniotic fluid was determined with a specific and sensitive immunoassay. Non-parametric statistics were used. A p value of < 0.05 was considered significant.


RESULTS
LBP was detected in 98% (335/343) of the amniotic fluid samples. MIAC was associated with a significant increase in amniotic fluid concentration of LBP in women with preterm labor and intact membranes, but not in preterm PROM. Spontaneous preterm parturition was associated with a significant increase in amniotic fluid concentration of LBP. Patients who had a spontaneous fetal loss after a mid-trimester amniocentesis had a significantly higher median amniotic fluid LBP concentration than those who had a mid-trimester amniocentesis and a normal perinatal outcome.


CONCLUSIONS
Preterm labor with MIAC and preterm parturition are associated with higher amniotic fluid concentrations of LBP than those with sterile amniotic fluid.
Espinoza
J
J
Perinatology Research Branch, National Institute of Child Health and Human Development, Bethesda, Maryland, USA.
Romero
R
R
Chaiworapongsa
T
T
Kim
J C
JC
Yoshimatsu
J
J
Edwin
S
S
Rathnasabapathy
C
C
Tolosa
J
J
Donnenfeld
A
A
Craparo
F
F
Gomez
R
R
Bujold
E
E
D000209:Acute-Phase Proteins; D000649:Amniocentesis; D000650:Amnion / Q000276:immunology / Q000382:microbiology*; D000653:Amniotic Fluid / Q000737:chemistry / Q000276:immunology*; D002352:Carrier Proteins / Q000032:analysis* / Q000276:immunology; D002821:Chorioamnionitis / Q000276:immunology* / Q000382:microbiology; D003430:Cross-Sectional Studies; D005260:Female; D005313:Fetal Death / Q000276:immunology; D005322:Premature Rupture of Fetal Membranes / Q000276:immunology; D006801:Humans; D008562:Membrane Glycoproteins; D007752:Obstetric Labor, Premature / Q000276:immunology; D036801:Parturition / Q000276:immunology*; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious / Q000276:immunology*; D000099231:Lipopolysaccharide-Binding Protein
D000209:Acute-Phase Proteins; D002352:Carrier Proteins; D008562:Membrane Glycoproteins; D000099231:Lipopolysaccharide-Binding Protein