Anaphylatoxins in preterm and term labor.

Area of Science:

• Immunology
• Reproductive Biology
• Biochemistry

Background:

• The complement system is crucial for innate immunity, releasing inflammatory mediators like anaphylatoxins (C3a, C4a, C5a).
• Anaphylatoxins are implicated in inflammatory processes during pregnancy and parturition.

Purpose of the Study:

• To investigate differences in maternal plasma anaphylatoxin concentrations between term and preterm parturition.
• To assess the role of anaphylatoxins in spontaneous labor at term versus preterm labor, with and without intra-amniotic infection (IAI).

Main Methods:

• Cross-sectional study of 296 pregnant women across different stages: normal pregnancy, term labor, and preterm labor (with and without IAI).
• Plasma concentrations of C3a, C4a, and C5a were quantified using enzyme-linked immunosorbent assays (ELISAs).
• Non-parametric statistical methods were employed for data analysis.

Main Results:

• Maternal plasma C5a concentrations were lower in women in spontaneous term labor compared to those not in labor.
• Women with preterm labor and intra-amniotic infection (IAI) exhibited significantly higher C5a levels than those without IAI or delivering at term.
• Elevated C5a was observed in preterm labor with IAI compared to normal pregnancy, while C3a was higher with IAI but not significantly different across other preterm subgroups or normal pregnancy.

Conclusions:

• Elevated maternal plasma C5a concentrations are associated with preterm labor, especially when intra-amniotic infection (IAI) is present.
• Spontaneous labor at term does not correlate with increased C5a levels.
• C5a may serve as a potential biomarker for predicting preterm labor with IAI.