Antibodies to the 70 kDa heat shock protein in midtrimester amniotic fluid and intraamniotic immunity

Objective: Antibodies to the 70 kDa heat shock protein (hsp70) immunoglobulin (Ig) G are markers for exposure to adverse or nonphysiological stimuli. In addition, these antibodies cross-link hsp-70 microbial antigen complexes and enhance development of antimicrobial immunity. The association between intraamniotic hsp70 IgG concentrations and intraamniotic immune responses were evaluated. Study Design: Midtrimester amniotic fluids from 90 women undergoing an amniocentesis were tested for hsp70 IgG, hsp70 antigen, tumor necrosis factor (TNF)-α, secretory leukocyte protease inhibitor (SLPI), and interferon (IFN)-α by enzyme-linked immunosorbent assay. Clinical outcomes were obtained after completion of all testing. Associations were analyzed by nonparametric statistics. Results: Intraamniotic hsp70 IgG concentrations, but not hsp70 antigen levels, were positively associated with levels of TNF-α (P < .0001), IFN-α (P = .0001), and SLPI (P = .0038). There were no associations between hsp70 IgG and maternal age or parity, race/ethnicity or pregnancy outcome. Conclusion: The hsp70 IgG levels correlate with intraamniotic concentrations of antimicrobial immune mediators. This antibody may potentiate antimicrobial immunity during fetal development.