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.