Association between levels of Toll-like receptors 2 and 4 and CD14 mRNA and allergy in pregnant women and their offspring

The microbial environment in early infancy or even in utero may modulate the risk to develop allergic disease. Since Toll-like receptors (TLR) recognize microbial products, we hypothesized that maternal allergies may be associated with decreased levels of TLR2, TLR4 and CD14 mRNA in mothers and their offspring. 185 healthy pregnant women from Germany (n = 48), Hungary (n = 50) and Spain (n = 87) were enrolled in a European multicenter study. Levels of TLR2, TLR4 and CD14 mRNA were quantified in maternal peripheral blood samples taken at delivery and placental cord blood samples. Numbers of TLR2+, TLR4+ and CD14+ monocytes were quantified by flow cytometry in 42 cord blood samples obtained from the German participants. Bivariate and multivariate regression analyses were performed. Maternal allergies were associated with significantly lower levels of TLR2/4/CD14 mRNA in maternal blood and cord blood samples. Maternal and fetal TLR2/4/CD14 mRNA levels were significantly correlated with each other (TLR2 r = 0.42; TLR4 r = 0.58; CD14 r = 0.54). The results suggest that maternal allergy status may affect allergic risk in offspring through a decreased expression of fetal TLR2/4/CD14.