Problem Regulatory factors seem to be essential to achieve transition from implantation window to placental vascularization. A novel function of interleukin (IL)-6 in the promotion of Th2 differentiation and inhibition of Th1 polarization has been demonstrated. Considering that Th2 response promotes antibody synthesis, we postulate that IL-6 could be modulating the quality of this response during pregnancy by increasing the proportion of blocking asymmetric antibodies.
Method of study We investigated expression of blocking-asymmetric-IgG during pregnancy of CBA/J × DBA/2 abortion model treated with IL-6, with regards to CBA/J × BALB/c. We also determined asymmetric-IgG production in IL-6-deficient pregnant mice.
Results We found that IL-6 treatment increased asymmetric-IgG in multiparous placentas from abortion combination whereas diminished abortion rate. Moreover, asymmetric-IgG proportion was diminished in sera from IL-6-deficient pregnant mice.
Conclusion Modulation of asymmetric antibody synthesis could be another mechanism implicated in the beneficial effect of IL-6 in prevention of murine recurrent abortion.