During pregnancy, in the context of a Th2-type cytokine profile, serum IL-6 levels might condition the quality of the synthesized antibodies

PROBLEM: In recent years, the central role of cytokines in the immune respo nse has been widely studied. It is considered that a T helper (Th)1-type cy tokine profile is associated with the rejection phenomenon, whereas a Th2-t ype cytokine profile is associated with immunological tolerance. In pregnan cy, the enhanced Th2/Th1 ratio seems to be necessary to fetal protection. T aking into account that a Th2-type response means antibody production by B cells, and that these antibodies could induce degradation of the paternal a ntigens, we investigated the quality of the antibodies produced during preg nancy and their regulation. METHOD OF STUDY: Review of previous data. RESULTS: The regulation of protective antibodies by IL-6 in a dose-dependen t fashion is proposed as a hypothesis. CONCLUSION: Cytokines play a central role in the success (or failure) of pr egnancy. However, the quality of the synthesized antibodies is also a regul atory key. The preferential synthesis of asymmetric immunoglobulin G antibo dies during pregnancy could be one of the several pathways that lead to a s uccessful pregnancy.