[Interferon-like substance in pregnancy sera].

Interferon(IFN) can be produced from lymphocytes in vitro as well as in vivo using various immune stimuli. This paper shows that the amount of IFN or IFN-like substance increases in pregnancy sera as pregnancy proceeds. 1) IFN activity was detected in 45% of 97 pregnant women overall and more frequently as pregnancy went on. 2) The IFN was trypsin sensitive, beat labile, acid sensitive and species specific. 3) Maternal lymphocytes produced approximately twice as much interferon as cord blood lymphocytes did by phytohemagglutinin stimulation. 4) IFN was detected in half of the mixed lymphocyte cultures(MLR) containing cord blood and maternal blood. Whether or not they can produce IFN may be an indication of the immunological competence of pregnant women and the interferon may contribute to the immunoregulation of fetal acceptance.