Laminin immunized monkeys develop sera toxic to cultured rat embryos and fail to reproduce

In a previous study antilaminin antibodies in a monkey with a poor reproductive history were found to be the cause of serum toxicity to cultured rat embryos. In the present study four monkeys were immunized with murine tumor laminin and a fifth with bovine serum albumin. Subsequently, sera from only the laminin immunized monkeys became toxic to cultured rat embryos. This serum toxicity was not mediated by complement but did require the antibody to have a divalent structure. Finally, mating trials were conducted with two of the laminin immunized monkeys that previously had excellent reproductive histories. Based on progesterone levels and observation the monkeys continued to have normal menstrual cycles but failed to initiate a successful pregnancy following immunization in over 2 years of mating trials. These data demonstrated that antibodies against laminin could have prevented conception or could have interrupted pregnancy because of embryotoxicity or failure of implantation.