In vitro and in vivo embryo toxicity of antilaminin antibodies in the rat.

Rats mated after laminin immunization had higher frequencies of resorptions (57%) than those immunized with bovine serum albumin (20%) and had sera that were toxic to cultured rat embryos. In addition, sera from rats immunized with laminin A chains but not B chains were toxic to cultured embryos. The toxicity of sera to embryos was related to the reactivity of sera to specific laminin fragments rather than to sera IgG levels against intact laminin. In addition, resorptions in pregnant rats immunized with laminin were not related to the sera antilaminin IgG levels. However, levels of uterine antilaminin IgA, the predominant uterine isotype, increased considerably during the first 3.5 days of pregnancy, while sera antilaminin IgG remained constant. (Am J Reprod Immunol.