Partial characterization of a novel growth factor from the blood of women with preeclampsia.

Sera obtained before delivery from women with preeclampsia contain greater mitogenic activity than sera drawn from the same women 24-48 h after parturition or sera from normal parturients. These studies describe the initial characterization of the blood-borne mitogenic factor(s) from preeclamptic women which we have named ELMER (Endogenous Ligand conferring MitogEnic Response). ELMER appears to be a unique mitogen with characteristics that are not identical to those of other known growth factors. ELMER is present in serum as an acid- and heat-labile protein, approximately 160,000 daltons in size, which is a potent mitogen for human fibroblasts but not for human endothelial cells. Its presence in plasma suggests that it is a circulating factor rather than a product of blood coagulation ex vivo. We believe that ELMER represents a potential serum marker of preeclampsia and that it may play roles in the vasospasm and proliferative vascular lesion, termed atherosis, frequently associated with the preeclamptic syndrome.