Immunoreactive digitalis-like substance in pre-eclampsia.

An endogenous digitalis-like substance (DLS) may be involved in the pathogenesis of essential hypertension and pre-eclampsia. The digoxin levels in maternal and cord blood of 504 randomly selected patients were determined. Since none of the patients received digoxin, these levels indicated a cross-reacting substance (immunoreactive DLS). DLS levels were significantly higher in the cord blood of pre-eclamptic patients than in the cord blood of controls. DLS levels in cord blood increased with the severity of pre-eclampsia, and levels were higher in primigravidas than in multigravidas. The structure and biological activity of DLS must be determined before definite conclusions about its role in the pathogenesis of pre-eclampsia can be made.