Plasminogen activator inhibitor-1: defining characteristics in the cerebrospinal fluid of newborns.

We measured plasminogen activator inhibitor-1 levels in the cerebrospinal fluid and plasma of newborns with and without posthemorrhagic hydrocephalus. We found that plasminogen activator inhibitor-1 levels in the cerebrospinal fluid of healthy newborns are <10 mg/mL but are greatly elevated in patients who have posthemorrhagic hydrocephalus and correlate directly with cerebrospinal fluid D-dimer and protein levels.