Cerebrospinal fluid ferritin in patients with cerebral infarction or bleeding.

By the use of a radioimmunoassay, ferritin was detected in the cerebrospinal fluid (CSF) of apparently healthy individuals at a mean concentration of 5.1 arb U/l, i.e. a level about 5% of the mean normal serum-ferritin concentration. Fourteen patients with acute cerebrovascular stroke or transient ischemic attacks (one case) were followed by serial determinations of CSF-ferritin during 2 weeks or more from onset of symptoms. After cerebral stroke all patients exhibited an increase of CSF-ferritin with peak levels between 4 and 6 days from admission. Those three patients in whom computed tomography showed cerebral bleeding had the highest peak CSF-ferritin was 28 +/- 11 arb U/l in the patients who had cerebral infarction without signs of bleeding. In seven patients CSF-ferritin returned to the control range after 2 weeks. The extent of the rise of ferritin in CSF could not be explained by damaged blood-CSF barrier. We suggest that the increment of ferritin in CSF of patients with cerebrovascular lesions may reflect an inflammatory response within the brain possibly mediated by macrophages.