[Alkaline phosphatase in the diagnosis of purulent and serous meningitis]

The authors have modified the method for measuring the cerebrospinal fluid (CSF) alkaline phosphatase (AP) activity. Their studies have revealed a considerable increase of CSF AP activity in purulent meningitides whereas in serous meningitides it grows negligibly. It is recommended that purulent meningitis be diagnosed when CSF AP concentrations are 3.5 U/l and higher and serous meningitis be diagnosed when these concentrations are below 2.5 U/l.