Objective: Activin A, and its binding protein, follistatin (FS), are expressed in the central nervous system (CNS). We have previously shown elevated concentrations of FS in the cerebrospinal fluid (CSF) of patients with meningitis and increased concentrations of activin A in the CSF of rabbits with bacterial meningitis.
Methods: We measured CSF and serum concentrations of activin A and FS in normal subjects and in patients with various neurological diseases using previously validated immunoassays specific for activin A or FS.