title: Activin A concentrations in human cerebrospinal fluid are age-dependent and elevated in meningitis.
abstract: 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.
  
  
  RESULTS
  In healthy persons, serum concentrations of both activin A and FS were age-dependent. In CSF, concentrations of activin A ranged from 0.03 to 0.33 ng/ml and were strongly correlated with age in both sexes, whereas FS CSF concentrations were below the assay detection limit in most of the patients. Activin A concentrations in CSF of patients with various neurological diseases, including meningitis, chronic inflammatory CNS diseases, neurodegenerative diseases, tumors in the CNS, cerebral ischemia, intracerebral/subarachnoid hemorrhages, subdural hemorrhages and epileptic seizures, were compared with age- and sex-matched control patients. The comparisons revealed significantly elevated concentrations of activin A in patients with meningitis (P=0.017). Serum concentrations of activin A or FS were not affected by any of the neurological diseases examined.
  
  
  CONCLUSIONS
  Our results show for the first time that in normal subjects concentrations of activin A in CSF are correlated with age, and furthermore, that activin A CSF concentrations are elevated in patients with meningitis. The latter underlines a role for activin A in acute inflammatory processes within the CNS.
authors.affiliation: Department of Neurology, University of Göttingen, Robert-Koch-Str. 40, 37075 Göttingen, Germany. sebert1@gwdg.de
authors.forename: Sandra
authors.initials: S
authors.lastname: Ebert
authors.forename: David J
authors.initials: DJ
authors.lastname: Phillips
authors.forename: Peter
authors.initials: P
authors.lastname: Jenzewski
authors.forename: Roland
authors.initials: R
authors.lastname: Nau
authors.forename: Anne E
authors.initials: AE
authors.lastname: O'Connor
authors.forename: Uwe
authors.initials: U
authors.lastname: Michel
mesh_terms: D028341:Activins / Q000032:analysis / Q000134:cerebrospinal fluid*; D000328:Adult; D000368:Aged; D000375:Aging / Q000378:metabolism*; D015415:Biomarkers / Q000134:cerebrospinal fluid; D002490:Central Nervous System / Q000378:metabolism / Q000382:microbiology / Q000503:physiopathology; D002556:Cerebrospinal Fluid Proteins / Q000032:analysis / Q000378:metabolism*; D004660:Encephalitis / Q000134:cerebrospinal fluid / Q000175:diagnosis / Q000503:physiopathology; D005260:Female; D038681:Follistatin / Q000032:analysis / Q000134:cerebrospinal fluid; D006801:Humans; D007118:Immunoassay; D008297:Male; D008581:Meningitis / Q000134:cerebrospinal fluid* / Q000175:diagnosis* / Q000503:physiopathology; D008875:Middle Aged; D011237:Predictive Value of Tests; D015854:Up-Regulation / Q000502:physiology
chemical_list: D015415:Biomarkers; D002556:Cerebrospinal Fluid Proteins; D038681:Follistatin; C422405:activin A; D028341:Activins