title: Cerebrospinal fluid ferritin--unspecific and unsuitable for disease monitoring.
abstract: OBJECTIVE
  Subarachnoid hemorrhage is sometimes difficult to diagnose radiologically. Cerebrospinal fluid (CSF) ferritin has been proposed to be highly specific and sensitive to detect hemorrhagic central nervous system (CNS) disease. We analyzed here the specificity of CSF ferritin in a large series of various CNS diseases and the influence of serum ferritin.
  
  
  METHODS
  CSF ferritin, lactate, protein and total cell count were analyzed in 141 samples: neoplastic meningitis (n=62), subarachnoid hemorrhage (n=20), pyogenic infection (n=10), viral infection (n=10), multiple sclerosis (n=10), borreliosis (n=5) and normal controls (n=24). Cerebrospinal fluid ferritin was measured with a microparticle immunoassay. In addition, serum and CSF ferritin were compared in 18 samples of bacterial and neoplastic meningitis.
  
  
  RESULTS
  In CNS hemorrhage, median ferritin was 51.55μg/L (sensitivity: 90%) after the second lumbar puncture. In neoplastic meningitis, the median CSF ferritin was 16.3μg/L (sensitivity: 45%). Interestingly, ferritin was higher in solid tumors than that in hematological neoplasms. In 90% of pyogenic inflammation, ferritin was elevated with a median of 53.35μg/L, while only 50% of patients with viral infection had elevated CSF ferritin. In ventricular CSF, median ferritin was 163μg/L, but only 20.6μg/L in lumbar CSF. Ferritin was normal in multiple sclerosis and borreliosis.
  
  
  CONCLUSIONS
  Ferritin was elevated not only in hemorrhagic disease, but also in neoplastic and infectious meningitis. Ferritin was not a reliable marker of the course of disease. The influence of serum ferritin on CSF ferritin is negligible. We conclude that elevated CSF ferritin reliably, but unspecifically indicates severe CNS disease.
authors.affiliation: Department of Neurosurgery, University of Giessen, Giessen, Germany. Electronic address: malgorzata.kolodziej@neuro.med.uni-giessen.de.
authors.forename: Malgorzata A
authors.initials: MA
authors.lastname: Kolodziej
authors.affiliation: Department of Neurology, University of Goettingen, Goettingen, Germany.
authors.forename: Peter
authors.initials: P
authors.lastname: Proemmel
authors.affiliation: Institute of Surgical Research, University of Marburg, Marburg, Germany.
authors.forename: Karl
authors.initials: K
authors.lastname: Quint
authors.affiliation: Department of Neurology, University of Marburg, Marburg, Germany.
authors.forename: Herwig M
authors.initials: HM
authors.lastname: Strik
mesh_terms: D015415:Biomarkers / Q000134:cerebrospinal fluid; D001899:Borrelia Infections / Q000134:cerebrospinal fluid; D005293:Ferritins / Q000097:blood / Q000134:cerebrospinal fluid*; D006801:Humans; D055756:Meningeal Carcinomatosis / Q000097:blood / Q000134:cerebrospinal fluid; D016920:Meningitis, Bacterial / Q000097:blood / Q000134:cerebrospinal fluid; D008587:Meningitis, Viral / Q000134:cerebrospinal fluid; D009103:Multiple Sclerosis / Q000134:cerebrospinal fluid; D011446:Prospective Studies; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012720:Severity of Illness Index; D013345:Subarachnoid Hemorrhage / Q000097:blood / Q000134:cerebrospinal fluid*
chemical_list: D015415:Biomarkers; D005293:Ferritins
keywords: Cerebrospinal fluid; Ferritin; Meningitis; Neoplastic meningitis; Subarachnoid hemorrhage