title: Preliminary study on the stability of beta-2 transferrin in extracorporeal cerebrospinal fluid.
abstract: OBJECTIVE
  Detection of beta-2 transferrin in rhinorrhea fluid is a sensitive and specific method for the diagnosis of a cerebrospinal fluid (CSF) leak. Patients may be asked to collect this fluid at home to obtain an adequate volume for detection, and thus the age and storage conditions of these specimens may be variable upon analysis. The purpose of this study is to understand how age, storage temperature, and exposure to mucus affect the ability to detect beta-2 transferrin in CSF.
  
  
  METHODS
  Case series with planned data collection.
  
  
  METHODS
  Tertiary care university hospital.
  
  
  METHODS
  This study consists of 6 patients undergoing endoscopic CSF leak repair. CSF was collected directly from a lumbar drain (n = 4) or from nasal drainage (n = 2). Specimens were stored at 4°C (n = 3) or room temperature (n = 3). Samples were tested for the presence of beta-2 transferrin for up to 7 days using standard immunofixation electrophoresis techniques.
  
  
  RESULTS
  Beta-2 transferrin was detected in all specimens through day 7 regardless of storage temperature or collection site (95% exact binomial confidence interval of 0%-46%).
  
  
  CONCLUSIONS
  Beta-2 transferrin remains detectable in extracorporeal CSF for up to 7 days regardless of storage at room temperature or exposure to nasal mucus. Negative detection in patient specimens up to a week old is therefore not likely to be caused by protein degradation.
authors.affiliation: Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, Massachusetts 02114, USA. bleierb@gmail.com
authors.forename: Benjamin S
authors.initials: BS
authors.lastname: Bleier
authors.forename: Indranil
authors.initials: I
authors.lastname: Debnath
authors.forename: Brendan P
authors.initials: BP
authors.lastname: O'Connell
authors.forename: W Alexander
authors.initials: WA
authors.lastname: Vandergrift
authors.forename: James N
authors.initials: JN
authors.lastname: Palmer
authors.forename: Rodney J
authors.initials: RJ
authors.lastname: Schlosser
mesh_terms: D000328:Adult; D000368:Aged; D002559:Cerebrospinal Fluid Rhinorrhea / Q000134:cerebrospinal fluid* / Q000175:diagnosis; D003937:Diagnosis, Differential; D004586:Electrophoresis / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012680:Sensitivity and Specificity; D013129:Spinal Puncture; D014168:Transferrin / Q000134:cerebrospinal fluid*
chemical_list: D014168:Transferrin