title: Separation of beta2-transferrin by denaturing gel electrophoresis to detect cerebrospinal fluid in ear and nasal fluids.
abstract: BACKGROUND
  Cerebrospinal fluid (CSF) leakage is a critical condition with a substantial risk of meningitis. We investigated the use of transferrin isoform analysis as a diagnostic marker for detection of CSF leakage in fluid samples.
  
  
  METHODS
  We analyzed 241 samples from patients with CSF leakage, most commonly presenting as otorrhea or rhinorrhea, by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) with subsequent Western blotting and immunostaining for transferrin. Tears, saliva, nasal fluid, and ear secretions (20 samples each) were analyzed in parallel, and normal human serum served as a control in each experiment. We compared the minimum volume of added CSF that could be detected in secretions by our assay with the minimum volume detected by the prostaglandin-D synthase (beta-trace) test. CSF was admixed with blood in different proportions to determine the influence of blood contamination on the transferrin pattern.
  
  
  RESULTS
  In all CSF samples, beta1- and beta2-transferrin were present in nearly equal amounts. In tears and ear secretions, beta2-transferrin migrated in the gel in the same manner as in CSF, but its concentration was noticeably lower than that of beta1-transferrin, a difference that allowed a clear distinction from the transferrin pattern of CSF. In saliva, both transferrin isoforms were also present but could be distinguished from those of other fluids by electrophoretic migration pattern rather than relative concentrations. With the beta-trace test, a minimum of 5 microL of CSF was needed for detection, whereas our beta2-transferrin assay yielded a signal of comparable intensity with a minimum of 2 microL of CSF.
  
  
  CONCLUSIONS
  Analysis of the transferrin microheterogeneity pattern by SDS-PAGE for the identification of CSF leakage is a highly sensitive and specific method that merits consideration as a routine technique.
authors: Department of Otorhinolaryngology, Head and Neck Surgery, University of Kiel, Kiel, Germany. gorogh@hno.uni-kiel.de
authors: Tibor
authors: T
authors: Görögh
authors: Pierre
authors: P
authors: Rudolph
authors: Jens Eduard
authors: JE
authors: Meyer
authors: Jochen A
authors: JA
authors: Werner
authors: Burkard M
authors: BM
authors: Lippert
authors: Steffen
authors: S
authors: Maune
mesh_terms: D015415:Biomarkers / Q000134:cerebrospinal fluid; D002558:Cerebrospinal Fluid Otorrhea / Q000134:cerebrospinal fluid / Q000175:diagnosis*; D002559:Cerebrospinal Fluid Rhinorrhea / Q000134:cerebrospinal fluid / Q000175:diagnosis*; D004423:Ear; D004591:Electrophoresis, Polyacrylamide Gel; D006801:Humans; D009666:Nose; D020033:Protein Isoforms / Q000134:cerebrospinal fluid / Q000302:isolation & purification; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012463:Saliva / Q000737:chemistry; D012680:Sensitivity and Specificity; D013666:Tears / Q000737:chemistry; D014168:Transferrin / Q000134:cerebrospinal fluid* / Q000302:isolation & purification
chemical_list: D015415:Biomarkers; D020033:Protein Isoforms; D014168:Transferrin