Cerebrospinal Fluid Leakage: Agarose Gel Electrophoresis Detection of β2-Transferrin and Nephelometric Quantification of β-Trace Protein

Abstract

Cerebrospinal fluid (CSF) leakage may occur with head trauma, surgery, inflammation, tumors, or congenital malformations. Determining the presence of CSF leakage is important so the leakage can be repaired and treatment can be initiated to prevent infection in the central nervous system. In this study, electrophoretic methods using three different detection systems for β2-transferrin (β2Trf) were compared with a nephelometric method for β-trace protein (βTP) for ease of use and sensitivity in the clinical laboratory setting to diagnose CSF leakage. Results were compared for 30 samples that had been submitted to the clinical laboratory for assessment of CSF leakage. Detection of β2Trf has been used as an endogenous marker to identify CSF in fluids to diagnose CSF leaks (1)(2)(3)(4). Transferrin that migrates in the β-1 electrophoretic fraction (β1Trf) is found in most body fluids. β2Trf is used as a CSF-specific variant of transferrin, but it is also found in the aqueous humor and serum of patients with rare metabolic glycoprotein disorders or genetic variants of transferrin. If β1Trf and β2Trf are detected in drainage fluids by electrophoresis and subsequent immunodetection, the specimen is presumed to be contaminated with CSF. The first electrophoresis method we evaluated used Titan Gel Silver Stain reagents (Helena) and anti-transferrin immunofixation. Samples, a negative control (serum), and a known positive control (CSF) were electrophoresed on the Titan Gel and immunofixed with 600 μL of anti-human transferrin that was diluted with 1200 μL of saline (1:3 dilution; DiaSorin Inc.); antigen-antibody complexes were then stained with Titan …