References

-Trace protein has been identified by rocket immuno-electrophoresis, which has a reported sensitivity of 91 % in diagnosing CSF leakage (4). For the automated assay from Dade Behring, a range of 0.22–1.69 mg/L for healthy individuals was reported, and a cutoff at 1.31 mg/L (97.5 percentile) was proposed (9). At concentrations between 1.31 and 1.69 mg/L, however, there is overlap of individ-uals without and patients with CSF leakage (9). In our study, -trace protein measured without predilution was 1 mg/L in individuals without CSF leakage. In the earlier study, nasal fluids were partly prediluted 1:100. At a cutoff of 1 mg/L, the Dade Behring assay had a 100% sensitivity (78–100%; P0.05) and specificity (86–100%; P 0.05) for diagnosing a CSF leakage. Thus, in our opinion the nephelometric quantification of -trace protein is preferable, particularly because this method is less time-consuming and labor-intensive than the electrophoretic method. We gratefully acknowledge the excellent technical assis-tance of Jutta Breidenich and Ursula Emmler