Human chorionic gonadotropin and α-fetoprotein in cerebral spinal fluid: Method validation and retrospective review

Objective: Measurement of human chorionic gonadotropin (hCG) and α-fetoprotein (AFP) in cerebrospinal fluid (CSF) can aid in the diagnosis of germ cell tumors (GCTs). Matrix effects can influence test results when alternative sample types are used, therefore, alternative sample types should always be validated before clinical use. Here we have validated the Advia® Centaur total hCG and AFP methods for use with CSF. We also performed a retrospective review of 5. years of CSF hCG and AFP measurements sent out from our institution. Design and methods: Both hCG and AFP concentrations were measured using the ADVIA Centaur® total hCG or AFP assay. Results: The Centaur hCG and AFP assays, performed on CSF, had intra- and inter-assay imprecisions <. 10.2% CV. The assays were linear over a dynamic range of 10-1000. IU/L for hCG and 10-1000. μg/L for AFP. Retrospective chart review confirmed that GCTs have a male predominance and are diagnosed most frequently in the second decade of life. The data also illustrate the importance of measuring both serum and CSF concentrations as CSF can be elevated in the absence of serum elevations. Conclusions: The Centaur total hCG and AFP methods accurately quantify hCG and AFP in CSF.