Comparison of chemical-activated luciferase gene expression bioassay and gas chromatography for PCB determination in human serum and follicular fluid

We assessed exposure to dioxin-like compounds using chemical and bioassay a nalysis in different matrices in a female population. A total of 106 serum and 9 follicular fluid samples were collected from infertile women attendin g Centers for Reproductive Medicine in Belgium from 1996 to 1998. Major pol ychlorinated biphenyl (PCB) congeners were quantified by chemical analysis using gas chromatography with electron-capture detection, and the chemical- activated luciferase gene expression (CALUX) bioassay was used to determine the total dioxin-like toxic equivalence (TEQ) of mixtures of polyhalogenat ed aromatic hydrocarbons present in body fluids, such as serum and follicul ar fluid. To the best of our knowledge, this is the first investigation to determine TEQ values by the CALUX bioassay in follicular fluid. The TEQ lev els in both matrices are well correlated (r = 0.83, p = 0.02). As the chemi cal and bioassay analysis executed in this study do not cover the same span of polyhalogenated aromatic hydrocarbons, we did not expect totally correl ated results. Moreover, the sample workup and quantification of the analyte s differed completely. Nonetheless, the TEQ values in human extracts correl ated well with the sum of four major PCB congeners chemically determined in both serum and follicular fluid. These results indicate that the CALUX bio assay may serve as a simple, relatively inexpensive prescreening tool for e xposure assessment in epidemiologic surveys.