Mitogen-activated lymphocytes: a good model for characterising lung CYP1A1 inducibility.

The CYP1A1 hyperinducibility phenotype occurring in some 10% of the human population corresponds to a higher risk of developing lung cancer. This study was undertaken to assess whether the inducibility factor, generally evaluated on mitogen-activated lymphocytes after PAH induction, represents correctly the lung situation. Optimal experimental conditions were determined for evaluating, on both lymphocytes and lung tissue explants, the inducibility factor, defined as the ratio of EROD activity (CYP1A1-specific) to cytochrome c reductase activity (unaffected by PAH induction). Paired results for lymphocytes and lung tissue samples from 10 lung cancer patients were compared. A good correlation was observed between lymphocyte and lung tissue inducibilities (R = 0.809; p = 0.005). In conclusion, mitogen-activated lymphocyte inducibility is indicative of lung tissue inducibility and constitutes a good marker for evaluating individual PAH inducibilities.