Infliximab exerts no direct hepatotoxic effect on HepG2 cells in vitro.

BACKGROUND

Infliximab-induced hepatotoxicity is reported in several case studies involving patients with inflammatory bowel disease (IBD) and a direct hepatotoxic effect has been proposed.

OBJECTIVE

The aim of this study was to determine the direct in vitro toxicity of infliximab. As a proof of principle the in vitro toxicity of thiopurines and methotrexate was also determined.

METHODS

Cell survival curves and the half maximal inhibitory concentrations (IC(50)) were obtained after 24, 48 and 72 h of incubation in HepG2 cells with the IBD drugs azathioprine, 6-mercaptopurine, 6-thioguanine, methotrexate or infliximab by using the WST-1 cytotoxicity assay.

RESULTS

No in vitro hepatotoxicity in HepG2 cells was seen with infliximab, while concentration-dependent cytotoxicity was observed when HepG2 cells were incubated with increasing concentrations of azathioprine, 6-mercaptopurine and 6-thioguanine.

CONCLUSION

Infliximab alone or given in combination with azathioprine showed no direct hepatotoxic effect in vitro, indicating that the postulated direct hepatotoxicity of infliximab is unlikely.