Idiosyncratic drug reactions (IDRs) can be defined as adverse drug reactions that occur in a small minority of the patients taking clinically-relevant doses and do not involve the known pharmacological effects of the drug. IDR related to hepatotoxicity or idiosyncratic drug-induced liver injury (IDILI) has been the top reason for withdrawing drugs from the market or for black box warnings. One of the mechanistic hypotheses regarding IDILI suggests that IDILI may arise from the interaction of a reactive metabolite of a drug with a mild inflammatory episode that renders the liver more sensitive to injury resulting in increased toxicity (inflammatory stress hypothesis). With the aim to find biomarkers that can detect IDILI ex vivo, we used mouse precision-cut liver slices (PCLS) to study the interaction of an inflammatory reaction and reactive-metabolite-producing drugs. PCLS retain the normal tissue architecture of an intact liver with all its cell types in their natural environment. Mouse PCLS were incubated for 24h with IDILI-related drugs ketoconazole (KC), clozapine (CZ), diclofenac (DF), carbamazepine (CBZ) and troglitazone (TGZ), or the non-toxic comparator drugs voriconazole (VC) and olanzapine (OZ) at NOAEL concentration or slightly above it in the absence or presence of lipopolysaccharide (LPS), an inflammation inducer. Cell viability (ATP, LDH leakage, histomorphology), reduced glutathione (GSH) level, nitric oxide (NO) production, and cytokine and chemokine release were assessed. LPS exacerbated the toxicity of KC and CZ but not of VC and OZ (the non-toxic comparator drugs in the same drug class as KC and CZ respectively). However, other IDILI-related drugs (DF, CBZ and TGZ) did not cause synergistic toxicity with LPS after 24h incubation, suggesting different mechanisms of action of IDILI for these drugs. LPS treatment alone did not reduce GSH levels in PCLS, yet together with KC or CZ but not with the other drugs, LPS appeared to further lower the GSH level when compared to the treatment with these drugs alone. LPS significantly increased NO, cytokine (IL-1β, IL-6, IFN-γ, TNF-α) and chemokine (CCL3, CCL5, G-CSF, GM-CSF) release into the media of PCLS, while the treatment with the drugs alone did not cause any substantial increase. All 7 drugs drastically reduced the LPS-induced NO production, while they caused different effects on the LPS-induced cytokine and chemokine release in PCLS. Interestingly, only KC and CZ increased the LPS-induced GM-CSF release. Therefore, a correlation between synergistic toxicity and upregulated GM-CSF release in LPS+KC and LPS+CZ treatment groups was found. Based on these results, GM-CSF can be a potential biomarker to detect IDILI related to the inflammatory stress hypothesis and PCLS appear to be a promising ex vivo model to further unravel the mechanism of inflammatory stress-related IDILI.
|Tijdschrift||ISSX Online Abstracts|
|Nummer van het tijdschrift||1|
|Status||Published - 2012|