A multicenter assessment of liver toxicity by MRI and biopsy in IBD patients on 6-thioguanine

Background/Aims: Although 6-thioguanine (6-TG) has been suggested as an effective treatment option for patients with inflammatory bowel disease (IBD), the recent description of its hepatotoxicity has led to the recommendation not to consider this drug. We initiated a multicenter safety study in IBD-patients treated with 6-TG to investigate hepatic changes by liver biopsy and magnetic resonance imaging (MRI). Methods: Forty-five patients from three European centers treated with 6-TG (40-80 mg/d) at least for 8 weeks were enrolled. In all patients liver biopsy and MRI were performed. Sides and MR images were independently read by two pathologists and radiologists, respectively, and interpreted according to predefined criteria by consent. Results: In 8 patients nodular regenerative hyperplasia (NRH) wars diagnosed by liver biopsy, in 8 additional patients NRH could not be excluded due to equivocal pathological findings. MRI demonstrated a sensitivity of 77% and a specificity of 72% in the detection of pathohistological findings consistent with and/or possibly related to NRH. Conclusions: Our study suggests that 6-TG therapy in IBD patients is associated with NRH of the liver. Based on a special MRI protocol, non-invasive diagnosis of NRH with promising sensitivity and specificity was demonstrated. (c) 2005 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.