Assessment and management of methotrexate hepatotoxicity in psoriasis patients: report from a consensus conference to evaluate current practice and identify key questions toward optimizing methotrexate use in the clinic

Experts in psoriasis, hepatology, pharmacokinetics and pharmacogenetics convened to discuss the safety and monitoring of methotrexate with respect to hepatotoxicity when used in the treatment of psoriasis. Methotrexate is an efficacious and cost-effective treatment for psoriasis, but is associated with significant safety issues, particularly relating to hepatotoxicity. Current British, Dutch, German, EU and US guidelines for baseline evaluations, monitoring and prevention of hepatotoxicity in patients with psoriasis receiving methotrexate were evaluated. Liver safety monitoring is currently reliant upon multiple methods, including biopsy, serological tests for biomarkers such as type III procollagen amino terminal propeptide (PIIINP), and liver function tests based on liver enzymes. Monitoring of patients receiving long-term therapy is expected to be improved by the utilization of serum biomarkers currently in development such as the Enhanced Liver Fibrosis (ELF) panel and other non-invasive tests of hepatic architecture, such as fibroelastography, microbubbles and magnetic resonance imaging. Appropriate studies to determine optimal dosing to maximize efficacy and minimize toxicity, potentially utilizing pharmacogenetic principles, are clearly needed. Key questions for future research are identified including needs for optimal screening and monitoring, identification of appropriate biomarkers, assessment of relationships between dosing and safety, utility of liver biopsy, optimal dosing regimens (including route of administration), methods to measure methotrexate levels in blood, and use of methotrexate as a standardized active comparator in trials of experimental drugs used to treat psoriasis.