Monitoring liver function during methotrexate therapy for psoriasis: are routine biopsies really necessary?

Methotrexate is a widely used and efficacious treatment for psoriasis. Current recommendations advise liver biopsy after each cumulative 1-1.5g dosage of methotrexate. Although studies of methotrexate hepatotoxicity in psoriasis are of variable quality, the evidence indicates that in patients with no risk factors for liver disease on long-term, low-dosage (<20mg), once-weekly methotrexate, liver biopsy is justified after an initial cumulative dosage of 4g. Advances in the non-invasive assessment of liver fibrogenesis may eventually further reduce the need for biopsy.