Methotrexate Polyglutamates as a Marker of Clinical Response and Toxicity in the Treatment of Psoriasis

Methotrexate Polyglutamates as a Marker of Clinical Response and Toxicity in the Treatment of Psoriasis

Methotrexate (MTX) is widely prescribed to treat inflammatory conditions including psoriasis, where it is the recommended first-line systemic therapy in moderate-to-severe disease. Approximately 40% of patients with psoriasis have a sub-optimal response to MTX and a significant number experience side effects that may include deranged liver enzymes. There is currently no validated test to predict how patients with psoriasis will respond to MTX, in terms of disease outcome and/or toxicity, or to guide dose escalation in this group.

Data for this study is drawn from the BSTOP (Biomarkers of Systemic Treatment Outcomes in Psoriasis) cohort. This is a multi-centre, prospective, cohort study to establish clinically relevant biomarkers and pharmacogenetic markers of systemic treatment outcomes in patients with severe psoriasis.

Inclusion Criteria:

• Patients with psoriasis
• Taking oral or subcutaneous methotrexate
• Measurement of methotrexate polyglutamates on at least one occasion during therapy.
• Patients who have given written informed consent

Exclusion Criteria:

• Unable to consent
• Not taking methotrexate