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

Study Overview
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Brief Summary
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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.

Detailed Description
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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.

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

Conditions
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Psoriasis Chronic, Injury of Liver

Participation Criteria
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Eligibility Criteria
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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

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Psoriasis<br>Patients with psoriasis taking methotrexate | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Serial erythrocyte methotrexate polyglutamate measurements using high performance liquid chromotography | To determine if there is a correlation between methotrexate polyglutamate concentrations and clinical response measured by Psoriasis Area Severity Index( PASI) in patients on methotrexate monotherapy with psoriasis. This will consider potential confounding factors, including age, gender and dose of MTX | From 3 months to 5 years after commencing methotrexate | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Alanine transaminase (ALT) and Full blood count (FBC) will be used to measure toxicity to methotrexate | To determine if there is an association between MTXPG levels and evidence of hepatotoxicity in patients with psoriasis taking either (1) methotrexate alone or (2) methotrexate in combination with another systemic drug. Evidence of hepatotoxicity will be determined by the use of current gold standard tests. | 3 months to 5 years after first MTX dose | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Methotrexate Polyglutamates, Injury of Liver, Psoriasis, Methotrexate