Kathryn Harrison and Satyapal Rangaraj
Juvenile Idiopathic Arthritis (JIA) is one of the commonest chronic diseases of childhood. Despite significant advances in the field of biologics offering a much wider a range of treatment options, Methotrexate remains the 1st line disease modifying drug [1] especially for those with polyarticular disease or associated uveitis. Response to methotrexate is variable and though work is ongoing to try and predict those who will respond well, this has not yet translated into clinical practice. Methotrexate can be associated with significant side effects [2,3] and adherence can be challenging. Currently assessment of adherence in the patient with apparently resistant disease relies on patient or parent reporting, which may not always be accurate.
Liver function is routinely monitored in children and young people (CYP) on Methotrexate to look for evidence of liver toxicity [4-6]. It is not uncommon for transaminases to be abnormal while taking methotrexate [7]. A perceived relationship between normal liver function and methotrexate adherence has been reported by some practitioners [8].