P442 Infliximab Versus Combination Infliximab and Immunosuppressant Therapy for Patients with Active Ulcerative Colitis: a Meta-Analysis

Background: Thiopurines (TP) are a mainstay of inflammatory bowel disease (IBD) therapy. Thiopurine methyltransferase (TPMT) and TP metabolites testing have been suggested to predict variation in metabolism and response to therapy. However, prospective data to confirm clinical benefits of metabolites guided dosing is still limited, as are guidelines for TP monitoring. We aimed to evaluate current Australian gastroenterologists' (GEs) practice in TP use for IBD, including TPMT testing, full blood count (FBC) monitoring, metabolites testing, allopurinol co-therapy, effects on clinical outcomes, and how practices have changed over time. Methods: An anonymous survey was distributed to GEs by email and at meetings across Australia over 6 months in 2013. The results were compared with a similar survey conducted in 2008. The Chi-squared test was used to calculate statistical significance. Results: Most GEs started TP at escalating rather than full doses (76.6%). FBC monitoring intervals varied most in the first 3 months. Compared to 2008, TPMT had become more frequently tested (79.1% vs 44.5%, p 1 week for the majority (87.6%), and >2 weeks for a large minority (41.1%). The majority of GEs perceived that TP metabolites had improved clinical outcomes: improved response rates (80.6%), reduced complication rates (60.4%) and altered clinical practice (79.2%). Allopurinol co-therapy was used by the majority (71%), although not all for the same indications [82.8% for shunters with abnormal liver function tests (LFTs), 24.7% for shunters irrespective of LFTs, and 36.6% for side effects irrespective of LFTs]. Conclusions: Over the past 5 years, the practices of TPMT and TP metabolites testing have increased markedly and have altered TP prescribing practice amongst Australian GEs. However, variability exists in FBC monitoring and TP dosing, especially in context of reduced TPMT levels, as well as indications for TP metabolites testing and allopurinol cotherapy. Despite these, the subjective appraisals of the majority of Australian GEs were that TP metabolites testing had improved clinical outcomes. Further studies to objectively confirm these, and evidence to inform standardization of TP prescribing and monitoring practices are keenly awaited.