SERUM TUMOUR NECROSIS FACTOR-α ANTAGONIST DRUG CONCENTRATIONS IN PATIENTS WITH PYODERMA GANGRENOSUM ASSOSCIATED WITH INFLAMMATORY BOWEL DISEASE

摘要

Background The utility of therapeutic drug monitoring for guiding the dosing of tumor necrosis factor-α antagonists (TNFAs) in luminal inflammatory bowel disease (IBD) is well-established and well-accepted. TNFAs, specifically infliximab and adalimumab, have become integral to the management of the rare, neutrophilic dermatosis, pyoderma gangrenosum (PG) in IBD. Little is known regarding the target serum TNFA concentrations to guide dosing to achieve resolution of PG in IBD. Aims To describe the serum TNFA concentrations (infliximab or adalimumab) associated with the resolution of PG lesions in patients with IBD. Methods Patients with IBD and associated PG treated with one of infliximab or adalimumab (collectively known as TNFAs) seen at two academic hospitals affiliated with Western University were identified. Serum TNFA concentrations were assessed at the time of PG treatment. Results Nine patients were identified. All patients had IBD-associated PG. Seven patients were treated with infliximab and 2 patients were treated with adalimumab. All patients received standard dosing. Eight patients had complete resolution of their PG, while one had near complete resolution at the time of last follow-up. A median serum infliximab concentration of 3.00 (IQR, 3.52) μg/ml at week 14 and a median serum adalimumab concentration of 2.02 (IQR, 0.98) μg/ml at week 12 were seen at the time of PG treatment. Conclusions Herein, we report low serum TNFA concentrations despite PG healing in a cohort of IBD patients. This is lower than what is in patients for successful TNFA treatment in luminal and fistulising IBD. Funding Agencies NoneNone.