Hinojosa J, et al. - Researchers sought to assess the association between serum adalimumab (ADA), an anti-tumor necrosis factor agent, levels and clinical outcome in the treatment of inflammatory bowel disease. A review of published studies on ADA serum levels and their relationship to the clinical outcome has been conducted over the last 5 years. According to results, the optimal therapeutic cut-off point for serum ADA levels ranges from 4.5–5 to 12 μg/mL, where ADA levels were linked to adequate clinical disease monitoring during maintenance therapy. These ranges vary by the target, suggesting 4.8 μg/mL levels as the clinical remission cut-off and ≥7.5 µg/mL levels for mucosal healing/endoscopic response. Controlled prospective studies are needed in order to determine the optimal therapeutic interval of serum ADA levels as both induction and maintenance therapy.