The incidence of Clostridium difficile (C. difficile) infection (CDI) is 1.8%-5.7% in admitted patients with ulcerative colitis (UC). CDI can worsen UC and increase the risk for colectomy or even death, thus necessitating therapy escalation, such as increasing the corticoid therapy or starting a biologic treatment. Several reported cases with infliximab therapy have provided favorable outcomes in UC patients with CDI, suggesting that infliximab treatment may be protective; however, the optimal infliximab treatment regimen for UC patients with CDI remains to be established. Here, we report a case of worsening UC in the presence of recurrent CDI. The patient had received prior ciprofloxacin and immunosuppressive therapy during a prolonged hospital stay. The deterioration in the patient's condition likely resulted from the ability of C. difficile to promote relapsing of UC by activating the immune response. Ultimately, the patient was treated with a high dose of infliximab after a low trough level of infliximab at week 8 was identified, yielding better clinical results. Infliximab was found to be safe after repetitive episodes of CDI. The trough level of infliximab was therefore a useful indicator to guide therapy and correlated well with the patient's outcome.
Keywords: Clostridium difficile; Inflammatory bowel disease; Infliximab; Trough level; Ulcerative colitis.