It has been observed that early infliximab (IFX) fecal excretion in patients with acute severe ulcerative colitis (ASUC) was associated with low treatment response.
The objective was to assess if severe endoscopic lesions (SEL) were associated with IFX loss in the stool as well as low IFX concentrations in plasma at day 1 and 2 in a cohort of patients admitted for ASUC.
Consecutive patients admitted for a steroid-refractory ASUC requiring IFX and who underwent flexible sigmoidoscopy before starting the drug were included in a case-control, prospective, two-center study. Cases were patients with SEL and controls those without SEL. Plasmatic and fecal IFX concentrations were measured at day 1 and 2.
Among the 15 patients analyzed (10 men; median age: 49 years), 6 were cases harboring SEL at baseline. IFX was detected in the stool in 2/6 (33%) of cases and 4/9 (44%) of controls (p = 1) and no difference was observed between the two groups regarding plasmatic concentrations at day 1 or 2 (p = 1).
In ASUC, SEL were not associated with more loss of IFX in the stool or lower plasmatic levels. Early IFX pharmacokinetics in this setting does not seem related to endoscopic severity.