Background Tumor necrosis factor alpha (TNFalpha) is considered as a central mediator of inflammation in inflammatory bowel disease (IBD) and fecal TNFα concentration has been reported to be increased with disease activity. The aim of this study was to evaluate the role of stool TNFα concentrations as a marker of infliximab (IFX) maintenance therapy in children.

Studied Groups and Methods Stool samples were collected from 22 active IBD children, 4 children with inactive IBD on therapy with infliximab every 8 weeks schedule (IFX IBD) and 20 children with functional abdominal pain (FAP), and 10 healthy controls (C). In the IFX IBD group stool samples were obtained a day before infliximab infusion and in one week intervals thereafter. At least two consecutive 8 weeks infliximab infusion cycles were analyzed. Fecal TNFα concentration was determined by EIA in stool extracts.

Results There were no differences in the age and body weight between studied groups. Fecal TNFα concentration was significantly higher in the active IBD patients as compared to other groups (73,1 +/− 90,0 pg/100 mg of stool; p<0,05). No statistical difference was observed between mean stool TNFα concentration in IFX IBD children and non-IBD patients (FAP: 6 +/− 90,0 pg/100 mg; C: 0,5 +/− 1,8 pg/100 mg; IBD-IFX before consecutive infusion of anty TNF – 0,03 +/− 0,07 pg/100 mg and after infusion – 0,09 +/− 0,15 pg/100 mg.

Conclusions Measurement of fecal TNFα concentration may provide a valuable, non-invasive way of monitoring maintenance anti-TNFalpha therapy in IBD children.