Anti-inflammatory effect of biological treatment in patients with inflammatory bowel diseases: calprotectin and IL-6 changes do not correspond to sRAGE changes.

Aim: The main objective was to examine the relationship between the soluble receptor for advanced glycation end products (sRAGE) and calprotectin concentrations in faeces and serum of patients with inflammatory bowel diseases (IBD) during biological treatment with infliximab.

Materials And Methods: A total of 29 IBD patients treated with infliximab were evaluated. Calprotectin and sRAGE in serum and faeces and serum IL-6 and CRP were measured during the induction regimen of infliximab treatment at weeks (W) 0, 2 and 10.

Results: At W0, a significant increase in faecal calprotectin was found in IBD compared to healthy persons (690 +/- 696 microg/g and 23 +/- 7 microg/g, respectively, p < 0.001). No clear difference was found in serum sRAGE levels in IBD cohort compared to healthy controls (772 +/- 274 pg/mL and 720 +/- 107 pg/mL, respectively, p = 0.159); however, a significant negative correlation was found between faecal calprotectin levels and serum concentrations of sRAGE in the active IBD cohort (r = -0.518, p = 0.004). In the stool eluates, sRAGE levels were non-measurable. In the group of responders-to-treatment, the initial surge in both faecal and serum calprotectin levels as well as CRP and IL-6 was followed by a significant decrease on W10. Surprisingly, no significant changeovers were seen in serum sRAGE concentrations in responders neither in W2 nor in W10.

Conclusions: Unlike other examined local and systemic inflammatory markers, serum sRAGE did not change during the infliximab treatment, despite the initial correlation with the degree of mucosal inflammation.