Exogenous pigment in Peyer patches of children suspected of having IBD.

Objectives: The base of human Peyer patches of the terminal ileum has been noted to contain black granular pigment deposits, composed of titanium dioxide and aluminosilicate, which are food additives typically present in a Western diet, and pharmaceuticals. In the present study, we investigated the distribution of exogenous pigment throughout the gastrointestinal tract of children suspected of having inflammatory bowel disease (IBD), the correlation between their age and the presence and amount of pigment in Peyer patches, and its relation to pediatric IBD.

Methods: Biopsies (upper and lower gastrointestinal tract) from children suspected of having IBD who underwent endoscopy, were reassessed by a blinded, expert pathologist. The amount of pigment in biopsies was scored using a semiquantitative scale (range 0 to +++).

Results: A total of 151 children were included: 62 with Crohn disease (CD), 26 with ulcerative colitis, and 63 with non-IBD. In 63 children (42%), deposits of black pigment were found only in biopsies from the terminal ileum, located in Peyer patches. A significant correlation was found between increasing age and the amount of pigment (P = 0.004). Pigment deposits were found significantly less in the patients with CD compared with those in patients with ulcerative colitis and those with non-IBD (26% vs 62% and 49%, P = 0.002).

Conclusions: These results provide support for the hypothesis that the amount of pigment, only present in Peyer patches in the terminal ileum, becomes denser with increasing age. Absence of pigment in Peyer patches in a higher number of patients with CD suggests that microparticles may have become involved in the inflammatory process, possibly because of disrupted autophagy.