S100A expression and interleukin-10 polymorphisms are associated with ulcerative colitis and diarrhea predominant irritable bowel syndrome.

Background: Both ulcerative colitis (UC) and diarrhea-predominant irritable bowel syndrome (IBS-D) are associated with alterations in enteric serotonin (5-HT) signaling.

Aims: The purpose of this study was to compare the rectal and sigmoid colonic mucosal expression of S100A proteins and functional polymorphisms of the 5-HT transporter (5HTT) and interleukin-10 genes in patients with IBS-D or UC with healthy controls.

Methods: mRNA expression of S100 proteins was measured in sigmoid and rectal biopsies and in rectal epithelium isolated by laser-captured microdissection.