Expansion of intestinal CD4+CD25(high) Treg cells in patients with ankylosing spondylitis: a putative role for interleukin-10 in preventing intestinal Th17 response.

Objective: Subclinical gut inflammation has been demonstrated in patients with ankylosing spondylitis (AS). This study was undertaken to determine the frequency of regulatory CD4+CD25(high) T cells (Treg cells) and to evaluate Treg cell-related cytokines (interleukin-2 [IL-2], transforming growth factor β [TGFβ], and IL-10) and transcription factors (FoxP3 and STAT-5) in the ileum of patients with AS.

Methods: Quantitative gene expression analysis, by reverse transcriptase-polymerase chain reaction, of Treg-related cytokines (IL-2, TGFβ, and IL-10) and transcription factors (STAT-5 and FoxP3) was performed on ileal biopsy specimens from 18 patients with AS, 15 patients with active Crohn's disease (CD), and 15 healthy subjects.