Objectives: To determine whether inflammation in the gut associated immune system is activated in rheumatoid arthritis (RA). The expression of chemokine receptor- (CCR4, CCR5) and cytokine- (interleukin (IL)2, IL10, interferon gamma (IFNgamma), tumour necrosis factor alpha (TNFalpha), and transforming growth factor beta (TGFbeta)) specific mRNA in intestinal biopsy samples from patients with RA was examined.
Methods: Duodenal biopsy samples from 13 patients with RA and 15 control subjects were studied. The mRNA expression of CCR4, CCR5, IL2, IL10, IFNgamma, TNFalpha, and TGFbeta in intestinal biopsy samples was demonstrated by real time quantitative reverse transcriptase-polymerase chain reaction.
Results: The mRNA expression of CCR4, CCR5, and IL10 in intestinal biopsy samples was increased in patients with RA in comparison with control subjects (p = 0.001, p = 0.046, p = 0.019). No difference in the expression levels of IL2, IFNgamma, TNFalpha, or TGFbeta was seen between patients with RA and controls.
Conclusions: The increased intestinal mRNA expression of IL10, CCR5, and CCR4 suggests that gut associated immune cells are activated in patients with RA.