Decreased interleukin-10 secretion by peripheral blood mononuclear cells in children with irritable bowel syndrome

BACKGROUND AND AIMS: The aim of the present study was to evaluate proinflammatory and anti-inflammatory cytokine levels in children with irritable bowel syndrome (IBS). PATIENTS AND METHODS: Thirty-five children with IBS (17 diarrhea-predominant, 7 constipation-predominant, and 11 mixed type) and 25 healthy children as healthy controls (HCs) were enrolled. All of the participants completed a questionnaire recording the duration, severity, and associated academic and social influences. Peripheral blood mononuclear cells were isolated and cultured for 24 hours with and without 1 or 5 ng/mL Escherichia coli lipopolysaccharide (LPS). Cytokine production including tumor necrosis factor-α (TNF-α), interleukin (IL)-6, and IL-10 was measured using enzyme-linked immunosorbent assays. RESULTS: Children with IBS revealed lower baseline and significantly lower IL-10 levels after LPS stimulation compared with HCs (P = 0.001). Although not to a significant level, TNF-α and IL-6 levels were higher in children with IBS compared with HCs. The IL-10 levels in patients with IBS with strong pain intensity were lower both in baseline and under 1 ng/mL LPS stimulation. The levels became significantly lower under 5 ng/mL LPS stimulation compared with those experiencing mild and moderate pain intensity (P = 0.025). CONCLUSIONS: Our study suggests that children with IBS tend to produce lower amounts of the anti-inflammatory cytokine IL-10 at baseline and after LPS stimulation, implying that defects in immune modulation may contribute to IBS in children.