Inflammatory cytokines in exhaled breath condensate in children with inflammatory bowel diseases

Although inflammatory bowel diseases (IBD) affect mainly the gastrointestinal tract, the extra-intestinal manifestations are not uncommon. Different diagnostic methods have been applied to assess pulmonary involvement in patients with IBD, but majority of these methods show significant limitations in children. The aim of our study was to evaluate the usefulness of exhaled breath condensate (EBC) measurements of pro-inflammatory cytokines in children with IBD.

Twenty-two children with Crohn's disease (CD) (mean age 13.8 ± 3.3 years), 25 with ulcerative colitis (UC) (mean age 14.1 ± 3.3 years) and 37 healthy volunteers (mean age 13.9 ± 3.6 years) were studied. IBD activity was assessed using appropriate scoring systems. None of the patients had signs or symptoms of pulmonary disease. Exhaled breath condensate was collected and EBC concentration of interleukin 6 (IL-6), tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and interleukin 8 (IL-8) was measured.

The concentrations of all the assessed cytokines were significantly higher in the study group as compared to controls. A negative correlation between IL-1β and CD activity index was found. There were no significant relationships between TNF-α, IL-6, or IL-8 level and CD activity index as well as between IL-1β, TNF-α, IL-6, IL-8 and UC activity index. No significant correlation between the concentration of IL-1β, TNF-α, IL-6, IL-8, and IBD duration or treatment duration was found.

Elevated concentration of pro-inflammatory cytokines in EBC in children with IBD may suggest the presence of asymptomatic inflammation in the lower airways.