Transdermal nicotine decreases mucosal IL-8 expression but has no effect on mucin gene expression in ulcerative colitis

Our goal was to determine the effect of transdermal nicotine on cytokine an d mucin gene transcription in ulcerative colitis (UC). Sixty-four nonsmokin g patients with active UC were randomly assigned to transdermal nicotine (m aximum dose 22 mg/day) or placebo for 4 weeks. Clinical assessment and colo nic mucosal biopsies were obtained at entry and after 4 weeks. Inflammatory and immunoregulatory cytokines were assessed by qualitative reverse transc riptase-polymerase chain reaction (RT-PCR). Based on this initial screen, I L-8 mRNA levels were measured by RT-competitive PCR. MUC1, MUC2, MUC3, MUC4 , MUC5AC, MUC5B, and MUC6 mRNA concentrations were measured by quantitative dot blot analysis. Cytokine mRNA expression, except for IL-8, was similar in all patients. IL-8 mRNA levels were significantly decreased in the colon ic mucosa. of nicotine-treated patients who improved (p = 0.04). IL-8 mRNA values were similar before and after treatment in nonresponding nicotine-tr eated patients and in all placebo-treated patients. Mucin gene expression w as similar in all patient groups. Beneficial effects of transdermal nicotin e in active UC may result from decrease of IL-8 expression at the transcrip tional level. Transdermal nicotine has no effect on mucin gene transcriptio n.