Fig. 3

Association of TNF hypomethylation with mucosal inflammation. (A) TNF methylation analysis of IBD cases stratified by local mucosal disease activity. Categories: 1, uninflamed biopsies from IBD patients without active disease (n = 44 samples); 2, uninflamed biopsies from IBD patients with active disease (n = 65 samples); 3, inflamed biopsies from IBD patients exhibiting mild or focal inflammation (n = 33 samples); 4, inflamed biopsies from IBD patients exhibiting chronic or acute colitis (n = 27 samples). Data points are average methylation values for individual biopsies. Mean ± SD are plotted. (B) TNF methylation analysis of paired uninflamed and inflamed mucosal samples from individual IBD cases (CD, green lines, n = 36 paired samples; UC, purple lines, n = 22 paired samples). Connecting lines indicate paired samples. P values were calculated using nonparametric Kruskal-Wallis (A) or Wilcoxon matched-pairs signed rank tests (B). CD, Crohn’s disease; IBD, inflammatory bowel disease; SD, standard deviation; TNF, tumor necrosis factor; UC, ulcerative colitis.