On the other hand, while Mahler et al. found high PR3-ANCA reactivity in 31.1% of adult patients with ulcerative colitis and 1.9% of patients with Crohn's disease using a chemiluminescence technique, by ELISA the reactivity was only 6% in ulcerative colitis and absent in Crohn's disease. This evidence concerns the gene PRTN3 and ulcerative colitis.