GP2 and Crohn disease: Crohn’s disease patients with an age less than 17 years at diagnosis (A1) demonstrated a significantly higher prevalence of CD-specific IgG antibodies [anti-GP2 IgG 16/31 (51.6%) vs 32/138 (23.2%), ASCA IgG 15/31 (48.4%) vs 33/138 (23.9%), PAB 22/31 (71.0%) vs 43/138 (31.2%); p < 0.004, p < 0.004, p < 0.001, respectively].