Food-specific IgG4-guided exclusion diets improve symptoms in Crohn's disease: a pilot study

Aim Exclusion diets have been shown to prolong remission in Crohn's disease (CD). We assessed IgG4-targeted exclusion diets in patients with CD. Method Forty patients with symptomatic CD were recruited. Their sera were tested for IgG4 antibodies to 14 specific food antigens and each subject's four most reactive foods were excluded for 4 weeks. Disease activity was assessed using a modified CD activity index (mCDAI). Questionnaire and inflammatory markers were measured before and on completion of the exclusion diet. Results Eleven patients did not complete the study, leaving 29 for analysis. Of these, 26 (90%) reported symptomatic improvement with a reduction in mCDAI from a mean of 171-97.5 (P = 0.0001). The ESR fell from 23 to 17 mm/h (P = 0.021) and the IgG4 titres for the excluded foods fell from a mean of 30152306 mcgA/l (P = 0.003). Conclusion IgG4-guided exclusion diets resulted in significant symptomatic improvement with an objective fall in an inflammatory marker. This approach may be useful in clinical practice.