Clinical relevance of IgG antibodies against food antigens in Crohn's disease: a double-blind cross-over diet intervention study.

Digestion. 2010;81(4):252-64

Plain language summary

Environmental factors are thought to play a part in the development of or exacerbation of symptoms in Crohn's disease (CD), and patients often implicate food as a contributing factor. Immunoglobulin E (IgE) food reactions can be rare in IBD and immunoglobulin G (IgG) testing can be controversial, this study set out to compare IgG antibody reactions in 79 CD patients and 20 healthy individuals. The pilot study measured IgG levels against 271 foods in the blood. It then went on to measure stool frequency, abdominal pain and general well-being following a 6 week specific elimination diet (based on foods identified by the IgG testing) or a 6 week sham diet. 23 participants were included in the follow on 12 week, cross-over double blinded study. Eosinophil-derived neurotoxin (EDN) in stool was also measured to evaluate disease activity. The pilot study showed a significantly higher IgG reaction in the CD patients. In the follow-up study there was a decrease in stool frequency, abdominal pain and general well-being during the specific diet compared to the sham diet. EDN was found to decrease in both the specific and sham diet. It was concluded that IgG antibodies may contribute to CD but the mechanism is still not clear.


BACKGROUND Environmental factors are thought to play an important role in the development of Crohn's disease (CD). Immune responses against auto-antigens or food antigens may be a reason for the perpetuation of inflammation. METHODS In a pilot study, 79 CD patients and 20 healthy controls were examined for food immunoglobulin G (IgG). Thereafter, the clinical relevance of these food IgG antibodies was assessed in a double-blind cross-over study with 40 patients. Based on the IgG antibodies, a nutritional intervention was planned. The interferon (IFN)gamma secretion of T cells was measured. Eosinophil-derived neurotoxin was quantified in stool. RESULTS The pilot study resulted in a significant difference of IgG antibodies in serum between CD patients and healthy controls. In 84 and 83% of the patients, respectively, IgG antibodies against processed cheese and yeast were detected. The daily stool frequency significantly decreased by 11% during a specific diet compared with a sham diet. Abdominal pain reduced and general well-being improved. IFNgamma secretion of T cells increased. No difference for eosinophil-derived neurotoxin in stool was detected. CONCLUSION A nutritional intervention based on circulating IgG antibodies against food antigens showed effects with respect to stool frequency. The mechanisms by which IgG antibodies might contribute to disease activity remain to be elucidated.

Lifestyle medicine

Fundamental Clinical Imbalances : Immune and inflammation
Patient Centred Factors : Mediators/Immunoglobulin G (IgG)
Environmental Inputs : Xenobiotics
Personal Lifestyle Factors : Environment
Functional Laboratory Testing : Blood ; Stool

Methodological quality

Jadad score : 5
Allocation concealment : Yes