Hapten Facilitates Food Allergen-Related Intestinal Hypersensitivity

Regional Differences in Food Allergies

The prevalence of food allergies is increasing worldwide. To understand the regional specificities of food allergies and develop effective therapeutic interventions, extensive regional epidemiological studies are necessary. While data regarding incidence, prevalence, regional variation, and treatment in food allergies are available for western countries, such studies may not be available in many Asian countries. China accounts for almost 20% of the world's population and has a vast ethnic diversity, but large-scale meta-analyses of epidemiological studies of food allergy in China are lacking. A literature search revealed 22 publications on the prevalence of food allergy in Chinese populations. A review of these studies showed that the prevalence of food allergies in China is comparable to that in western countries, even though the Chinese diet is vastly different from that of the West and may vary even greatly within China, and finally, specific antigenic triggers of food allergy vary between China and the West and also within China. Current clinical management of food allergy in China includes allergen-specific immunotherapy, Chinese herbal medicine, acupuncture, and Western medicine. This study demonstrates an unmet need in China for a thorough investigation of the prevalence of food allergies in China, the specific foods involved, and characterization of the specific antigenic triggers of food allergy with respect to ethnicity, age, and diet in China.

Physiological concept of hapten-carrier adduct vis-a-vis Garavisha

The human body defends itself from harmful agents such as microorganisms present in the environment, which otherwise damage the individual's health. This defensive mechanism is the immune response mediated by the activation of T-cell and B-cell antibody production. The body recognizes and destroys these antigenic harmful agents. The defensive response is altered sometimes in the presence of allergens, causing hypersensitive reactions. The allergens are antigens. The hapten-carrier adduct often behaves as an allergen-producing hypersensitivity with a manifestation of sign and symptoms those are at times lethal. Garavisha is an artificial type of poison formed by combination of two nonpoisonous substances as depicted in the treaties of Ayurveda. It has identical characteristics to that of hapten-carrier adduct. In the present article, Garavisha is substantiated with conceptual reference to hapten-carrier adduct and hypersensitivity.

[Establishment of a rat model of oral food allergy]

OBJECTIVE

To establish a food allergy model in Brown Norway (BN) rats by gavage of ovalbumin (OVA) without any adjuvant, and to evaluate this model.

METHODS

A total of 20 male BN rats aged 3 weeks were randomly divided into allergy group and control group (n=10 each). BN rats in the allergy group were given OVA 1 mg per day by gavage, and all the rats were treated for 41 days continuously. On day 42, the rats in the allergy group were given OVA 100 mg by gavage for challenge. The rats in the control group were given normal saline of the same volume by gavage. Differences in body length, body weight, and food intake were compared between the two groups on days 7, 14, 21, 28, 35, and 42. ELISA was used to measure the serum OVA-IgE level and plasma histamine level after challenge on day 42, and the changes in rats' appearance and fecal properties were observed. The model of food allergy was considered successful when the serum OVA-IgE level in the allergy group was no less than the mean serum OVA-IgE level + 3 standard deviation in the control group.

RESULTS

There were no significant differences in body length, body weight or food intake between the allergy and control groups at all time points (P>0.05). On day 21, the control group had a significantly higher food intake than the allergy group (P<0.05). On day 42 after challenge, the allergy group showed significantly higher serum OVA-IgE and plasma histamine levels than the control group (P<0.05). The sensitization rate (rate of successful modeling) was 90%. The fecal properties showed no significant differences between the two groups.

CONCLUSIONS

OVA by gavage without any adjuvant can successfully establish the model of food allergy in BN rats and has a high success rate. Food allergy induced by OVA may reduce food intake within a short period of time, but no influence on rats' body length or body weight has been observed.