NUTRITION RESEARCH, Vol. 1, pp. 211-212, 1981 0271-5317/81/020211-02502.00/0 Printed in the USA. Copyright (c) 1981 Pergamon Press Ltd. All rights reserved.
CONFERENCE SUMMARY Third International Food Allerqy Symposium The meeting was organized by the American College of Allergists in Boston, October 18-21, 1980. A distinguished faculty reviewed all aspects of food intolerance. A summary of selected presentations follows: CHARLESD. MAY provided a historical perspective of the subject and discussed the principles of diagnosis and management. He cautioned against acceptance of study results other than those derived from double blind controlled t r i a l s of exclusion and challenge. JOHN F. SOOTHILL outlined the interactions between immunodeficiency and allergy. Human atopic allergy is related to a range of common minor defects of immunity function, such as transient IgA deficiency, defective yeast opsonization and low levels of complement component C2. Prospective studies in newborns, fed exclusively on the breast and mutual exclusion of the defects in individua~ patients, provides supportive evidence that the immunologic deficits are causative. W. ALLAN WALKER described the phenomenon of antigen processing by the gastrointestinal tract. Food proteins, toxins and microorganisms can penetrate the mucosal barrier and enter the systemic circulation, causing c l i n ical disease manifested by infection, allergy or autoimmunity. Both immunological and nonspecific barriers r e s t r i c t the uptake of macromolecules. The role of the glycocalyx as an active metabolic compartment is being recognized. DEAN D. METCALFE described the role of the mast cell in gastrointestinal function and disease. The link between the appearance locally of invading organisms and subsequent mast cell degranulation is either IgE-antigen interaction or complement activation, resulting in the release of various chemical mediators of inflammation and vascular permeability. ANDERSDANNAEUSdiscussed the role of hereditary and developmental factors in food allergy. Cord serum IgE levels were predictive of subsequent development of atopic symptoms. At six months of age, the serum IgA levels were lower in the children of atopic mothers. High cord t i t e r s of IgG antibodies to milk proteins were found in children who remained asymptomatic, indicating a possible protective function. D.C. HEINER discussed the objective methods of diagnosis of cow's milk allergy and gluten-induced enteropathy. CLIFTONT. FURUKAWAdescribed IgE specific suppressor cell dysfunction and overactive B cell function in some atopic patients. Antigen processing can be defective as a consequence of several mechanisms. SAMI L. BAHNAenumerated the respiratory manifestations of food alle~y. JOHN W. GERRARDand C. COLLINS-WILLIAMS provided a clinical approach to the diagnosis and management of the food allergic patient. KJELL AAS discussed the advantages and limitations of skin prick tests and the radioallergosorbent test. He emphasized the need for highly reliable and purified allergen extracts for both techniques. R.K. CHANDRAdescribed the effects of nutritional deficiency on gastrointestinal immunity and i t s clinical consequences. Cell-mediated immunity is reduced as is secretory IgA response. The number of plasma cells and T lymphocytes is reduced. The significance of decreased intraepithelial lymphocytes is not clear. The permeability of the gut to macromolecules is increased. CHANDP~A also dis~ssed hypersensitivity to food additives such as pesticides, preservatives, flavouring agents, and dyes. Clinical manifestations include u r t i c a r i a , anjgioedema, polymorphic skin rashes, abdominal pain and asthma. Diagnosis can be established by careful history, selected provocation tests and in vitro methods. JAMESM. SWANSONdescribed the effects of food dyes on neurotransmitter accumulation and on behavior in rats and in hyperactive children. ROBERT 211
M. STROUDdescribed the construction and use of a controlled environment unit for the diagnosis and management of d i f f i c u l t patients. Treatment of food allergy by dietary exclusion, cromolyn, and hyposensitization was summarized by a number of speakers. The texts of various presentations and discussions are available as a series of tapes from the American College of A l l e r g i s t s .