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The MAST Allergen System is a new assay for serum specific IgE, and allows up to 35 allergens to be tested simultaneously. We evaluated this system in 264 children with allergic diseases. Good correlation was obtained between MAST and RAST in 24 out of 35 allergens, with correlation coefficient more than 0.60. The positive rate of inhalant allergens by the MAST system were 88% Dermatophagoides pteronyssinus, 82% Dermatophagoides farinae, 77% house dust, 39% cat epithelium, 34% dog epithelium and 26% Japanese ceder, The positive rate of food allergens were 35% soy bean, 24% egg white, 23% rice, 22% barley and 20% wheat. The positive rate for children, suffering from both allergic respiratory and skin diseases, was higher than that of those suffering from only one of the two. We found that the types of allergens varied with their age. Food allergens predominated in infancy and early childhood, and decreased with age. In contrast, specific IgE to inhalant allergens developed later in childhood and generally persisted. There was a sharp increase in the positive rate of house dust and mites, followed by a slow increase of animal epithelia and pollens. The incidence of mould allergens remained unchanged, and started to increase garadually as the patients reached a certain age. Among 35 allergens, an average of 7.5 different allergens were simultaneously detected in one serum sample. More than five allergens were detected in 57% of 264 cases. Based on these findings we must conclude that simultaneous determination of specific IgE using the MAST system is useful in diagnosing specific allergens in children suffering from a variety of allergies.

An 8-year-old boy with IgA nephropathy, who is hypersensitive since infancy to many foods including hen's eggs, cow's milk and soy beans, has been studied. Specific IgE antibodies to these foods were detected in his serum. The patient has taken small amounts of milk and eggs, and hematuria was noticed when he was 7 years old. After admission to our study, he was given a diet completely free of egg and milk proteins, and the amount of protein and red blood cells in the urine decreased gradually without drug therapy. After oral provocation tests with hen egg white or cow's milk, an increase in the protein/creatine ratio of morning urine was noticed. However, specific IgA antibodies to either egg white or cow's milk proteins could not be detected in his serum by the immunablotting technique. In this case, ingestion of egg or milk was suspected to have increased the urinary protein/creatinine ratio by a mechanism other than that mediated by specific IgA antibodies to these food antigens.

A child of squid allergy is reported. We detected specific IgE antibodies to squid in his serum with a microliter solid-phase radioimmunoassay using extract of squid (including 50% glycerin, Torii & Co. Ltd, Tokyo) as an antigen, which have been used for scrach or prick testing in Japan.Furthermore, we demonstrated cross-allergenicity between squid and octopus with inhibition technique.