Sustaining the graft-versus-tumor effect through posttransplant immunization with granulocyte-macrophage colony-stimulating factor (GM-CSF)-producing tumor vaccines.

For many cancers, autologous bone marrow transplantation (BMT) achieves a minimal residual disease state, yet relapse rates remain high. Using a syngeneic murine bone marrow transplant model, we demonstrate that vaccination with irradiated granulocyte-macrophage colony-stimulating factor (GM-CSF)-producing autologous tumor cells is effective in the post-BMT period and actually results in a greater tumor-free survival than vaccination in the nontransplant setting. Employing T cells specific for a model tumor-antigen, we find that transplantation of the tumor-bearing host results in a massive expansion and activation of tumor-specific T cells in the early posttransplant period, but this response rapidly declines in association with tumor progression. Immunization with irradiated GM-CSF tumor cells during the period of immune reconstitution results in the sustained amplification and activation of this response that closely correlates with freedom from relapse. These results demonstrate the feasibility of integrating GM-CSF vaccines in the postautologous BMT setting and suggest mechanisms that may contribute to the observed efficacy of immunization during the critical period of immune reconstitution.

Allergenic properties of ovomucoid in man.

Ovomucoid, the dominant allergen in hen's egg, is a highly glycosylated protein comprising 186 amino acids arranged in three tandem domains (Gal d 1.1, 1.2, and 1.3). The purpose of this study was to evaluate the allergenic properties of ovomucoid. The three ovomucoid domains were isolated and evaluated with sera from egg allergic patients to determine B cell domain specificity, B cell epitopes, and the relative importance of linear and conformational structures and carbohydrate chains to B cell epitopes. Peripheral blood T cells from egg allergic patients were used to evaluate T-dominant domains and reactivity to reduced and oxidized ovomucoid. There was significantly more IgE activity to the second ovomucoid domain (median percentage of ovomucoid-specific IgE: Gal d 1.2, 40%; Gal d 1.1, 23%; Gal d 1.3, 26%). Quantities of patient IgG Ab were comparable for all three domains. Five IgE and seven IgG binding regions were identified. IgE Ab binding to reduced ovomucoid and IgG binding to oxidized ovomucoid were significantly reduced compared with that to native ovomucoid (28 and 69%, respectively). Peripheral blood T cells of 21 of 33 patients reacted to Gal d 1.3, 18 of 33 reacted to Gal d 1.2, and 18 of 33 reacted to Gal d 1.1. T cell proliferation in vitro in response to reduced and oxidized ovomucoid were significantly greater than that in response to the native protein. These results indicate a dichotomy between T and B cell domain dominance, and the presence of both unique and common IgE and IgG epitopes. Furthermore, the results suggest that conformational B cell epitopes play a more significant role in ovomucoid allergenicity than previously appreciated, and that carbohydrate moieties have a minor effect on allergenicity.

Clinical reactivity to beef in children allergic to cow's milk.

BACKGROUND: Cow's milk is one of the most common food allergens in children. Limited information is available on the prevalence of reactivity to a related food source, beef. The purposes of this study were to examine the prevalence of symptomatic sensitivity to beef in a selected pediatric population and to determine the frequency of concomitant reactivity to cow's milk and beef. METHODS: Children referred for assessment of atopic dermatitis and possible food hypersensitivity were evaluated for symptomatic reactivity to beef by double-blind placebo-controlled food challenges (DBPCFCs) and subsequent open feedings of beef. Sodium dodecyl-sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), immunoblot, and immunodot blot analyses were performed with patients' sera on preparations of beef extracts subjected to different cooking conditions: raw (no heating), medium, and well-cooked. RESULTS: Eleven of 335 children referred for evaluation of atopic dermatitis and possible food hypersensitivity were found to have symptomatic sensitivity to beef; eight were also sensitive to milk, as demonstrated in previous DBPCFCs. Eight patients reacted to beef during DBPCFC, and three tolerated beef in a DBPCFC and well-cooked beef in an open challenge but reacted to ingestion of less well-cooked beef. SDS-PAGE of raw beef revealed at least 24 protein fractions. Several protein bands in raw beef appeared to denature with heating. Bovine serum albumin and bovine gamma globulin were heat-labile in the beef extract, but six protein fractions persisted even after heating the beef extract for 2 hours at 85 degrees C. IgE from patients reacting to rare and well-cooked beef bound up to six of these heat-resistant fractions, but IgE from patients reacting only to rare beef failed to bind any of these fractions with one exception. In addition, patients reacting to rare and well-cooked beef had specific IgE to a 17.8 kd fraction, which was only weakly recognized by one patient reacting only to rare beef. CONCLUSIONS: Specific IgE antibodies to heat-labile beef proteins might explain why some patients can tolerate well-cooked beef but not medium-rare and rare beef. Patients reacting only to rare beef may not need to maintain a complete beef elimination diet.

Immunologic cross-reactivity among cereal grains and grasses in children with food hypersensitivity.

BACKGROUND: Because of a lack of clinical data from food challenges, allergists often recommend dietary restriction of all cereal grains in patients with sensitivity to at least one grain. OBJECTIVES: The purposes of this study were to assess the degree of intrabotanical cross-reactivity among cereal grains and related grasses, to better define the prevalence of multiple grain hypersensitivity, and to define the protein fractions associated with wheat hypersensitivity. METHODS: One hundred forty-five patients evaluated by food challenges and skin prick tests were divided into three groups: group 1, cereal grain and grass allergies; group 2, wheat allergy alone; and group 3, grass allergy alone. Fifteen patients were further selected from groups 1 to 3. Sodium dodecylsulfate--polyacrylamide gel electrophoresis and immunoblot analyses were performed on six grains and four related grasses with sera from these patients. RESULTS: Only 21% of patients had symptomatic reactivity as determined by food challenge; 80% had reactivity to only one grain. As determined by immunoblot analyses, patients in groups 1 and 2 showed extensive cross-reactivity (within each group) among grains but little cross-reactivity among grasses, whereas patients in group 3 showed cross-reactivity between the grains and grasses. Patients with wheat allergy had specific IgE binding to wheat fractions 47 kd and 20 kd, bands not recognized by patients with grass allergy. CONCLUSIONS: Clinically insignificant cross-reactivity exists among cereal grains and grasses; therefore, elimination of all grains from the diet of a patient with grain allergy is unwarranted. Further purification and characterization of the 47 kd and 20 kd wheat fractions is needed to provide more specific in vitro testing.

Egg hypersensitivity and adverse reactions to measles, mumps, and rubella vaccine.

We evaluated the safety of the measles-mumps-rubella (MMR) combination vaccine in 140 children with egg hypersensitivity. All children, regardless of vaccine skin test results or severity of egg hypersensitivity, were safely immunized with the MMR vaccine. Systemic reactions to MMR vaccine in two nonallergic children were documented, indicating that reactions unrelated to egg protein can occur. With the use of a competitive enzyme-linked immunosorbent assay, the standard MMR injection was found to contain approximately 37 pg of ovalbumin-like material. This study provides 95% confidence that at least 97.5% of egg-allergic children will tolerate MMR vaccine without significant difficulty. Skin testing was not found to be helpful in predicting an adverse reaction. We recommend that the American Academy of Pediatrics consider revising its current policy regarding skin test response to MMR vaccine and administration of MMR vaccine to egg-allergic children.

Anaphylactic reactions to a psyllium-containing cereal.

Historical data were obtained by questionnaire and telephone survey on 20 of 24 women with reported allergic reactions to a psyllium-containing cereal, Heartwise. Protein fractions from this new cereal, as well as from psyllium mucilloid and a psyllium-containing laxative, Metamucil, were extracted, quantitated, and separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Patients' sera were collected, and specific IgE and IgG antibodies to these psyllium antigens were detected by immunoblotting techniques. Of the 20 women evaluated, all but six were nurses. Eighteen (90%) of the women had historical and/or laboratory evidence of atopy. Exposures included ingestion or dispensing of psyllium-containing products. Only three women denied prior exposure to psyllium. Symptoms developed shortly after small amounts of the cereal were ingested and most commonly included moderate to severe wheezing, throat and chest tightness, and urticaria. All the women required medical therapy, 11 (55%) in an emergency room. Specific IgE and IgG antibodies to various psyllium protein fractions were documented in all the subjects. It was concluded that individuals sensitized by occupational exposure to psyllium dust are at high risk for allergic reactions to ingested psyllium-containing products.

Food allergy and the potential allergenicity-antigenicity of microparticulated egg and cow's milk proteins.

Approximately 3-4 million Americans experience food allergic reactions at some time in their lives. In the pediatric population, eggs and milk are most frequently implicated in food allergic reactions. The most well-understood adverse reactions to foods are secondary to the development of IgE antibodies to specific food antigens. Once an individual becomes sensitized (i.e., makes specific IgE antibodies), ingestion of the food may lead to a variety of cutaneous, respiratory, and/or gastrointestinal symptoms, and anaphylactic shock. The use of SDS-PAGE and immunoblot analyses with sera from documented food allergic patients provide a very sensitive indicator of the antigenic/allergic composition of various foods. As demonstrated in a study of infant formulas of hydrolyzed cow's milk protein, the absence of demonstrable bands on SDS-PAGE gels and immunoblots correlates with an inability to provoke an allergic response. In addition, it was demonstrated that SDS-PAGE with silver staining could detect protein fractions at a concentration of 50-100 ng/ml, a concentration below which allergic individuals are unlikely to react. These studies confirmed that patients clinically allergic to egg and/or cow's milk possess IgE and IgG antibodies to protein fractions in egg and cow's milk, as well as the microparticulated egg/cow's milk proteins, Simplesse and Beta IL. Compared to egg and cow's milk, there is no evidence that the Simplesse or Beta IL test materials possess any "novel" protein fractions or antigens. In addition, there is no evidence that these microparticulated proteins result in increased immunologic activity, as determined by the intensity of protein band staining.(ABSTRACT TRUNCATED AT 250 WORDS)