Peanut Protein Concentrate Research Articles

Peanut allergic subjects' peripheral blood mononuclear cell proliferative responses to crude peanut protein.

Peanut allergy is characterized by a high frequency of severe and occasionally fatal reactions. To determine if there are features of the in vitro cellular response that may account for the observed severity of peanut allergy. Skin-prick testing (SPT), RAST assay of serum peanut-specific and total IgE and mixed peripheral blood mononuclear cells (PBMC) proliferative responses to crude peanut protein were measured in 44 peanut allergics with varying severity of clinical reactions. PBMC responses of 13 non-peanut allergic controls (six atopic) were also studied. Subjects' PBMCs proliferated more than controls', even without stimulation. Subjects' PBMC proliferative responses did not correlate with clinical severity, SPT weal size or peanut-specific IgE levels. Controls' PBMCs did not respond to peanut. There was no correlation between PBMC response and time since last reaction to peanut. Subjects' PBMCs responded more than controls, to mitogen as well as allergen. Proliferation increased with increasing concentration of peanut protein (P < 0.0001). PBMCs of peanut allergics demonstrate a dose-dependent response to peanut which does not correlate with clinical severity, SPT reaction or levels of peanut specific IgE. The response is antigen-specific. Peanut protein is not mitogenic and is not acting as a superantigen. While there are non-specific differences in the PBMC responses of peanut allergic individuals compared with atopic and non-atopic controls, these differences do not explain the unique severity of peanut allergy.

Enzyme Immunoassay for Determination of Peanut Proteins in Food Products

Food allergy presents a problem for many parts of society, including sensitive subjects, schools, health authorities, and the food industry. Once food allergy is diagnosed, dietary avoidance is the principle method of management. Because trace levels of peanuts can elicit an adverse to fatal reaction, unintentional exposure to the offending allergens may have devastating consequences to sensitive individuals. However, determination of trace amounts of unintentional peanut contamination in our food supply is very difficult. Recently, we developed polyclonal antibodies specific to peanut proteins that do not cross-react with 22 legumes, tree nuts, or other common snack ingredients. An antiserum containing the polyclonal antibodies was used to develop a sensitive enzyme-linked immunosorbent assay (ELISA) for determination of peanut proteins in snack foods. This study reports the first successful ELISA test to detect trace amounts of peanut allergens in a variety of foods. The concentration of peanut protein that inhibited 50% of antibody-antigen binding (IC50) was 12 ng/mL, the linear range was 1-63 ng/mL, and the detection limit was 400 ng/g (ppb) for the various foods tested. Recoveries ranged from 68 to 90%, with coefficients of variation of 2-22%, depending on the commodity. Using this new procedure, allergy-related complaint samples from various food groups were analyzed, and undeclared peanut proteins were identified in some products.