Pathophysiologic mechanisms of allergic and pseudo-allergic reactions to foods, food additives and drugs.
Allergic or pseudo-allergic reactions elicited by per os intake of foods, food additives or drugs may be based on one or several of the following immunopathologic mechanisms: 1) specific IgE bound to mast cells and/or basophils; 2) antigen-IgE soluble complexes hitting various target cells; 3) antigen-IgG complexes generating anaphylatoxins; 4) generation of anaphylatoxins by alternate pathway complement activation; 5) release of mast cell mediators by other direct triggering mechanisms (e.g., basic peptides, peptones); 6) effects on other target cells such as neutrophils and platelets; 7) reactions mediated by specific effector lymphocytes. While allergic reactions in a classical sense involve a sensitization process leading to the formation of specific immunologic agents such as antibodies or specific T lymphocytes, pseudo-allergic reactions appear to involve the same inflammatory mediators which are formed and/or released through different mechanisms and without the necessity for specific sensitization. The complexity of the phenomena possibly involved continues to create great difficulties in the objective diagnosis of food allergy.
D000706:Anaphylatoxins / Q000276:immunology; D000818:Animals; D000936:Antigen-Antibody Complex / Q000276:immunology; D000941:Antigens / Q000276:immunology; D001491:Basophils / Q000276:immunology; D001792:Blood Platelets / Q000276:immunology; D003176:Complement C3 / Q000276:immunology; D015926:Complement C3a; D003182:Complement C5 / Q000276:immunology; D015936:Complement C5a; D004342:Drug Hypersensitivity / Q000276:immunology*; D005503:Food Additives / Q000009:adverse effects*; D005512:Food Hypersensitivity / Q000276:immunology*; D006098:Granulocytes / Q000276:immunology; D006632:Histamine / Q000276:immunology; D006801:Humans; D007073:Immunoglobulin E / Q000276:immunology; D007074:Immunoglobulin G / Q000276:immunology; D008407:Mast Cells / Q000276:immunology; D009294:Narcotics / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology
D000706:Anaphylatoxins; D000936:Antigen-Antibody Complex; D000941:Antigens; D003176:Complement C3; D003182:Complement C5; D005503:Food Additives; D007074:Immunoglobulin G; D009294:Narcotics; D007073:Immunoglobulin E; D015926:Complement C3a; D015936:Complement C5a; D006632:Histamine