Immunoelectrophoresis for the Characterization of Allergen Extracts.

Immunoelectrophoresis can be used for analysis of individual proteins in complex mixtures. The conditions involved in immunoelectrophoresis are mild, avoiding the risk of denaturation, and it is possible to perform relative quantification of individual components. The fundamental disadvantage is the dependence on rabbit antisera as reagents. The usefulness of immunoelectrophoresis in allergy research is greatly enhanced by the possibility of identification of allergens to which the individual in question has IgE.The common principle is characterized by two independent electrophoreses having direction of current perpendicular to each other, i.e., crossed immunoelectrophoresis (CIE). This ultimately results in the formation of characteristic bell-shaped precipitates, each precipitate representing one antigen. There is a linear relationship between the amount of antigen and size of precipitate for a given antibody concentration for each precipitate and so relative quantification can be performed. The sensitivity and resolution power of CIE are very high and there are multiple variations of the technique, some of which will be illustrated in this chapter.

Immunoelectrophoresis for the characterization of allergen extracts.

Immunoelectrophoresis can be used for analysis of individual proteins in complex mixtures. The conditions involved in immunoelectrophoresis are mild, avoiding the risk of denaturation, and it is possible to perform relative quantification of individual components. The principle disadvantage is the dependence on rabbit antisera as reagents. The usefulness of immunoelectrophoresis in allergy research is greatly enhanced by the possibility of identification of allergens to which the individual in question has IgE. The common principle is characterized by two independent electrophoreses having direction of current perpendicular to each other, i.e., crossed immunoelectrophoresis (CIE). This ultimately results in the formation of characteristic bell-shaped precipitates, each precipitate representing one antigen. There is a linear relationship between the amount of antigen and size of precipitate for a given antibody concentration for each precipitate and so relative quantification can be performed. The sensitivity and resolution power of CIE is very high and there are multiple variations of the technique, some of which will be illustrated in this chapter.

Bites of the European pigeon tick (Argas reflexus): Risk of IgE-mediated sensitizations and anaphylactic reactions.

BACKGROUND: Local and systemic reactions can occur after bites of Argas reflexus (Argas), a soft tick parasitizing pigeons. OBJECTIVE: Risk assessment of IgE-mediated sensitizations and systemic reactions after Argas bites. METHODS: Case histories, skin prick tests (SPTs) with a whole-body extract of Argas containing major allergen Arg r 1, and common inhalants and specific IgE measurements were obtained from 148 subjects who had had Argas bites and 20 volunteers as a control group. RESULTS: Systemic reactions (urticaria, angioedema, dyspnea, cardiovascular dysregulation, unconsciousness) were reported in 12 of 148 (8%); 146 of 148 (99%) had local reactions. Atopy was found in 37 of 146 (25%) with local reactions and 3 of 12 (25%) with systemic reactions. SPT to Argas was positive in 24 of 148 (16%) with a high proportion of atopics 10 of 24 (42%); specific IgE to Argas was detectable in 12 of 135 (8% of 148) with moderate concordance to systemic reactions. No positive SPT or specific IgE results to Argas were obtained in the control group. Immunoblotting of 23 sera revealed an IgE-binding protein in 19 of 23 sera (82%) at 22 kd, indicating a major allergen of Argas. CONCLUSION: Severe anaphylactic reactions were infrequently (approximately 8%) found after bites of the soft tick Argas reflexus. Atopy is a risk factor for skin sensitizations to Argas, but not for systemic reactions after bites by Argas. Using a whole-body extract of Argas, diagnosis through SPT and specific IgE is hampered by false-negative and irrelevant positive results, particularly in atopy.