Tolerance Mechanisms in Response to Antigens Responsible for Baker's Asthma in Different Exposed People

Abstract

Background. Baker's asthma is among the most common occupational disease. The risk factors and immune features that may be important as predictors of tolerance or development of the disease are not completely understood. Objective. To study the evolution over time of antigenic reactivity on baker's asthma in Spain and in France, in order to find differences in their allergenic response and evidence of protective or risks mechanisms against this disease. Methods. Two groups of subjects were randomly selected. A group of bakers with asthma from Spain and a second group from France whose blood was taken 30 years ago: bakers with asthma, bakers without occupational respiratory allergy, and wives and children living close to the bakery. In all subjects skin tests were carried out with cereals, insects and the most common allergens in their area. Specific IgE, IgG₄ and IL 10 measurement were also determined. Results. Spanish patients were mainly sensitized to cereal allergens and presented higher levels of IgE (p < 0.001). French patients are more often sensitised to insects than the Spanish ones: 5.26% versus 80% (p < 0.005). Symptom free or without aggravation at work subjects have higher specific IgG₄ and IL 10 levels than the others (p < 0.01). Conclusions. Antigens implicated in baker's asthma may change with time. The presence of higher levels of IgG₄, IL10 and diversity of sources of sensitisation in French patients may have helped them to develop a kind of natural hyposensitization.

Keywords:

• Baker's asthma
• pests
• IgG
• IgG₄
• IL10