Frequency of Local Allergic Asthma in Bronchial Asthma Patients: Role of Conjunctival Challenge and Neutrophil Histamine Release

Background: There is sufficient evidence to demonstrate the importance of local allergies in the various clinical conditions encompassed by allergic pathology. We sought to examine the frequency of Local Allergic Asthma (LAA) and to investigate whether neutrophils from patients with LAA were able to release histamine compared to neutrophils from patients with asthma diagnosed by skin prick test (SPT) and specific serum IgE (sIgE). Methods: Sixty-eight patients with bronchial asthma and 15 healthy subjects were selected. All underwent SPT, and sIgE levels were determined. An allergen-specific conjunctival challenge (ASCC) and the allergen provocation test (APT) were carried out. Neutrophils were isolated, and their potential for histamine release was determined along with their influence on IgE receptors. Results: Eighteen patients had a positive ASCC and a negative SPT and sIgE to certain allergens (52.9%), coexisting in 16 patients who were SPT and sIgE-positive to other allergens (CO-LOCAL ALLERGY); these were designated LOCAL ASTHMA A (LAA). Another group of 16 patients (47.1%) only had a positive ASCC (SENSITIZED) and were designated LOCAL ASTHMA B (LAB). The total number of patients who presented a local type of asthma was 34 (50%) (TOTAL LOCAL ASTHMA (TLA)). Neutrophils isolated from patients with local asthma were capable of releasing histamine, as were neutrophils from patients diagnosed by SPT and sIgE. Conclusions: We have differentiated the clinical groups that may present LAA and have demonstrated how the neutrophils of these patients were capable of releasing histamine if stimulated with the allergen responsible for the clinical symptoms, with this release being IgE-dependent.