A Review on the Relationship between Fungal Allergens with Allergy and Respiratory Diseases

For years, fungi have been associated with asthma and other reactive airway diseases. In contrast to type I-mediated allergies caused by pollen, fungi cause many allergic diseases such as rhinitis, allergic bronchopulmonary mycoses, hypersensitivity pneumonitis and allergic sinusitis. Aspergillus fumigatus is the most prevalent fungi which causes severe pulmonary allergic diseases, including allergic bronchopulmonary aspergillosis (ABPA). ABPA is associated with chronic lung injury and worsening in pulmonary function in patients with cystic fibrosis (CF) and chronic asthma. Diagnosis of ABPA is demanding since it is based on different clinical and laboratory findings but serology results are of great importance in diagnosis of ABPA. Production of recombinant allergens has contributed to improve a component resolved diagnosis of the disease. Serological studies showed that the responded specific IgE to four A. fumigatus allergens (Asp f2, 4, 6, and 8) are specific for ABPA. These specific allergens allow a serological discrimination between ABPA and other A. fumigatus-sensitivity. However, to reconstruct the whole allergenicity of the fungal extract it is required to produce and clinically evaluate more recombinant allergens. With the rapid development in knowledge about 3D structures of allergens, researchers could expand their knowledge about the function of each single structure in the pathophysiology of ABPA and, perhaps, could develop a group of allergens for the immunotherapy of the disease.