The important role of patients suffering from severe form of AD play also the molecular components of Aspergillus fumigatus; in these patients, a high level of specific IgE (class 3) to Asp f 6 was recorded in 24% of patients, a very high level of specific IgE (class 4) to Asp f 6 was recorded in 12% of patients, a moderate level of sIgE (class 2) to Asp f 3 was recorded in 20% of patients. This evidence concerns the gene IGHE and Alzheimer disease.