The present invention provides the in-vitro use of at least one in-vivo-target antigen of Aspergillus fumigatus for selective activation, detection and/or analysis of Aspergillus fumigatus specific CD4+ T cells in a sample comprising cells, wherein said at least one in-vivo-target antigen is selected from the group consisting of antigens Scw4, Pst1, Shm2, GliT and TpiA, the method therefor and pharmaceutical composition thereof.