Abstract: The invention relates to the use of a secretor variant cell-line expressing the alpha moiety of human IgE binding protein to determine the allergic status of a given individual. Moreover, the cell-line is also used to provide an assay system for determining the allergenicity of substances and for subsequently providing therapeutic compositions which render said substances ineffective. In addition, the invention also relates to the use of said cell-line to determine the IgE independent irritancy of substances and compositions effective for attenuating the effects of said substances.