SHORT COMMUNICATION Application of ELISA-inhibition to Aspergillus antigen standardization for immunodiagnosis

An inhibition ELISA method was used to test culture filtrate antigens of Aspergillusfumigatus for the avidity of antibodies to them. Four different culture media were used to check the ability of this assay to distinguish between similar antigenic preparations. Differences between antigens exhibiting similar crossed immunoelectrophoresis patterns were observed by inhibition ELISA. Antigens for immunodiagnosis must react with the highest possible quantity of different specific antibodies in patients ' sera. But detectability of some antibodies i strongly dependent on their avidity for binding antigen. Thus, maximum sensitivity assays, where antibodies of high and low avidity can be detected, are only likely to be satisfactory if antigens are carefully selected. Selection of Aspergillusfumigatus antigens by crossed-immunoelectrophoresis (XIE) [2, 4, 6, 7] provides information only on the antigenic omposition of extracts not on the avidity of antibodies against hem. Thus a method to select antigenic extracts according to the avidity of antibodies in sera from patients is needed. Recently an inhibition ELISA (iE) method to determine the affinity distribution of antibody molecules against a single antigen preparation has been described [13]. Th