An evaluation of the immunoperoxidase technique in renal biopsy diagnosis.

An evaluation of the use of horseradish peroxidase labelled antisera against IgG, IgM, IgA and C3 compared with corresponding antisera labelled with fluorescein isothiocyanate has been carried out on renal biopsy material from 200 patients with renal disease. A disparity between the two methods was observed in 10-19% of the readings according to the antigen being demonstrated. The majority of differences recorded would not have influenced the executive diagnosis. Where the immunological results could have influenced the executive diagnosis, 5 probable false results were obtained using innumofluorescence and 4 with immunoperoxidase. Immunoperoxidase has the advantage over immunofluorescence in that it provides a permanent preparation which can be reviewed months or years later. In addition it provides more accurate localization of the immune deposits since the section can be counterstained with Mayer's hemalum and viewed by conventional light microscopy. In view of these advantages we recommend that serious consideration should be given to using immunoperoxidase in place of immunofluorescence for the examination of renal biopsy material.