[The value of immunofluorescence on frozen sections and immunoperoxidase methods on paraffin sections with different...

171 kidney biopsies were tested with the peroxidase- antiperoxidase (PAP)-method on paraffin sections. A comparison of the PAP-results with corresponding ones for the immunofluorescence method (IMF) on frozen sections was possible in 131 of the biopsies. When results of the 2 techniques were compared, outcomes showed a very strong accordance for both methods in tissues of postinfectious and perimembraneous GN an a strong accordance in mesangioproliferative GN tissue. In membrano-proliferative GN the immunopathological findings were more readily delinated with the PAP-method than with IMF. Cases involving IgA-nephritis, focal sclerosis and lupus nephritis with smaller deposits did not show consistant reactivity in the PAP-method as compared with IMF. 40 kidney biopsies, not examined by IMF, were diagnosed as GN by light microscopy and could be shown in 29 cases to contain evidence of an immune pathogenesis with the PAP-method.