Comparison of the results of semi-thin sections with those of conventional paraffin histology and immunohistology in renal biopsy specimens.

One hundred renal biopsy specimens out of the routine material were investigated by the usual paraffin technique, by semi-thin sections and by the immunofluorescence technique. The findings were compared in regard of the diagnoses made by each technique. The results indicate that the paraffin technique is inadequate in a considerable proportion of the specimens, because very small glomerular lesions cannot be recognized. The semi-thin section technique enabled us to correct the light-microscopic diagnosis in 17 per cent, particularly in establishing membranous glomerulonephritis. In another 31 per cent the histologic diagnoses could be improved. The immunofluorescence technique provided evidence of active glomerulonephritis in 57 per cent (24 cases with immune complex nephritis and 3 cases with basement membrane antibody nephritis). We found a much closer correlation between results of the semi-thin section technique and immunohistology that between the paraffin technique and immunohistology.