A simple technique for detecting the antigen of Heymann nephritis in glomeruli by immunofluorescence.

In the past, on routine 2-4 micron renal cortical frozen sections it has been difficult to demonstrate the putative glomerular antigen of Heymann nephritis (HN) by indirect immunofluorescence. We describe, herein, a technique which overcomes this difficulty and can be used to reliably detect glomerular antigen(s). The technique consists of first isolating individual glomeruli by sieving and then preparing a suitable frozen block that contains only glomeruli and no tubules to cut 2-4 micron frozen sections. Using this technique and the putative heterologous and autologous antibodies of HN we have succeeded in showing a clear and convincing reactivity of these antibodies with the glomerular antigen(s) by indirect immunofluorescence. In addition the results obtained provide at least a partial explanation for the puzzling discrepancy observed by many investigators of the findings of either no or poor reactivity of these antibodies to normal glomeruli on rat kidney sections in vitro and their readily demonstrable glomerular localization in vivo upon intravenous injection to normal rats. This technique may also prove useful in detecting reactivity of antibodies to other glomerular antigens that are difficult to demonstrate on routine frozen sections of kidney.