Immunoglobulin deposition in membranous glomerulonephritis: immunofluorescence and immuno-electron microscopy findings.

In a series of 250 renal biopsies (transplants excluded) the diagnosis of membranous glomerulonephritis was made in 22. This was done on light microscopy in 17, while the addition of immunofluorescence enabled the diagnosis to be made in a further five. Electron microscopy confirmed the diagnosis in all cases. Immunoperoxidase studies emphasized the basement membrane distribution of the deposits of immunoglobulin and relative sparing of the mesangium. They showed at an ultrastructural level the presence of IgG in the deposits.