Lupus nephritis. Electron-dense and immunofluorescent deposits and their correlation with proteinuria and renal function.

Thirteen patients who had systemic lupus erythematosus were studied for the purpose of correlating the findings of light and electron microscopy and immunofluorescent studies with renal function and the presence of proteinuria. Subendothelial deposits of electron-dense material were found in all biopsy specimens, whereas mesangial and subepithelial deposits were not always present. IgG and beta 1c were constant findings in the glomerular membrane. The seven patients who were found to have extensive subendothelial deposits had moderate to massive proteinuria, and four of these patients had decreases in renal function. Most of the patients who had smaller subendothelial deposits had slight or insignificant proteinuria. Massive subendothelial deposits were mainly found in specimens showing histologic evidence of active lesions. Correlation was also found between proteinuria and the overall amount of deposits and their distribution. The prognosis was dependent on the severity of subendothelial deposits, the overall amount of deposits, and the morphologic form of lupus nephropathy.