Renal, major histocompatibility complex antigens and cellular components in rapidly progressive glomerulonephritis identified by monoclonal antibodies.

Identification of crescent-forming cells in rapidly progressive glomerulonephritis (RPGN) is very difficult, and controversial results on the participation of different epithelia as well as of monocytes have been reported. In the present study different monoclonal antibodies were used to analyze cellular infiltrates of crescents and the interstitium as well as the distribution of well-defined renal antigens and major histocompatibility complex (MHC) encoded antigens along the human nephron in cryostat sections of renal biopsies from patients with RPGN. The results demonstrate that monocytes/macrophages infiltrate Bowman's space and that cellular components of crescents present with phenotypes of parietal glomerular and proximal tubular cells. T lymphocytes are significantly found in glomeruli and also in interstitium with predominance for CD4+ lymphocytes. Reduction of MHC class-II antigens within diseased glomeruli correlates with changes in renal antigen expression. Tubular cells, however, often presented an abnormal expression of MHC class-II antigens. Differences of renal and MHC-encoded antigen expression may be due to rapid regeneration episodes of renal parenchymal cells in RPGN.