A study of apoptosis in human glomerulonephritis as determined by in situ non-radioactive labelling of DNA strand breaks.

It is postulated that programmed cell death via apoptosis may be critical for successful remodelling of glomeruli after inflammation injury. Recently, several methods of analysis of apoptotic cells have been developed, most of them based on the detection of DNA degradation. To determine whether apoptosis is present in renal tissue we compared 36 renal biopsy specimens in patients with various types of glomerulonephritis with 8 samples of the normal kidney using the In situ Cell Death Detection kit, POD, which detects single cell apoptosis in formalin-fixed tissue. In addition, we tried to correlate apoptosis with the type of renal injury. The apoptotic cells were scored using a computerized digital image analyzer. There were greater numbers of glomerular apoptotic cells in IgA nephropathy (IgA-N) compared with the normal kidney, minimal change nephrotic syndrome (MCNS) and mesangial proliferative glomerulonephritis (Mes-Pro-GN). In proliferative types of glomerulonephritis the intensity of apoptosis in glomeruli correlated significantly with the total number of glomerular cells. The relationship between apoptotic cells in glomeruli and degree of proteinuria showed statistical significance only in patients with Mes-Pro-GN. There was no difference in the number of interstitial and tubular apoptotic cells between all studied groups. Our data suggest the possibility of altered regulation in apoptotic mode of cell death in mechanisms of glomerular damage.