A repeat biopsy study in spontaneous crescentic glomerulonephritis mice

Spontaneous crescentic glomerulonephritis (SCG)/Kj mice are a candidate for suitable animal model of human pauci-immune crescentic glomerulonephritis (GN). In the present study, we used renal biopsy technique and analyzed time sequence correlations among crescent formation and glomerular neutrophil infiltration in SCG/Kj mice.

We observed the progress of GN in SCG/Kj mice according to the urinary abnormalities, and performed the serial renal biopsies. The kinetics of histopathology and glomerular neutrophil influx corresponding disease stage were examined by enzyme-histochemistry and immunohistochemistry.

We divided natural course of GN into three periods in view of urinalysis: a proteinuria-negative/hematuria-negative (P- H-) period, followed by a proteinuria-positive/hematuria-negative (P+ H-) period, and finally a proteinuria-positive/hematuria-positive (P+ H+) period. Endocapillary proliferation phase existed in P+ H- period, whereas crescent formation occurred and extended in P+ H+ period. In P+ H- period, prominent glomerular neutrophil infiltration was observed, while these numbers decreased with the progression of crescent formation.

These observations suggest that there is a good correlation between urinalysis and histopathological events of SCG/Kj mice, and that endocapillary proliferation, which contains neutrophil infiltration, may contribute to the subsequent crescent formation in these mice.