Monocytes and glomerulonephritis associated with remote visceral infection

The biopsies of 8 patients with diffuse proliferative glomerulonephritis associated with remote visceral infection (GN-RVI) were evaluated by histochemistry and electron microscopy for the presence and extent of intraglomerular monocytic infiltration. The sites of infection were cardiac valves (2 cases), ventriculoatrial shunts (2 cases), lungs (2 cases), blood (1 case) and retroperitoneal space (1 case). Seven of the patients had an elevated serum creatinine (1.5-6.5 mg/dl) and all had proteinuria, hematuria and an active urinary sediment. Histochemical investigation using the alpha-naphthyl acetate stain for nonspecific esterase (NSE) was conducted in 7 of the biopsies and showed relatively numerous intraglomerular monocytes in 5 cases. Electron microscopy demonstrated conspicuous monocytic infiltration of glomeruli in the 1 biopsy in which histochemistry was not done and in the 5 cases with high NSE indices (mean number of NSE + cells/glomerulus). The mean NSE index for the group was 4.5 (+/- 3.1) (range = 0.6-10.0). This was compared to the mean NSE indices for other types of diffuse proliferative glomerulonephritis (GN) - GN associated with mixed essential cryoglobulinemia (GN-CRY) (4 cases), membranoproliferative GN, type I (MPGN) (18 cases), post-infectious GN (PIGN) (9 cases) and diffuse lupus GN (GN-SLE) (35 cases). The NSE index for GN-RVI was less than that of GN-CRY (9.1 +/- 5.8) but greater than those of PIGN (3.5 +/- 2.5), GN-SLE (2.6 +/- 2.3) and MPGN (1.3 +/- 1.3). The differences between the GN-RVI index and those of GN-CRY, PIGN and GN-SLE were not significant but the difference between GN-RVI and MPGN was (p less than 0.01, Student's test).