[Proliferative mesangial glomerulonephritis (PMGN) and IgA nephropathy (IgAGN). Immunohistochemical comparative analysis of cellular infiltrates and clinico-morphological correlations].

Glomerular and interstitial leukocyte subpopulations were analyzed in renal biopsies from 20 patients with proliferative mesangial glomerulonephritis (PMGN) and from 20 patients with IgA nephropathy (IgAGN), by immunoperoxidase techniques with monoclonal antibodies. Few; intraglomerular leukocytes were seen, the majority of them belonging to the monocyte/macrophage phenotype. T-cells and monocyte/macrophages constituted the predominant infiltrating cell type in the interstitium. Significant differences were found in the numbers of intraglomerular macrophages between PMGN and IgAGN, and in the numbers of T-cells between IgAGN and control group. Rang Spearman Correlations showed proteinuria values in PMGN to be closely dependent on density of intraglomerular infiltrates and the number of macrophages. Hematuria values in IgAGN were closely dependent on the number of intraglomerular macrophages. Interstitial macrophages and T-cells were well correlated with the degree of interstitial damage and the serum creatinine level in PMGN and in IgAGN. No association was found between intraglomerular cells and serum creatinine level, and between interstitial cells and proteinuria values, as well hematuria values at the time of biopsy. These findings suggest that mononuclear cells may play a role in the pathogenesis of PMGN and IgAGN, and that cellular immune mechanisms may be important determinants of the severity of histological lesions and the degree of renal function.