Intraglomerular monocytes in human glomerulonephritis.

A total of 246 cases of 166 primary glomerulonephritis (GN) and 80 secondary GN were examined for the presence of intraglomerular monocytes using nonspecific esterase reaction of alpha-naphthyl butyrate methods. The high score of monocyte index (MI) as the numbers of monocytes per glomerulus was found in crescentic GN (n = 5, MI = 3.72 +/- 1.98), endocapillary proliferative GN (n = 8, MI = 2.17 +/- 2.13), lupus nephritis (n = 43, MI = 2.21 +/- 3.35), and cryoglobulinemia-related GN (n = 1, MI = 11.5). The intermediate score of MI was observed in IgA nephropathy (IgA-N, n = 64, MI = 0.63 +/- 0.42) and Henoch-Schönlein purpura nephritis (HSP-N, n = 11, MI = 1.09 +/- 0.87). Out of IgA-N and HSP-N, the scores of MI in patients with more severe proliferation and/or with segmental lesions were higher than those without this histological finding. However, there was not a significant correlation between the glomerular monocytic infiltration and clinical findings in each group. In primary GN including minor glomerular abnormalities, focal glomerular sclerosis and membranous GN, and in secondary renal diseases except for SLE, HSP, and cryoglobulinemia, the score of intraglomerular monocytic infiltration was of little value. The participation of monocytes was predominant in extra- and intracapillary GN, lupus nephritis, and cryoglobulinemia-related GN, as previously reported. Moreover, in some types of proliferative GN, especially IgA-N and HSP-N, some parts of glomerular hypercellularity result from the participation of monocyte-macrophage series, although the main parts of cell proliferation are intrinsic mesangial cells.