Leukocyte analysis using monoclonal antibodies in human glomerulonephritis

The leukocyte subpopulations were analyzed within both the glomeruli and the interstitium in renal biopsies from 145 patients with various forms of glomerulonephritis. Cells were identified by monoclonal antibodies to leukocyte cell-surface antigens and immunoperoxidase labelling. Leukocytes, as defined by a monoclonal antibody to the leukocyte common antigen (PHM1), were present in normal, human renal tissue in both glomeruli (2.8 +/- 0.6 cells/glom. cross section) and interstitium (102 +/- 18 cells/mm2). Monocytes constituted the predominant infiltrating cell type in normal glomeruli (1.3 +/- 0.2) and T cells were rarely found (0.3: range 0 to 0.8), whereas both monocytes (34 +/- 10/mm2) and T lymphocytes (33 +/- 14/mm2) were found in the normal interstitium. In the non-proliferative forms of glomerulonephritis there was no significant increase in the number of glomerular inflammatory cells when compared with normal glomeruli. However, significantly increased numbers of T lymphocytes were seen in the interstitium of biopsies with minor non-specific changes (67 +/- 15/mm2), membranous nephropathy (134 +/- 30/mm2), focal glomerulosclerosis (207 +/- 53/mm2), and diabetic nephropathy (198 +/- 81/mm2). In the proliferative forms of glomerulonephritis only crescentic GN and post-infectious GN demonstrated significantly-increased glomerular monocytes and granulocytes. There was no significant increase in the number of glomerular T cells when compared with normal glomeruli. However, there was a significant increase in the number of interstitial T lymphocytes in all forms of proliferative glomerulonephritis when compared with the normal interstitial cell population.(ABSTRACT TRUNCATED AT 250 WORDS)     

Detection of urinary macrophages expressing the CD16 (Fc gamma RIII) molecule: a novel marker of acute inflammatory glomerular injury

BACKGROUND: The CD16 antigen is the Fc gamma receptor III. CD14+CD16+ cells are proinflammatory monocytes/macrophages (Mo/M phi) that constitute a minor population in the peripheral blood of healthy individuals. Little is known about the expression of CD16 antigen on Mo/M phi in glomerulonephritis. METHODS: Flow cytometric analyses were performed on urine and blood samples obtained from 209 patients with various renal diseases. Patients variously suffered from rapidly progressive crescentic glomerulonephritis (RPGN), membranoproliferative glomerulonephritis (MPGN), postinfectious acute glomerulonephritis (AGN), Henoch-Sch?nlein purpura nephritis (HSPN), IgA nephropathy (IgAN), membranous nephropathy (MN), minimal change nephrotic syndrome (MCNS), lupus nephritis (LN), acute interstitial nephritis, hereditary nephropathy, idiopathic renal hematuria (IRH), and renal stone. RESULTS: The CD16+ M phi population of cells was present in the urine of hematuria-positive patients with proliferative glomerulonephritis, including AGN, IgAN, RPGN, MPGN, and LN with acute inflammatory lesions, such as endocapillary proliferation, tuft necrosis, and cellular crescents. In contrast, the urinary CD16+ M phi population was negligible in hematuria-positive patients with nonproliferative renal disease, including hereditary nephropathy, IRH, and renal stone and also in patients with proliferative glomerulonephritis lacking acute inflammatory lesions. Total urinary M phi of these patients were much less than those of patients having proliferative glomerulonephritis with acute inflammatory lesions. Transient expansion of the CD16+ M phi population in urine was observed during the acute exacerbation of urinary abnormalities, whereas the disappearance of CD16+ M phi closely preceded the amelioration of urinary abnormalities in patients with proliferative glomerulonephritis. In 38 of the 98 patients positive for CD16+ M phi population in urine, the CD16+ Mo population was negligible in peripheral blood. Immunohistochemically, CD16+ M phi were present in the glomeruli of active proliferative glomerulonephritis, whereas such cells were absent in inactive proliferative glomerulonephritis or nonproliferative glomerular diseases. CONCLUSION: CD16+ M phi may be effector cells involved in the acute inflammation common to all types of proliferative glomerulonephritis. Furthermore, the detection of CD16+ M phi in urine, as well as urinary M phi counts, may serve as a useful indicator of the active stage of proliferative glomerulonephritis.     

Tubulointerstitial mast cell infiltration in glomerulonephritis

Mast cells are involved in chronic inflammation and tissue fibrosis. To determine whether these cells are also involved in tubulointerstitial injury in glomerulonephritis, we assayed mast cell infiltration in the kidneys of 107 patients with primary or secondary glomerulonephritis. Using a monoclonal antihuman tryptase antibody, we detected mast cells in the renal cortical tubulointerstitium, the periglomerular areas, and the medullary interstitium, but not in glomeruli. Renal cortical tubulointerstitial mast cells, including periglomerular area, were estimated as 0.8+/-1.6 cells/mm2 in minimal change nephrotic syndrome (n=7), 1.5+/-0.7 cells/mm2 in minor glomerular abnormalities without nephrotic syndrome (n=7), 6.5+/-7.7 cells/mm2 in membranous nephropathy(n=10), 12.9+/-15.5 cells/mm2 in lupus nephritis (n=15), 13.4+/-8.3 cells/mm2 in focal segmental glomerular sclerosis (n=6), 18.5+/-21.1 cells/mm2 in ANCA-related nephropathy (n=5), 19.8+/-14.2 cells/mm2 in membranoproliferative glomerulonephritis (n=5), 21.3+/-17.7 cells/mm2 in immunoglobulin A (IgA) nephropathy (n=42), and 33.0+/-33.8 cells/mm2 in diabetic nephropathy (n=10). Except for patients with the rapidly progressive glomerulonephritic syndrome (RPGN), the number of infiltrating mast cells significantly correlated with the serum concentration of creatinine at the time of renal biopsy (r=0.59; P < 0.0001) and with the intensity of tubulointerstitial injury as measured by leukocyte infiltration (r=0.72; P < 0.0001) and fibrosis (r=0.75; P < 0.0001). In contrast, mast cell infiltration did not correlate with urinary protein excretion. In relation to serum creatinine concentration, the number of mast cells was fewer in patients with RPGN than in those with chronic glomerulonephritis. These data suggest that mast cells may contribute to the renal deterioration in glomerulonephritis by inducing chronic tubulointerstitial injury.     

Cellular immunity analysis using monoclonal antibodies in human glomerulonephritis

Monoclonal antibodies against class II antigens of the human major histocompatibility complex (MHC) (Edu 1), von Willebrand factor-related antigen marker of endothelial cell, T cells (Cris 1), helper/inducer T cells (T4) and cytotoxic/suppressor T cells (T8) by indirect immunofluorescence, and stain for nonspecific esterase characterizing monocytes-macrophages (Mo-Ma) were applied in 64 renal biopsies--54 glomerulonephritis (GN), 10 non-GN- and in 14 normal kidneys. Class II antigens were expressed on the endothelium of renal microvasculature in all specimens. Intraglomerular T cells and Mo-Ma were only present in GN. Mo-Ma appeared associated with endo- and extracapillary proliferation (Xc2 = 4.68; p less than 0.05), C3 (X2 = 4.21; p less than 0.05), and fibrinogen (X2 = 3.84; p less than 0.05) deposition; and those were most numerous in biopsies with intraglomerular T cells. Interstitial MHC-class II+ cells (Xc2 = 5.5; p less than 0.02), T cells (F = 3.37; p less than 0.005) and Mo-Ma (F = 2.45; p less than 0.05) were significantly higher in GN with endo- or extracapillary proliferation than in the remaining. In GN, correlations were seen between T cells and MHC-class II+ cells (r = 0.63; p less than 0.001), and Mo-Ma (r = 0.38; p less than 0.02), infiltrating the interstitium. Our results suggest that both humoral and cellular immunity contribute to macrophage glomerular infiltration in the human GN. Mononuclear cells, and no intrinsic renal cells, would be implicated in the cellular immune interactions in situ.     

Mast cells in rapidly progressive glomerulonephritis.

The role of mast cells (MC) in tubulointerstitial damage in glomerulonephritis (GN) is not fully understood. The distribution of MC was compared in renal biopsies from 50 patients with different stages of rapidly progressive GN (RPGN) and in 20 control samples. The immunoreactivity of renal MC with anti-tryptase and anti-chymase antibodies was studied. Interstitial myofibroblasts were stained with anti-alpha-smooth muscle actin (alpha-SMA) antibody, and inflammatory cells were identified by anti-CD3, -CD20, and -CD68 monoclonal antibodies. Positively stained cells were counted, and the relative interstitial and fractional areas of anti-alpha-SMA-stained cells were measured. MC were rarely found in control samples. In contrast, samples showing crescentic GN contained numerous tryptase-positive MC (MC(T)) (43.7+/-4.65 versus 7.14+/-1.3/mm2) and fewer tryptase- and chymase-positive MC (MC(TC)) (13.8+/-1.86 versus 1.89+/-0.86/mm2) in the renal interstitium but never in the glomerulus. Double immunostaining demonstrated the presence of both phenotypes of MC. Accumulation of MC was significantly correlated with the numbers of T lymphocytes (MC(T), r = 0.67) and interstitial macrophages (MC(T), r = 0.455). There was also a significant correlation between the number of MC(T) and the relative interstitial area. The number of MC(TC) was well correlated with the fractional area of alpha-SMA-positive interstitium (r = 0.749) and the percentage of the interstitial fibrotic area (r = 0.598). There was also a significant negative correlation between interstitial MC(TC) accumulation and creatinine clearance (r = 0.661). The density of MC(TC) was higher (1.4-fold) in advanced forms of GN associated with fibrocellular crescents and interstitial fibrosis. These results show the potential involvement of MC in the fibroproliferative process in the renal interstitium of patients with RPGN. The results indicate that these cells constitute part of the overall inflammatory cell accumulation in RPGN.     

Expression of HLA-DQ, -DR, and -DP antigens in normal kidney and glomerulonephritis

Expression of the defined subtypes of HLA-class II antigens DQ, DR, DP, as well as of a putatively new HLA-class II determinant DY was evaluated with specific monoclonal antibodies on frozen sections of 15 normal kidneys, as well as of renal tissue of 65 patients with different forms of glomerulonephritis (GN). In normal kidney HLA-DR and/or -DY versus DQ or DP antigens were shown to be differentially expressed on subpopulations of glomerular and interstitial cells, as well as vascular endothelia. Normal proximal tubular epithelia lacked HLA-DQ and -DP antigens, but carried -DY and variably -DR products constitutively. In comparison, aberrant presence of HLA-DQ and/or -DP antigens was found on proximal tubular cells in the majority of patients with rapidly progressive (RPGN), membranoproliferative GN (MPGN), or focal glomerular sclerosis (FGS), but more rarely observed in other forms of proliferative or non-proliferative GN. In addition all cases with RPGN revealed reduction of HLA-DQ, -DR, -DP or -DY+ glomerular cells. Decline of HLA-DP and/or -DR+ glomerular cells was variably seen in mesangioproliferative glomerulonephritis (MesPGN) and MPGN, whereas in FGS HLA-DQ antigens appeared to be increased in glomeruli. HLA-DQ, -DR, -DY+ interstitial cellular infiltrates were present in RPGN, FGS and MPGN and only occasionally occurred in other forms of GN. Altered renal expression of HLA-class II antigens may indicate specific sites of immunologically-mediated kidney injuries in GN.     

T-cells and macrophages in rapidly progressive glomerulonephritis: clinicopathologic correlations

We phenotyped with monoclonal antibodies (MAb) the cellular infiltrates in kidneys of patients with rapidly progressive glomerulonephritis (RPGN) responsive (R) or nonresponsive (NR) to pulse methylprednisolone therapy (PM)-eight anti-GBM, six no immune deposits, three immune complex, two vasculitis, and one proliferative GN. There were glomerular, periglomerular, crescentic, and interstitial T and T-cell subsets. Few interstitial and no glomerular B and NK cells were observed. TH cells were much more common than TS. Phenotypes were quantitatively evaluated in 221 nephritic and 32 control glomeruli. T and/or TH cells were positively correlated with M phi, r = 0.30 to 0.74, P less than 0.05 to 0.0005. Although differences in phenotypes were observed, these differences were insufficient to distinguish between subtypes. Analysis of R and NR revealed no relationship to percent crescents, entry serum creatinine, oliguria, or need for dialysis. NR was related to presence of anti-GBM disease, P = 0.001, as was ability to stop dialysis, 0 of 7 GBM versus 9 of 10 other, P less than 0.001. Mild infiltrates of lymphocytes and M phi correlated with R, P less than or equal to 0.02. R had fewer numbers of TH and M phi in glomeruli, P = 0.0001, in crescents, P less than 0.02, and total TH and M phi compared to NR, P less than 0.001. Crescentic and total TH/S ratios were lower in NR than R, P less than 0.05. These findings demonstrate that components of the cell-mediated immune (CMI) system are present by MAb analysis, that subtypes cannot be differentiated by CMI constitution, and R to PM is related to intensity and composition of CMI involvement. Independence of the CMI system relative to anti-GBM disease remains to be clarified.     

The detection of monocytes in human glomerulonephritis

Renal biopsy specimens from 343 patients with primary or secondary glomerulonephritis (GN) were examined for monocytes by the non-specific esterase reaction. Large numbers of monocytes per glomerulus (M/G) were found in essential cryoglobulinemia GN (29 pts, M/G 30.6 +/- 22.4), in acute post-infectious GN (27 pts, M/G 9.1 +/- 8.3), in rapidly progressive crescentic GN (20 pts, M/G 5.6 +/- 2.7), in systemic lupus GN (61 pts, M/G 5.0 +/- 5.6), and in IgA-GN associated with chronic liver disease (5 pts, M/G 6.4 +/- 5.9) or Sch?nlein-Henoch purpura (15 pts, M/G 3.3 +/- 6.4). Clinico-histological correlation showed that monocyte infiltration was correlated with the extent of proteinuria (all groups), with the presence of endoluminal "thrombi" (cryoglobulinemia GN), of polymorphonuclear leukocyte infiltration (post-infectious GN), of cellular crescents (crescentic GN), of "active" lesions (lupus GN), and with the extension of lesions to the peripheral capillary walls (IgA-associated GN). The M/G index was negligible in renal amyloidosis (21 pts), in idiopathic membranoproliferative GN (10 pts), in idiopathic IgA mesangial GN (63 pts), in membranous GN (40 pts), in focal glomerulosclerosis (29 pts), in minimal change nephropathy (18 pts), and in diabetic glomerulosclerosis (5 pts). The results confirm the participation of cells of the monocyte-macrophage series in the genesis of proliferative lesions, both intracapillary and extracapillary, in immune-mediated human GN and suggest their direct involvement in glomerular injury.     

The relationship of infiltrating renal leucocytes to disease activity in lupus and cryoglobulinaemic glomerulonephritis

In order to evaluate the contribution of cellular immune mechanisms in the pathogenesis of immune complex-mediated glomerulonephritis, renal biopsies from 18 patients with lupus glomerulonephritis and 26 with cryoglobulinaemic glomerulonephritis were studied. Leucocyte profiles including T cell subsets and 'activated' macrophages within both glomeruli and interstitium were determined, using a panel of monoclonal antibodies as markers, and a sensitive 4-layer peroxidase technique to localize these within tissues. The infiltrating leucocytes were correlated with clinical, histological and immunological parameters of disease activity. Normal glomeruli contained few leucocytes though normal interstitium did (145 +/- 30 mm2), made up predominantly of T lymphocytes and macrophages. There was a significant increase in intraglomerular leucocytes in both systemic lupus erythematosus 4-fold, and essential mixed cryoglobulinaemia 7-fold, as compared to normal. These leucocytes consisted mainly of macrophages, and particularly in cryoglobulinaemia of 'activated' macrophages as demonstrated by their surface expression of the procoagulant tissue factor recognized by the A13 monoclonal antibody. In cryoglobulinaemic glomerulonephritis (GN) there was also a significant increase in T lymphocytes due to a predominance of suppressor-cytotoxic cells (OKT8+). There was a significant increase in interstitial leucocytes in both diseases, lymphocytes (mainly OKT8+ve), and macrophages (mainly 'activated' A13+ve). There were significant positive correlations between disease activity and interstitial leucocyte infiltration including, in lupus nephritis, degree of proteinuria and total leucocytes, hypocomplementaemia and T lymphocytes, increased numbers of monocytes and lymphocytes with a higher histological index of activity, and in cryoglobulinaemic GN of T lymphocytes and proliferative lesions, and T lymphocytes and C1q deposition. This study has demonstrated the importance of the interstitium in the pathogenesis of both diseases, delineated the presence of both T lymphocytes and activated monocytes which make cell-mediated immune mechanisms feasible, and linked the presence of immune mediators to disease activity.     

The role of interstitial infiltrates in IgA nephropathy: a study with monoclonal antibodies

The leucocyte subpopulations in the interstitium and the glomeruli in renal biopsies from 34 patients with IgA nephropathy were analysed using monoclonal antibodies and immunoperoxidase techniques. Monocyte/macrophages and T-cells constituted the predominant infiltrating cell type in the interstitium (278 +/- 24 and 269 +/- 37 cells/mm2 respectively). Few intraglomerular leucocytes were seen, the majority of them belonging to the monocyte/macrophage phenotype (1.1 +/- 0.1 cells/glomerular cross-section). CD4+ lymphocytes predominated among the interstitial and glomerular T-cell populations and the CD4:CD8 ratio was 2.1 +/- 1.1 and 2.4 +/- 1.5 respectively. Only small numbers of NK cells and B cells were found in the interstitium, and almost none in the glomeruli. In contrast, significantly increased numbers of DR-expressing interstitial cells were seen (487 +/- 29/mm2), whereas DR expression by the tubular cells was minimal (37 +/- 6/mm2). Numbers of total leukocytes and T-cells were well correlated with the degree of tubulointerstitial damage and there was a significant correlation between renal functional impairment at the time of biopsy and the numbers of interstitial T cells (P less than 0.05) and CD4+ T cells (P less than 0.01). In contrast, interstitial mononuclear cells did not correlate with subsequent progression of the disease over 2-3 years. However, a more rapid decline of renal function was associated with increased numbers of interstitial B cells. No association was found between intraglomerular cells and degree of renal impairment either at the time of biopsy or in the long term.(ABSTRACT TRUNCATED AT 250 WORDS)     

Depletion of CD4(+) T cells aggravates glomerular and interstitial injury in murine adriamycin nephropathy

BACKGROUND: CD4(+) T cells play an important role in various types of immunologic renal disease, including lupus nephritis, IgA nephropathy, and crescentic glomerulonephritis. CD4(+) T cells are also major infiltrating lymphocytes in chronic tubulointerstitial inflammation associated with nonimmunological renal diseases. We suspected that CD4(+) T cells might contribute to disease progression and loss of renal function in chronic proteinuric renal disease (CPRD). To investigate this possibility, the effect of monoclonal antibody against CD4(+) lymphocytes (anti-CD4) was studied in a murine model (adriamycin nephropathy) of CPRD. METHODS: Adriamycin nephropathy was produced in male BALB/c mice by a single intravenous injection of adriamycin (11 mg/kg). Anti-CD4 was given by intraperitoneal injection following the development of proteinuria at days 5, 6, 7, 21, and 37 after adriamycin. After six weeks, renal function and histology were studied by histomorphometry, immunohistochemistry, and flow cytometry. RESULTS: Flow cytometric analysis showed a marked decrease in the number of CD4(+) T cells in blood and spleen of the antibody-treated animals (N = 7, P < 0.01). Adriamycin plus CD4(+) depletion mice had significantly greater mesangial expansion, glomerular sclerosis, and interstitial expansion than the mice on adriamycin alone. Interstitial infiltration with macrophages and CD8(+) cells was significantly increased in adriamycin plus CD4(+) depletion mice. Creatinine clearance (17.5 +/- 0.54 vs. 29.2 +/- 0.89 microL/min, P < 0.001) was significantly worse in the adriamycin plus CD4(+) depletion mice than in adriamycin alone mice and correlated with histologic change in glomeruli and interstitium. CONCLUSIONS: Depletion of CD4(+) T cells promotes glomerular and interstitial injury in mice with established adriamycin nephropathy. These findings suggest that CD4(+) T cells have a protective role against the progression of adriamycin nephropathy.     

Glomerular T cell and monocyte populations in patients with IgA nephropathy

Renal tissues from 19 patients with the minimal or slight stage of IgA nephropathy were examined for evidence of glomerular T cell or monocyte infiltration using monoclonal antibodies to identify T cells (OKT3, OKT11), T cell subsets (OKT4, OKT8), and monocytes and null cells (OKM1) by indirect immunofluorescence. Renal tissues from 12 patients at the same stage of mesangial proliferative glomerulonephritis without IgA deposition were also investigated by these procedures. Light microscopic examination of the same renal tissues was also performed. Reactive glomerular mononuclear cells were found to be numerous in patients with IgA nephropathy. The most prominent type of glomerular cells was OKT8 positive. T cell subsets and OKM1 positive cells in glomeruli from patients with IgA nephropathy were significantly increased as compared to those from patients with mesangial proliferative glomerulonephritis. Focal segmental proliferation of mesangial cells was observed in glomeruli which showed an accumulation of OKT8 positive cells. It is concluded that the immuno-regulatory mechanism involving T cells and/or monocytes might be one of the exacerbating factors in patients with IgA nephropathy.     

Expression of the fractalkine receptor (CX3CR1) in human kidney diseases

BACKGROUND: CX3CL1 (fractalkine) is a membrane bound chemokine that can function as an adhesion molecule for cells expressing the receptor CX3CR1. This receptor is involved in the recruitment of inflammatory cells in a rat model of crescentic glomerulonephritis, where blockade of CX3CR1 has been shown to be of benefit. Here we describe the distribution of CX3CR1 positive cells in a variety of kidney diseases and renal development. METHODS: A total of 84 formalin-fixed, paraffin-embedded specimens including fetal kidneys (N = 12), normal areas of kidneys uninvolved by neoplasia from tumor nephrectomies (N = 4), renal transplant nephrectomies (N = 5), renal transplant biopsies (N = 19), and kidney biopsies from patients with crescentic glomerulonephritis (N = 7), membranous nephropathy (N = 7), membranoproliferative glomerulonephritis (N = 8), focal and segmental glomerulosclerosis (N = 10), collapsing glomerulopathy (N = 6), and minimal change disease (N = 6) were studied. Immunohistochemistry was performed on consecutive tissue sections for CD3 positive T cells, CD68 positive monocyte/macrophages, CCR5 positive cells and CX3CR1 positive cells. RESULTS: The majority of inflammatory leukocytes infiltrating the kidney expressed CX3CR1. The distribution pattern was consistent with expression by both T cells and monocytes/macrophages. In contrast to the distribution of CCR5, which was expressed on a subset of infiltrating cells predominantly localized in the interstitium, CX3CR1 was present on both interstitial and glomerular infiltrating leukocytes. In developing kidneys CX3CR1 positive cells formed a small, scattered population of cells, consistent with the distribution of infiltrating leukocytes. CONCLUSIONS: The high number of CX3CR1-positive inflammatory cells in various disease entities is consistent with its having a role in the accumulation of intrarenal inflammatory cells, but does not provide evidence of specificity of leukocytes bearing this receptor for specific types of injury. Other chemokine gradients, like those created by the ligands for the chemokine receptor CCR5, might subsequently guide leukocyte subsets to specific microenvironments.     

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-Sch?nlein 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.     

Monocyte chemoattractant protein-1 and osteopontin differentially regulate monocytes recruitment in experimental glomerulonephritis

BACKGROUND: This study evaluated the mechanisms of monocyte/macrophage (M/M) infiltration in a rat model of anti-glomerular basement membrane glomerulonephritis (GN). We focused on chemokines and osteopontin, which are known regulators of M/M recruitment. METHODS: Using immunohistology, in situ hybridization, and Northern blotting, the expression levels of chemokines and osteopontin were evaluated in isolated glomeruli and tubules 4, 10, and 20 days after the induction of GN. In vivo blocking experiments were performed by application of neutralizing antibodies against osteopontin and monocyte chemoattractant protein-1 (MCP-1). RESULTS: In nephritic animals, high glomerular MCP-1 and RANTES (regulated upon activation normal T cell expressed and secreted) expression levels were observed on days 4 and 10. The tubular expression of MCP-1, however, was only slightly enhanced. In contrast, tubular osteopontin production was maximally stimulated (day 10) and paralleled with peaks of albuminuria and tubulointerstitial M/M infiltration. Application of an anti-osteopontin antibody ameliorated tubulointerstitial and glomerular M/M recruitment, whereas treatment with an anti-MCP-1 antibody selectively reduced glomerular M/M recruitment. However, tubulointerstitial M/M infiltration remained unchanged. CONCLUSION: These studies show that chemokines and osteopontin are differentially expressed in glomeruli and tubules in this model of GN. Chemokines play a primary role in the glomeruli, whereas osteopontin has a predominant role in tubulointerstitial M/M recruitment. The roles of chemokines and osteopontin may thus be dependent on the renal compartment and on the disease model.     

The role of monocyte chemotactic and activating factor (MCAF)/monocyte chemoattractant protein (MCP)-1 in subgroups of rapidly progressive glomerulonephritis

To elucidate the role of monocyte chemotactic and activating factor (MCAF)/monocyte chemoattractant protein(MCP)-1 in the pathogenesis of rapidly progressive glomerulonephritis (RPGN), we determined the urinary levels of MCAF/MCP-1 in 20 healthy subjects, 30 patients showing RPGN with crescents, and 39 patients with various types of renal diseases without crescents. We divided RPGN into two subgroups, the acute type and the insidious type, with regard to the declination rate of reciprocals of serum creatinine with time as previously reported. In addition, we divided the patients with RPGN into anti-neutrophil cytoplasmic antibody(ANCA)-related diseases and immune complex(IC)-mediated diseases with regard to etiology. Urinary levels of MCAF/MCP-1 were significantly higher in patients with RPGN as compared with those of other renal diseases and healthy volunteers(21.8 +/- 4.5 vs. 11.6 +/- 3.5, 1.0 +/- 0.1 pg/ml creatinine, respectively, p < 0.01, mean +/- SEM). There was no difference in the urinary levels of MCAF/MCP-1 between the acute and insidious types of RPGN patients. In addition, there was no difference in the urinary levels of MCAF/MCP-1 between the patients with ANCA-related and IC-mediated diseases. Urinary levels of MCAF/MCP-1 in patients with RPGN were correlated well with the percentage of both total crescents and fibrocellular/fibrous crescents and the number of CD68-positive infiltrating cells in the interstitium. Immunohistochemical examinations revealed that MCAF/MCP-1 positive cells were detected in tubular epithelial and endothelial cells and mononuclear infiltrated cells in the interstitium. Moreover, elevated urinary MCAF/MCP-1 levels in patients with RPGN, regardless of subgroups, were dramatically decreased during methylprednisolone pulse therapy induced convalescence. These results suggest that MCAF/MCP-1 may be involved in the pathogenesis of RPGN via macrophage recruitment and activation.     

The chemokine receptor antagonist AOP-RANTES reduces monocyte infiltration in experimental glomerulonephritis

The chemokine receptor antagonist AOP-RANTES reduces monocyte infiltration in experimental glomerulonephritis. BACKGROUND: This study was designed to evaluate the role of the novel chemokine receptor antagonist amino-oxypentane RANTES (AOP-RANTES), which blocks the binding of macrophage inflammatory protein-1alpha (MIP-1alpha), MIP-1beta, and RANTES to the chemokine receptor-5 (CCR-5) on the infiltration of monocytes in experimental glomerulonephritis. METHODS: Rats were treated twice daily with 12.5 microg AOP-RANTES following an induction of anti-rat-thymocyte antibody-mediated glomerulonephritis. The white blood cell count, glomerular monocyte infiltration, chemokine expression, and collagen type IV deposition were assessed. RESULTS: The induction of glomerulonephritis increased glomerular monocyte/macrophage (M/M) infiltration at 24 hours and at 5 days was still higher than in controls. AOP-RANTES prevented glomerular M/M infiltration at 24 hours and at 5 days. This was paralleled by reduced glomerular collagen type IV deposition as a fibrotic marker in nephritic animals. CONCLUSION: These data show that the CCR-5 chemokine receptor antagonist AOP-RANTES ameliorates M/M infiltration and improves glomerular pathology in experimental glomerulonephritis. The use of chemokine receptor antagonists may offer a new therapeutic option in inflammatory renal injuries.     

Differential effects of steroids on leukocyte-mediated glomerulonephritis in the rabbit

The effects of steroids on the development of injury in two models of experimental glomerulonephritis (GN), (one mediated by neutrophils, the other by macrophages) were compared. The neutrophil-associated lesion [initiated by heterologous antiglomerular basement membrane (GBM) antibody] was characterized by the development of an exudative endocapillary GN with heavy neutrophil accumulation [mean, 6.9 neutrophils/glomerular cross section (N/GCS) +/- 2.9 SD], minor macrophage infiltration [7.9 macrophages/glomerulus (M/G) +/- 2.2 SD] and heavy proteinuria (1905 mg/24 hr +/- 520 SD). Steroid-treated (methylprednisolone, 2 mg/kg/12 hr i.v.) rabbits developed a marked monocytopenia, mild neutrophilia, and significant reduction in glomerular macrophage accumulation (0.3 M/G 0.02 SD). However, neutrophil accumulation (6.1 N/CGS +/- 2.5 SD), histological appearances, and proteinuria (1820 mg/hr +/- 490 SD) were unaffected. The macrophage-associated model of GN was induced by passive autologous rabbit anti-sheep IgG 15 hr after the injection of a subnephritogenic dose of the same anti-GBM antibody. The glomerular lesion was characterized by a diffuse endocapillary proliferative GN with heavy macrophage infiltration (54 M/G +/- 8 SD), insignificant neutrophil accumulation (0.8 N/GCS 0.02 SD), and the regular development of proteinuria (420 mg/24 hr +/- 80 SD). Steroid-treated rabbits developed a mild neutrophilia and a significant monocytopenia associated with abrogation of glomerular macrophage accumulation (2.3 M/G +/- 0.8 SD). This was associated with the prevention of the development of GN and proteinuria (22 +/- 9.5 SD). Thus, steroids produce monocytopenia and prevent glomerular macrophage accumulation and associated injury whereas neutrophil accumulation and injury is unaffected. These data suggest steroids may have widely varying effects on the outcome of leukocyte-associated experimental GN depending on the nature of the infiltrating cells.