Dietary components and progression of renal lesions.
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Biomedical subjects
Publications and source records attributed to N Hinglais.
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The localization of S protein (Vitronectin) antigen was studied by indirect immunofluorescence and immunoelectron microscopy in normal adult human kidneys and in biopsy specimens from patients with a wide range of renal diseases, and compared with that of neoantigens of the C5b-9 terminal complement complex. S protein antigen was diffusely present in arteriolar perimyocytic matrices, the glomerular basement membrane and mesangial matrix, and tubular basement membranes in the cortex of normal and diseased kidneys without superimposable staining for C5b-9 neoantigens. Cell remnants embedded in normal and sclerotic extracellular matrices expressed S protein antigen and also stained for C5b-9 neoantigens. Several lines of evidence suggested that S protein present in connective matrices most likely represents S protein or C5b-9 complexes trapped from the circulation. Glomerular immune deposits and arteriolar hyalin deposits which contained C5b-9 neoantigens also contained S protein antigen in the same location. In a few specimens from patients with membranous nephritis stage I and IgA nephropathy, immune deposits contained neither detectable C5b-9 neoantigens nor S protein. The observed strong co-staining of immune deposits for S-protein and C5b-9 caution against the generalization that C5b-9 within glomerular immune deposits represent membrane-bound cytolytic complement complexes.
The expression of complement receptor antigens by human Kupffer cells (KC) was investigated by immunohistochemical techniques in seven normal human liver biopsies. Polyclonal and monoclonal antibodies were revealed by double labeling of cells using indirect immunofluorescence and immunoenzymatic techniques or by using double immunoenzymatic techniques. In most experiments, one antigen was revealed by streptavidin-biotin-peroxidase complexes whose reaction product was examined by light microscopy and the second antigen stained using the alkaline phosphatase antialkaline phosphatase method visualized by fluorescence microscopy using fluorescein isothiocyanate or tetramethylrhodamine isothiocyanate filters. KC were identified using monoclonal antibody EBM11 that recognizes 100% of KC in hepatic lobules and was paired with each antibody directed against complement receptors. CR1 and CR3 (alpha- and beta-chains) were found to be the predominant receptor antigens expressed by human KC. CR4 (p150,95) was expressed on all KC, but staining with anti-CR4 monoclonal antibodies was consistently weaker than that observed with anti-CR3 antibodies. No staining of KC was observed with anti-CR2 (CD 21) antibodies. Expression of CR1, CR3, and CR4 complement receptors on KC provides the cells with an optimal capacity to bind and phagocytize particles or immune complexes coated with any type of ligands for C3 receptors.
Idiopathic nephrosis (IN), which includes minimal change (MCD), diffuse mesangial proliferation (DMP) and focal segmental glomerular sclerosis (FSGS), is classically characterized by the absence of significant deposits by immunofluorescence microscopy (IF), except for the focal lesions of segmental sclerosis and/or hyalinosis of FSGS, which fix IgM and C3 antiserums. Since IF is available in most centres, an increasing number of unexpected findings has been reported. In order to evaluate the clinical significance of the glomerular deposits revealed by IF in some instances, we reviewed the renal biopsy findings of 222 consecutive children presenting with IN and in whom IF microscopy was available. By light microscopy, 122 patients showed MCD, 10 DMP, and 90 FSGS with DMP (11 cases) or without (79 cases). By IF, 125 specimens were negative and served as controls; 54 showed mesangial IgM deposits, 24 mesangial IgG deposits (associated with Clq deposits in 16), 15 scattered granules of C3 and 4 predominant deposits of mesangial IgA. We correlated these findings with initial response to steroid therapy and outcome and could find no significant difference between the various categories defined by IF and the control group. Repeat biopsies, performed in 21 cases, showed the persistence of deposits in 11 and their transformation in 10. The particular problem raised by the patients who present with IN and mesangial IgA deposits is discussed. Our results demonstrate that patients presenting with IN and "positive IF", whether showing IgM, IgG and Clq, C3 or IgA, do not represent distinct clinicopathological entities.
Seventy-nine children with haemolytic uraemic syndrome (mean age 28 months) were randomly assigned either to a group receiving plasma infusions (plasma group, n = 39) or to a group treated conservatively (control group, n = 40). The duration of haemolysis, thrombocytopenia and anuria was similar in the two groups. Serum creatinine levels were similar in the two groups at the 1-month follow-up but were higher in the control group at 3 months (plasma group 49 +/- 14, control group 66 +/- 28 mumol/l; P less than 0.02) and at 6 months (plasma group 48 +/- 13, control group 63 +/- 21 mumol/l; P less than 0.005). The prevalence of proteinuria was also higher in the control group at the 6-month follow-up (plasma group 17%, control group 46%; P less than 0.02). However, differences were no longer significant after 1 year. Renal tissue was examined in 54 cases (plasma group, n = 27; control group, n = 27). Diffuse cortical necrosis was present in 7 cases in the control group but was absent in the plasma group (P less than 0.02). Taking into consideration the higher serum creatinine levels, the higher prevalence of proteinuria during the first 6 months of follow-up in the control group and the presence of diffuse cortical necrosis in this group compared with the plasma group, we conclude that plasma infusions should be regarded as beneficial. Further study is needed to determine which plasma fraction is involved.
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Phenotypic analysis of interstitial mononuclear cell infiltrates was undertaken in 40 transplant renal specimens obtained from 38 patients in order to assess the influence of immunosuppressive therapy. Thirteen patients were given conventional immunosuppressive treatment (azathioprine and prednisone) and the other 25 received cyclosporine. The immunostaining was performed using seven antileucocyte antibodies by alkaline phosphatase-anti-alkaline phosphatase method. Interstitial infiltrates were distributed in two patterns: diffuse infiltrates and periglomerular/perivascular aggregates. The phenotypic composition was distinct in these two patterns: in diffuse infiltrates, monocytes/macrophages (EBM 11) represented the predominant inflammatory cell and were associated with a minor component of T cells (T 11). In contrast, aggregates had a major T lymphocyte phenotype in addition with few foci of B cells. T4 subset of T lymphocytes always predominated over T8 subset. The repartition and the proportion of each cell type were not significantly different in rejecting and not rejecting grafts and were not affected by the immunosuppressive regimen.
The incidence of de novo membranous glomerulonephritis (MGN) in transplanted kidneys is around 1 to 2%. In our series, of the 310 grafts that were examined by immunofluorescence microscopy (IF), 29 (9.3%) showed subepithelial IgG deposits, a pattern consistent with the diagnosis of MGN. Transplant biopsy had been performed because of the occurrence of proteinuria in 8 patients (pts), for suspected rejection in 16 and systematically in the remaining 9 who had no proteinuria and a normal renal function. In all cases the lesions were identified by IF and were confirmed by electron microscopy (EM) in 14 pts. Granular deposits of IgG were diffuse in 22 cases and segmental in 7. Sequential specimens were available in 17 pts and showed the persistence or the increase of the IgG deposits in all patients but one in whom they had disappeared. Age at transplantation (Tx) ranged from 2 years 3 months to 16 years. Grafts were from cadaveric donors in 27 pts and from living related donors in 2 pts. In none of the recipients was MGN the nephropathy of the native kidneys. With a follow-up of 18 to 74 months, 6 pts never developed a proteinuria. In the remaining 23, proteinuria developed 1 to 70 months after Tx, associated with a nephrotic syndrome (NS) in 6 pts.(ABSTRACT TRUNCATED AT 250 WORDS)
Thirty-five children (12 girls, 23 boys), aged from 1 year and 5 months to 14 years at the onset of idiopathic nephrotic syndrome, received cyclosporin A (CyA) because of steroid toxicity or failure to respond to steroids. The initial oral dose was 6 mg/kg per day and this was adjusted to obtain trough plasma levels of 50-150 ng/ml. The duration of treatment was between 2 and 8 months. In patients who responded to CyA treatment, the dosage was tapered off; treatment was stopped if found to be ineffective. Of the 35 children, 20 were frequent-relapsing steroid responders who suffered serious side-effects from steroid therapy. Seventeen of them either went into remission or did not relapse despite the withdrawal of prednisone. Prednisone doses could be lowered but not stopped in 1 patient and the remaining 2 patients relapsed when prednisone was tapered off. At the final examination, 10 of the 12 children in whom CyA was tapered off and who had initially responded to CyA had relapsed. A second course was given to these 10 patients and 3 failed to respond. Five children were partial steroid responders and CyA induced a remission in 1 and a partial remission in another. Among the 10 children who were steroid resistant, only 1 responded to CyA, 2 had a partial response and 7 failed to respond to CyA. A reduction of glomerular filtration rate occurred in 8 patients, 7 of whom had either persistent nephrotic syndrome or were in relapse, which suggests that factors other than CyA nephrotoxicity may have been operative. Complete reversal occurred in only 4 patients. Significant histological changes, likely to be related to CyA, were seen in 2 repeat renal biopsies out of the 11 performed.
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The glomerular pathology of 634 transplant specimens (526 biopsies and 108 transplantectomies) from 410 children was studied. Three types of glomerulopathies were observed: (1) recurrent glomerulonephritis (GN) (40 of 142 patients with glomerular nephropathy), (2) de novo GN (52 grafts), and (3) transplant glomerulopathy (29 grafts). The study of recurrent GN is considered of great interest because of the possible insight into the nature of the original disease and the opportunity to observe the evolution of the disease in sequential biopsies of the transplant. The two major forms of de novo GN were membranous GN and IgG linear deposits along glomerular and tubular basement membranes. Transplant glomerulopathy, although distinctive morphologically, may resemble membranoproliferative GN (MPGN) or thrombotic microangiopathy.
A glomerular extra-cellular roughly granular material (ERGM) has been described by several authors, mainly in association with membranoproliferative glomerulonephritis. This material is clearly identified on light and electron microscopy. Another peculiar morphological character of ERGM is its property of autofluorescence detailed in this study. The precise nature of this granular material remains questionable. Immunostaining shows the lack of superposition of autofluorescent ERGM with C3 and with C5b9. Nuclear origin of ERGM suspected on ultrastructural features failed to be proven by using immunolabelling with an anti-DNA serum.
The kidney distribution of 28 kDa vitamin D-induced calcium binding protein (CaBP) was studied in 15 fetuses (11 to 33 weeks old), six children and adults (12 days to 32 years old) by immunocytochemistry using a specific antibody to rat renal 28 kDa CaBP. Similar results were obtained on frozen and fixed tissues. Kidneys from one adult and three fetuses were studied by immunoelectronmicroscopy for antigen localization at the subcellular level using the indirect immunoperoxidase technique. The 28 kDa CaBP was present in all kidneys from the eleventh week of gestation. At that stage, all deep parts of collecting ducts were homogeneously stained and a few distal tubules located in the deep cortex were intensely labeled. No labeling was observed in the early stage of nephron differentiation (S-body). 28 kDa CaBP distribution changed with kidney maturation. There was a progressive reduction of the deep part of collecting duct labeling and a concomitant increase in the number and intensity of stained distal tubular cells. At the ultrastructural level, 28 kDa CaBP was observed in the cytosol and the nuclear euchromatin. Our study demonstrates the early cellular synthesis of 28 kDa CaBP and its transient expression by deep collecting duct cells during early fetal life, at a time when only a few distal convoluted tubular cells synthetize it.
The kidney distribution of angiotensin-I converting enzyme (ACE) was studied in 14 fetuses (11 to 30 weeks old) and 7 children (2 days to 13 years old) by immunohistochemistry using specific antibodies to human kidney ACE. Immunohistochemical techniques included indirect immunofluorescence on cryostat sections of frozen tissue, immunoperoxidase and immunofluorescence of fixed tissue embedded in Paraplast, and immunoelectron microscopy. The ACE distribution in the fetal kidneys was independent of the age of the fetus. ACE was detected in two locations: 1) on the basolateral membranes and primary apical microvilli of epithelial cells from early differentiating proximal tubules; the labeling was intense in brush borders of fully developed proximal tubules; and 2) on glomerular endothelial cells; cells were lined by reaction product as soon as capillaries invaded the inferior cleft of the S-shaped body. Tubular ACE distribution was identical in the postnatal kidneys. The staining of the glomerular endothelium was extremely inconstant. The presence of ACE in proximal tubular cells and glomerular endothelial cells at the beginning of nephron differentiation may indicate that it is involved in the development of nephron function and renal hemodynamic.
The mechanism involved in glomerular fibrin deposition was investigated during mercuric chloride (HgCl2)-induced autoimmune glomerulonephritis in the Brown Norway rat. To ascertain whether the local hemostatic system was activated secondarily to the immunological conflict, the ability of glomerular lysates to induce coagulation in vitro was assessed in treated and control rats. Glomerular procoagulant activity (PCA) of HgCl2-injected rats was measured on day 12 (latent phase of the disease), day 20 (acme), and days 32 and 42 (recovery phase) after the first mercury injection. PCA rose 3-fold (p less than 0.02) at day 20 and then almost returned to control values. Proteinuria, PCA, and the incidence of glomerular fibrin deposits peaked concomitantly at day 20. Glomerular PCA was characterized as thromboplastin. The number of Ia positive cells detected by monoclonal OX-6 antibody was not different from the control number at any phase of the disease; the number of macrophages per glomerular section detected by electron microscopy at day 20 in HgCl2-injected rats was 1.80 +/- 0.60, versus 0.30 +/- 0.11 in the controls. No correlation was found between glomerular PCA and either the number of monocytes/macrophages or of Ia-positive cells present in the glomeruli. Since glomerular PCA was maximal at the onset of fibrin formation in the glomeruli and then decreased toward its basal level, and since the fibrin disappeared, it is concluded that increased production of thromboplastin by glomeruli, with activation of the extrinsic coagulation pathway, may contribute to intraglomerular fibrin deposition in HgCl2-induced glomerulonephritis.
The localization of immunoreactive angiotensin I-converting enzyme (ACE) has been investigated at the optical and ultrastructural level with anti-human ACE antibodies in the human kidney and small intestine. In both tissues ACE was found in blood vessels and in extravascular situation in the absorptive epithelial cells of intestinal mucosa and renal proximal tubules. Ultrastructural immunohistochemistry showed that in intestinal and renal proximal tubular cells ACE was prominent in microvilli and brush borders. In the kidney ACE was also present on the basolateral part of the plasmalemmal membrane, where it may contribute to the regulation of angiotensin II-dependent absorption processes. Intracellular positivities were also observed inside the renal vascular endothelial and proximal tubular cell in endoplasmic reticulum and nuclear envelope reflecting the synthesis and the cellular processing of ACE. The intestinal microvascular endothelium was strongly labeled suggesting that the mesenteric circulation is an important site for the production of angiotensin II. Vascular endothelial ACE was also detected in the peritubular but not glomerular capillaries of the kidney.
The effect of prostaglandin E1 on mercury-induced autoimmune disease in brown Norway rats has been investigated. Daily doses of 6 to 24 micrograms prolonged survival and significantly decreased proteinuria, deposition of immune reactants in the glomeruli, circulating anti-glomerular membrane antibody production, total serum IgE, and circulating immune complex level. A dose of 3 micrograms was also effective but to a lesser degree. These results show the efficiency of prostaglandin E1 in yet another autoimmune disease, show that the beneficial effect of prostaglandin E1 in this model is related to its immunosuppressive effects, and suggest that modification of prostaglandin-mediated suppression induced by HgCl2 might play a role in the pathogenesis of this autoimmune disease.
The presence and localization of the C5b-9 neoantigens of the terminal complement sequence, of antigens expressed by cleavage fragments of C3, and of Factor H antigens have been studied by immunohistochemical techniques in morphologically normal adult human kidneys and in biopsy specimens from patients with a wide range of renal diseases with and without immune deposits. In morphologically normal kidneys, C5b-9 neoantigens were observed within all connective matrices (arteriolar media, glomerular basement membrane (GBM), mesangial matrix and tubular basement membrane). The C3d and C3g antigens of the C3dg, and C3bi cleavage fragments of C3 and Factor H antigens were found in similar locations. None of the matrices stained for immunoglobulins. Immunoelectron microscopy demonstrated that C3d, C3g, H antigens and the C5b-9 neoantigens were localized on membranous and vesicular structures embedded in the connective matrices. These structures represent cell membranes shed from adjacent cells as evidenced by their ultrastructural appearance and by the fact that those which were in close vicinity to pedicles within the GBM expressed the C3b receptor antigen, a specific marker for podocyte membranes. Formation of C5b-9 complexes in the shielded environment of connective matrices may explain their persistence over long periods of time in the absence of apparent immunopathological consequences. Biopsies from pathological kidneys were classified into three groups based on the pattern of glomerular staining with anti-C5b-9 antibodies. In the first group, a sparse mesangial labeling was seen, similar to that observed in normal kidneys. In the second group, abundant clusters of C5b-9 were seen in the same location as immune deposits. Activation of the complement system to completion could be documented in the absence of detectable C3 (C3c) antigen in glomeruli. Immunoelectron microscopy demonstrated that C5b-9 neoantigens were present on cell remnants in connective matrices in all specimens that were studied. Labeled cell remnants were present in large amounts in sclerotic matrices. C5b-9 neoantigens were constantly found on old and large immune deposits, and absent or occasionally present on recent and small immune deposits. In membranous nephropathy stage I, proteinuria appeared to be independent of the presence or absence of detectable C5b-9 neoantigens on immune deposits. Thus, the presence of C5b-9 neoantigens in pathological renal tissue does not have an univocal significance, and requires analysis of the localization of the antigens and appropriate controls in order to assess the potential role of C5b-9 in tissue damage.