Polyvalent immunoglobulins in sensitised renal transplant recipients.
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Graft Enhancement, Immunologic↗
Biomedical subjects
E Rondeau
Publications and source records attributed to E Rondeau.
[Treatment of cytomegalovirus infections in renal transplants].
Primary cytomegalovirus (CMV) disease can be prevented in renal transplant recipient with the use of either CMV hyperimmune globulin or acyclovir. When started before transplantation and continued for 12 to 16 weeks, these treatments decrease significantly the incidence of primary CMV disease. However they are not always effective and their effectiveness for the prevention of CMV reinfection or reactivation has not been established. Other prophylactic methods, such as vaccination or interferon alpha are not effective. Ganciclovir has been shown to be effective for the treatment of overt CMV disease, provided it is administered early. Combined treatments with CMV hyperimmune globulins and ganciclovir can be used in the most severe forms of the disease. Foscarnet can also be effective, however its nephrotoxicity limits its use in renal transplant recipients.
Acyclovir↗
Nordihydroguaiaretic acid inhibits urokinase synthesis by phorbol myristate acetate-stimulated LLC-PK1 cells.
Protein kinase C (PKC) activation is regulated by Ca2+, phospholipids, diacylglycerol (DAG) and fatty acids. Phorbol myristate acetate (PMA) which mimics the effect of DAG on PKC induces transcriptional activation of the urokinase-type plasminogen activator (u-PA) gene in LLC-PK1 cells. We examined in the present work the relationships between PKC activity, fatty acids, and u-PA synthesis in this cell line. We showed that H7, an inhibitor of PKC, inhibited the PMA-induced u-PA synthesis by LLC-PK1 cells. PMA-induced u-PA synthesis was enhanced by eicosatetraynoic acid (ETYA), a competitive inhibitor of both the lipoxygenase and cyclooxygenase pathways and inhibited by nordihydroguaiaretic acid (NDGA), an inhibitor of the lipoxygenase pathway. Three other unrelated lipoxygenase inhibitors (phenidone 100 microM, BW755 50 microM and diethylcarbamazine 50 microM) had no effect on u-PA biosynthesis. Two polyunsaturated fatty acids other than ETYA, arachidonic acid and linoleic acid, also potentiated the PMA effect and a lipoxygenase derivative, 12 hydroxyeicosatetraenoic acid (12 HETE), did not modify the basal and PMA-stimulated u-PA syntheses. PKC activity purified from cytosol of LLC-PK1 cells was stimulated by addition of 16 nM PMA in vitro and this effect was blunted by simultaneous addition of 5 microM NDGA. By Northern blot analysis using a pig u-PA cDNA probe we found that PMA increased the steady state level of u-PA mRNA after 2 h of incubation and that NDGA inhibited this effect. These data suggest that NDGA inhibits PMA-stimulated PKC activity in intact cells leading to a decrease of u-PA mRNA level and u-PA biosynthesis in PMA-stimulated LLC-PK1 cells. Polyunsaturated fatty acids have opposite effects.
1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗
Linkage study of a large family with autosomal dominant polycystic kidney disease with reduced expression. Absence of linkage to the PKD 1 locus.
We describe a large three generation family with autosomal dominant polycystic kidney disease (PKD). Ultrasonographic screening of 60 family members revealed 20 individuals, whose age ranged from ten to eighty years, with one or several cysts in only one kidney and 7 individuals with cysts in both kidneys. Transmission of unilateral cysts seems to be autosomal dominant, although there are some generation gaps. Linkage studies with several markers of the PKD1 locus on the short arm of chromosome 16 showed no linkage with the disease. Lod scores for linkage between the disease and the most informative marker 3'HVR were computed using different penetrance models and several hypotheses concerning the clinical status of individuals with unilateral renal cysts. Results varied from Z = 1.31 to Z = -21.47 (theta = 0). Smith's test of heterogeneity gave a conditional probability of non-linkage between 0.9 and 1.0. We conclude that this family presents a form of autosomal dominant PKD with reduced penetrance and no linkage to the PKD1 locus on the short arm of chromosome 16. Other hypotheses, such as the existence of two distinct hereditary diseases in this large family, or neomutation in one branch of the family associated with a high frequency of isolated renal cysts, are also considered.
Family↗
Thrombin regulates components of the fibrinolytic system in human mesangial cells.
Besides its procoagulant activity, thrombin has been shown to stimulate cell proliferation and to regulate the fibrinolytic pathway. We report here the effect of purified human alpha thrombin on the synthesis of tissue-type plasminogen activator (t-PA) and plasminogen activator inhibitor 1 (PAI-1) by cultured human mesangial cells. Thrombin (0 to 2.5 U/ml) increased in a time- and dose-dependent manner the production of t-PA and PAI-1 (2- to 3-fold increase of secreted t-PA and PAI-1 release during a 24 hour incubation). This effect was associated with a twofold increase in DNA synthesis measured by 3H-thymidine incorporation. Zymographic analysis and reverse fibrin autography showed that thrombin also increased the level of the 110 Kd t-PA-PAI-1 complex, whereas PAI-1 was present as a free 50 Kd form in the culture medium conditioned by unstimulated and thrombin-stimulated cells. Free t-PA was never observed. Both membrane binding and catalytic activity of thrombin were required since the effects of 1 U/ml thrombin were inhibited by addition 2 U/ml hirudin, which inhibits the membrane binding and catalytic activity of thrombin, and since DFP-inactivated thrombin, which has the ability to bind but which has no enzymatic activity, did not induce t-PA or PAI-1. Gamma thrombin, which does not bind to thrombin receptor, did not increase t-PA and PAI-1 releases. The effects of thrombin were probably mediated by protein kinase C activation since H7, an inhibitor of protein kinases, inhibited significantly thrombin effects on t-PA and PAI-1 production, and since addition of an activator of protein kinase A, 8-bromocyclic AMP (100 microM), induced a significant inhibition of the thrombin effect. The effects of thrombin were also suppressed by 1.25 micrograms/ml alpha amanitin, suggesting a requirement of de novo RNA synthesis. Northern blot analysis indicated that thrombin induced an increase in the mRNA levels of t-PA and of PAI-1. We conclude that thrombin increases DNA synthesis in human mesangial cells and enhances the synthesis of both t-PA and PAI-1. The latter is released in a large excess as compared to t-PA. Hence, thrombin may have a role in provoking a localized hypofibrinolytic state and may contribute to the persistence of glomerular fibrin deposits during proliferative glomerulonephritis.
Blotting, Northern↗
Dexamethasone increases preproparathyroid hormone messenger RNA in human hyperplastic parathyroid cells in vitro.
To determine if parathyroid hormone release in man is directly stimulated by glucocorticoids, dispersed human parathyroid cells from hyperplastic glands obtained from eight renal transplant recipients were studied in vitro. Dexamethasone (10(-11) to 10(-6) mol l-1) increased PTH release in a time- and dose-dependent manner. A plateau was reached at 10(-8) mol l-1 (1015 +/- 149 vs. 230 +/- 27 pg 10(-4) cells for control value, after 24 h incubation; P less than 0.0001). An interaction with a glucocorticoid receptor was suggested since 10(-6) mol l-1 RU 486 blunted the dexamethasone-induced PTH release. By Northern blot analysis, dexamethasone was found to increase the amount of preproPTH mRNA in these cells. The effect of dexamethasone was probably at the gene level since (1) 1,25 dihydroxy vitamin D3 inhibited both iPTH and preproPTH mRNA increases induced by dexamethasone and (2) alpha-amanitin (1,25 micrograms ml-1) also completely suppressed the dexamethasone-induced PTH release. Thus, for the first time, we demonstrate that dexamethasone induces an increase of PTH synthesis, probably by increasing PTH gene transcription. This effect may play an important pathogenic role in persisting hyperparathyroidism and steroid-induced bone complications in renal transplant recipients.
Amanitins↗
Systemic and renal fibrinolytic activity in a patient with anticardiolipin syndrome and renal thrombotic microangiopathy.
A 24-year-old white woman with a past history of recurrent venous thromboses of the lower extremities was admitted for hypertension and renal failure. She had a chronic cutaneous ulcer on the anterior side of the left leg and oral ulcers of the palatum. Laboratory tests demonstrated rapidly progressive renal failure and the presence of an anticardiolipin antibody (ELISA). Thrombosis of the inferior vena cava was shown by phlebocavography. Renal biopsy revealed typical thrombotic microangiopathy. Tissue-type plasminogen activator (tPA) was visualized by immunofluorescence in endothelial cells of renal arterioles and glomeruli. Normal plasma levels of tPA, urokinase and plasminogen activator inhibitor 1 were found by ELISA, and tPA antigen levels rose after desmopressin acetate infusion. Thus, in this case, the diffuse thrombotic process was not related to defective circulating or renal fibrinolytic systems and could be promoted by the procoagulant effect of antiphospholipid antibodies.
Adult↗
Plasminogen activator inhibitor 1 in renal fibrin deposits of human nephropathies.
The persistency of fibrin deposits in the kidney during renal diseases could reflect either a defective release of plasminogen activators (PA) or a local excess of PAI. In order to investigate this question, we studied human renal biopsies by immunofluorescence technique with specific antibodies for fibrin, tissue-type plasminogen activator (t-PA), urokinase (u-PA), PAI-1 and PAI-2. By this technique t-PA could be detected in the glomerular flocculus and the endothelium of small arteries of the normal control kidneys. We failed to detect significant fluorescence with other antibodies in normal kidneys. Conversely, in cases of vascular nephropathy with thrombosis the positive fluorescence obtained with anti-fibrin antibodies at the site of thrombosis was associated with a positive fluorescence with anti-PAI-1 and to a lesser extent with anti-t-PA antibodies. u-PA and PAI-2 were not detected in these lesions. Similarly in the most severe forms of crescentic glomerulonephritis, extracapillary fibrin deposits were associated with PAI-1. In one case u-PA was also detected. This is in agreement with our previous findings that glomerular epithelial cells release both PAI-1 and the inactive form of u-PA (pro u-PA). Thus, our results support the hypothesis that PAI-1, which is able to inhibit both t-PA and u-PA, may play a major role in the persistency of fibrin deposits in the human kidneys during pathological conditions.
Female↗
Efficacy of early treatment of cytomegalovirus infection by ganciclovir in renal transplant recipients.
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Adult↗
[Biological markers of allograft rejection].
The main cause of graft failure is rejection. Beside clinical manifestations of graft dysfunction, biological markers of graft rejection have been proposed. These are biochemical markers related to inflammatory response or lymphocyte activation (cytokines, thromboxane B2, beta 2 microglobulin, neopterin) and cellular markers. Cells may be obtained from peripheral blood, the graft itself or urine, biliary or pancreatic fluid. Phenotypic (IL2 receptors, HLA DR, CD4, CD8) or functional (mitotic index, cell specific cytotoxicity) properties have been studied. Numerous markers have been proposed but few of them are specific enough and routinely used.
Biomarkers↗
Fibrin deposition and adaptive changes in glomerular procoagulant and fibrinolytic activities in rat renoprival nephropathy.
To investigate the mechanisms which may influence fibrin deposition in the remnant kidney, glomerular morphology and the haemostatic properties of isolated glomeruli were assessed in two groups of rats, 30 days after surgical removal of three-quarters of the total renal parenchyma, and compared to glomeruli in sham-operated controls. One group was given the thromboxane synthetase inhibitor OKY 046 and the other was not. Fibrin deposition occurred in about 20% of glomeruli, of which 4% exhibited segmental necrotizing lesions. Concomitantly, glomerular procoagulant activity dropped to 40% of the control level and glomerular fibrinolytic activity rose to 120-130% of this level. Inhibition of thromboxane synthesis did not affect fibrin deposition, glomerular haemostasis or the development of renal insufficiency. In an additional group of unilaterally nephrectomized rats, procoagulant activity also markedly decreased in the remaining kidney. These results indicate that in the rat remnant kidney, alterations in glomerular haemostatic properties tend to have antithrombotic effects which seem to constitute an adaptive reaction by an autacoid system to glomerular fibrin deposition.
Adaptation, Physiological↗
Tumor necrosis factor alpha (TNF-alpha) production by cells of bronchioloalveolar lavage (BAL) and peripheral blood mononuclear cells (PBMC) in cardiopulmonary transplant recipients.
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Cells, Cultured↗
Interleukin-2 stimulation of tumor necrosis factor synthesis by peripheral blood mononuclear cells in renal allograft rejection.
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Biopsy, Needle↗
Urokinase synthesis and binding by glomerular epithelial cells in culture.
Fibrin deposits are frequently observed in the course of proliferative extracapillary glomerulonephritis and could be related to a defective local fibrinolysis. We studied human glomerular epithelial cells in culture which were found to release mainly a urokinase-type plasminogen activator (u-PA) identified on zymography by its molecular weight (53 kD), its plasminogen activator activity, and its neutralization by specific polyclonal anti-u-PA IgG. Trace amounts of tissue-type plasminogen activator (t-PA) complexed to a plasminogen activator inhibitor type 1 (PAI-1) were identified with specific antibodies. Specific binding sites were found at the surface of glomerular epithelial cells (kD: 2.10(-9) M), partially occupied by secreted u-PA. The spontaneous u-PA activity of the culture medium conditioned by glomerular epithelial cells was very low, suggesting that u-PA was released in its inactive single chain proenzyme form (SC-u-PA). After activation of SC-u-PA by plasmin, u-PA activity of the culture medium was found to increase in a time- and dose-dependent manner when cells were incubated with phorbol myristic acetate (PMA). This effect was inhibited by H7, a protein kinase C inhibitor. Stimulation of u-PA synthesis by PMA was also observed in two different epithelial tubular cell lines. LLC-PK1 and MDCK cells. However, 8 bromo cyclic AMP which increased u-PA release by LLC-PK1 cells was found to inhibit u-PA release by PMA-stimulated glomerular epithelial cells and MDCK cells. By Northern blot analysis we found that PMA induced an increase of u-PA mRNA level in glomerular epithelial cells and that cyclic AMP had an opposite effect.(ABSTRACT TRUNCATED AT 250 WORDS)
Blotting, Northern↗
Characterization of a plasminogen activator and its inhibitor in human mesangial cells.
In the course of some pathological and experimental nephropathies, intraglomerular fibrin deposits develop, possibly as a consequence of inefficient fibrinolysis. In vitro human glomeruli exhibit fibrinolytic activity due to the synthesis of plasminogen activators (PAs) such as, tissue-type PA (t-PA) and urokinase-type PA (u-PA). Immunofluorescence studies have previously shown that t-PA is localized in the capillary tufts and u-PA in the visceral epithelial cells. We have now investigated the fibrinolytic activity of cultured human mesangial cells. Inhibitory activity towards u-PA or t-PA but not plasmin was found in both conditioned medium and cellular extracts. Analysis of the conditioned medium by zymography revealed a single band of PA-activity (Mr: 110 to 120 kDa). Immunoneutralization with anti-t-PA and anti-plasminogen activator inhibitor (PAI-1) IgG but not anti-u-PA or anti-PAI-2 removed this band. Reverse fibrin autography demonstrated the presence of PAI-1 in both cellular extracts and in conditioned medium. Western Blot analysis showed that two bands (50 kD and 120 kD) were recognized by the anti-PAI-1 antibody. By ELISA t-PA and PAI-1 antigens were found to increase progressively with time in the culture medium but not in cellular extracts. Both t-PA and PAI-1, but not u-PA and PAI-2, were also detected by immunofluorescence studies. Thus human glomerular mesangial cells synthesize and secrete t-PA and PAI-1 in vitro. PAI-1 is produced in excess, therefore t-PA is only found in the form of a complex with PAI-1.
Electrophoresis, Polyacrylamide Gel↗
Production of tumor necrosis factor by rat mesangial cells in response to bacterial lipopolysaccharide.
Tumor necrosis factor (TNF) is a cytokine which is produced by mononuclear phagocytes upon activation by bacterial lipopolysaccharide (LPS) and various other stimuli. In immune-mediated glomerulonephritis, infiltration of glomeruli by monocytes-macrophages is associated with production of TNF. The purpose of the present experiments was to determine whether mesangial cells could also contribute to glomerular TNF synthesis. TNF activity has been determined in the culture medium of rat mesangial cells using a L-929 fibroblast lytic assay. This activity was detectable only when the cells were exposed to LPS (0.1 to 10 micrograms/ml) and for periods longer than one hour. The cytotoxic factor was identified as TNF since: (1) the lytic activity was completely inhibited by an anti-mouse TNF polyclonal antibody and was associated with suppression of lipoprotein lipase activity in adipocytes; (2) its molecular weight (110,000 daltons) corresponded to that observed for murine TNF under non-denaturing conditions; and (3) mRNA encoding TNF was expressed by mesangial cells two hours after addition of LPS. To assess the mechanisms whereby TNF production was regulated, the role of prostaglandin E2 (PGE2) was determined. LPS caused a dose-dependent increase of PGE2 synthesis by mesangial cells. Treatment by indomethacin promoted a suppression of PGE2 production together with an increase of TNF synthesis, indicating that PGE2 acted in a negative feedback manner to regulate the production of TNF. Addition of PGE2 (0.1 to 300 nM) or 8-bromo cyclic AMP (0.1 to 100 microM) induced similar dose-dependent reductions of TNF synthesis. Thus the inhibitory effect of PGE2 probably required in part cyclic AMP accumulation.(ABSTRACT TRUNCATED AT 250 WORDS)
8-Bromo Cyclic Adenosine Monophosphate↗
Plasma exchange and immunosuppression for rapidly progressive glomerulonephritis: prognosis and complications.
Rapidly progressive glomerulonephritis frequently leads to death or dialysis. In 21 cases treated by plasma exchange and immunosuppression we observed seven deaths, with 12 others progressing to chronic renal failure within 3 months. Patients who died were older than those who survived (57.5 +/- 17.7 vs 40.5 +/- 16.5 years, mean +/- SD, P = 0.05), but had similar clinical symptoms (hypertension, haematuria, proteinuria, extrarenal signs) and biochemical presentation (initial creatininaemia). They required the same degree of haemodialysis, of plasma exchanges and of bolus methylprednisolone. The causes of death were infection (three cases), cardiac arrhythmia (two cases) and gastrointestinal bleeding (two cases). Among the 14 remaining patients, only two recovered normal renal function. Twelve had chronic renal failure, six of them requiring chronic dialysis or transplantation. Severe renal failure at entry and anuria were more frequently observed in patients whose renal function did not improve during treatment. Plasma exchange and steroid bolus infusions also seemed to have a beneficial effect on renal function.
Adult↗
Tamm-Horsfall protein accumulation in glomeruli during acetazolamide-induced acute renal failure.
A patient with ocular hypertension was treated with acetazolamide. Acute renal failure developed rapidly and renal biopsy showed mild tubular lesions and crystal formation in a tubular lumen. By immunofluorescence studies with a monoclonal antibody, Tamm-Horsfall protein, normally absent from the proximal segments of the nephron, was detected in most glomeruli. This strongly suggests that tubular obstruction plays a major part in some cases of acetazolamide-induced acute renal failure.
Acetazolamide↗