Outcome of patients with systemic lupus erythematosus on chronic dialysis: an observational study of incident patients of the French National Registry 2002-2012.

OBJECTIVES: The objective of this article is to describe the outcome (mortality, kidney transplantation) of patients with systemic lupus erythematosus (SLE) on chronic dialysis. METHODS: The overall and cardiovascular (CV) mortality and access to kidney transplantation were studied in all SLE patients incident on chronic dialysis in France between 2002 and 2012 (REIN registry). They were compared to age- and sex-matched patients with diabetic nephropathy and with autosomal dominant polycystic kidney disease (PKD) on chronic dialysis. RESULTS: A total of 368 SLE patients were included in the national REIN registry between 2002 and 2012. Cumulative incidence of death was 16.9% at five years, with no difference between haemodialysis and peritoneal dialysis. Independent risk factors of death were age, past history of cardiovascular disease (CVD) and chronic respiratory insufficiency. At five years, CV and all-cause mortality in SLE patients were lower than in matched diabetic patients, but three-fold higher than in matched PKD patients. Access to the kidney transplant waiting list and to kidney transplantation was higher in SLE patients than in matched diabetic patients, but lower than in matched PKD patients. CONCLUSIONS: SLE patients on chronic dialysis are a population at high risk of death influenced by CV burden and chronic respiratory failure, but not by the method of dialysis. Their outcome, in terms of mortality and access to kidney transplantation, is intermediate between diabetic patients and patients with PKD.

ANCA-related crescentic glomerulonephritis in systemic sclerosis: revisiting the "normotensive scleroderma renal crisis".

The scleroderma renal crisis is characterized by acute onset of severe hypertension and by rapidly progressive hyperreninemic renal failure. There is, however, a very limited subset of patients with rapidly progressive renal failure who remain normotensive and develop ANCA-positive crescentic glomerulonephritis. We report a case of normotensive acute renal failure secondary to anti-MPO antibody-associated crescentic glomerulonephritis in a patient with diffuse systemic sclerosis. She was referred to our department with normal blood pressure and no extrarenal clinical manifestation ofvasculitis. She presented with rapidly progressive renal failure, microscopic hematuria and minimal proteinuria. P-ANCA were positive by immunofluorescence, with ELISA-confirmed specificity for myeloperoxidase. Renal biopsy revealed typical features of pauciimmune glomerulonephritis with crescent formation and fibrinoid necrosis. The patient was initially treated with i.v. cyclophosphamide only. Because of ongoing deteriorating renal function, additional treatment with intravenous pulses of methylprednisolone followed by oral prednisone was started and allowed renal function improvement. After 9 months, serum creatinine had almost returned to normal level with minimal proteinuria, no hematuria and negative ANCA testing. Control kidney biopsy only revealed scar lesions. The association of ANCA-positive crescentic glomerulonephritis and systemic sclerosis is a very rare event. Treatment with intravenous cyclophosphamide and corticosteroids allows rapid and long-term improvement of renal function. The onset of typical scleroderma renal crisis triggered by high-dose corticosteroids is unlikely but requires a close follow-up of patients with overlapping systemic sclerosis. Diagnosis and treatment are discussed and previously published cases are reviewed.

Effect of anti-LFA1 (CD11a) monoclonal antibodies in acute rejection in human kidney transplantation.

A murine IgG1 monoclonal antibody, 25-3 (Immunotech, France), directed against the alpha chain (CD11a) of the human LFA1 molecule was used in the treatment of 7 histologically documented first acute rejection in first kidney transplantations under cyclosporine. Four patients (group I) received 20 mg/day for 2 days and 10 mg/day for 8 days of 25-3 MoAb. One developed Quincke's edema after the first injection of 25-3 and was immediately withdrawn from the study. In 2 patients, whose serum creatinine continued to increase, 25-3 MoAb was replaced by steroids, followed by ALG after 3 and 4 days of treatment, respectively. In the last case, rejection was reversed by 25-3 MoAb alone. As the clinical response of rejection to 25-3 was poor, another group of 3 patients (group II) was treated with 25-3 at a dose of 40 mg/day for 2 days, 20 mg/day for 2 days, and 10 mg/day for 6 days, but 25-3 was still unsuccessful in reversing acute rejection, and rescue treatment was initiated between days 5 and 8 in all cases. MoAb tolerance was excellent in 3 patients. With the exception of the one case of Quincke's edema, only minor side effects were noted in the last 3 recipients. 25-3 MoAb serum trough levels peaked between 1.5-3.5 micrograms/ml at day 3 in group I and between 2-9 micrograms/L at day 2 in group II. Surprisingly, only one patient, in group I, exhibited a borderline IgG immune response against 25-3. These findings suggest that the 25-3 anti-CD11a MoAb is ineffective in controlling the course of acute rejection in kidney transplantation. However as already reported for another anti-LFA1 or with an anti-CD4 MoAb in mouse, 25-3 would be the first example in humans of a MoAb that does not elicit a strong immune response against its own determinants. This property might have important applications if 25-3 can prevent rejection in a prophylactic protocol or block the immune response against other MoAbs.

Phenotypic and functional characteristics of porcine peritoneal mesothelial cells.

The objective of this study was to establish a technique to isolate porcine mesothelial cells (PMCs) from omental tissue and to compare them to human mesothelial cells (HMCs). The PMCs were dispersed by collagenase digestion and isolated on a Ficoll layer. Their morphologic and ultrastructural features were assessed at confluence by light and electronic microscopy, and they were characterized by immunohistochemistry using specific HMC markers. PMC proliferation was studied in the presence of growth factors platelet-derived growth factor (PDGF), epidermal growth factor (EGF) or transforming growth factors beta1, beta2, or beta3 (TGF). Fibrinolytic PMC activity was detected by zymography for tissue plasminogen activator (tPA) and by reverse zymography for plasminogen activator inhibitor-1 (PAI-1). The recalcification time of cell lysates was used to define PMC procoagulant activity, and gelatinase zymography was used to detect metalloproteinase production. At confluence, PMCs formed typical cobblestone monolayers and exhibited structural features characteristic of HMCs. Weibel Palade bodies were never seen. Specific HMC markers (HBME1, ME1, WT1) cross-reacted with PMCs. As HMCs and PMCs coexpressed cytokeratin and vimentin, and also expressed vinculin and alpha-actin. Addition of PDGF or EGF to the culture medium stimulated PMC proliferation. PMCs constitutively expressed fibrinolytic and procoagulant activity and secreted MMP9 and MMP2. The technique described in this study allows isolation of mesothelial cells from porcine omental tissue. These porcine cells exhibit a mesothelial phenotype and functional properties similar to those of HMCs. Our data warrant an evaluation of mesothelial cells as targets in several therapeutic strategies with porcine models.

Autoimmune haemolytic anaemia after ABO-match, ABDR full match kidney transplantation.

We report a case of autoimmune haemolysis after an ABO- and ABDR-identical kidney transplantation which leads to the discussion of the role of cyclosporin A (CsA). A 46-year-old woman with end-stage renal disease and no history of auto-immune disease received an ABO- and ABDR-identical first renal allograft from a cadaver donor. On day 16, while on a heavy sequential immunosuppressive regimen including anti-thymoglobulins, azathioprine (Aza), prednisolone (Pred) and CsA, she developed an autoimmune haemolysis with positive Coombs test, IgM+C type. Elution of antierythrocyte antibodies did not enable us to identify any specificity. Haemolysis lasted 45 days before haemoglobin slowly increased after CsA had been greatly reduced. Direct antiglobulin tests remained positive 5 months after transplantation and became negative the following month. Eight months after the transplantation the patient had a normal haemoglobin level and normal renal function. Although the typing of autoantibodies was not possible, our data suggest that this patient's haemolysis may be related to the clonal development of donor B lymphocytes in the recipient, favoured by an HLA A-B-DR identity and post-transplant CsA therapy, as exceptionally reported in the literature.

Hyperosmolality suppresses but TGF beta 1 increases MMP9 in human peritoneal mesothelial cells.

Peritoneal mesothelial cells are directly exposed to hyperosmolar dialysates which may enhance extracellular matrix accumulation and hence compromise ultrafiltration. Because these cells are laid on a type IV collagen containing basement membrane, we examined the pattern of type IV collagenases produced by cultured human mesothelial cells and their regulation by hyperosmolality and TGF beta 1. A cell line (HMrSV5) exhibiting major features of normal peritoneal mesothelial cells was derived from a primary culture retrovirally transduced with SV40 large-T antigen. Zymography and Western blot analysis showed that: (i) human peritoneal mesothelial cells produced and excreted MMP2 and MMP9 and their inhibitors TIMP1 and TIMP2; (ii) hyperosmolality drastically reduced the expression of MMP9 irrespective of the osmolyte used in a time- and concentration-dependent manner; (iii) TGF beta 1 unexpectedly increased MMP9 activity and protein in exponentially growing cells and could restore MMP9 activity suppressed by hyperosmolality in confluent cultures. To exclude a specific effect of SV40 large-T antigen on matrix metalloproteinases production and regulation, these results were confirmed in primary cultures derived from visceral peritoneal samples from different donors. Therefore, the hyperosmolality of dialysates may favor an accumulation of type IV collagen and thickening of peritoneal basement membrane, while TGF beta 1 released during infections may induce the degradation of type IV collagen and its replacement by interstitial collagens.

PAI-1 secretion and matrix deposition in human peritoneal mesothelial cell cultures: transcriptional regulation by TGF-beta 1.

BACKGROUND: Plasminogen activator inhibitor-1 (PAI-1), the main inhibitor of plasminogen activators in plasma and in peritoneum, impairs plasmin formation that is essential for the repair processes of the mesothelium damaged by peritoneal dialysis fluids and peritonitis. The fibrogenetic cytokine transforming growth factor-beta (TGF-beta) displays variable effects on extracellular matrix remodeling enzymes and their inhibitors depending on tissues and cell lines. We previously found an unexpected stimulating effect of TGF-beta 1 on matrix metalloproteinase-9 in peritoneal mesothelial cells. In this study, we analyzed the effects of TGF-beta 1 on PAI-1 production and deposition in extracellular matrix. METHODS: We used primary cultured mesothelial cells and a recently established human peritoneal mesothelial cell line (HMrSV5). Cell-associated and secreted plasminogen activators and their inhibitors were detected and characterized by substrate gel zymography. PAI-1 was identified by reverse zymography and by Western blotting, and total PAI-1 was measured by ELISA. Secreted and cell-associated PA activity was measured by its ability to activate plasminogen into plasmin, that is, by the release of paranitroaniline from the plasmin synthetic substrate S-2251. PAI-1 mRNA accumulation was assessed by Northern blot. In vitro nuclear run-on assays were carried out to determine whether TGF-beta 1 had transcriptional effects on PAI-1 expression. Finally, the subcellular distribution of PAI-1 was analyzed by immunofluorescence and by immunogold silver staining. RESULTS: TGF-beta 1 increased PAI-1 antigen in the conditioned media of HMrSV5 cells, in a time- and concentration-dependent manner. This induced a dramatic decrease of free tPA in the cell medium and of membrane-bound uPA, and a parallel increase of high molecular weight PA-PAI complexes. Consequently, secreted and cell-associated plasminogen activator activities were considerably reduced. In primary cultured peritoneal mesothelial cells, TGF-beta 1 also induced PAI-1 secretion and the shift of tPA toward high molecular weight complexes. TGF-beta 1 increased PAI-1 mRNA in a time- and concentration-dependent manner. This effect was at least in part transcriptional since an approximately threefold increase in the rate of PAI-1 gene transcription was observed in nuclei sampled after a four-hour cell exposure to 5 ng/ml TGF-beta 1. Finally, TGF-beta 1 substantially increased the amount of intracellular and matrix-associated PAI-1. CONCLUSIONS: These results suggest that excessive TGF-beta 1 stimulated PAI-1 could prevent appropriate peritoneal healing by impairing the degradation of fibrin and of unorganized matrix components, and by interfering with cell migration.

Expression of hydrophilic surfactant proteins by mesentery cells in rat and man.

Human peritoneal dialysis effluent (PDE) contains a phosphatidylcholine-rich compound similar to the surfactant that lines lung alveoli. This material is secreted by mesothelial cells. Lung surfactant is also characterized by four proteins essential to its function. After having long been considered as lung-specific, some of them have been found in gastric and intestinal epithelial cells. To explore further the similarity between lung and peritoneal surfactants, we investigated whether mesothelial cells also produce surfactant proteins. We used rat transparent mesentery, human visceral peritoneum biopsies and PDE. Surfactant proteins were searched for after one- and two-dimensional SDS/PAGE and Western blotting. On a one-dimensional Western blot, bands at 38 and 66 kDa in rat mesentery, and at 38 and 66 kDa in human peritoneal mesothelial cells (in vivo and in vitro) and PDE, corresponded to monomeric and dimeric forms of lung surfactant protein A (SP-A). On two-dimensional Western blots, the 32 and 38 kDa spots in mesentery and PDE localized at the acidic pH appropriate to the SP-A monomer's isoelectric point. SP-D was also identified at the same 43 kDa molecular mass as in lung. SP-B was not detected in mesenteric samples. Expression of SP mRNA species was also assessed by reverse transcriptase-PCR, which was performed with specific primers of surfactant protein cDNA sequences. With primers of SP-A and SP-D, DNA fragments of the same size were amplified in lung and mesentery, indicating the presence of SP-A and SP-D mRNA species. These fragments were labelled by appropriate probes in a Southern blot. No amplification was obtained for SP-B. These results show that mesentery cells produce SP-A and SP-D, although they are of embryonic origin (mesodermal) and are different from those of the lung and digestive tract (endodermal) that secrete these surfactants.

The stromal proteinase MMP3/stromelysin-1 promotes mammary carcinogenesis.

Matrix metalloproteinases (MMPs) are invariably upregulated in the stromal compartment of epithelial cancers and appear to promote invasion and metastasis. Here we report that phenotypically normal mammary epithelial cells with tetracycline-regulated expression of MMP3/stromelysin-1 (Str1) form epithelial glandular structures in vivo without Str1 but form invasive mesenchymal-like tumors with Str1. Once initiated, the tumors become independent of continued Str1 expression. Str1 also promotes spontaneous premalignant changes and malignant conversion in mammary glands of transgenic mice. These changes are blocked by coexpression of a TIMP1 transgene. The premalignant and malignant lesions have stereotyped genomic changes unlike those seen in other murine mammary cancer models. These data indicate that Str1 influences tumor initiation and alters neoplastic risk.

Human complement factor H deficiency associated with hemolytic uremic syndrome.

This study reports on six cases of deficiency in the human complement regulatory protein Factor H (FH) in the context of an acute renal disease. Five of the cases were observed in children presenting with idiopathic hemolytic uremic syndrome (HUS). Two of the children exhibited a homozygous deficiency characterized by the absence of the 150-kD form of Factor H and the presence, upon immunoblotting, of the 42-kD Factor H-like protein 1 (FHL-1) and other FH-related protein (FHR) bands. Southern blot and PCR analysis of DNA of one patient with homozygous deficiency ruled out the presence of a large deletion of the FH gene as the underlying defect for the deficiency. The other four children presented with heterozygous deficiency and exhibited a normal immunoblotting pattern of proteins of the FH family. Factor H deficiency is the only complement deficiency associated with HUS. These observations suggest a role for FH and/or FH receptors in the pathogenesis of idiopathic HUS.