Low-dose corticosteroid and mycophenolate for primary treatment of minimal change disease.

BACKGROUND: Mycophenolate has been shown to be effective in glomerular disease. However, the role of mycophenolate in the first-line treatment of adult-onset idiopathic minimal change disease (MCD) has not been systematically studied in a randomized fashion. AIM: To evaluate the therapeutic efficacy of enteric-coated mycophenolate sodium combined with low-dose corticosteroid as first-line treatment for MCNS. DESIGN: A prospective, open-label, randomized clinical trial. METHODS: Twenty adult patients with biopsy proven MCD were recruited and randomly assigned to receive either enteric-coated Mycophenolate Sodium (EC-MPS) plus low-dose prednisolone (Group 1: Prednisolone 0.25 mg/kg/day, n = 10) or standard-dose prednisolone (Group 2: Prednisolone 1 mg/kg/day, n = 10). RESULTS: After 24 weeks of therapy, eight patients in Group 1 vs. seven of patients in Group 2 achieved complete remission (P = 0.606). Both groups showed a significant reduction of urine protein excretion (P < 0.05) and increased serum albumin (P < 0.001) vs. baseline levels. However, no significant between-group differences were demonstrated. The relapse rate was also similar in both groups. Both treatment regimens were well tolerated but there were more patient reported adverse effects in the standard-dose prednisolone group. CONCLUSION: EC-MPS plus low-dose prednisolone is non-inferior to standard-dose prednisolone therapy in inducing clinical remission and preventing relapse in adult-onset idiopathic MCD and is associated with better tolerability and less adverse effects. This trial is registered with the ClinicalTrials.gov number NCT01185197.

Downregulation of renal tubular Wnt/ß-catenin signaling by Dickkopf-3 induces tubular cell death in proteinuric nephropathy.

Studies on the role of Wnt/ß-catenin signaling in different forms of kidney disease have yielded discrepant results. Here, we report the biphasic change of renal ß-catenin expression in mice with overload proteinuria in which ß-catenin was upregulated at the early stage (4 weeks after disease induction) but abrogated at the late phase (8 weeks). Acute albuminuria was observed at 1 week after bovine serum albumin injection, followed by partial remission at 4 weeks that coincided with overexpression of renal tubular ß-catenin. Interestingly, a rebound in albuminuria at 8 weeks was accompanied by downregulated tubular ß-catenin expression and heightened tubular apoptosis. In addition, there was an inverse relationship between Dickkopf-3 (Dkk-3) and renal tubular ß-catenin expression at these time points. In vitro, a similar trend in ß-catenin expression was observed in human kidney-2 (HK-2) cells with acute (upregulation) and prolonged (downregulation) exposure to albumin. Induction of a proapoptotic phenotype by albumin was significantly enhanced by silencing ß-catenin in HK-2 cells. Finally, Dkk-3 expression and secretion was increased after prolonged exposure to albumin, leading to the suppression of intracellular ß-catenin signaling pathway. The effect of Dkk-3 on ß-catenin signaling was confirmed by incubation with exogenous Dkk-3 in HK-2 cells. Taken together, these data suggest that downregulation of tubular ß-catenin signaling induced by Dkk-3 has a detrimental role in chronic proteinuria, partially through the increase in apoptosis.

Superior mesenteric artery syndrome complicating dialysis patients with peritoneal failure--report of 3 cases.

We report 3 cases of superior mesenteric artery syndrome in patients previously on maintenance peritoneal dialysis converted to hemodialysis after peritoneal failure. All 3 patients presented with repeated vomiting and severe malnutrition. It is postulated that complications arising from peritoneal dialysis such as peritoneal sclerosis, adhesions and collections after CAPD peritonitis may be important contributing factors for the SMA syndrome in these 3 patients. All of them succumbed within six months of diagnosis. The first 2 patients received gastrointestinal bypass surgery and died post-operatively due to impaired wound healing and nosocomial sepsis. The 3rd patient was treated conservatively with nasoduodenal feeding but succumbed to aspiration pneumonia. It is postulated that complications arising from peritoneal dialysis including peritoneal sclerosis, adhesions and collections after CAPD peritonitis may contribute to the SMA syndrome in these patients. Our experience suggests that SMA syndrome in end-stage renal disease patients is associated with high surgical morbidity and mortality possibly related to their poor pre-morbid condition and pre-existing malnutrition. Aggressive parenteral nutrition should be considered to build up the general status before proceeding to surgical intervention.

Non-viral Smad7 gene delivery and attenuation of postoperative peritoneal adhesion in an experimental model.

BACKGROUND: Postoperative intra-abdominal adhesion is associated with high morbidity and mortality. Smad7, a protein that occupies a strategic position in fibrogenesis, inhibits the transforming growth factor (TGF) beta/Smad signalling pathway. In this study the therapeutic potential of exogenous Smad7 in preventing fibrogenesis in postoperative intra-abdominal adhesion was investigated. METHODS: Intra-abdominal adhesion was induced in a rodent model by peritoneal abrasion. Smad7 was delivered into the peritoneal cavity by a non-viral ultrasound-microbubble-mediated naked gene transfection system. The effect of Smad7 transgene on adhesion formation was studied by measuring changes in TGF-beta, fibrogenic factors, alpha-SMA and Smad2/3 activation in the anterior abdominal wall. RESULTS: Four weeks after surgical abrasion, all rats developed significant peritoneal adhesion with enhanced TGF-beta expression, increased levels of extracellular matrix components and activated myofibroblasts, accompanied by decreased Smad7 expression and increased Smad2/3 activation. In rats treated with the Smad7 transgene, the incidence and severity of peritoneal adhesion were significantly reduced, with biochemical downregulation of fibrogenic factors and inhibition of Smad2/3 activation. Serial quantitation using magnetic resonance imaging revealed a significant reduction in adhesion areas from day 14 onwards. CONCLUSION: Ultrasound-microbubble-mediated gene transfection provides timely targeted gene delivery for the treatment of postoperative peritoneal adhesions.

BRE is an antiapoptotic protein in vivo and overexpressed in human hepatocellular carcinoma.

BRE binds to the cytoplasmic domains of tumor necrosis factor receptor-1 and Fas, and in cell lines can attenuate death receptor-initiated apoptosis by inhibiting t-BID-induced activation of the mitochondrial apoptotic pathway. Overexpression of BRE by transfection can also attenuate intrinsic apoptosis and promote growth of the transfected Lewis lung carcinoma line in mice. There is, however, a complete lack of in vivo data about the protein. Here, we report that by using our BRE-specific monoclonal antibody on the immunohistochemistry of 123 specimens of human hepatocellular carcinoma (HCC), significant differences in BRE expression levels between the paired tumoral and non-tumoral regions (P<2.2e-16) were found. Marked overexpression of BRE was detected in majority of the tumors, whereas most non-tumoral regions expressed the same low level of the protein as in normal livers. To investigate whether BRE overexpression could promote cell survival in vivo, liver-specific transgenic BRE mice were generated and found to be significantly resistant to Fas-mediated lethal hepatic apoptosis. The transgenic model also revealed post-transcriptional regulation of Bre level in the liver, which was not observed in HCC and non-HCC cell lines. Indeed, all cell lines analysed express high levels of BRE. In conclusion, BRE is antiapoptotic in vivo, and may promote tumorigenesis when overexpressed.

Rhodococcus lung abscess complicating kidney transplantation: successful management by combination antibiotic therapy.

In this report, a renal transplant recipient with Rhodococcus lung abscess is described. A high clinical suspicion and appropriate combination antibiotic therapy obviated the need for surgical intervention and was associated with a good clinical outcome. The optimal regimen of combination antibiotic therapy is discussed.

Angiotensin converting enzyme inhibitor but not angiotensin receptor blockade or statin ameliorates murine adriamycin nephropathy.

Angiotensin-converting enzyme inhibitors, angiotensin II receptor blockers, and statins have renoprotective effects. We studied the cellular mechanisms for this effect in adriamycin-treated mice receiving captopril, losartan, simvastatin, or their combinations. The mice developed albuminuria, renal insufficiency, and parenchymal inflammation/fibrosis accompanied by overexpression of intrarenal converting enzyme and angiotensin II. Only captopril consistently improved these abnormalities and reduced the cortical expression of several proinflammatory and profibrotic factors including transforming growth factor-beta (TGF-beta). These effects were independent of blood pressure, accompanied by increased urine N-acetylseryl-aspartyl-lysyl-proline (Ac-SDKP) levels, and the restoration of renal angiotensin-converting enzyme and angiotensin II to baseline levels. Losartan or simvastatin alone or together had no effect, and their addition to captopril did not enhance protection. In vitro, angiotensin II stimulated TGF-beta in renal tubular cells via mitogen-activated protein kinase (MAPK) signaling. Captopril or Ac-SDKP suppressed angiotensin II-induced MAPK activation and TGF-beta secretion. Angiotensin-converting enzyme inhibition confers renoprotection in adriamycin nephropathy by reducing intrarenal angiotensin II and augmenting Ac-SDKP expression that together attenuate MAPK signaling and its downstream proinflammatory and fibrogenic properties. The addition of receptor blocker and/or statin failed to potentiate such effects.

Ultrasound-contrast agent mediated naked gene delivery in the peritoneal cavity of adult rat.

Gene transfer into the peritoneal cavity by nonviral methods may provide an effective therapeutic approach for peritoneal diseases. Herein, we investigated the feasibility and the effectiveness of ultrasound-microbubble-mediated delivery of naked plasmid DNA into the peritoneal cavity in rats. Following the intraperitoneal or the intravenous administration of a mixture of plasmid DNA (100 microg) and ultrasound contrast agent microbubbles, an ultrasound transducer was applied on the abdominal wall. The reporter pTRE plasmid encoding Smad7 was used to evaluate transfection efficiency. Smad7 expression was induced by doxycycline in drinking water. We detected less than 10% apoptotic cells and no inflammatory reaction in peritoneal tissues following the ultrasound-microbubble-mediated transfection. More importantly, the insonation significantly improved the transfection efficiency in peritoneal tissues. The transfection efficiency by intraperitoneal delivery route was higher than the intravenous route. The reporter gene, pTRE-Smad7, was readily detected in the parietal peritoneum, mesentery, greater omentum and adipose tissue. The peak of transgene expression occurred 2 days after transfection and the transgene expression diminished in a time-dependent manner thereafter. Overall, the effectiveness and simplicity of the ultrasound-microbubble-mediated system may provide a promising nonviral means for improving gene delivery for treating peritoneal diseases in vivo.

Membranous nephropathy: when and how to treat.

The treatment of idiopathic membranous nephropathy is heavily debated because of wide variation in outcome. A rational treatment strategy is needed to appropriately administer conservative treatment to the low-risk group but immunosuppressive therapy to those with medium or high risk of renal deterioration. Currently, combinations of steroids with alkylating agents are best studied. Newer forms of immunosuppressive treatment are currently under study.

Interaction between proximal tubular epithelial cells and infiltrating monocytes/T cells in the proteinuric state.

We hypothesize an interaction between T cells/monocytes and the tubules in the development of tubulointerstitial injury in chronic proteinuric nephropathy. We established in vitro co-culture systems of proximal tubular epithelial cells (PTEC) and T cells/monocytes to study the contribution of soluble factors and cell-to-cell contact in the development of tubulointerstitial injury. The release of monocyte chemoattractant protein-1 (MCP1 or CCL2), Regulated upon Activation, normal T cell Expressed and Secreted (RANTES or CCL5), soluble intracellular adhesion molecules-1 (sICAM-1), or interleukin-6 (IL-6) was increased in PTEC following apical exposure to human serum albumin (HSA). The release of CCL2, CCL5, or sICAM-1 from PTEC was enhanced by contact of monocytes/T cells on the basolateral surface. Tumor necrosis factor-alpha (TNF-alpha) and IL-1beta are important soluble factors as suggested by the blocking effect of antibodies (Abs) against TNF-alpha or IL-1beta but not against other cytokines. The percentage of CD4+ T cells expressing both chemokine receptors, CCR2 and CCR5, was increased after culturing with supernatant from the apical or basolateral surface of PTEC following apical exposure to HSA. However, only CCR2 was upregulated in CD8+ T cells, whereas CCR5 expression was increased in monocytes. The chemotaxis of CD4+ or CD8+ T cells to supernatant from PTEC upon apical exposure to HSA was reduced with neutralizing Abs against CCL5 and/or CCL2, whereas the chemotaxis of monocytes was only reduced by anti-CCL5 but not by anti-CCL2. In summary, chemokines released by HSA-activated PTEC are amplified by monocytes/T cells. Mediators released by HSA-activated PTEC can differentially modulate the expression of chemokine receptors in monocytes/T cells and hence, alter their chemotaxis towards activated PTEC. These interactions are pivotal in the development of tubulointerstitial injury.

An animal study of the effects on p16 and PCNA expression of repeated treatment with high-energy laser and intense pulsed light exposure.

BACKGROUND AND OBJECTIVE: Non-ablative skin rejuvenation treatments that involve the use of laser/light sources together with cooling devices have gained much popularity in recent years due to the lack of down time that is associated with them. One important but neglected issue is long-term safety. Does the repeated use of non-ablative skin rejuvenation lead to photoaging? Are we creating another sun-bed phenomenon? Recently, we performed an in vitro study to examine the effect of sub-lethal QS 755 nm lasers on the expression of p16INK4a on melanoma cell lines, and found that sub-lethal laser damage could increase DNA damage, which led to an increase in p16 expression. Our objective was to assess the cutaneous effect of repeated exposure to high-energy lasers and intense pulsed light sources on male Institute of Cancer Research (ICR) mice. STUDY DESIGN/MATERIALS AND METHODS: Twenty-eight male ICR mice were divided into four groups. Other than the control group, all groups received either laser (585 nm pulsed dye laser or 1,320 nm Nd:YAG laser) or intense pulsed light (IPL) treatment. All four groups were anesthetized with a mixture of Hypnorm/Dormicum before treatment. The animals were irradiated twice a week for 6 months. Signs of toxicity such as mortality and weight loss were checked once a week. Skin tumor formation was evidenced by lesions of greater than 1 mm in diameter that persisted for 2 weeks. At the end of the 6 months, the expression of proliferating cell nuclear antigen (PCNA) and p16 in the mouse skin was determined by immunohistochemical staining and immunoblotting using specific monoclonal antibodies for mouse PCNA and p16. The results were expressed as mean +/- standard error of the mean (SEM). Statistical difference was assessed by multiple ANOVA. A P-value of <0.05 was considered to be significant. RESULTS: At the end of the 6 months, none of the animals had developed any signs of toxicity such as mortality or weight lost. There was no evidence of tumor formation. There were significant elevations of p16 and PCNA in all treated groups as compared to the control group (ANOVA P < 0.05). This particularly applied to the group that was treated with the 1,320 nm Nd:YAG laser. CONCLUSION: The repeated use of high-energy laser and intense pulsed light source did not cause any toxicity in mice. The changes in p16 and PCNA imply that further studies are necessary to consider the implications of repeated exposure to longer wavelength radiation in human skin.

Recurrent glomerulonephritis after kidney transplantation.

Thirty to fifty percent of kidney transplant recipients have glomerular diseases as the underlying causes of end-stage renal failure. While recurrence of glomerulonephritis is an important cause of late renal allograft failure, the risk factors for recurrence are largely unknown or imprecise and prediction remains difficult. Recurrent disease usually presents with similar manifestations as the native disease. With regard to treatment of recurrent glomerular disease in the renal allograft, plasma exchange may be effective in reducing proteinuria in patients with early recurrence of focal and segmental glomerulosclerosis, but immunosuppressive therapy is generally ineffective in the prevention or treatment of recurrent disease. General supportive measures including strict blood pressure control and inhibition or blockade of the rennin-angiotensin pathway are helpful in retarding the rate of deterioration in renal allograft function. Despite the risk of recurrence, kidney transplantation following primary glomerulonephritides enjoys graft and patient survival rates comparable to other causes of end-stage renal failure. With a few exceptions, living related renal transplantation is not contraindicated in view of the favorable outcome and the donor shortage. This review discusses commonly encountered recurrent glomerulonephritides, with special emphasis on the influence of post-transplant prophylactic immunosuppression and emerging treatments.

Pathogenic IgA in IgA nephropathy: still the blind men and the elephant?

IgA nephropathy (IgAN), the most common glomerulonephritis worldwide, remains an important cause of end-stage renal failure. The pathology is characterized by mesangial deposition of IgA. The disease is now recognized as arising from anomalies of the IgA molecule and the kidneys are innocent bystanders. The immunochemical nature of the IgA molecule and its mesangial uptake command a pivotal role in the pathogenesis of IgAN.

The importance of residual renal function in dialysis patients.

Preserving residual renal function has always been the primary clinical goal for every nephrologist managing patients with chronic kidney disease. There is no reason why this important goal should not extend to patients with stage 5 chronic kidney disease receiving dialysis. Indeed, there is now clear evidence that preserving residual renal function remains important after the commencement of dialysis. Residual renal function contributes significantly to the overall health and well-being of dialysis patients. It not only provides small solute clearance but also plays an important role in maintaining fluid balance, phosphorus control, and removal of middle molecular uremic toxins, and shows strong inverse relationships with valvular calcification and cardiac hypertrophy in dialysis patients. Decline of residual renal function also contributes significantly to anemia, inflammation, and malnutrition in patients on dialysis. More importantly, the loss of residual renal function, especially in patients on peritoneal dialysis, is a powerful predictor of mortality. In addition, there is increasing evidence that residual renal and peritoneal dialysis clearance cannot be assumed to be equivalent qualitatively, thus indicating the need to preserve residual renal function in patients on dialysis. In this article, we will review evidence that residual renal function is important in dialysis patients (especially peritoneal dialysis) and outline potential strategies that may better preserve residual renal function in dialysis patients.

Leptin induces TGF-beta synthesis through functional leptin receptor expressed by human peritoneal mesothelial cell.

Marked increase in leptin concentration in spent peritoneal dialysate has been reported following continuous ambulatory peritoneal dialysis treatment. The present study was designed to determine whether functional leptin receptor is expressed by human peritoneal mesothelial cells and if so, the possible implication in dialysis. Expression of leptin receptors in cultured mesothelial cells and omental tissue was examined. The effect of leptin on the production of transforming growth factor-beta (TGF-beta) by mesothelial cells in the presence or absence of high glucose was determined using in vitro culture model of human peritoneal mesothelial cells and adipocytes. The signaling mechanism involved in leptin-induced TGF-beta synthesis by mesothelial cells was studied. Both mRNA and protein of the full-length leptin receptor are constitutively expressed in mesothelial cells. The leptin receptor expression in mesothelial cells was upregulated by glucose but not leptin. In adipocytes, glucose increased the mRNA expression and synthesis of leptin. The Janus kinase-signal transducers and activation (JAK-STAT) signal transduction pathway in mesothelial cells was activated by either exogenous or adipocytes-derived leptin. Exogenous leptin induced the release of TGF-beta by mesothelial cells. The TGF-beta synthesis induced by leptin was amplified by glucose through increased leptin receptor expression. Our novel findings reveal that functional leptin receptor is present on human peritoneal mesothelial cells. The leptin-induced TGF-beta synthesis in mesothelial cells is associated with the expression of leptin receptor and the activation of the JAK-STAT signal transduction pathway.

Mycophenolate mofetil in the treatment of steroid-resistant primary focal segmental glomerulosclerosis.

We report our experience in using mycophenolate mofetil (MMF) for the treatment of steroid-resistant focal segmental glomerulosclerosis (FSGS) in two patients. Patient 1, who was treated on disease presentation, responded well with sustained complete remission. Patient 2, who had unsuccessful steroid treatment 4 yrs before and was re-treated with MMF, showed transient retardation in renal disease progression but eventually progressed to end-stage renal failure. Our observation illustrates that MMF could be useful in treating steroid-resistant FSGS if administered at an early phase of the disease, well before histologic damage becomes irreversible. Its efficacy requires validation in randomized, controlled trials. The current armamentaria for the treatment of this condition are also discussed.