β1-Integrin blockade prevents podocyte injury in experimental models of minimal change disease

INTRODUCTION

Activation of the focal adhesion kinase (FAK) in podocytes is involved in the pathogenesis of minimal change disease (MCD), but the pathway leading to its activation in this disease is unknown. Here, we tested whether podocyte β1 integrin is the upstream modulator of FAK activation and podocyte injury in experimental models of MCD-like injury.

METHODS

We used lipopolysaccharide (LPS) and MCD sera to induce MCD-like changes in vivo and in cultured human podocytes, respectively. We performed functional studies using specific β1 integrin inhibitors in vivo and in vitro, and integrated histological analysis, western blotting, and immunofluorescence to assess for morphological and molecular changes in podocytes. By ELISA, we measured serum LPS levels in 35 children with MCD or presumed MCD (idiopathic nephrotic syndrome [INS]) and in 18 healthy controls.

RESULTS

LPS-injected mice showed morphological (foot process effacement, and normal appearing glomeruli on light microscopy) and molecular features (synaptopodin loss, nephrin mislocalization, FAK phosphorylation) characteristic of human MCD. Administration of a β1 integrin inhibitor to mice abrogated FAK phosphorylation, and ameliorated proteinuria and podocyte injury following LPS. Children with MCD/INS in relapse had higher serum LPS levels than controls. In cultured human podocytes, β1 integrin blockade prevented cytoskeletal rearrangements following exposure to MCD sera in relapse.

CONCLUSIONS

Podocyte β1 integrin activation is an upstream mediator of FAK phosphorylation and podocyte injury in models of MCD-like injury.

Efficacy of Rituximab for Minimal Change Disease and Focal Segmental Glomerulosclerosis with Frequently Relapsing or Steroid-Dependent Nephrotic Syndrome in Adults: A Chinese Multicenter Retrospective Study

INTRODUCTION

Rituximab has been proven effective and safe in pediatric patients with frequently relapsing or steroid-dependent nephrotic syndrome (FR/SDNS). We aimed to analyze the efficacy and safety of rituximab in adult FR/SDNS patients with minimal change disease (MCD) and focal segmental glomerulosclerosis (FSGS).

METHODS

A retrospective cohort study at three nephrology centers in China included adult FR/SDNS patients with biopsy-proven MCD or FSGS. Primary outcomes were relapse frequency and first relapse-free survival time. Adverse events were well recorded, and logistic regression analyses were used to investigate the risk factors of relapse.

RESULTS

Eighty-one patients (age, 25.0 years; interquartile range, 20.0-40.5; 67% males; 82.7% MCD) received an average rituximab dose of 1,393.8 ± 618.7 mg/2 years during the 2-year follow-up period. The relapse frequency, calculated as the ratio of relapse times to follow-up years, significantly decreased after rituximab treatment (0.04 [0.00, 0.08] vs. 1.71 [1.00, 2.45], p < 0.001). The first relapse-free survival time was 16.7 ± 8.0 months. Fifty-seven patients (70.4%) achieved cessation of corticosteroids and immunosuppressants within 3 months after the first rituximab infusion. Adverse events were mostly mild, and no severe treatment-related adverse events were observed. Low serum albumin level before rituximab and high CD56+CD16+ natural killer cell count after rituximab were independent risk factors of relapse within 2 years after rituximab treatment.

CONCLUSION

Rituximab was proven an effective and safe treatment option for adult FR/SDNS patients with MCD or FSGS in maintaining disease remission and minimizing corticosteroid exposure.

Histological transition from minimal change disease to THSD7A-associated membranous nephropathy in a patient receiving long-term steroid treatment: A case report

RATIONALE

A predominant Th2 immune response is suggested in the pathogenesis of both minimal change disease (MCD) and membranous nephropathy (MN); however, consecutive development of the 2 diseases in a patient is extremely rare.

PATIENT CONCERN

A Japanese man, who developed nephrotic syndrome in his 50s and was diagnosed with MCD by renal biopsy, experienced a relapse of proteinuria approximately 3 years later during long-term steroid treatment. Since the proteinuria was resistant to increase in steroid dosage, repeat renal biopsy was performed, which revealed a small amount of glomerular subepithelial immune deposits containing immunoglobulin (Ig)G (dominantly IgG4). Immunostaining for thrombospondin-type-1-domain-containing-7A (THSD7A) was positive on the glomerular capillary walls, whereas that for other causative antigens of MN, such as phospholipase A2 receptor or neural epidermal growth factor-like 1 protein, was negative. Detailed examination found no associated condition, including malignancies and allergic diseases.

DIAGNOSIS

The diagnosis of THSD7A-associated idiopathic MN was made.

INTERVENTIONS AND OUTCOMES

He received further increased dose of steroids. Thereafter he maintained clinical improvement because his urinary protein level was decreased.

LESSONS

The present case suggested that histological transition from MCD to MN is possible and repeat biopsy would be crucial for accurate diagnosis.

Contribution of IL-33/ILC2-mediated Th2 cytokines during the progression of minimal change disease

Minimal change disease (MCD) is a common type of nephrotic syndrome with high recurrence rate. This study aims to explore the impacts of interleukin (IL)-33 in MCD and to discuss its potential mechanism. In adriamycin (ADM) and puromycin aminonucleoside (PAN)-induced MCD rat model, IL-33 was used for treatment. H&E staining was applied for detecting histological changes. Critical proteins were examined by western blot. Corresponding commercial kits tested oxidative stress- and inflammation-related factors. Cell apoptosis was measured by TUNEL assay. ADM-induced podocyte injury model was establish to mimic MCD in vitro. Cell proliferation and apoptosis were detected by CCK-8 and TUNEL assays. Finally, podocyte was stimulated by innate lymphoid type-2 cells-secreted Th2 cytokines (ILC2s: IL-13 and IL-5 respectively), with or without incubation with M1 macrophage medium to further explore the immune-regulation of ILC2s behind the inflammatory environment of MCD. It was found that PAN-induced kidney jury, inflammation, oxidative stress and apoptosis were severer than ADM, and IL-33 treatment significantly alleviated the above injuries in PAN and ADM-induced MCD rat model. Moreover, IL-33 reversed the reduced viability and increased oxidative stress and apoptosis in ADM-induced podocyte injury model. Further, the capacities of IL-13 alone in inducing M1/M2 macrophage polarization, apoptosis, inflammation, kidney injury and reducing cell viability are stronger than IL-5. However, IL-13 reversed reduced cell viability and stimulated apoptosis, inflammation, kidney injury mediated by co-incubation with M1-conditioned medium. Collectively, IL-33 might protect against immunologic injury in MCD via mediating ILC2s-secreted IL-13.

Interventions for minimal change disease in adults with nephrotic syndrome

BACKGROUND

Steroids have been used widely since the early 1970s for the treatment of adult-onset minimal change disease (MCD). Recently, newer agents have been used in adult MCD aiming to reduce the risk of adverse effects. The response rates to immunosuppressive agents in adult MCD are more variable than in children. The optimal agent, dose, and duration of treatment for the first episode of nephrotic syndrome, or for disease relapse(s) have not been determined. This is an update of a review first published in 2008.

OBJECTIVES

We aimed to 1) evaluate the benefits and harms of different agents, including both immunosuppressive and non-immunosuppressive agents, in adults with MCD causing the nephrotic syndrome; and 2) evaluate the efficacy of interventions on 'time-to-remission' of nephrotic syndrome, in adults with MCD causing the nephrotic syndrome.

SEARCH METHODS

We searched the Cochrane Kidney and Transplant Register of Studies up to 21 July 2021 through contact with the Information Specialist using search terms relevant to this review. Studies in the Register are identified through searches of CENTRAL, MEDLINE, and EMBASE, conference proceedings, the International Clinical Trials Register (ICTRP) Search Portal and ClinicalTrials.gov.

SELECTION CRITERIA

Randomised controlled trials (RCTs) and quasi-RCTs of any intervention for MCD with nephrotic syndrome in adults over 18 years were included. Studies comparing different types, routes, frequencies, and duration of immunosuppressive agents and non-immunosuppressive agents were assessed.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed study quality and extracted data. Statistical analyses were performed using the random-effects model and results were expressed as a risk ratio (RR) for dichotomous outcomes, or mean difference (MD) for continuous data with 95% confidence intervals (CI). Confidence in the evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach.

MAIN RESULTS

Fifteen RCTs (769 randomised participants) were identified; four studies evaluated different prednisolone regimens, eight studies evaluated the calcineurin inhibitors (CNIs) (tacrolimus or cyclosporin), two studies evaluated enteric-coated mycophenolate sodium (EC-MPS) and one study evaluated levamisole. In all but two studies of non-corticosteroid agents, reduced-dose prednisolone was given with the treatment agent and the comparator was high-dose prednisolone. In the risk of bias assessment, 11 and seven studies were at low risk of bias for sequence generation and allocation concealment, respectively. No studies were at low risk of performance bias and eight studies were at low risk of detection bias. Thirteen, 10 and six studies were at low risk of attrition bias, reporting bias and other bias, respectively. Compared with no specific treatment, it is uncertain whether prednisolone increases the number with complete remission (1 study, 28 participants: RR 1.44, 95% CI 0.95 to 2.19), complete or partial remission (1 study, 28 participants: RR 1.38, 95% CI 0.98 to 1.95), subsequent relapse (1 study, 28 participants: RR 0.75, 95% CI 0.48 to 1.17), or reduces the adverse effects because the certainty of the evidence is very low. Compared with oral prednisolone alone, it is uncertain whether intravenous methylprednisolone and prednisolone increase the number with complete remission (2 studies, 35 participants: RR 1.76, 95% CI 0.17 to 18.32; I² = 90%), relapse (two studies, 19 participants. RR 1.18, 95% CI 0.65 to 2.15; I² = 0%) or adverse events because the certainty of the evidence is very low. Compared with prednisolone alone, CNIs with reduced-dose prednisolone or without prednisolone probably make little or no difference to the number achieving complete remission (8 studies; 492 participants: RR 0.99, 95% CI 0.93 to 1.05; I² = 0%), complete or partial remission (4 studies, 269 participants: RR 1.01, 95% CI 0.96 to 1.05; I² = 0%), or relapse (7 studies; 422 participants: RR 0.73, 95% CI 0.51 to 1.03; I² = 0%) (moderate certainty evidence), may reduce the risk of obesity or Cushing's Syndrome (5 studies; 388 participants: RR 0.11, 95% CI 0.02 to 0.59; I² = 45%) and the risk of acne (4 studies; 270 participants: RR 0.15, 95% CI 0.03 to 0.67; I² = 0%) (low certainty evidence); and had uncertain effects on diabetes or hyperglycaemia, hypertension, and acute kidney injury (AKI) (low certainty evidence). Compared with prednisolone alone, EC-MPS with reduced-dose prednisolone probably make little or no difference to the number undergoing complete remission at 4 weeks (1 study, 114 participants: RR 1.12, 95% CI 0.84 to 1.50), and at 24 weeks probably make little or no difference to the number undergoing complete remission (2 studies, 134 participants: RR 1.12, 95% CI 0.84 to 1.38; I² = 0%) (moderate certainty evidence), complete or partial remission (2 studies 134 participants: RR 0.92, 95% CI 0.75 to 1.12; I² = 0%), relapse (2 studies, 83 participants: RR 0.50, 95% CI 0.07 to 3.74; I² = 56%) (low certainty evidence); or to the adverse events of new-onset glucose intolerance, death, or AKI (low certainty evidence). One study (24 participants) compared levamisole and prednisolone with prednisolone in patients with relapsing disease. The authors identified no differences in mean relapse rate or adverse effects but no standard deviations were provided.

AUTHORS' CONCLUSIONS

This updated review has identified evidence for the efficacy and adverse effects of CNIs and EC-MPS with or without reduced-dose prednisolone compared with prednisolone alone for the induction of remission in adults with MCD and nephrotic syndrome with some reductions in steroid-associated adverse events. RCT data on the efficacy and adverse effects of rituximab in adults with MCD are awaited. Further, adequately powered RCTs are required to determine the relative efficacies of CNIs and EC-MPS and to evaluate these medications in patients with relapsing or steroid-resistant disease.

Minimal change disease following the Moderna COVID-19 vaccine: first case report

BACKGROUND

There have been cases of minimal change disease (MCD) reported following previous vaccines. During the COVID-19 era, only 3 cases of new-onset MCD and a case of MCD relapse were reported following the Pfizer-BioNTech COVID-19 vaccine. We herein report the first case of MCD after receiving the Moderna COVID-19 vaccine.

CASE PRESENTATION

A 43-year-old man presented to hospital 3 weeks after receiving the first dose of the Moderna vaccine, with both bilateral lower extremities and scrotal edema. He initially developed a sudden-onset bilateral lower extremities swelling on day 7 post-vaccine. He, then, developed dyspnea and scrotal swelling over a time span of 2 weeks. On physical examination, his blood pressure was 150/92 mmHg. There was a decreased air entry at lung bases, bilateral lower extremities and scrotal edema. Labs revealed hypoalbuminemia, hyperlipidemia and 15 g of proteinuria. His immunologic and serologic work up was negative. Renal biopsy showed concomitant MCD and IgA nephropathy. Patient was treated with oral steroids and had a good response; his edema resolved, serum albumin improved, and proteinuria decreased to 1 g within 2 weeks of treatment.

CONCLUSIONS

To the best of our knowledge, MCD has not been previously reported after receiving the Moderna COVID-19 vaccine. It remains unclear whether the COVID-19 mRNA vaccines are associated with the development of MCD, or it coincided with the mass vaccination. Further studies are needed to determine the incidence of MCD post COVID-19 vaccines and the underlying pathophysiology of glomerular injury post vaccination.

Efficacy of a mitochondrion-targeting agent for reducing the level of urinary protein in rats with puromycin aminonucleoside-induced minimal-change nephrotic syndrome

Background

Oxidative stress is a major factor responsible for minimal-change nephrotic syndrome (MCNS), which occurs most commonly in children. However, the influence of oxidative stress localized to mitochondria remains unclear. We examined the effect of a mitochondrion-targeting antioxidant, MitoTEMPO, in rats with puromycin aminonucleoside (PAN)-induced MCNS to clarify the degree to which mitochondrial oxidative stress affects MCNS.

Materials and methods

Thirty Wistar rats were divided into three groups: normal saline group (n = 7), PAN group (n = 12), and PAN + MitoTEMPO group (n = 11). Rats in the PAN and PAN + MitoTEMPO groups received PAN on day 1, and those in the PAN + MitoTEMPO group received MitoTEMPO on days 0 to 9. Whole-day urine samples were collected on days 3 and 9, and samples of glomeruli and blood were taken for measurement of lipid peroxidation products. We also estimated the mitochondrial damage score in podocytes in all 3 groups using electron microscopy.

Results

Urinary protein excretion on day 9 and the levels of lipid peroxidation products in urine, glomeruli, and blood were significantly lower in the PAN　+　MitoTEMPO group than in the PAN group (p = 0.0019, p = 0.011, p = 0.039, p = 0.030). The mitochondrial damage score in podocytes was significantly lower in the PAN　+　MitoTEMPO group than in the PAN group (p <0.0001).

Conclusions

This mitochondrion-targeting agent was shown to reduce oxidative stress and mitochondrial damage in a MCNS model. A radical scavenger targeting mitochondria could be a promising drug for treatment of MCNS.

[Minimal change disease during lithium therapy: case report]

Lithium is a largely used and effective therapy in the treatment of bipolar disorder. Its toxic effects on kidneys are mostly diabetes insipidus, hyperchloremic metabolic acidosis and tubulointerstitial nephritis. Also, a correlation between lithium and minimal change disease has sometimes been described. We report here the case of a patient with severe bipolar disorder on lithium therapy who, without any pre-existing nephropathy, developed nephrotic syndrome and AKI with histopathologic findings pointing to minimal change disease. The patient was treated with symptomatic therapy; the discontinuation of lithium therapy resulted in the remission of AKI and of the nephrotic syndrome, thus suggesting a close relationship between lithium and minimal change disease.

Minimal change disease related to rifampicin presenting with acute renal failure during treatment for latent tuberculosis infection: A case report

RATIONALE

The standard drugs used to treat tuberculosis are rifampicin and isoniazid. These agents are usually safe and inexpensive for short-term use in treatment of latent tuberculosis infection, but sometimes cause adverse renal effects, including minimal change disease (MCD).

PATIENT CONCERNS

Here, we report a 51-year-old woman with latent tuberculosis infection who developed nephrotic syndrome during treatment with rifampicin and isoniazid for 25 days.

DIAGNOSES

Renal biopsy findings were compatible with MCD, and she had no relevant medical history and was not taking other medications. A diagnosis of anti-tuberculosis drug- induced MCD was made. This is the first report of acute renal failure due to rifampicin and/or isoniazid-induced MCD.

INTERVENTIONS

After cessation of rifampicin and isoniazid, however, acute renal failure progressed and she was treated with temporary dialysis and oral prednisolone.

OUTCOMES

The patient achieved complete remission after cessation of rifampicin and isoniazid with steroid therapy.

LESSONS

This case demonstrates that rifampicin and/or isoniazid can cause nephrotic syndrome with acute renal failure during the first months of continuous latent tuberculosis therapy. Therefore, renal function and proteinuria should be monitored carefully in all patients taking rifampicin and isoniazid, especially during the first few months of therapy.

miR-499 Ameliorates Podocyte Injury by Targeting Calcineurin in Minimal Change Disease

BACKGROUND

Podocyte injury is a hallmark of minimal change disease (MCD). Calcineurin inhibitors have been widely used in the current treatment of MCD, and miR-499 may target calcineurin. We aimed to study the function of miR-499 in MCD and test whether miR-499 delivery can improve MCD.

METHODS

An MCD mouse model was generated using puromycin aminonucleoside (PAN). MiR-499 was delivered using lentiviruses. Biochemical indicators including serum albumin, triglyceride, cholesterol, and 24-h urine protein were determined. Targets of miR-499 were confirmed using reporter gene activity assays. The ultrastructure of podocytes was analyzed using transmission electron microscopy.

RESULTS

MiR-499 significantly improved MCD-related symptoms and signs. Foot-process effacement was caused by PAN and partially reversed by miR-499. We identified that both CnAα and CnAβ were targets of miR-499, and were overexpressed in the presence of PAN. However, miR-499 reduced the expression of CnAα and CnAβ, leading to a decreased activity of calcineurin signaling in mouse podocytes in vitro and in vivo. In addition, miR-499 recovered PAN-induced reduction of cell viability.

CONCLUSIONS

MiR-499 ameliorated podocyte injury by targeting CnAα and CnAβ in a PAN-induced MCD mouse model. Delivery of miR-499 can be a novel strategy for MCD treatment.

Rifampicin-induced minimal change disease is improved after cessation of rifampicin without steroid therapy

There are several reports to demonstrate that rifampicin, a major anti-tuberculosis agent, is associated with some adverse renal effects, with a few cases of rifampicin-induced minimal change disease (MCD). In the present case, a 68-year-old female presented with nausea, vomiting, foamy urine, general weakness and edema. She had been taking rifampicin for 4 weeks due to pleural tuberculosis. The patient had no proteinuria before the anti-tuberculosis agents were started, but urine tests upon admission showed heavy proteinuria with a 24-h urinary protein of 9.2 g/day, and serum creatinine, albumin, and total cholesterol levels were 1.36 mg/dL, 2.40 g/dL, and 283 mg/dL, respectively. MCD was diagnosed, and the patient achieved complete remission after cessation of rifampicin without undergoing steroid therapy.

Enhanced Steroid Therapy in Adult Minimal Change Nephrotic Syndrome: A Systematic Review and Meta-analysis

The best regimen for adult minimal change nephrotic syndrome (MCNS) is still unknown. Due to an excessive number of adverse events caused by oral steroid monotherapy, enhanced steroid therapy (low dose of prednisolone with a short course of methylprednisolone or with another immunosuppressant) has been studied extensively for years. In this study, the PubMed, Embase, EBSCO and Cochrane Library databases were searched for clinical trials which compared enhanced steroid therapy with oral steroid monotherapy in adult MCNS and a meta-analysis was performed. Seven studies involving 357 patients were included. We found that patients treated with enhanced steroid therapy responded more quickly to complete remission (CR) [mean difference = -9.52, 95% confidence interval (CI): -12.66--6.39, p<0.00001] and showed fewer adverse events [risk radio (RR) = 0.72, 95% CI: 0.54-0.97, p=0.03] than patients receiving oral steroid monotherapy. The CR rate (RR= 0.96, 95% CI: 0.83-1.10, p=0.53) and relapse rate (RR=0.87, 95% CI: 0.57-1.34, p=0.53) were similar in both groups.

Minimal change nephrotic syndrome associated with gefitinib and a successful switch to erlotinib

Minimal change nephrotic syndrome (MCNS) is a common form of nephrotic syndrome (NS). We herein present the case of a 57-year-old woman with advanced lung adenocarcinoma treated with the tyrosine kinase inhibitor (TKI) gefitinib who developed NS. A renal biopsy revealed minor glomerular abnormalities, and the patient's symptoms improved exclusively with the discontinuation of gefitinib. Therefore, we diagnosed her with MCNS associated with gefitinib treatment. A few months later, however, she developed recurrent lung tumors. Following the challenging initiation of the TKI erlotinib, she achieved remission without proteinuria. We thus conclude that erlotinib is a potential treatment option in patients with NS associated with gefitinib therapy.

Kidney diseases associated with anti-vascular endothelial growth factor (VEGF): an 8-year observational study at a single center

Expanded clinical experience with patients taking antiangiogenic compounds has come with increasing recognition of the renal adverse effects. Because renal histology is rarely sought in those patients, the renal consequences are underestimated. Antiangiogenic-treated-cancer patients, who had a renal biopsy for renal adverse effects from 2006 to 2013, were included in the current study. Clinical features and renal histologic findings were reviewed. Our cohort was 100 patients (58 women) with biopsy-proven kidney disease using anti-vascular endothelial growth factor (VEGF) therapy with a mean age of 59.8 years (range, 20-85 yr). Patients were referred for proteinuria, hypertension, and/or renal insufficiency. Kidney biopsy was performed 6.87 ± 7.18 months after the beginning of treatment. Seventy-three patients experienced renal thrombotic microangiopathy (TMA) and 27 patients had variable glomerulopathies, mainly minimal change disease and/or collapsing-like focal segmental glomerulosclerosis (MCN/cFSGS). MCN/cFSGS-like lesions developed mainly with tyrosine-kinase inhibitors, whereas TMA complicated anti-VEGF ligand. Thirty-one percent of TMA patients had proteinuria up to 1 g/24 h. Half of TMA cases are exclusively renal localized. Pathologic TMA features are intraglomerular exclusively. MCN/cFSGS glomeruli displayed a high abundance of KI-67, but synaptopodin was not detected. Conversely, TMA glomeruli exhibited a normal abundance of synaptopodin-like control, whereas KI-67 was absent. Median follow-up was 12 months (range, 1-80 mo). Fifty-four patients died due to cancer progression. Hypertension and proteinuria resolved following drug discontinuation and antihypertensive agents. No patient developed severe renal failure requiring dialysis. Drug continuation or reintroduction resulted in a more severe recurrence of TMA in 3 out of 4 patients requiring maintenance of anti-VEGF agents despite renal TMA. In conclusion, TMA and MCN/cFSGS are the most frequent forms of renal involvement under anti-VEGF therapy. Careful risk-benefit assessment for individual patients should take into account risk factors related to the host and the tumor.

Angiotensin II type 1 receptor blockade ameliorates proteinuria in puromycin aminonucleoside nephropathy by inhibiting the reduction of NEPH1 and nephrin

BACKGROUND

The precise pathogenic mechanism and role of angiotensin II (Ang II) action in the development of proteinuria in minimal change nephrotic syndrome (MCNS) is uncertain.

METHODS

The glomerular expressions of the slit diaphragm (SD) molecules nephrin, podocin and NEPH1 in rat puromycin aminonucleoside (PAN) nephropathy, a mimic of MCNS, were analyzed. The effects of Ang II receptor blockade (ARB) (irbesartan 15 mg/kg body weight/day) on proteinuria and on the expression of the SD molecules were analyzed.

RESULTS

mRNA expressions of nephrin, podocin and NEPH1 were decreased to an undetectable level at 1 h. The staining of these SD molecules shifted to a discontinuous pattern, and their intensity was reduced. NEPH1 staining was reduced to an undetectable level on day 10. ARB treatment ameliorated the peak value of proteinuria (237.6 ± 97.0 vs. 359.0 ± 63.3 mg/day, p < 0.05), and prevented the decrease in the mRNA expression of the SD molecules (nephrin 66.96 %, podocin 60.40 %, NEPH1 77.87 % of normal level). The immunofluorescence staining of NEPH1 was restored by ARB. ARB treatment enhanced the expression of NEPH1 of normal rats.

CONCLUSIONS

Dysfunction of the SD molecules including NEPH1 is a crucial initiation event of PAN nephropathy. ARB treatment ameliorates proteinuria in PAN nephropathy by inhibiting the reduction of NEPH1 and nephrin. Ang II action regulates the expression of NEPH1 and nephrin in not only the pathological but also physiological state.

[A case of glomerulopathy associated with the vascular endothelial growth factor inhibitor bevacizumab]

The patient was a 73-year-old Japanese female diagnosed with stage IIIc primary peritoneal cancer. After undergoing total hysterectomy and bilateral oophorectomy, she received regimens consisting of paclitaxel (PTX) and carboplatin (CBDCA). She subsequently developed recurrence four years after the disease onset and was treated with PTX, CBDCA and the vascular endothelial growth factor (VEGF) inhibitor bevacizumab (Bev). Although clinical remission was maintained with the administration of Bev monotherapy every three weeks, proteinuria was detected six months later, and gradually increased. The findings of a renal biopsy showed diffuse wrinkling and double contouring of the glomerular tufts under light microscopy, although no immune complex deposition was observed on immunostaining. Additionally, electron microscopy showed hypertrophy of glomerular endothelial cells and widening of the subendothelial spaces. These histopathological findings were fully consistent with those of reported patients treated with VEGF inhibitors. The proteinuria attenuated following the initiation of treatment with losartan. Therefore, the administration of renoprotective therapy contributed to the patient's ability to continue the anticancer regimen with Bev in this case.

Nephrotic-range proteinuria and interstitial nephritis associated with the use of a topical loxoprofen patch

A 76-year-old woman with a history of lumbar fracture and marked proteinuria, bilateral pitting edema, malaise and pruritus was referred for an evaluation of an impaired renal function. A renal biopsy led to a tentative diagnosis of acute interstitial nephritis (AIN) with minimal change disease caused by nonsteroidal anti-inflammatory drugs (NSAIDs). Following the discontinuation of oral NSAIDs, the patient's symptoms disappeared spontaneously. However, nephrotic-range proteinuria relapsed one month after discharge, following loxoprofen patch use. The withdrawal of the topical loxoprofen patches once again resulted in the disappearance of all symptoms. This is the first case report of nephrotic-range proteinuria and AIN secondary to topical NSAID patch use.

Minimal change disease caused by exposure to mercury-containing skin lightening cream: a report of 4 cases

Mercury is a known cause of nephrotic syndrome and the underlying renal pathology in most of the reported cases was membranous nephropathy. We describe here 4 cases of minimal change disease following exposure to mercury-containing skin lightening cream for 2 - 6 months. The mercury content of the facial creams was very high (7,420 - 30,000 parts per million). All patients were female and presented with nephrotic syndrome and heavy proteinuria (8.35 - 20.69 g/d). The blood and urine mercury levels were 26 - 129 nmol/l and 316 - 2,521 nmol/d, respectively. Renal biopsy revealed minimal change disease (MCD) in all patients. The use of cosmetic cream was stopped and chelation therapy with D-penicillamine was given. Two patients were also given steroids. The time for blood mercury level to normalize was 1 - 7 months, whereas it took longer for urine mercury level to normalize (9 - 16 months). All patients had complete remission of proteinuria and the time to normalization of proteinuria was 1 - 9 months. Mercury-containing skin lightening cream is hazardous because skin absorption of mercury can cause minimal change disease. The public should be warned of the danger of using such products. In patients presenting with nephrotic syndrome, a detailed history should be taken, including the use of skin lightening cream. With regard to renal pathology, apart from membranous nephropathy, minimal change disease should be included as another pathological entity caused by mercury exposure or intoxication.

Serial Tc-99m MAG3 renography evaluating the recovery of acute kidney injury associated with minimal change nephrotic syndrome

Acute kidney injury (AKI) is a well-recognized complication of minimal change nephrotic syndrome (MCNS). Previous reports support the concept that AKI associated with MCNS is reversible; however, information regarding the hemodynamic basis of AKI in MCNS is insufficient. We herein describe a case of AKI in a man with MCNS. In this case, monitoring the longitudinal changes in renal perfusion using serial Tc-99m-MAG3 renal scanning was beneficial for evaluating the pathophysiological background associated with the development of AKI. The potential impact of serial renal scanning in MCNS patients with AKI will also be discussed.

Proteomic analysis indicates altered expression of plasma proteins in a rat nephropathy model

BACKGROUND

Minimal-change nephrotic syndrome is an idiopathic disease in which protein leaks through podocytes into the urine. We used proteomic tools to examine differences of plasma protein expression in healthy rats and rats with doxorubicin-induced nephropathy treated with or without prednisone.

METHODS

Healthy three-month-old Sprague-Dawley male rats were randomly chosen for one injection of doxorubicin (5.5 mg/kg) through the caudal vein to induce nephropathy (n = 50) or the same volume of saline (control, n = 20). After 1 week, 25 rats in the nephropathy group received topical prednisone (5.5 mg/kg/day) for 21 days and another 25 rats (untreated nephropathy) and the control rats received topical water. At 4 weeks, protein chips generated from rat plasma samples were analyzed by surface enhanced laser desorption/ionization-time of flight mass spectrometry (SELDI-TOF-MS) to obtain mass-to-charge ratios (m/z) of proteins of 2-50 kDa.

RESULTS

Relative to control rats, untreated nephropathic rats had four significantly higher and seven significantly lower m/z peaks. Prednisone treatment significantly normalized the intensities of peaks 9069 and 15005 (which correspond to cortexin-1 and interleukin-17A, respectively, according to Swiss Prot database) by increasing the expression of 9069 but reducing expression of 15005.

CONCLUSION

Significant differences in plasma proteins can be identified by proteomic analysis using SELDI-TOF-MS in a rat model of nephropathy.

Minimal-change nephrotic syndrome associated with isoniazid in anti-tuberculosis chemoprophylaxis for a patient with rheumatoid arthritis

A 66-year-old woman with seropositive rheumatoid arthritis (RA) and latent tuberculosis infection developed minimal-change nephrotic syndrome following the initiation of anti-tuberculosis chemoprophylaxis with isoniazid. This is the first reported case of an isoniazid-induced nephrotic syndrome. Isoniazid as a single-drug intervention is widely accepted as a safe and effective means of anti-tuberculosis chemoprophylaxis, particularly for RA patients with latent tuberculosis infection; the present case, however, demonstrates that isoniazid has the potential to induce minimal-change nephrotic syndrome, even when used as a single-drug intervention.

[Expression of interleukin-6 in rat model of doxorubicin-induced nephropathy]

OBJECTIVE

The pathogenesis of minimal change nephrotic syndrome (MCNS) remains unclear. This study aimed to investigate the expression of interleukin-6 (IL-6) in rats with doxorubicin-induced nephropathy and its possible roles in the pathogenesis of MCNS.

METHODS

Eighty-three male Wistar rats were randomly assigned into a control group (n=32) and a nephropathy group (n=51). Nephropathy was induced by a single tail vein injection of doxorubicin (5 mg/kg). The control group was injected with normal saline. Twenty-four-hour urinary protein excretion was measured 7, 14, 28 and 42 days after doxorubicin injection. IL-6 expression in urine and renal tissues was determined using ELISA 7, 14, 28 and 42 days after doxorubicin injection.

RESULTS

The urinary protein excretion increased significantly in the nephropathy group 7, 14, 28 and 42 days after doxorubicin injection compared with that in the control group (P<0.01). IL-6 expression in urine and renal tissues increased significantly 7, 14, 28 and 42 days after doxorubicin injection compared with that in the control group (P<0.01). IL-6 expression in urine and renal tissues was positively correlated with 24-hour urinary protein excretion in the nephropathy group (r=0.794, P<0.01; r= 0.870, P<0.01). IL-6 expression in urine was positively correlated with that in renal tissues (r=0.739, P<0.01).

CONCLUSIONS

IL-6 expression in the urine and renal tissues is increased in MCNS rats. IL-6 might play an important role in the pathogenesis of MCNS.

[Bone mesenchymal stem cell transplantation repairs glomerular podocytes in rats with puromycin aminonucleoside-induced nephrosis]

OBJECTIVE

To investigate the effect of bone mesenchymal stem cell (BMSC) transplantation on repair of glomerular podocytes and on the Nephrin expression in rats with puromycin aminonucleoside (PAN) -induced nephrosis.

METHODS

Forty-five Sprague-Dawley rats were randomly divided into three groups (n=15 each): a nephrosis model group that received a single intraperitoneal injection of PAN (0.15 mg/g); a BMSC transplantation group that received a single intraperitoneal injection of PAN (0.15 mg/g) followed by BMSC transfusion; a control group that received a single intraperitoneal injection of normal saline. Ten days after injection, the rats were sacrificed. The 24 hrs urinary protein content and serum albumin and cholesterol levels were measured 24 hrs before sacrifice. Changes of glomerular podocytes were observed under an electron microscope. Brdu labeled positive cells in kidneys were measured by immunohistochemical technology. RT-PCR and Western blot were used to assess the expression of mRNA and protein of Nephrin.

RESULTS

In the nephrosis model group, urinary protein and blood cholesterol contents increased, plasma albumin content decreased compared with those in the control group. Extensive fusion of podocyte foot processes was observed in the nephrosis model group. The BMSC transplantation group had decreased urinary protein and blood cholesterol contents and increased plasma albumin content compared with the nephrosis model group. Fusion of podocyte foot processes was also improved. Brdu labeled positive cells were seen in kidneys in the BMSC transplantation group, but not in the nephrosis model and the control groups. Nephrin mRNA and protein expression decreased significantly in the nephrosis model group compared with that in the control group. The BMSC transplantation group had increased Nephrin mRNA and protein expression compared with the nephrosis model group.

CONCLUSIONS

BMSCs can repair glomerular podocytes in PAN-induced nephrosis rats, and the changes of Nephrin expression may be involved in the process.

Fatal renal vasculitis and minimal change glomerulonephritis complicating treatment with penicillamine. Report on two cases

Two cases with different and not previously described fatal renal complications during treatment with penicillamine are reported. A man with seronegative rheumatoid arthritis with features of systemic lupus erythematosus was treated with penicillamine for six months and developed a mild membranous glomerulonephritis and a severe renal vasculitis leading to uremia and death. A woman with primary biliary cirrhosis was treated with penicillamine for nine months and developed a nephrotic syndrome, the renal biopsy showing minimal change glomerulonephritis. The nephrotic syndrome responded to prednisone but the patient died, probably from septicemia. Penicillamine may thus cause glomerular damage without deposition of immune complexes. A restricted use of the drug is recommended.

Nephrotic syndrome associated with interferon-beta-1b therapy for multiple sclerosis

A 43-year-old woman with multiple sclerosis (MS) had nephrotic syndrome 21 months after starting treatment with interferon (IFN)-beta-1b (subcutaneous administration). She had taken no drug except for the IFN-beta-1b. Because nephrotic syndrome may be induced by IFN therapy, the IFN was stopped. Percutaneous renal biopsy revealed that she had minimal change nephrotic syndrome. As nephrotic-range proteinuria, hypoalbuminemia, and general edema were worsening even 2 weeks after cessation of the drug, oral corticosteroid therapy (prednisolone 40 mg/day) was started. The nephrotic syndrome was treated successfully with prednisolone. The dosage of prednisolone was tapered, without a relapse, and then the corticosteroid therapy was stopped. IFN-beta-1b therapy was then resumed, and the patient is in remission for both nephrotic syndrome and MS. Though proteinuria and nephrotic syndrome is a rare adverse effect of IFN-beta-1b therapy, physicians treating MS patients with this agent should pay careful attention to new clinical symptoms and laboratory findings.

Minimal change disease following exposure to mercury-containing skin lightening cream

A 34-year-old woman developed nephrotic syndrome after using a skin lightening cream that contained an extremely high level of mercury. Blood and urine mercury levels were elevated and a renal biopsy revealed minimal change disease. Membranous nephropathy was excluded using immunofluorescence and electron microscopy. Her proteinuria remitted 9 months after she stopped using the cosmetic cream. This is the first reported case in the English literature of proven minimal change disease secondary to mercury exposure. It is important that mercury poisoning due to cosmetic cream is considered in the differential diagnoses for any woman who presents with nephrotic syndrome.

Drug-induced glomerulopathies

Normal renal function depends upon an intact glomerular apparatus. Many drugs and chemicals are capable of damaging the glomerulus, causing its increased permeability to large molecules. Glomerular lesions are usually responsible for proteinuria and the nephrotic syndrome. This also holds true for the drug-induced glomerulopathies, of which membranous glomerulo-nephritis is the most frequent type of lesion encountered. Apart from this, several cases of different glomerular changes such as focal segmental glomerulosclerosis and crescentic glomerulonephritis have also been reported. The drug-induced glomerulopathies are probably immune mediated. This is, for instance, reflected in the fact that patients with drug-induced nephritic syndrome frequently have the HLA-B8 and DR3 antigens. In depth information is provided for the previously mentioned disorders.

Glomerular tip lesion associated with nonsteroidal anti-inflammatory drug-induced nephrotic syndrome

Glomerular tip lesion and its relation to different glomerular diseases is a subject of controversy. The therapeutic and prognostic clinical implications of glomerular tip lesions are ambiguous. We present a case of glomerular tip lesion associated with nonsteroidal anti-inflammatory drug-induced nephrotic syndrome that further complicates this issue. To our knowledge, this is the first case report of glomerular tip lesion associated with nonsteroidal anti-inflammatory drug-induced nephrotic syndrome.

Cyclooxygenase-2 inhibitor-associated minimal-change disease

Selective cyclooxygenase-2 (COX-2) inhibitors are relatively newer anti-inflammatory drugs that produce comparable antiinflammatory and analgesic effects to the nonselective nonsteroidal antiinflammatory drugs (NSAIDs); but with fewer symptomatic gastric and duodenal ulcers. Limited data are available concerning the toxicity associated with COX-2 inhibitors outside the gastrointestinal tract. The NSAIDs have been known for their nephrotoxic potentials including minimal-change disease (MCD) with interstitial nephritis. Although the recent data suggests that COX-2 inhibitors may have the same adverse renal effect as NSAIDs, there is only one case report describing minimal change disease and acute interstitial nephritis (AIN) associated with a COX-2 inhibitor, celecoxib. We are reporting a case of MCD and acute tubular necrosis (ATN) but without interstitial nephritis in a patient treated with celecoxib. Although the proteinuria in our patient resolved completely after discontinuation of celecoxib, the renal function did not. We suggest that heightened suspicion of this side effect of COX-2 inhibitors should be maintained in all patients taking this class of drugs who present with nephrotic syndrome.

Combined therapy of cilazapril and losartan has no additive effects in ameliorating adriamycin-induced glomerulopathy

AIMS

Effects of the blockade of renin-angiotensin system (RAS), by angiotensin-converting enzyme inhibitor (ACEi), type 1 angiotensin II receptor blocker (ARB), or a combination of both, were evaluated in Adriamycin (ADR)-induced glomerulopathy.

METHODS

Male Sprague-Dawley rats (180-250 g) were induced of glomerulopathy by treatment with ADR (2 mg/kg, i.v.). Six weeks later, they were treated with cilazapril (1 mg/kg/day) and/or losartan (10 mg/kg/day) for an additional 6 weeks.

RESULTS

The urinary excretion of protein progressively increased following the treatment with ADR, which was prevented by ACEi, ARB, and a combination of both. Similarly, the glomerulopathy assessed by glomerulosclerosis index was also ameliorated by ACEi or ARB. However, combined therapy of both ACEi and ARB was without an additional effect (Control 1.4 +/- 0.4%, ADR 10.7 +/- 2.7%**, ACEi 0.8 +/- 0.4%, ARB 2.6 +/- 1.0%, ACEi+ARB 1.7 +/- 1.5%, ** p < 0.01 vs. Control). The expression of transforming growth factor-beta(1) was increased following the treatment with ADR (1.4 +/- 0.07-fold, p < 0.05 vs. Control), however, the degree of which was similarly blunted by either ACEi, ARB, or the combination of both. The expression of type 1 angiotensin II receptor mRNA increased following the treatment with ADR, the degree of which was further upregulated by ACEi and decreased by ARB to the control level (ADR 1.3 +/- 0.06-fold*, ACEi 1.8 +/- 0.05-fold***, ARB 1.0 +/- 0.04-fold, * p < 0.05 and *** p < 0.001 vs. Control). The combined therapy of ACEi and ARB still showed an upregulation of type 1 angiotensin II receptor mRNA, however, of which degree was mitigated compared with that induced by ACEi alone (ACEi+ARB 1.5 +/- 0.04-fold, ** p < 0.01 vs. Control). On the contrary, the expression of type 2 angiotensin II receptor mRNA was downregulated following the treatment with ADR, which was similarly restored to the control level by ACEi, ARB, and a combination of both (ADR 0.5 +/- 0.08-fold**, ACEi 1.0 +/- 0.06-fold, ARB 1.0 +/- 0.05-fold, ACEi+ARB 1.0 +/- 0.05-fold, ** p < 0.01 vs. Control).

CONCLUSION

It is suggested that combined therapy of ACEi and ARB with relatively high or maximal doses of each drug has no additive or synergistic benefits on the progression of ADR-induced glomerulopathy. Effects of RAS blockade may in part be related to differential regulation of type 1 and type 2 angiotensin II receptors.

[Experimental study on treatment of minimal change nephropathy with Lespedeza michx]

OBJECTIVE

To study the therapeutic effect of Lespedeza Michx in experimental rat model of minimal change nephropathy (MCN).

METHOD

The rat MCN model was reproduced by tail-intravenous injection of Adriamycin. The treatment effect of Lespedeza Michx was determined by the detection of urine protein collection for 24 hours, malondialdehyde (MDA), superoxide dismutase (SOD), ATCO, IL-8, TNF-alpha in serum, and renal histopathological changes were observed by microscope.

RESULT

Lespedeza Michx could decrease the contents of urine proteinuria, MDA, IL-8, and TNF-alpha in serum, increase SOD level and improved the pathological change of glomeruli.

CONCLUSION

Lespedeza Michx was effective on MCN.

[Experimental study on treatment of minimal change nephropathy with niaozhuoqing]

OBJECTIVE

To study the therapeutic effect of niaozhuoqing on minimal change nephropathy (MCN) in rats.

METHODS

The MCN rat model was induced by intravenous injection of adriamycin. The effect of treatment on 24h urine protein, serum protein, lipid metabolism, malondialdehyde (MDA), superoxide dismutase (SOD) in serum, and renal histopathological changes were observed.

RESULTS

Niaozhuoqing could decrease the contents of proteinuria, blood lipid and MDA in serum, increase serum protein, SOD level and pathologically restore the glomeruli.

CONCLUSION

Niaozhuoqing has good effects on MCN, which probably related to decrease serum lipids level and reduce oxygen free radicals.

[Minimal changes nephrotic syndrome associated to penicillamine treatment]

We describe three patients with minimal change nephrotic syndrome associated with penicillamine treatment. Two patients had systemic sclerosis and one had rheumatoid arthritis. Cumulative dose of D-penicillamine was similar in all cases, and nephrotic syndrome appeared after 15-33 months of treatment. The drug was stopped and nephrotic syndrome disappeared in 2-4 months, suggesting a possible causal relationship between penicillamine and minimal change disease.

Photodynamic therapy using verteporfin-induced minimal change nephrotic syndrome

PURPOSE

To report a case of minimal change nephrotic syndrome (MCNS) after photodynamic therapy using verteporfin.

DESIGN

Interventional case report.

METHODS

After four cycles of photodynamic therapy, general weakness with generalized edema developed in an otherwise healthy 66-year-old woman, resulting in dyspnea and ascites. Urinalysis showed heavy proteinuria (4+) with decreased serum total protein and albumin, and increased total cholesterol levels, suggesting nephrotic syndrome. Renal biopsy and pathologic diagnosis were performed.

RESULTS

Renal biopsy revealed normal glomeruli and tubulointerstitium by light microscopy, with no immunoglobin or complement deposition. Transmission electron microscopy showed diffuse effacement of the foot processes of visceral epithelial cells, which is the characteristic finding of minimal change nephrotic syndrome.

CONCLUSIONS

We herein report a case of minimal change nephrotic syndrome after photodynamic therapy using verteporfin.

Guillain-Barré syndrome associated with minimal change glomerulopathy and tubular dysfunction - related to acetone-based organic solvent?

A 55-year-old woman presented with Guillain-Barré syndrome, nephrotic syndrome and multiple tubular dysfunction under occupational exposure to an organic solvent, which contained acetone as the principal solvent. In this case, the onset of the nephrotic syndrome and tubular dysfunction coincided with the development of the neurological manifestation. Renal biopsy demonstrated minimal change glomerulopathy with moderate tubulointerstitial nephritis. Several clearance tests that evaluated tubular transport functions revealed multiple tubular defects (including the Na(+)-K(+)-Cl(-) cotransporter of thick ascending limb and distal proton pump). The simultaneous occurrence of Guillain-Barré and nephrotic syndrome has previously been reported. However, both minimal glomerulopathy with multiple tubular dysfunction and progressive peripheral neuropathy under occupational exposure to an organic solvent remain unreported. Herein, we presented a rare association of minimal change nephrotic syndrome, tubular dysfunction with Guillain-Barré syndrome under the risk of exposure to an acetone-based cleansing solution; the case raises our concerns about possible chronic nephrotoxic or neurotoxic effects of common chemical organic solvents.

Downregulation of vascular endothelial growth factor and its receptors in the kidney in rats with puromycin aminonucleoside nephrosis

AIM

We aimed to examine the possible involvement of vascular endothelial growth factor (VEGF) in the pathogenesis of puromycin aminonucleoside nephrosis (PAN).

METHODS

The expression and localization of the mRNA of VEGF and its receptors, flt-1 and flk-1, were analyzed in the kidneys of puromycin aminonucleoside-injected rats by use of Northern blotting and in situ hybridization.

RESULTS

In association with the induction of proteinuria, VEGF mRNA underwent decrease in amount from 3 days after the injection, reaching the minimum level at 7 days, followed by a gradual recovery by 28 days. The levels of flk-1 and flt-1 mRNA showed similar transient decrease in PAN kidney, whereas the mRNA of von Willebrand factor, a marker of endothelial cells, showed no change in amount. In the normal rat kidney, VEGF mRNA was localized primarily to podocytes, and flk-1 mRNA was localized exclusively to endothelial cells with much higher intensity in glomeruli than in peritubular capillaries. In PAN kidney, the intensities of both VEGF and flk-1 signals in podocytes and glomerular endothelial cells, respectively, appeared much lower at 7 days than in normal kidney.

CONCLUSION

These results indicate that the VEGF-VEGF receptor system is downregulated in PAN, implying that it is not involved in the mechanism of proteinuria in PAN.

The selective adenosine A1 receptor antagonist KW-3902 prevents radiocontrast media-induced nephropathy in rats with chronic nitric oxide deficiency

Several studies have recently suggested a principal role of adenosine in the pathogenesis of radiocontrast media-induced nephropathy. In the present experiments, we therefore investigated the renal protective effects of 8-(noradamantan-3-yl)-1,3-dipropylxanthine (KW-3902), a potent and selective adenosine A1 receptor antagonist, on radiocontrast media-induced nephropathy in the model of the N-pi-nitro-L-arginine methyl ester (L-NAME) hypertensive, chronic nitric oxide (NO)-depleted rat. Chronic NO depletion was induced by pretreatment with L-NAME, 50 mg/ml, added to drinking water for 8 weeks. Clearance experiments were performed in anesthetized rats and glomerular filtration rate was assessed prior to and following the application of high osmolar radiocontrast media (sodium diatrizoate, 3 ml/kg, i.v.) or an equivalent volume of isoosmolar mannitol to examine the role of hyperosmolarity in radiocontrast media-induced nephropathy. Subgroups received KW-3902 (0.1 mg/kg, i.v.), 20 min prior to radiocontrast media administration. Age-matched, untreated rats served as controls. Radiocontrast media application induced a significant decline in glomerular filtration rate in L-NAME hypertensive animals, whereas no effects were observed in control rats. KW-3902 fully prevented the drop in glomerular filtration rate in response to radiocontrast media in L-NAME hypertensive rats. No renal hemodynamic alterations were observed in mannitol-infused animals. The present experiments demonstrate that the decrease in glomerular filtration rate following radiocontrast media occurred independently of the osmotic load, and that KW-3902 effectively prevented the radiocontrast media-induced deterioration in renal function. KW-3902 may be especially beneficial in patients at high risk for developing acute renal failure following radiocontrast media application or in patients in which extracellular fluid volume expansion is limited by clinical conditions such as congestive heart failure.

Glomerulosclerosis in adriamycin-induced nephrosis is accelerated by a lipid-rich diet

The present study was performed to determine quantitatively the effect of hypercholesterolemia induced by a lipid-rich diet on glomerulosclerosis in an animal model of nephrotic syndrome (NS) induced by Adriamycin (ADR). Twenty NS Wistar rats administered ADR with a single intravenous dose of 5 mg/kg body weight were divided into standard and lipid-rich chow groups. Another 20 weight-matched non-NS rats that received a vehicle alone were grouped as controls. Quantitative analyses of renal histological changes were performed with determination of blood and urine biochemical parameters. It was found that serum cholesterol was markedly higher in rats with lipid-rich chow in both NS and non-NS rats. Urinary protein was significantly higher in rats on the lipid-rich diet in the NS group. The mesangial matrix and cell indices were significantly increased in rats with the lipid-rich diet and the most obvious changes were found in the NS group. Lipid deposits and foam cells were observed in mesangial areas, and some glomeruli had progressed to form focal and segmental glomerulosclerosis in the NS group. Findings indicated that diet-induced hyperlipidemia can lead to proliferation of mesangial cells and accumulation of mesangial matrices, and further aggravate glomerulosclerosis in Adriamycin-induced nephrosis.

[Tiopronin-induced nephrotic syndrome with minimal glomerular lesions]

BACKGROUND

In the very large majority of cases, nephrotic syndrome with minimal glomerular lesions is an idiopathic condition. Drugs can favor the glomerulopathy. The effect of non-steroidal antiinflammatory drugs is well known, but other drugs, particularly tiopronin may be incriminated.

CASE REPORT

A 73-year-old patient developed severe nephrotic syndrome with minimal glomerular lesions 6 weeks after tiopronin therapy was initiated. Complete and spontaneous remission of the nephrotic syndrome was achieved 5 weeks after drug withdrawal. No recurrent lipoidic nephrosis has been observed at 3 years follow-up.

CONCLUSION

Tiopronin-induced nephrotic syndrome with minimal glomerular lesions is usually severe and develops rapidly. Remission occurs rapidly after drug withdrawal. Weekly urine checks with dip-strips should be proposed in patients treated with tiopronin.

Effects of recombinant human serum albumin on ascites in rats with puromycin aminonucleoside-induced nephropathy

1. Recombinant human serum albumin (rHSA) (1 g/kg) significantly decreased the weight of ascites in rats with puromycin aminonucleoside-induced nephropathy. 2. Furosemide (1-30 mg/kg) did not significantly reduce the weight of ascites in this model. 3. A combination of rHSA (1 g/kg) with furosemide (5 mg/kg) significantly decreased the weight of ascites in this model compared with furosemide alone. 4. In consideration of these results, rHSA can be a substitute for human serum albumin products prepared from human plasma in therapy for ascites or edema in furosemide-resistant nephrotic syndrome.

Structure-activity relationship for two lipoxygenase inhibitors and their potential for inducing nephrotic syndrome

In a study of structure-activity relationship with drug-induced nephropathy two lipoxygenase inhibitors, the N-hydroxyurea derivative 70C ((E)-N-{3-[3-(4-fluorophenoxy) phenyl]-1-(R, S)-methylprop-2-enyl}-N-hydroxyurea) and the N-hydroxamic acid analogue 360C ((E)-N-{3-[3-(4-fluorophenoxy) phenyl]-1-(R, S)-methylprop-2-enyl}-N-hydroxamic acid), were administered to rats. 70C and 360C were dosed to female Wistar rats at 100 mg/kg po daily for 7 days. Another group of rats was given a single intravenous bolus dose of puromycin aminonucleoside (PAN) at 100 mg/kg. Urine samples were collected from all groups during the study and plasma samples were collected after 7 days. Kidneys were excised and fixed for examination by electron microscopy. 70C- and PAN-treated groups both showed early changes in the glomeruli, in which the visceral cells appeared enlarged and showed varying degrees of foot process loss. This foot process loss was associated with decreases in total plasma protein and albumin and increases in the plasma cholesterol, triglycerides, creatinine, and urea were recorded. Marked proteinuria was observed in both the 70C and PAN groups. The foot process loss together with increased proteinuria, hypoalbuminemia, hypercholesterolemia, and lipemia are all characteristic of the human condition, Minimal Change Nephrotic Syndrome. All the biochemical and morphological investigations showed that 360C-treated rats were similar to the control group, suggesting that the hydroxyurea moiety of 70C is responsible, either directly or indirectly, for the induction of the nephrotic syndrome seen in rats.