Angiotensin antagonists and steroids in the treatment of focal segmental glomerulosclerosis

The outcomes of patients with kidney failure due to focal segmental glomerulosclerosis (FSGS) in Australia and New Zealand: A cohort study using the Australia and New Zealand Dialysis and Transplant Registry (ANZDATA)

BACKGROUND

The outcomes of patients with focal segmental glomerulosclerosis (FSGS) on kidney replacement therapy (KRT) have not been well described. This study evaluated the outcomes of patients with kidney failure due to FSGS on KRT including dialysis and kidney transplantation.

METHOD AND MATERIALS

All adult patients with kidney failure who commenced KRT in Australia and New Zealand from 15th of May 1963 to 31st of December 2018 were retrospectively extracted from the Australia and New Zealand Dialysis and Transplant (ANZDATA) Registry. Outcomes of patients with FSGS were compared to those with other causes of kidney failure (non-FSGS).

RESULTS

85,052 patients commenced KRT during the study period, of whom 2991 (3.5%) were patients with FSGS. Compared to patients with non-FSGS, patients with FSGS experienced similar mortality on dialysis (adjusted hazard ratio [aHR] 0.98, 95% CI 0.90-1.06, p = 0.55) and following kidney transplantation (aHR 0.92, 95% CI 0.73-1.15, p = 0.47). The risk of first kidney allograft loss was higher in patients with FSGS (aHR 1.20, 95% CI 1.04-1.37, p = 0.01). However, when death was analysed as a competing risk, the survival in both groups was similar (sub-hazard ratio [SHR] 1.09, 95% CI 0.94-1.28, p = 0.26). Patients with FSGS had a longer waiting time for kidney transplantation (aHR 0.92, 95% CI 0.86-0.98, p = 0.02) and experienced an increased risk of disease recurrence in the allograft (aHR 1.73, 95% CI 1.35-2.21, p<0.001). Compared to patients with other forms of glomerular disease, patients with FSGS experienced similar dialysis and transplant patient survival and death-censored rate of kidney transplantation and allograft loss but higher rates of primary kidney disease recurrence.

CONCLUSION

FSGS was associated with similar dialysis and transplant patient survival and death-censored first allograft loss compared to non-FSGS and other forms of glomerular disease.

Protease-activated receptors in kidney diseases: A comprehensive review of pathological roles, therapeutic outcomes and challenges

Studies have demonstrated that protease-activated receptors (PARs) with four subtypes (PAR1-4) are mainly expressed in the renal epithelial, endothelial, and podocyte cells. Some endogenous and urinary proteases, namely thrombin, trypsin, urokinase, and kallikrein released during diseased conditions, are responsible for activating different subtypes of PARs. Each PAR receptor subtype is involved in kidney disease of distinct aetiology. PAR1 and PAR2 have shown differential therapeutic outcomes in rodent models of type-1 and type-2 diabetic kidney diseases due to the distinct etiological basis of each disease type, however such findings need to be confirmed in other diabetic renal injury models. PAR1 and PAR2 blockers have been observed to abolish drug-induced nephrotoxicity in rodents by suppressing tubular inflammation and fibrosis and preventing mitochondrial dysfunction. Notably, PAR2 inhibition improved autophagy and prevented fibrosis, inflammation, and remodeling in the urethral obstruction model. Only the PAR1/4 subtypes have emerged as a therapeutic target for treating experimentally induced nephrotic syndrome, where their respective antibodies attenuated the podocyte apoptosis induced upon thrombin activation. Strikingly PAR2 and PAR4 subtypes involvement has been tested in sepsis-induced acute kidney injury (AKI) and renal ischemia-reperfusion injury models. Thus, more studies are required to delineate the role of other subtypes in the sepsis-AKI model. Evidence suggests that PARs regulate oxidative, inflammatory stress, immune cell activation, fibrosis, autophagic flux, and apoptosis during kidney diseases.

Steroid resistant focal segmental glomerulosclerosis: effect of arterial hyalinosis on outcome: single center study

Background. Few data with adequate evidence exists as regards the effect of Cyclosporine (CsA) and mycophenolate mofetil (MMF) on pathological prognostic parameters in patients with steroid resistant focal segmental glomerulosclerosis (FSGS). The purpose of the present study is to compare the effect of cyclosporin and mycophenolate mofetil in addition to steroids on functional and histopathologic renal parameters in patients with steroid resistant FSGS one year after treatment.Material and methods. Thirty-seven adults with primary FSGS patients resistant to steroid therapy consecutively randomized to treatment with either MMF or cyclosporine. Low dose prednisolone added to both groups. Glomerular filtration rate (GFR) and blood pressure (BP) were determined at all examinations and a second renal biopsy was taken 12 months after treatment with either of cyclosporin and mycophenolate mofetil.Results. GFR significantly increased in MMF group p < 0.01 after 6 months and unchanged after 12 months. On the other hand, GFR significantly decrease in CsA group p < 0.001 after 6 months and reduced more after 12 months p < 0.001 compared to base line levels. There was a significant difference of GFR between the 2 groups at 6 months p < 0.001. The extent of proteinuria decreased significantly in CsA group after 12 months p < 0.001. The extent of arteriolar hyalinosis increased significantly in CsA group (0.78 to 1.81 score, p < 0.001) but was unchanged in MMF group (0.93 to 0.96 score), whereas interstitial fibrosis increased to same level in both groups (grade 3).Conclusion. Conversion to MMF in those patients may be superior to CsA as regards GFR after 12 months after treatment in spite of the presence of greater level of protein excretion. The increased arteriolar hyalinosis during CsA treatment most likely results in higher BP compared to MMF treatment in patients with FSGS resistant to steroids.

Focal Segmental Glomerulosclerosis, Risk Factors for End Stage Kidney Disease, and Response to Immunosuppression

Background

FSGS is a heterogeneic glomerular disease. Risk factors for kidney disease ESKD and the effect of immunosuppression treatment (IST) has varied in previously published cohorts. These cohorts were limited by relatively small case numbers, short follow-up, lack of racial/ethnic diversity, a mix of adult and pediatric patients, lack of renin-angiotensin-aldosterone system (RAAS) inhibition, or lack of subgroup analysis of IST.

Methods

We compared demographics, clinical characteristics, histopathology, and IST to long-term renal survival in a large, ethnically diverse, adult cohort of 338 patients with biopsy-proven FSGS with long-term follow-up in the era of RAAS inhibition using data from the US Department of Defense health care network.

Results

Multivariate analysis showed that nephrotic-range proteinuria (NRP), eGFR <60 ml/min per 1.73 m², hypoalbuminemia, interstitial fibrosis and tubular atrophy, and interstitial inflammation at diagnosis and the absence of remission were all associated with worse long-term renal survival. IgM, C3, and a combination of IgM/C3 immunofluorescence staining were not associated with reduced renal survival. IST was not associated with improved renal survival in the whole cohort, or in a subgroup with NRP. However, IST was associated with better renal survival in a subgroup of patients with FSGS with both NRP and hypoalbuminemia and hypoalbuminemia alone.

Conclusions

Our study suggests that IST should be reserved for patients with FSGS and nephrotic syndrome. It also introduces interstitial inflammation as a potential risk factor for ESKD and does not support the proposed pathogenicity of IgM and complement activation.

Open-Label Clinical Trials of Oral Pulse Dexamethasone for Adults with Idiopathic Nephrotic Syndrome

BACKGROUND

In adults with primary focal segmental glomerulosclerosis (FSGS), daily prednisone may induce complete remissions (CR) and partial remissions (PR), but relapses are frequent and adverse events are common.

METHODS

We carried out 2 open-label, uncontrolled trials to explore the efficacy and tolerability of pulse oral dexamethasone as an alternative to daily prednisone. We enrolled adult patients with proteinuria > 3.5 g/day despite the use of renin-angiotensin-aldosterone blockade. In the first trial, we enrolled 14 subjects with FSGS and administered 4 dexamethasone doses (25 mg/m2) daily for 4 days, repeated every 28 days over 32 weeks. The second trial involved a more intensive regimen. Eight subjects received 4 dexamethasone doses of 50 mg/m2 every 4 weeks for 12 weeks, followed by 4 doses of 25 mg/m2 every 4 weeks for 36 weeks; subjects were randomized to 2 doses every 2 weeks or 4 doses every 4 weeks.

RESULTS

In the first trial, we enrolled 13 subjects with FSGS and 1 with minimal change disease and found a combined CR and PR rate of 36%. In the second trial, we enrolled 8 subjects. The combined CR and PR rate was 29%. Analysis combining both trials showed a combined CR and PR rate of 33%. Adverse events were observed in 32% of subjects, with mood symptoms being most common. There were no serious adverse events related to the study.

CONCLUSION

We conclude that high dose oral dexamethasone is well tolerated by adults with idiopathic nephrotic syndrome and may have some efficacy.

Steroid-resistentes nephrotisches Syndrom

Das steroid-resistente nephrotische Syndrom (SRNS) mit dem histomorphologischen Korrelat der fokal-segmentalen Glomerulosklerose (FSGS) stellt eine bedeutende Ursache für eine terminale Niereninsuffizienz im Kindesalter, aber auch bei erwachsenen Patienten dar. Das Erkrankungsspektrum zeichnet sich durch eine große genetische Heterogenität aus, wobei auch nicht genetische Ursachen bei der FSGS beobachtet werden. Die genetische Grundlage des SRNS/FSGS-Komplexes ist v. a. für ältere Kinder/Jugendliche und Erwachsene bisher noch unzureichend verstanden. Die eindeutige Abgrenzung genetischer SRNS/FSGS-Ursachen ist unerlässlich, da sich bereits heute hieraus eine Vielzahl an klinischen Implikationen ergeben. Die Identifikation unbekannter Erkrankungsallele oder Erkrankungsgene kann zudem Erkenntnisse bringen, die ein gänzlich neues Verständnis der Pathomechanismen ermöglichen. Durch umfassende genetische Untersuchungen besteht die Möglichkeit, die ungelöste genetische Basis der Rekurrenz der FSGS-Erkrankung bei bislang Varianten-negativen Patienten zu finden.

Glucocorticoids in the treatment of patients with primary focal segmental glomerulosclerosis and moderate proteinuria

BACKGROUND

To compare the efficacy of glucocorticoids in primary focal segmental glomerulosclerosis (pFSGS) patients with moderate proteinuria. Registered at http://www.chictr.org.cn/ , study No. ChiCTR-OPN-17012789.

METHODS

pFSGS patients with urine protein between 1.0 and 3.5 g/24 h were recruited from 2006 to 2016. No decline in urine protein > 50% was observed after 2 months of run-in angiotensin-converting enzyme inhibitors/angiotensin-receptor blockers (ACEI/ARB) treatment. Patients were assigned to study group (glucocorticoids with ACEI/ARB) or control group (ACEI/ARB without glucocorticoids). Variables including 24-h urinary protein, serum albumin and serum creatinine during the trial were recorded. Remission was defined as proteinuria < 0.3 g/24 h or declined > 50%, and our composite end point as > 30% decrease of eGFR or eGFR < 30 ml/min.

RESULTS

A total of 102 patients were enrolled (study group N = 52, control group N = 50), and the median follow-up time was 36 (12-117) months without significant difference between groups. During the 12-month follow-up, the remission rate was significantly higher in study group [73.1 vs 50.0% (P = 0.01)], and the initial median response time was 3 months in the study group while 6 in the control group. The end point was reached by 22.2% cases in study group, and 42.0% in control. The medium survival times were study group 72 months and control 57 (P = 0.03). Minor adverse reactions were observed in 10 patients (study group N = 8, control group N = 2).

CONCLUSIONS

Additional glucocorticoids therapy is more efficacious compared to ACEI/ARB alone in the treatment of patients with pFSGS and moderate proteinuria.

CCR2 antagonism leads to marked reduction in proteinuria and glomerular injury in murine models of focal segmental glomerulosclerosis (FSGS)

Focal segmental glomerulosclerosis (FSGS) comprises a group of uncommon disorders that present with marked proteinuria, nephrotic syndrome, progressive renal failure and characteristic glomerular lesions on histopathology. The current standard of care for patients with FSGS include immunosuppressive drugs such as glucocorticoids followed by calcineurin inhibitors, if needed for intolerance or inadequate response to glucocorticoids. Renin-angiotensin-aldosterone (RAAS) blockers are also used to control proteinuria, an important signature of FSGS. Existing treatments, however, achieved only limited success. Despite best care, treatment failure is common and FSGS is causal in a significant proportion of end stage renal disease. Thus, an unmet need exists for novel disease modifying treatments for FSGS. We employed two widely-used murine models of FSGS to test the hypothesis that systemic inhibition of chemokine receptor CCR2 would have therapeutic benefit. Here we report that administration CCX872, a potent and selective small molecule antagonist of CCR2, achieved rapid and sustained attenuation of renal damage as determined by urine albumin excretion and improved histopathological outcome. Therapeutic benefit was present when CCX872 was used as a single therapy, and moreover, the combination of CCX872 and RAAS blockade was statistically more effective than RAAS blockade alone. In addition, the combination of CCR2 and RAAS blockade was equally as effective as endothelin receptor inhibition. We conclude that specific inhibition of CCR2 is effective in the Adriamycin-induced and 5/6 nephrectomy murine models of FSGS, and thus holds promise as a mechanistically distinct therapeutic addition to the treatment of human FSGS.

Direct inhibition of plasmatic renin activity with aliskiren: a promising but under-investigated therapeutic option for non-diabetic glomerulonephritis

Non-diabetic glomerulonephritis is a frequent cause of end-stage renal disease. The use of renin-angiotensin-aldosterone system blockers is a fundamental therapeutic approach. However, converting enzyme inhibitors (ACE-is) and angiotensin receptor blockers do not always achieve the desired target of proteinuria. The induction of the prorenin and renin up-regulation is a possible explanation. Aliskiren is the first drug acting as direct inhibitor of plasmatic renin activity, also able to interfere with the prorenin and renin profibrotic escape. We aimed at reviewing the literature for the assessment of potential efficacy and safety of aliskiren in the treatment of non-diabetic glomerulonephritis. The data on this topic are limited; however, we concluded for a possible usefulness of aliskiren. The renal safety profile appears potentially acceptable in non-diabetic patients although extreme carefulness, particularly with respect to long-term renal and cardiovascular tolerability, is recommended.

Current and emerging treatments for idiopathic focal and segmental glomerulosclerosis in adults

Idiopathic focal and segmental glomerular sclerosis is a frequent cause of nephrotic syndrome and end-stage renal disease. The pathogenesis is still unknown, although the body of evidence suggests that focal and segmental glomerular sclerosis is caused by a not clearly identified circulating factor that alters the permselectivity of the glomerular barrier. Proteinuria is followed by podocyte injury. Glucocorticoids, calcineurin inhibitors, cytotoxic agents and mycophenolate mofetil, either given alone or in combination, may obtain complete or partial remission of proteinuria in 50-60% of patients and protect them from end-stage renal disease, but the remaining patients are resistant to the available drugs. A number of new drugs, including rituximab, galactose and antifibrotic agents, are under investigation.

Tacrolimus versus cyclophosphamide in steroid-dependent or steroid-resistant focal segmental glomerulosclerosis: a randomized controlled trial

BACKGROUND

The efficacy and safety of tacrolimus (TAC) and cyclophosphamide (CTX) were prospectively examined in steroid-dependent or steroid-resistant primary focal segmental glomerulosclerosis (FSGS).

METHODS

Patients with biopsy-proven FSGS were enrolled and randomly divided into two groups: CTX and TAC. Patients treated with CTX (0.5-0.75 g/m(2)·month, i.v.) received prednisone at 0.8 mg/kg·day, while patients treated with TAC (0.1 mg/kg·day) received prednisone at 0.5 mg/kg·day. The plasma concentration of TAC was monitored and maintained at 5-10 ng/ml. After a 6-month treatment the patients were evaluated. Patients with complete remission (CR) and partial remission (PR) continued the treatment for 12 months with the dose tapered, whereas the patients with no response were excluded from the study and underwent an alternative treatment.

RESULTS

A total of 33 patients were recruited and 27 completed the 12-month follow-up. The TAC-treated patients (n = 15) showed a quick remission. The initial remission time averaged 1.23 ± 0.21 versus 2.21 ± 0.77 months in the CTX group (n = 18), but no significant difference was achieved (p > 0.05). At 6 months, the two groups showed a similar outcome. Ten patients from each group showed remission (7 CR and 3 PR). At 12 months, the CTX group had 9 CR and 3 PR while the TAC group had 6 CR and 5 PR. Remission rates in TAC tended to be higher than that in CTX, but there was no difference. CTX patients had a high prevalence of infections (50.0 vs. 13.3% in TAC, p < 0.05). In contrast, TAC-treated patients showed a high incidence of hyperglycemia (26.7 vs. 0.0% in CTX, p < 0.05).

CONCLUSION

These results suggest that CTX and TAC had a similar efficacy in steroid-dependent and steroid-resistant FSGS as manifested by reduced proteinuria, improved serum albumin level and renal function.

Treatment of primary FSGS in adults

Over the last 20 years, primary FSGS has emerged as one of the leading causes of idiopathic nephrotic syndrome in adults, particularly among African Americans. In nephrotic patients, progression to ESRD often occurs over the course of 5-10 years, whereas non-nephrotic patients and those entering a remission have an extremely favorable prognosis. As a result, it is in patients who remain persistently nephrotic despite conservative therapy that a more aggressive therapeutic approach is taken. Primary FSGS was once considered an entity nonresponsive to prednisone or immunosuppressive agents, but it has become apparent over the last 20 years that a substantial portion of nephrotic adults with primary FSGS do respond to treatment with a significantly improved prognosis. The recent histologic classification proposed for FSGS has provided additional insights into the prognosis and response to therapy. This article reviews the current knowledge regarding the presentation, prognosis, and therapeutic approach in adults with primary FSGS.

Target organ damage in African American hypertension: role of APOL1

Apolipoprotein L1 (APOL1) gene association studies and results of the African American Study of Kidney Disease and Hypertension are disproving the longstanding concept that mild to moderate essential hypertension contributes substantially to end-stage renal disease susceptibility in African Americans. APOL1 coding variants underlie a spectrum of kidney diseases, including that attributed to hypertension (labeled arteriolar or hypertensive nephrosclerosis), focal segmental glomerulosclerosis, and HIV-associated nephropathy. APOL1 nephropathy risk variants persist because of protection afforded from the parasite that causes African sleeping sickness. This breakthrough will lead to novel treatments for hypertensive African Americans with low-level proteinuria, for whom effective therapies are lacking. Furthermore, APOL1 nephropathy risk variants contribute to racially variable allograft survival rates after kidney transplantation and assist in detecting nondiabetic forms of nephropathy in African Americans with diabetes. Discovery of APOL1-associated nephropathy was a major success of the genetics revolution, demonstrating that secondary hypertension is typically present in nondiabetic African Americans with nephropathy.

Systemic AA amyloidosis

Systemic AA amyloidosis is a rare complication of chronic inflammatory disorders. The amyloid fibrils are derived from serum amyloid A protein, an acute phase protein synthesized in the liver. Clinical presentation is most commonly due to the consequences of renal involvement, with proteinuria and progressive renal decline. Progression to end stage renal failure is common. Management is currently centred on reducing the supply of the precursor protein by treating the underlying inflammatory condition, whilst supporting the affected organs. Monitoring of the serum amyloid A protein is vital to assess whether there is adequate suppression of the underlying disease. The level of serum amyloid A protein is a powerful predictor of both patient survival and renal outcome. In patients with adequate suppression of the serum amyloid A protein amyloid deposits can be seen to regress and renal function can be stabilised and even improve.

Novel therapies for resistant focal segmental glomerulosclerosis (FONT) phase II clinical trial: study design

Background

The lack of adequate randomized clinical trials (RCT) has hindered identification of new therapies that are safe and effective for patients with primary focal segmental glomerulosclerosis (FSGS), especially in patients who fail to respond to corticosteroids and immunosuppressive therapies. Recent basic science advances have led to development of alternative treatments that specifically target aberrant pathways of fibrosis which are relevant to disease progression in FSGS. There is a need for a flexible Phase II study design which will test such novel antifibrotic strategies in order to identify agents suitable for phase III testing.

Methods/Design

The Novel Therapies for Resistant Focal Segmental Glomerulosclerosis (FONT) project is a multicenter Phase I/II RCT designed to investigate the potential efficacy of novel therapies for resistant FSGS. Adalimumab and galactose will be evaluated against conservative therapy consisting of the combination of lisinopril, losartan and atorvastatin. The sample size is defined to assure that if one of the treatments has a superior response rate compared to that of the other treatments, it will be selected with high probability for further evaluation. Comparison of primary and secondary endpoints in each study arm will enable a choice to be made of which treatments are worthy of further study in future Phase III RCT.

Discussion

This report highlights the key features of the FONT II RCT including the two-step outcome analysis that will expedite achievement of the study objectives. The proposed phase II study design will help to identify promising agents for further testing while excluding ineffective agents. This staged approach can help to prevent large expenditures on unworthy therapeutic agents in the management of serious but rare kidney diseases

Trial Registration

ClinicalTrials.gov, NCT00814255

Effect of angiotensin-converting enzyme gene insertion/deletion polymorphism on steroid resistance in Egyptian children with idiopathic nephrotic syndrome

Introduction. The presence of the deletion (D) allele in the angiotensin-converting enzyme (ACE) gene has been reported as a probable genetic risk factor for idiopathic nephrotic syndrome (INS), but its role in determining resistance to steroid therapy remains to be evaluated.

Methods. Fifty-one patients were enrolled in the study and received oral steroids. The pattern of response to steroid therapy was determined. A group of 50 healthy adults served as a control group. The genotypes for ACE insertion (I)/D polymorphism were analysed using a PCR-based method.

Results. Twenty patients were steroid sensitive (SS) and 31 were non-SS. The presence of hypertension at presentation was significantly related to steroid unresponsiveness. Among the SS group, the frequencies of the II, ID, and DD genotypes of the ACE gene were 20% (n=4), 65% (n=13), and 15% (n=3), respectively, while the frequencies among the non-SS group were 19.4% (n=6), 74.2% (n=23), and 6.5% (n=2), respectively. The differences between the two groups were not statistically significant (Chi square=0.59).

Conclusion. The current study on Egyptian children with INS reveals no association between the ACE gene I/D polymorphism and clinical parameters, histological findings, and steroid resistance.

Mycophenolate mofetil in children with steroid/cyclophosphamide-resistant nephrotic syndrome

The purpose of this study was to assess the results of therapy with mycophenolate mofetil (MMF) in children with idiopathic nephrotic syndrome (INS) who were both steroid- and cyclophosphamide-resistant. Treatment lasted a minimum of 6 months, and follow-up data were collected over a 2-year period. The children were divided into two groups: Group 1 (n=34) comprised patients who had received cyclosporine A (CsA) before the initiation of MMF therapy; Group 2 (n=18) comprised patients who received only MMF. Among the 34 patients of Group 1, complete and partial remission were achieved in seven (20.6%) and 13 patients (38.6%), respectively; there was no response in 14 patients (41.2%). Among the 18 patients in Group 2, complete and partial remission occurred in five (27.8%) and six (33.3%) patients, respectively; there was no response in seven patients (38.9%). Eight patients developed chronic kidney disease. The main side-effects were gastrointestinal complaints (n=11, 21%), recurring severe infections (n=1, 1.9%), and mild thrombocytopenia/leucopenia (n=1, 1.9%). MMF proved to be therapeutically effective in 59.5% of the cases. These beneficial effects need to be confirmed in studies with a long-term follow-up after discontinuation of the treatment. Our statistical analysis of the results of therapy with MMF did not reveal any significant difference between its use alone or following CsA administration.

Progression of glomerular and tubular disease in pediatrics

Chronic kidney disease may be stimulated by many different etiologies, but its progression involves a common, yet complex, series of events that lead to the replacement of normal tissue with scar. These events include altered physiology within the kidney leading to abnormal hemodynamics, chronic hypoxia, inflammation, cellular dysfunction, and activation of fibrogenic biochemical pathways. The end result is the replacement of normal structures with extracellular matrix. Treatments presently are focused on delaying or preventing such progression, and are largely nonspecific. In pediatrics, such therapy is complicated further by pathophysiological issues that render children a unique population.

Podocyte foot process effacement as a diagnostic tool in focal segmental glomerulosclerosis

Podocyte foot process effacement is characteristic of proteinuric renal diseases. In minimal change nephrotic syndrome (MCNS) foot processes are diffusely effaced whereas the extent of effacement varies in focal segmental glomerulosclerosis (FSGS). Here we measured foot process effacement in FSGS and compared it to that in MCNS and in normal kidneys. A clinical diagnosis was used to differentiate idiopathic FSGS from secondary FSGS. Median foot process width, determined morphometrically by electron microscopy, was 3236 nm in 17 patients with idiopathic FSGS, 1098 nm in 7 patients with secondary FSGS, and 1725 nm in 15 patients with MCNS, as compared to 562 nm in 12 control patients. Multivariate analysis showed that foot process width did not correlate with proteinuria or serum albumin levels but was significantly associated as an independent factor with the type of disease. Foot process width over 1500 nm differentiated idiopathic from secondary FSGS with high sensitivity and specificity. Our results show that quantitative analysis of foot processes may offer a potential tool to distinguish idiopathic from secondary FSGS.

Focal segmental glomerulosclerosis complicating solitary kidney

A 78-year old woman with complicating solitary kidney had nephrotic syndrome. Renal biopsy specimens showed focal segmental glomerulosclerosis (FSGS). First, the patient was treated with angiotensin receptor blocker (ARB) and angiotensin converting enzyme inhibitor (ACEI). Proteinuria decreased from 10 to 6 g/day, but overall the nephrotic syndrome did not improve. Additional treatment with prednisolone and cyclosporine reduced proteinuria to less than 1.0 g/day. We report that combination therapy with ARB, ACEI, prednisolone, and cyclosporine was successful for FSGS complicating solitary kidney.

Renin-angiotensin axis blockade reduces proteinuria in presymptomatic patients with familial FSGS

Familial and genetic forms of focal segmental glomerulosclerosis (FSGS) are associated with six different mutations in genes affecting the podocyte (NPHS2, ACTN4, CD2AP, WT1, TRPC6, and PLCE1). Immunosuppressive agents are often unsuccessful in treating this condition. Data regarding the efficacy of renoprotection through blockage of the renin-angiotensin axis is lacking. We describe three children from two different families with familial FSGS in whom partial to complete remission of proteinuria was attained through early blockade of the renin-angiotensin axis. In addition, there was no deterioration of renal function. We speculate that presymptomatic patients with normal renal function who have genetic or familial FSGS may benefit from early blockade of the renin-angiotensin axis and that this may also prevent progressive renal disease.

Cyclosporin in idiopathic glomerular disease associated with the nephrotic syndrome : workshop recommendations

Management of idiopathic glomerular disease associated with nephrotic syndrome (INS) remains controversial and one of the most complex areas relates to utilization of the drug cyclosporin. This is despite its demonstrated effectiveness in several histologic types of the INS in randomized controlled trials. Cyclosporin is effective in inducing remission of proteinuria in approximately 80% of steroid-sensitive cases of minimal change disease (MCD). Cyclosporin is also effective in both the induction of remission and long-term preservation of renal function in steroid-dependent/-resistant MCD and steroid-resistant focal segmental glomerulosclerosis (FSGS). The overall response rate in FSGS is lower than in MCD, and long-term therapy (>12 months) may be required to both achieve remission and sustain it. Cyclosporin therapy is also of benefit in reducing proteinuria in 70-80% of patients with steroid-resistant membranous nephropathy (MGN). In MGN, the maximum benefit is often delayed compared to MCD (>12 weeks). Cyclosporin is generally well tolerated and safe. The major concern remains the nephrotoxicity, but with careful monitoring of the patient's renal function; minimizing the maintenance dose and utilizing repeat renal biopsy in those receiving long-term therapy, this risk can be minimized. The algorithms have been developed derived from the best evidence in the literature in each of the histologic types to help provide a guide to the integration of cyclosporin into the management of INS for the practicing nephrologist.

Pirfenidone slows renal function decline in patients with focal segmental glomerulosclerosis

BACKGROUND AND OBJECTIVES

Pirfenidone is an orally available antifibrotic agent that has shown benefit in animal models of pulmonary and renal fibrosis and in clinical trials of pulmonary fibrosis, multiple sclerosis, and hepatic cirrhosis. Our objective was to determine whether pirfenidone slows the loss of renal function in focal segmental glomerulosclerosis.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

An open-label trial was performed to evaluate the safety and efficacy of pirfenidone in patients with idiopathic and postadaptive focal segmental glomerulosclerosis. The monthly change in estimated GFR, expressed as ml/min per 1.73 m2, was compared between the baseline period and the treatment period. During both periods, patients received angiotensin antagonist therapy if tolerated. Twenty-one patients were enrolled, and 18 patients completed a median of 13 mo of pirfenidone treatment.

RESULTS

The monthly change in GFR improved from a median of -0.61 ml/min per 1.73 m2 (interquartile range -1.31 to -0.41) during the baseline period to -0.45 ml/min per 1.73 m2 (interquartile range -0.78 to -0.16) with pirfenidone therapy. This change represents a median of 25% improvement in the rate of decline (P < 0.01). Pirfenidone had no effect on BP or proteinuria. Adverse events attributed to therapy included dyspepsia, sedation, and photosensitive dermatitis.

CONCLUSIONS

It is concluded that pirfenidone is an attractive candidate for placebo-controlled trials in patients with progressive chronic kidney disease.

A pilot study on tacrolimus treatment in membranous or quiescent lupus nephritis with proteinuria resistant to angiotensin inhibition or blockade

Persistent proteinuria in patients with quiescent lupus can result from membranous lupus nephritis and/or glomerular scarring following previous flares. This pilot study examined the effects of tacrolimus over two years in six patients with membranous/inactive lupus nephritis and persistent proteinuria despite angiotensin inhibition/blockade. Tacrolimus treatment reduced proteinuria and increased serum albumin (time effect, P = 0.047 and 0.032 respectively). Compared with baseline levels, proteinuria improved by more than 50% in five patients (83.3%) and hypoalbuminaemia was corrected in four patients. The efficacy was most prominent in four patients with biopsy-proven membranous lupus nephritis, whose protienuria improved by over 80%. One patient developed biopsy-proven chronic nephrotoxicity after 10 months of tacrolimus treatment, despite non-excessive blood levels. These data suggest that tacrolimus is an effective treatment for proteinuria due to membranous lupus nephritis, but should probably be reserved for patients who are refractory to other non-nephrotoxic treatments, in view of the potential risk of subclinical nephrotoxicity.

Sirolimus Therapy of Focal Segmental Glomerulosclerosis Is Associated With Nephrotoxicity

To evaluate the safety and efficacy of sirolimus in treating patients with focal segmental glomerulosclerosis (FSGS), we performed a phase 2, open-label clinical trial. Inclusion criteria were adults and children 13 years and older with biopsy-proven idiopathic FSGS, proteinuria with protein of 3.5 g/d or greater while on angiotensin antagonist therapy, glomerular filtration rate (GFR) of 30 mL/min/1.73 m(2) or greater (>or=0.50 mL/s), and failure to achieve sustained remission with at least 1 immunosuppressive agent. Eligible patients received sirolimus doses adjusted to achieve trough levels of 5 to 15 ng/mL during the first 4 months and 10 to 20 ng/mL for the subsequent 8 months. The primary outcome was decrease in proteinuria, expressed as complete remission (protein < 0.3 g/d) or partial remission (protein >or= 50% decrease and <3.5 g/d). Six adult patients with FSGS were enrolled in the study; they had median disease duration of 4.0 years, mean age of 39 +/- 11 years, mean baseline Modification of Diet in Renal Disease-estimated GFR of 52 +/- 15 mL/min/1.73 m(2) (0.87 +/- 0.25 mL/s), and median baseline proteinuria with protein of 6.6 g/d (interquartile range, 4.2 to 9.4). Five patients had received cyclosporine. No patient experienced a complete or partial remission. Sirolimus therapy was stopped prematurely in 5 patients for the following reasons: (1) precipitous decrease in GFR in 4 patients after 7 to 9 months of therapy with a greater than 2-fold increase in proteinuria in 3 patients and (2) hypertriglyceridemia with triglyceride levels greater than 1,600 mg/dL (>18 mmol/L) at 5 months in 1 patient. Because of a rapid decrease in GFR with worsening proteinuria, the protocol was closed to further recruitment. We conclude that sirolimus may be associated with nephrotoxicity in some patients with FSGS, particularly those with prolonged disease duration and prior cyclosporine therapy.

Pathophysiology of focal segmental glomerulosclerosis

Focal segmental glomerulosclerosis (FSGS) is a major cause of idiopathic steroid-resistant nephrotic syndrome (SRNS) and end-stage kidney disease (ESKD). In recent years, animal models and studies of familial forms of nephrotic syndrome helped elucidate some mechanisms of podocyte injury and disease progression in FSGS. This article reviews some of the experimental and clinical data on the pathophysiology of FSGS.

Mycophenolate mofetil therapy in frequently relapsing steroid-dependent and steroid-resistant nephrotic syndrome of childhood: current status and future directions

Clinicians are often faced with therapeutic dilemmas and challenges while treating children with frequently relapsing steroid-dependent nephrotic syndrome (SDNS) and steroid-resistant nephrotic syndrome (SRNS). In the past, children with SDNS have been treated with long-term alternate day steroids cyclophosphamide, cyclosporine (CSA), chlorambucil, levamisole, and azathioprine. The essential aim of these therapies is to maintain remission while limiting exposure to steroids. These medications have variable efficacy and undesirable toxicity profiles. Recently, mycophenolate mofetil (MMF) has emerged as a new therapeutic option for the management of SDNS in a few uncontrolled clinical trials. Preliminary data are encouraging. MMF was found to be useful in maintaining remission and has a steroid-sparing effect. Clearly, more data are needed to further characterize the safety and efficacy of MMF, define adequate length of treatment, and optimize drug exposure and monitoring. The management of SRNS is primarily aimed at decreasing proteinuria and inducing remission, if possible. By doing so, one would aim to preserve renal function. CSA therapy is known to be useful in this regard but has undesirable side effects, the most concerning being nephrotoxicity. MMF in combination with steroids and angiotensin-converting enzyme-inhibitor drugs is known to have some efficacy in the management of SRNS. These preliminary data have prompted the National Institutes of Health to sponsor a multicentric controlled trial to compare the safety and efficacy of MMF with that of CSA in the treatment of steroid-resistant focal segmental glomerulosclerosis (FSGS). If MMF therapy is found to be efficacious, it would help obviate the need for CSA and its associated nephrotoxicity. Clearly, MMF has emerged as an important new therapeutic option for the treatment of childhood nephrotic syndrome and FSGS. Further data are required to assess those conditions most likely to respond.

WAGR syndrome: a clinical review of 54 cases

WAGR syndrome is a rare genetic disorder characterized by a de novo deletion of 11p13 and is clinically associated with Wilms' tumor, aniridia, genitourinary anomalies, and mental retardation (W-A-G-R). Although the genotypic defects in WAGR syndrome have been well established, the large variety of phenotypic manifestations of the syndrome has never been reported. We report on 54 cases of WAGR syndrome to demonstrate both the classical clinical signs and nonclassical manifestations found in a large population of individuals with this disorder. An understanding of WAGR syndrome and its clinical findings can provide important insight regarding the functions of the involved genetic region. Recommendations for diagnosis, evaluation, and surveillance of patients with WAGR syndrome are also presented.

Cyclophosphamide in the treatment of focal segmental glomerulosclerosis

Prednisone is the initial treatment of primary focal segmental glomerulosclerosis. However, when immunosuppressive agents in combination with steroids are used in the treatment of prednisone-dependent and prednisone-resistant patients the remission rate is variable. We report a long-term trial using cyclophosphamide (2.0 to 3.0 mg/kg body weight for 12 weeks) in combination with prednisone (1.0 to 2.0 mg/kg body weight), as compared with prednisone alone for the treatment of prednisone-resistant and frequently relapsing nephrotic syndrome and focal segmental glomerulosclerosis. Fifty-four patients (34 males and 20 females) with a diagnosis of idiopathic nephrotic syndrome and focal segmental glomerulosclerosis, followed-up for an average of 86.1 +/- 82.4 months, were evaluated. Complete remission occurred in 20.4% and partial remission in 14.8% of the patients treated with steroids and in 26.7 and 20.0% of the patients treated with cyclophosphamide + prednisone, respectively. Of the 24 prednisone-resistant patients treated with steroids in combination with cyclophosphamide, 33.3% obtained a complete/partial response. At the time of final evaluation, 25% of the patients treated with prednisone and 10.0% of those treated with prednisone in combination with cyclophosphamide had reached end-stage renal disease. Persistent nephrotic syndrome and progressive renal insufficiency were more frequently observed among the patients treated with prednisone alone (50.0 vs 33.3% and 33.3 vs 16.7%, respectively). The treatments were well tolerated and no patient experienced adverse reactions requiring discontinuation of medications. Although open-label and non-randomized, the present trial showed that cyclophosphamide is a reasonable choice for the treatment of primary focal segmental glomerulosclerosis and prednisone-resistant nephrotic syndrome.