Significantly rapid relief from steroid-resistant nephrotic syndrome by LDL apheresis compared with steroid monotherapy

Post-transplant recurrence of focal segmental glomerular sclerosis: consensus statements

Focal segmental glomerular sclerosis (FSGS) is 1 of the primary causes of nephrotic syndrome in both pediatric and adult patients, which can lead to end-stage kidney disease. Recurrence of FSGS after kidney transplantation significantly increases allograft loss, leading to morbidity and mortality. Currently, there are no consensus guidelines for identifying those patients who are at risk for recurrence or for the management of recurrent FSGS. Our work group performed a literature search on PubMed/Medline, Embase, and Cochrane, and recommendations were proposed and graded for strength of evidence. Of the 614 initially identified studies, 221 were found suitable to formulate consensus guidelines for recurrent FSGS. These guidelines focus on the definition, epidemiology, risk factors, pathogenesis, and management of recurrent FSGS. We conclude that additional studies are required to strengthen the recommendations proposed in this review.

Updated evidence of beneficial effect of LDL apheresis for refractory nephrotic syndrome due to a variety of causative diseases for nationwide and global approval

Low-density lipoprotein apheresis (LDL-A) therapy has shown reasonable efficacy in treating nephrotic syndrome (NS) refractory to initial drug therapy and has been covered by National Health Insurance for the indication of drug-resistant focal segmental glomerulosclerosis (FSGS) since 1992 in Japan and has contributed to liberating substantial number of patients of this disease from entering into end-stage renal disease by easier practical application in actual clinical settings. Subsequently, various beneficial evidence of this treatment has accumulated on those other than FSGS, however, due to the limitation of covered disease insurance only for FSGS, patients with diseases other than FSGS are unlikely to benefit from this treatment in practice. This review summarizes the therapeutic evidence of the beneficial effect of LDL-A accumulated to date and the mechanisms of action analyzed from multifaceted perspectives. examines the applicability of expanding insurance coverage for diseases other than FSGS.

Efficacy of extracorporeal plasma therapy for adult native kidney patients with Primary FSGS: a Systematic review

PURPOSE

This study aimed to assess efficacy of extracorporeal plasma therapy (EPT), including plasmapheresis (PE), immunoadsorption (IA), low-density lipoprotein apheresis (LDL-A), and lymphocytapheresis (LCAP) for adult native kidney patients with primary focal segmental glomerulosclerosis (FSGS).

METHODS

A literature search was conducted using MEDLINE, EMBASE and Cochrane Databases through August 2022. Studies that reported outcomes of EPT in adult native kidneys with primary FSGS were enrolled.

RESULTS

18 studies with 104 therapy-resistant or refractory primary native FSGS patients were identified. Overall EPT response rate was 56%, with long-term benefit of 46%. Of the 101 non-hemodialysis (HD) patients, 54% achieved remission, with 30% complete remission (CR) and 23% partial remission (PR). Of 31 patients with PE, response rate was 65%; CR and PR rates were 27% and 37% in 30 non-HD patients. Of 61 patients with LDL-A, the response rate was 54%; CR and PR rates were 41% and 3% in 29 non-HD patients. Of 10 patients with IA, response rate was 40%. Of 2 patients with LCAP, 1 achieved CR, and one developed renal failure. All 3 HD patients showed increase in urine output and gradual decrease in urine protein excretion following PE (n = 1) or LDL-A (n = 2). 2 of 3 HD patients ultimately discontinued dialysis.

CONCLUSION

EPT with immunosuppressive therapy showed benefit in some patients with refractory primary FSGS, and PE appeared to have a higher response rate.

Delayed diagnosis and exacerbation of hyperlipidemia in idiopathic nephrotic syndrome in children during the COVID-19 pandemic

BACKGROUND

During the coronavirus disease-2019 (COVID-19) pandemic, there was a lack of access to outpatient facilities for other diseases. Conversely, few studies have reported changes in clinical features of idiopathic nephrotic syndrome (INS) in children before and after the COVID-19 pandemic.

METHODS

Thirty-two children with primary INS, who were admitted to four Showa University-affiliated hospitals between January 2017 and December 2022, were enrolled in this retrospective study. Children were divided according to the onset of INS into a post-COVID-19 group (onset in 2020-2022, n = 25) and a pre-COVID-19 group (onset in 2017-2019, n = 32). We compared the clinical characteristics and features of initial INS between two groups.

RESULTS

In the post-COVID-19 group, these patients had interval between noticing symptoms of INS, such as edema and INS diagnosis was significantly longer (7 days versus 3.5 days; p = 0.0047), and had significantly raised serum LDL cholesterol levels at the time of INS diagnosis than in the pre-COVID-19 group (314 mg/dL versus 260 mg/dL; p = 0.028). Likewise, steroid-resistant nephrotic syndrome was significantly more common in the post-COVID-19 group [32% (n = 8) versus 6% (n = 2); p = 0.016]. A correlation analysis revealed a moderate positive correlation between the interval from symptom to diagnosis and LDL cholesterol (r = 0.460015, p = 0.0003).

CONCLUSIONS

Children with INS after the COVID-19 pandemic showed a longer time between noticing symptoms of INS and diagnosis, increased serum LDL cholesterol and more steroid resistance than before the pandemic.

Favorable therapeutic efficacy of low-density lipoprotein apheresis for nephrotic syndrome with impaired renal function

Many reports have shown the therapeutic efficacy of LDL apheresis (LDL-A) in drug-resistant nephrotic syndrome (NS) for improvement of heavy proteinuria and severely impaired renal function. To obtain comprehensive results in a large number of cases, a post hoc analysis of the Prospective Observational survey on the Long-Term Effects of the LDL-Apheresis on the Drug Resistant Nephrotic Syndrome (POLARIS) study was performed by stratifying enrolled cases according to the pretreatment estimated glomerular filtration rate (eGFR) levels indicating normal (N) (≥60 ml/min/1.73 m² ), moderately impaired (M) (≥30 to <60 ml/min/1.73 m² ), and severely impaired (S) (<30 ml/min/1.73 m² ) renal function. Significant improvements of proteinuria and renal function were found in Group N and, most interestingly, in Group M. A tendency for improvement in proteinuria was found in Group S. Most cases in all groups had not entered end-stage renal disease at 2 years after LDL-A treatment. These results suggest that LDL-A has therapeutic efficacy even in cases in which renal function has declined to 30 ml/min/1.73 m² .

An update on LDL apheresis for nephrotic syndrome

Low-density lipoprotein (LDL) apheresis has been used increasingly in clinical practice for the treatment of renal diseases with nephrotic syndrome (NS), specifically focal segmental glomerulosclerosis (FSGS). Persistent hyperlipidemia for prolonged periods is nephrotoxic and leads to chronic progressive glomerular and tubulointerstitial injury. Effective management of hyperlipidemia with HMG-CoA reductase inhibitors or LDL apheresis in drug-resistant NS patients may prevent the progression of renal disease and, in some patients, resolution of NS symptoms. Available literature reveals beneficial effects of LDL apheresis for NS refractory to drug therapy. Here we update on the current understanding of lipid nephrotoxicity and application of LDL apheresis to prevent progression of renal diseases.

Immunoadsorption in nephrotic syndrome: Where are we now and where are we going from here?

Idiopathic nephrotic syndrome (INS) is characterized by three different entities, namely minimal change disease (MCD), focal segmental glomerulosclerosis (FSGS) and membranous nephropathy (MN). While there is an increasing understanding of primary MN with the discovery of antibodies directed against phospholipase A2 receptor (PLA2R Ab) and thrombospondin type 1 domain-containing 7A, circulatory factors causative of inducing MCD and FSGS remain in part elusive. Extracorporeal treatment forms (mostly plasma exchange) have been reserved for patients with either a disease course refractory to commonly prescribed immunosuppressive drugs or to patients with recurrence after kidney transplantation. There is a paucity of data supporting the use of immunoadsorption (IAS) in the management of MCD and MN and evidence to perform LDL-apheresis in the former is limited to reports from Japan. Treatment with IAS in primary FSGS has shown mixed responses, possibly biased by including treatment-resistant cases in the absence of genetic testing. In those with recurrence of the disease following kidney transplantation, IAS has shown high remission rates with an acceptable safety profile. There is a need to compare IAS to plasma exchange (PLEX) in this indication and due to a higher amount of plasma processed during one session, IAS may have advantages over PLEX. Removal of PLA2R Ab by IAS is currently being tested in a phase II clinical trial. More clinical trials in a prospective and randomized fashion need to be designed to prove the concept that IAS may be a treatment option for INS. While PLEX is still the leading extracorporeal treatment form in these indications, this review aims to highlight the efficacy and safety of IAS in the management of INS.

Effect of Low-Density Lipoprotein Apheresis for Nephrotic Idiopathic Membranous Nephropathy as Initial Induction Therapy

Low-density lipoprotein apheresis (LDL-A) has been used for nephrotic syndrome (NS) caused by focal segmental glomerulosclerosis in Japan. Idiopathic membranous nephropathy (iMN) can also cause treatment-resistant NS. Therefore, we investigated the effect of LDL-A during initial induction for it. This retrospective, observational, and single-center study enrolled consecutive iMN patients who received steroids from March 2000 to May 2015. We compared data between 11 patients treated with LDL-A (LDL-A group) and 27 patients without (non-LDL-A group) at baseline and 4 and 8 weeks later. Reduction rate of proteinuria and increase rate of serum albumin in LDL-A group were significantly higher than the other after 4 weeks (P = 0.036 and 0.030) and 8 weeks (P = 0.030 and <0.001), respectively. There was no adverse event caused by LDL-A and immunosuppressant dose was not significantly different. In conclusion, LDL-A may be an effective choice for initial induction of nephrotic iMN.

Dextran-Sulfate Plasma Adsorption Lipoprotein Apheresis in Drug Resistant Primary Focal Segmental Glomerulosclerosis Patients: Results From a Prospective, Multicenter, Single-Arm Intervention Study

Background: Focal segmental glomerulosclerosis (FSGS) causes end stage renal disease (ESRD) in significant proportion of patients worldwide. Primary FSGS carries poor prognosis and management of FSGS patients, refractory to standard treatments or resistant to steroids, remains a major challenge. Lipoprotein apheresis is a therapeutic approach for drug resistant primary FSGS and post-renal transplant primary FSGS recurrence. Objectives: To examine the safety and probable benefit at 1, 3, 6, 12, and 24-months following completion of apheresis treatment using Liposorber® LA-15 system in patients with nephrotic syndrome (NS), due to refractory primary FSGS or primary FSGS associated NS, in post renal transplant children. Material and Methods: Prospective, multicenter, single-arm intervention study using Liposorber® LA-15 system. Patients ≤21 years old with drug resistant or drug intolerant NS secondary to primary FSGS with glomerular filtration rate (GFR) ≥60 ml/min/1.73 m² or post renal transplant patients ≤21 years old with primary FSGS associated NS were included in the study. Each patient had 12 dextran-sulfate plasma adsorption lipoprotein apheresis sessions over a period of 9 weeks. All patients were followed up at 1, 3, 6, 12, and 24-months following completion of treatment. Results: Of 17 patients enrolled, six were excluded from the outcome analysis (protocol deviations). Of the remaining 11 patients, all but one have completed apheresis treatments. Three patients were lost to follow-up immediately after completion of apheresis and excluded from outcome analysis. At one-month follow-up, 1 of 7 patients (14.3%) attained partial remission of NS while 2 of 4 subjects (50%) and 2 of 3 subjects (66.7%) had partial/complete remission at 3- and 6-months follow-up, respectively. One of two patients followed up for 12 months had complete remission and one patient had partial remission of NS after 24 months. Improved or stable eGFR was noted in all patients over the follow-up period. Conclusion: The results of our multicenter study showed improvement in the response rates to steroid or immunosuppressive therapy and induced complete or partial remission of proteinuria in some of the patients with drug resistant primary FSGS. The main limitation of our study is the small number of subjects and high dropout rate.

Treatment-resistant PLA2R-negative membranous nephropathy responsive to low-density lipoprotein apheresis

Idiopathic membranous nephropathy is the most common cause of nephrotic syndrome in nondiabetic adults. The antibody most often implicated is the M-type phospholipase A2 receptor (PLA2R) antibody, found in >70% of primary membranous nephropathy cases. First-line therapy is immunosuppressive in nature, but for patients who are treatment-resistant there is a significant risk of end-stage renal disease and mortality. Hypercholesterolemia is not only a side effect of nephrotic syndrome, but also its presence may worsen renal function. A recent single-arm observational study in Japan found that low-density lipoprotein apheresis (LDL-A) was able to ameliorate nephrotic syndrome in half of patients who were resistant to medication. We present a case of treatment resistant PLA2R negative membranous nephropathy who had significant improvement following two courses of LDL-A. To our knowledge, this is the first such reported case in the United States.

Emerging therapeutic strategies for minimal change disease and focal and segmental glomerulosclerosis

INTRODUCTION

Minimal change disease (MCD) and Focal and segmental glomerulosclerosis (FSGS) are two of the major causes of nephrotic syndrome (NS) in children and adults. According to KDIGO (Kidney Disease: Improving Global Outcomes) guidelines, the treatment of adult primary MCD and FSGS should be based on immunosuppressants and antiproteinuric drugs. Recently, Rituximab, a humanized monoclonal antibody (mAb) has emerged as a potential treatment for steroid or calcineurin inhibitor-dependent patients; it has however demonstrated lower efficacy in those with nephrotic syndrome that is resistant to the above indicated drugs.

AREAS COVERED

Analysis of ongoing and already completed clinical trials, retrieved from clinicaltrials.gov, clinicaltrialsregister.eu and PubMed involving new therapies for nephrotic syndrome secondary to MCD and FSGS.

EXPERT OPINION

The most promising drugs under investigation for MCD and FSGS are mAbs. We are hopeful that new therapeutic options to treat multi-drug resistant MCD and FSGS will emerge from currently ongoing studies. What appears certain is the difficulty in enrolling patients affected by orphan renal diseases and the selection of valid endpoints in clinical trials, such as kidney failure.

Preoperative Low-Density Lipoprotein Apheresis for Preventing Recurrence of Focal Segmental Glomerulosclerosis after Kidney Transplantation

Background

Focal segmental glomerulosclerosis (FSGS) often develops rapidly and frequently progresses to renal failure, while the recurrence rate after kidney transplantation is 20–50%. We performed low-density lipoprotein (LDL) apheresis before kidney transplantation in FSGS patients to prevent recurrence.

Methods

Five adult patients with chronic renal failure due to FSGS undergoing living related donor kidney transplantation were investigated retrospectively. LDL apheresis was done 1-2 times before transplantation. Postoperative renal function and recurrence of FSGS were assessed.

Results

The patients were two men and three women aged 24 to 41 years. The observation period ranged from 60 days to 22 months. Preoperative LDL apheresis was performed once in one patient and twice in four patients. Blood LDL cholesterol levels were normal before LDL apheresis and remained normal both after LDL apheresis and after kidney transplantation. Additional LDL apheresis was performed once in one patient with mild proteinuria after transplantation. The renal graft survived in all patients and there was no evidence of recurrent FSGS.

Conclusions

Although the observation period was short, FSGS did not recur in all 5 patients receiving preoperative LDL apheresis. These results suggest that LDL apheresis can be effective in preventing recurrence of FSGS after kidney transplantation.

Atheromatous embolization

Atheromatous embolization is a multisystem disease complicating advanced atherosclerosis. It occurs most often as a complication of angiography, an endovascular procedure or cardiovascular surgery. Atheromatous embolization can present in a subtle manner where it is often under-recognized, or with catastrophic results including myocardial infarction, strake or acute renal failure. It may mimic other disease processes and often goes underdiagnosed and undertreated. A high clinical suspicion is the key to diagnosis. Atheromatous embolization results in significant morbidity and mortality; therefore, early recognition followed by aggressive management may help to prevent end-organ damage and improve overall clinical outcomes. Management strategies should include risk factor modification, prevention of further insults by discontinuing or avoiding predisposing factors, supportive treatment and interventional or surgical approaches to remove the atheroembolic source. Atheromatous embolization is expected to increase as our population ages and the epidemics of diabetes mellitus and obesity increase.

Treatment Strategies of Adult Primary Focal Segmental Glomerulosclerosis: A Systematic Review Focusing on the Last Two Decades

Adult primary focal segmental glomerulosclerosis (FSGS) remains a therapeutic challenge for the treating physician. With the advent of novel immunosuppressive measures, our arsenal of therapeutic options increased considerably. The aim of this review was to summarize reports published over the last two decades which reported on treatment outcome. Most reports included patients with a steroid-resistant (SR) disease course, yet the cohort with the highest unmet need, since persistent nephrotic range proteinuria is associated with a poor renal prognosis and portends a high risk of developing end-stage renal disease. While in first-line treatment, steroid treatment remains the recommended standard with an overall remission rate of 50% and higher, optimal treatment strategies for steroid-dependent/multirelapsing (SD/MR) and SR patients have to be defined. In both entities, calcineurin inhibitors showed good efficacy, while mycophenolate mofetil was less effective in SR cases compared to those with SD/MR. The same was true for rituximab, a monoclonal antibody targeting B-cells. In resistant cases, addition of extracorporeal treatment options or treatment with alkylating agents may be considered. To shape the future for treatment of FSGS, international collaborations to conduct larger clinical trials are needed to identify potential novel efficacious immunosuppressive or immunomodulatory therapies.

Lipoprotein Apheresis

Patients with familial hypercholesterolemia (FH) have early development of atherosclerosis and cardiovascular disease (CVD). Lipid level-lowering medications are not always successful in reducing increased low-density lipoprotein C (LDL-C) levels. Lipoprotein apheresis (LA) therapy has proven its clinical benefit in reducing CVD events for patients with FH with hypercholesterolemia. LA reduces LDL-C levels by more than 60% in patients with FH and reduces CVD events. LA also reduces Lp(a) levels and CVD events. LA reduces inflammatory markers and blood viscosity.

A Prospective Observational Survey on the Long-Term Effect of LDL Apheresis on Drug-Resistant Nephrotic Syndrome

BACKGROUND/AIMS

LDL apheresis (LDL-A) is used for drug-resistant nephrotic syndrome (NS) as an alternative therapy to induce remission by improvement of hyperlipidemia. Several clinical studies have suggested the efficacy of LDL-A for refractory NS, but the level of evidence remains insufficient. A multicenter prospective study, POLARIS (Prospective Observational Survey on the Long-Term Effects of LDL Apheresis on Drug-Resistant Nephrotic Syndrome), was conducted to evaluate its clinical efficacy with high-level evidence.

METHODS

Patients with NS who showed resistance to primary medication for at least 4 weeks were prospectively recruited to the study and treated with LDL-A. The long-term outcome was evaluated based on the rate of remission of NS 2 years after treatment. Factors affecting the outcome were also examined.

RESULTS

A total of 58 refractory NS patients from 40 facilities were recruited and enrolled as subjects of the POLARIS study. Of the 44 subjects followed for 2 years, 21 (47.7%) showed remission of NS based on a urinary protein (UP) level <1.0 g/day. The UP level immediately after LDL-A and the rates of improvement of UP, serum albumin, serum creatinine, eGFR, and total and LDL cholesterol after the treatment session significantly affected the outcome.

CONCLUSIONS

Almost half of the cases of drug-resistant NS showed remission 2 years after LDL-A. Improvement of nephrotic parameters at termination of the LDL-A treatment was a predictor of a favorable outcome.

Low-density lipoprotein apheresis for proteinuria in lupus nephritis with intraglomerular foam cells containing cholesterol crystals

A 28-year-old woman with systemic lupus erythematosus was referred to our hospital due to nephrotic-level proteinuria despite approximately 1 year of treatment with 50 to 60 mg/d of prednisolone and 100 to 150 mg/d of cyclosporine with methylprednisolone pulse therapy. Kidney biopsy showed diffuse global lupus nephritis (World Health Organization class 4-G A/C) with many intraglomerular foam cells containing cholesterol crystals. Surprisingly, proteinuria diminished after only 5 low-density lipoprotein (LDL) cholesterol apheresis sessions. This case demonstrated the potential of LDL apheresis to exhibit a remarkable effect on not only focal segmental glomerulosclerosis, but also other types of nephritis, particularly nephritis with intraglomerular foam cells.

Immediate therapeutic efficacy of low-density lipoprotein apheresis for drug-resistant nephrotic syndrome: evidence from the short-term results from the POLARIS Study

BACKGROUND

Hyperlipidemia is not merely a complication but a major exacerbating factor in longstanding nephrotic syndrome (NS). Low-density lipoprotein apheresis (LDL-A) has been reported to ameliorate dyslipidemia and induce rapid remission of NS. Several clinical studies have suggested the therapeutic efficacy of LDL-A, but the level of clinical evidence is insufficient. Therefore, a multicenter prospective study, POLARIS (Prospective Observational Survey on the Long-Term Effects of LDL Apheresis on Drug-Resistant Nephrotic Syndrome), was initiated in Japan.

METHOD

Patients with drug-resistant NS were prospectively recruited into the study and treated with LDL-A in facilities that were registered in advance. In the POLARIS study design, the clinical data are to be followed up for 2 years. In the current study, we aimed at evaluating the short-term efficacy based on the treatment outcome of LDL-A immediately after completion of treatment.

RESULTS

Along with rapid improvement of hyperlipidemia, LDL-A significantly improved proteinuria and hypoproteinemia after treatment. More than half of the patients showed remission of NS based on the urinary protein level at the completion of LDL-A. The duration of NS before the start of treatment was significantly shorter in patients who responded to LDL-A.

CONCLUSIONS

An analysis of patients registered in the POLARIS study indicated that LDL-A has short-term efficacy for drug-resistant NS. Rapid relief of dyslipidemia by LDL-A may provide early remission in about half of the NS patients who are resistant to conventional medication. Completion of the POLARIS study may reveal additional long-term effects of LDL-A in these patients.

Beneficial effect of LDL-apheresis in refractory nephrotic syndrome

LDL-apheresis is a method to correct dyslipidemia rapidly. It is expected to alleviate the tissue toxicity of persistent dyslipidemia in not only primary, but also in secondary dyslipidemia associated with refractory nephrotic syndrome, and to have a protective effect against glomerular and tubular injury as expected in atherosclerosis. In addition, the effectiveness of LDL-apheresis to promote the remission of nephrotic syndrome has been recognized. In Japan, LDL-A to control hyperlipidemia in patients with refractory nephrotic syndrome associated with focal segmental glomerulosclerosis is covered by national health insurance. Here, the hypothetical mechanism behind its effect and the evidence for its effectiveness over a long period are reviewed.

The blood compatibilities of blood purification membranes and other materials developed in Japan

The biocompatibilities in blood purification therapy are defined as "a concept to stipulate safety of blood purification therapy by an index based on interaction in the body arising from blood purification therapy itself." The biocompatibilities are associated with not only materials to be used but also many factors such as sterilization method and eluted substance. It is often evaluated based on impacts on cellular pathways and on humoral pathways. Since the biocompatibilities of blood purification therapy in particular hemodialysis are not just a prognostic factor for dialysis patients but a contributory factor for long-term complications, it should be considered with adequate attention. It is important that blood purification therapy should be performed by consistently evaluating not only risks associated with these biocompatibilities but also the other advantages obtained from treatments. In this paper, the biocompatibilities of membrane and adsorption material based on Japanese original which are used for blood purification therapy are described.

Applications of LDL-apheresis in nephrology

LDL-apheresis (LA) was originally used for familial hyperlipidemia, and then in Japan extended to use for the treatment of patients with peripheral arterial disease (PAD) and nephrotic syndrome due to steroid-resistant focal glomerular sclerosis (FGS). The reason why this treatment is applicable for these disorders is due to the fact that LA exerts its favorable effects beyond the lipid-lowering effect. The main underlying mechanisms, for example, in the case of LA application in patients with PAD are: (1) improvement of hemorheology, (2) improvement of endothelial dysfunction, (3) elevations of serum levels of NO and bradykinin, (4) increase in serum levels of vascular endothelial growth factor, and (5) reduction of adhesion molecules on monocytes. Furthermore, we have reported that LA could have anti-inflammatory effects because LA reduces serum levels of P-selectin, which is known to play an important role in the development of atherosclerosis as well as a reduction of serum C-reactive protein levels as standard biomarker of atherosclerosis. Massive proteinuria is also an important challenge in nephrology. The possible mechanisms besides removal of toxic lipids are the reduction of the vasoconstrictive prostanoid and thromboxane A2 (TXA2) and an improvement in macrophage function evidenced by a significant amelioration of interleukin-8 production by lipopolysaccharide-stimulated peripheral blood mononuclear cells. It is intriguing to note that in terms of pharmacodynamics, LA improves steroid and cyclosporine uptake into lymphocytes. Although there are no randomized controlled trials, it is clear that LA has various effects beyond lowering lipids. Making the device more concise and changing it into a whole blood adsorption type, we need to collect more clinical cases and to study the underlying mechanisms further.

Long-term efficacy of low-density lipoprotein apheresis for focal and segmental glomerulosclerosis

Recently, there have been reports on the efficacy of low-density lipoprotein (LDL) apheresis (LDL-A) for focal and segmental glomerulosclerosis (FSGS) in pediatric patients. However, there have been few reports on the long-term efficacy of LDL-A for FSGS in such patients. We report here a case of long-term efficacy of LDL-A for FSGS. The patient was a 13-year-old boy with FSGS who presented with steroid-resistant and cyclosporine-resistant nephrotic syndrome and hyperlipidemia. LDL-A was performed 24 times on one year. Following LDL-A, serum concentrations of LDL, very low-density lipoprotein (VLDL), apoprotein B, and vascular endothelial growth factor significantly decreased, and urinary excretion of protein also decreased. In addition, 3 years after LDL-A, the pathology findings on a second renal biopsy had improved. The patient has been in remission from FSGS for 12 years since LDL-A. These findings suggest that LDL-A may be useful in maintaining long-term remission from pediatric FSGS.

Effect of low-density lipoprotein apheresis on urinary protein and podocyte excretion in patients with nephrotic syndrome due to diabetic nephropathy

BACKGROUND

The aim of the present study is to determine whether low-density lipoprotein (LDL) apheresis affects proteinuria and urinary podocyte excretion in patients with type 2 diabetes and nephrotic syndrome.

METHODS

LDL apheresis was performed on patients with diabetes with long-standing nephrotic syndrome, and urinary protein level and number of urinary podocytes were compared between these patients (5 men, 3 women; mean age, 54.6 years) and 10 nephrotic patients with diabetes not treated with LDL apheresis (6 men, 4 women; mean age, 56.5 years).

RESULTS

LDL apheresis reduced total cholesterol (P < 0.001), LDL cholesterol ( P < 0.001), lipoprotein(a) (P < 0.001), creatinine (P < 0.05), and blood urea nitrogen (P < 0.05) levels and increased creatinine clearance (P < 0.05). The LDL apheresis group showed a significant decrease in urinary protein excretion (from 10.8 +/- 3.2 to 1.8 +/- 1.1 g/d; P < 0.001) and number of urinary podocytes (from 4.8 +/- 2.2 to 0.9 +/- 0.4 cells/mL; P < 0.01).

CONCLUSION

These data suggest that LDL apheresis effectively reduces proteinuria and podocyte excretion, ameliorating renal dysfunction in patients with nephrotic syndrome caused by diabetic nephropathy.

Clinical applications of long-term LDL-apheresis on and beyond refractory hypercholesterolemia

Premature coronary heart disease (CHD) can result from high LDL cholesterol levels even in the absence of any other risk factors. A striking example is found in children who have the homozygous form of familial hypercholesterolemia (FH) with extremely high levels of LDL-cholesterol, and severe atherosclerosis and CHD often develop during the first decades of life. LDL-apheresis was developed for the treatment of severe type of FH patients who are resistant to lipid-lowering drug therapy. Clinical efficacy and safety of the therapeutic tool which directly removes LDL from circulation have already been established in the treatment for refractory hypercholesterolemia in FH patients. The most recently developed method enables lipoproteins to be adsorbed directly from whole blood, using polyacrylate column. In addition to benefits derived from the stabilization or regression of arterial lesions, we highlight other possible clinical applications of LDL-apheresis. However, most of these clinical benefits came from case reports or retrospective studies. Mechanisms related these clinical improvement remain unclear, and prospective randomized controlled trials should be performed for the new clinical indications of LDL-apheresis.

A case of marked hyperlipoprotein(a)emia associated with nephrotic syndrome and advanced atherosclerosis

In 1989, we encountered a 68-year-old male patient with marked hyperlipoprotein(a)emia (hyperLp(a)emia), who was being treated for hypertension and arteriosclerotic obliterans (ASO) at an outpatient clinic of our hospital. He began to develop leg edema in 2002 and was referred to the Department of Internal Medicine. It was determined that he had severe hyperlipidemia (total cholesterol, 362 mg/dl), proteinuria, and hypoalbuminemia, suggesting the presence of nephrotic syndrome. On lipoprotein analysis, he was found to have very high levels of Lp(a) in the plasma (329 mg/dl). Severe atherosclerosis was also found: that is, abdominal aortic aneurysm (AAA) and coronary artery disease (CAD) were detected, in addition to ASO. After remission of the nephrotic syndrome, the plasma Lp(a) level decreased to 204 mg/dl and the total cholesterol concentration decreased to 179 mg/dl, while very high levels of Lp(a) persisted. We estimate that the markedly elevated Lp(a) plasma levels in this patient may have played some role in the progression of atherosclerosis.

The focal segmental glomerulosclerosis permeability factor: biochemical characteristics and biological effects

Focal segmental glomerulosclerosis (FSGS) is characterized by steroid resistant nephrotic syndrome and progression to end-stage renal disease. Proteinuria in certain patients with FSGS may be caused by a circulating factor (FSGS permeability factor [FSPF]). The current report documents the biochemical characteristics and the biological and molecular effects of 70% ammonium sulfate supernatant of plasma from patients with recurrence of FSGS after transplantation (FSGS 70% supernatant). FS permeability activity, defined as the capacity of plasma from patients with FSGS to increase albumin permeability (P(alb)) of isolated glomeruli, was assessed in vitro. Permeability activity was not affected by lyophilization. FSPF bound strongly to matrices containing Mono-Q anion exchanger or protein A. It eluted from matrix-bound Cibacron blue F3GA over a wide range of salt concentrations, indicating a potential binding with other proteins, such as albumin. FSPF caused a maximal increase in P(alb) within 2 mins of incubation in vitro. Cellular proteins isolated from glomeruli with increased P(alb) showed decreased tyrosine phosphorylation of focal adhesion kinase, paxillin, and other proteins. Tyrosine phosphatase ]inhibition prevented the increase in P(alb). Intravenous administration of as little as 3 mg protein in FSGS 70% supernatant increased P(alb), while 9 mg or more were required to produce proteinuria. We conclude that FSPF is a low-molecular-weight protein, carries an anionic charge, and binds to protein A. Effects of FSPF on the glomerular permeability barrier are rapid and dose dependent and involve signaling through altered phosphorylation of cellular proteins. Identification of these biochemical and biological characteristics may be used to design strategies for removing FSPF from circulation and for purification and identification of this factor.

Effective Therapy of a Child Case of Refractory Nephrotic Syndrome with Tacrolimus

We report here the case of a 9-year-old Japanese boy with nephrotic syndrome caused by focal segmental glomerulosclerosis, which was refractory to treatment. Although aggressive immunosuppressive therapy consisting of methylprednisolone pulse therapy combined with cyclosporine A (CsA) and intermittent low density lipoprotein apheresis was effective in overcoming his steroid-resistant state, the child became persistently steroid-dependent, that is, more than 0.75 mg/kg per day of prednisolone combined with CsA was required to maintain a negative test for proteinuria. Since adverse effects of prednisolone, such as short stature, obesity, osteoporosis and cataract, were noted, CsA in his treatment regimen was replaced with tacrolimus at the dose of 0.1 mg/kg per day, with the trough blood level of the drug maintained at around 10 ng/ml. Within 4 months of the inclusion of tacrolimus in the treatment regimen, complete remission was achieved, with no recurrence of the proteinuria, while the prednisolone dose could be tapered to 0.3 mg/kg per day. No adverse effects of tacrolimus were observed. These clinical results suggest that tacrolimus may be the drug of choice in selected patients with refractory nephrotic syndrome, even if pediatric-onset cases, at least those in whom the steroid-sparing effects of CsA is unsatisfactory.

A combined low-density lipoprotein apheresis and prednisone therapy for steroid-resistant primary focal segmental glomerulosclerosis in children

BACKGROUND

Treatment of steroid-resistant (SR) primary focal segmental glomerulosclerosis (FSGS) remains a major challenge in nephrology. A prospective study was conducted to clarify the therapeutic role of low-density lipoprotein apheresis (LDL-A) in 11 nephrotic children with SR and cyclosporine A (CsA)-resistant primary FSGS.

METHODS

Based on entry criteria, all 11 eligible patients had biopsy-proven primary FSGS presenting with nephrotic syndrome (NS) and were resistant to steroid and conventional-dose CsA therapy. LDL-A was performed twice a week for 3 weeks (first course), then weekly for 6 weeks (second course). Beginning from the second LDL-A course, a dosage of 1 mg/kg/d of prednisone was administered for 6 weeks, then tapered.

RESULTS

Seven patients experienced remission of NS, 5 of whom achieved complete remission within 4 weeks after initiating prednisone therapy with LDL-A. These 5 patients maintained normal renal function during follow-up (median, 4.4 years). Of 2 patients with partial remission, 1 patient maintained stable renal function during follow-up (4.5 years), whereas the other patient showed a gradual decline in renal function and progressed to end-stage renal failure (ESRF) 7.8 years after LDL-A therapy. Four patients who were considered to experience treatment failure had persistent NS and progressed to ESRF in 1.3 years (median) after LDL-A therapy. Complete remission (n = 5) was associated with significantly more highly selective proteinuria compared with treatment failure (n = 4).

CONCLUSION

This study suggests that combined LDL-A and prednisone therapy can be a valuable addition to therapeutic options for treating patients with SR-FSGS. The role of LDL-A in treating these patients deserves to be assessed further in larger randomized controlled trials.

Other immunosuppressive agents for focal segmental glomerulosclerosis

A prolonged course with corticosteroids represents the first therapeutic approach for nephrotic patients with focal segmental glomerulosclerosis (FSGS). In patients with contraindications to steroids or in those who do not respond to steroids or cyclosporine, cytotoxic agents, mycophenolate mofetil (MMF), plasmapheresis, and low-density lipoprotein (LDL) apheresis have been tried as alternative treatments. A short-term treatment with cytotoxic agents often is ineffective in steroid-resistant patients However, an aggressive and prolonged treatment with cytotoxic agents combined with corticosteroids proved to be effective in more than half of steroid-resistant children. In adults, the response to cytotoxic agents was good in steroid-responsive patients, but was poor in steroid-resistant patients. Better results were observed when cytotoxic therapy was prolonged for several months. The problem with these drugs is that long-term immunosuppression may be complicated by severe side effects including a major risk for cancer. Uncontrolled studies reported that MMF can induce some reduction of proteinuria, but complete remission of proteinuria was rare and no data on long-term follow-up evaluation with this drug are available. Good results have been reported with plasmapheresis, immunoadsorption, and lipopheresis. However, all the reports were uncontrolled, small sized, and with short-term follow-up evaluation. In conclusion, there are several therapeutic options for patients who respond to steroids and have further relapses of nephrotic syndrome, but how to treat steroid-resistant patients is still a matter of debate. Nevertheless, a 6-month trial with cytotoxic agents or MMF can be offered to steroid-resistant patients to identify the few patients who respond to these agents. The preliminary results with plasmapheresis or lipopheresis are promising but further studies are needed to assess the role of these treatments.

Permeability factors in focal segmental glomerulosclerosis

The pathologic diagnosis of focal segmental glomerulosclerosis (FSGS) is associated with a syndrome of steroid-resistant nephrotic syndrome and progressive renal insufficiency. The incidence of FSGS has increased in recent years. Known causes of FSGS include genetic abnormalities, viral infections, decreased nephron number, and hyperperfusion/hyperfiltration. The etiology is unknown in the majority of cases. FSGS recurs after initial renal transplantation in as many as 30% to 50% of patients. Recent studies have verified the hypothesis that plasma of patients with FSGS contains a factor or factors that increase permeability of glomerular capillaries and cause proteinuria after injection into rats. Patients who experience posttransplant recurrence of FSGS and those with rapidly progressive disease exhibit this activity. Permeability activity has been verified in functional assays and defined by measurement of albumin permeability (P(alb)) or glomerular volume variation (GVV). Permeability activity is decreased by plasmapheresis or immunoadsorption and can be recovered from discarded plasma or eluate from adsorption materials. Studies from our laboratory indicate that permeability activity is carried by small, highly glycosylated, hydrophobic protein(s)/peptide(s). Normal plasma contains substances capable of blocking or inactivating the FSGS permeability factor. Pharmacologic agents including cyclosporine, indomethacin, and derivatives of Trypterigium wilfordii also block permeability activity in vitro. The observation that permeability activity can be blocked by diverse agents raises hope that specific therapy may be designed for FSGS. Future investigations will permit identification of the active FSGS permeability factor, of mechanisms that initiate and perpetuate proteinuria, and of interventions to prevent renal failure in native kidneys and recurrence of disease in renal allografts.

Blood purification therapies using dextran sulfate cellulose columns Liposorber and Selesorb

Liposorber is a column used for plasma purification that adsorbs low-density lipoproteins with high selectivity, while Selesorb is a column that selectively adsorbs anti-DNA antibodies, anticardiolipin antibodies, and immune complexes. Both columns are packed with carriers, where a dextran sulfate ligand is bound to porous cellulose beads. Liposorber is used to treat familial hypercholesterolemia (FH), peripheral arterial disease (PAD), and focal segmental glomerulosclerosis (FGS): Selesorb is used to treat systemic lupus erythematosus (SLE). Treatment utilizing both columns is being used effectively in patients with refractory disease that is resistant to pharmacotherapy.