The Potential Role of HMG-CoA Reductase Inhibitors in Pediatric Nephrotic Syndrome

Skimmed breast milk for treatment of hypertriglyceridemia in an infant with congenital nephrotic syndrome

Congenital nephrotic syndrome (CNS) is a complex condition that requires multidisciplinary care. Hyperlipidemia is a characteristic feature with elevation of serum cholesterol and triglycerides. Little evidence is available to guide treatment of dyslipidemia in infants with CNS. We describe successful treatment of severe hypertriglyceridemia through dietary changes in a boy with CNS. A 9-day-old boy presented to the emergency department with lower extremity edema caused by deep venous thrombosis. Laboratory evaluation identified hypoalbuminemia, nephrotic-range proteinuria, and a pathogenic variant of the NPHS1 gene. The initial triglyceride concentration of 369 mg/dl increased to 3096 mg/dl by 5 weeks of age, when his diet consisted of breast milk. Refrigerated breast milk was skimmed by removing the top layer after allowing it to separate for 24 h. This process was repeated prior to use. Skimmed breast milk was supplemented with medium-chain triglyceride oil and an infant protein powder. After 2 days, the triglyceride concentration declined to 481 mg/dl and, by day 10, to 148 mg/dl. When breast milk supply decreased, a 1:1 ratio of skimmed maternal breast milk to an elemental, very low-fat formula was utilized. The triglyceride concentration remained below 400 mg/dl for the first year of life, except when skimmed breast milk was not available during hospitalization. Severe hypertriglyceridemia caused by CNS can present in the neonatal period and be difficult to manage. In our patient, skimmed maternal breast milk was successful in reducing the triglyceride concentration and should be considered a therapeutic option for children with hyperlipidemia caused by CNS.

Dyslipidemia and cardiovascular health in childhood nephrotic syndrome

Children with steroid-resistant nephrotic syndrome (SRNS) are exposed to multiple cardiovascular risk factors predisposing them to accelerated atherosclerosis. This risk is negligible in steroid-sensitive nephrotic syndrome, but a substantial proportion of children with SRNS progress to chronic kidney disease, exacerbating the already existing cardiovascular risk. While dyslipidemia is an established modifiable risk factor for cardiovascular disease in adults with NS, it is uncertain to what extent analogous risks exist for children. There is increasing evidence of accelerated atherosclerosis in children with persistently high lipid levels, especially in refractory NS. Abnormalities of lipid metabolism in NS include hypertriglyceridemia and hypercholesterolemia due to elevated apolipoprotein B-containing lipoproteins, decreased lipoprotein lipase and hepatic lipase activity, increased hepatic PCSK9 levels, and reduced hepatic uptake of high-density lipoprotein. Existing guidelines for the management of dyslipidemia in children may be adapted to target lower lipid levels in children with NS, but they will most likely require both lifestyle modifications and pharmacological therapy. While there is a lack of data from randomized controlled trials in children with NS demonstrating the benefit of lipid-lowering drugs, therapies including statins, bile acid sequestrants, fibrates, ezetimibe, and LDL apheresis have all been suggested and/or utilized. However, concerns with the use of lipid-lowering drugs in children include unclear side effect profiles and unknown long-term impacts on neurological development and puberty. The recent introduction of anti-PCSK9 monoclonal antibodies and other therapies targeted to the molecular mechanisms of lipid transport disrupted in NS holds promise for the future treatment of dyslipidemia in NS.

Anti-proteinuria effect of antibody against ANGPTL3 coil-coiled domain on adriamycin-induced nephropathy in mice

Proteinuria is an important marker and is closely related to the progressive decline of renal function. Our previous research showed that angiopoietin-like-3 (ANGPTL3) plays a crucial role in proteinuria. In this study, we prepared an antibody against ANGPTL3 coil-coiled domain (ANGPTL3-CCD) and investigated the protective effect of anti-ANGPTL3-CCD antibody in mice with adriamycin-induced nephropathy. Nephropathy was established by adriamycin injection at a dose of 25 mg per kg in 8-12 week-old male mice in the ADR group. Blockade of ANGPTL3 by anti-ANGPTL3-CCD antibody (20 mg per kg) was performed every three days nine times after adriamycin injection in the ADR plus anti-angptl3-antibody group. The anti-ANGPTL3-CCD antibody can specifically recognize ANGPTL3. After anti-ANGPTL3-CCD antibody intervention, the urinary protein level in the ADR plus anti-angptl3-antibody group was significantly lower than that in the ADR group. Serum albumin was higher and triglyceride and total cholesterol were lower in the ADR plus anti-angptl3-antibody group than in the ADR group. The levels of serum creatinine did not significantly differ among the groups. Focal sclerotic glomeruli and podocyte foot processes extensive fusion were found in the renal tissue of the ADR group, whereas no sclerotic glomeruli and only partial fusion were found in the ADR plus anti-angptl3-antibody group. This study demonstrated that the anti-ANGPTL3-CCD antibody ameliorated proteinuria and podocyte dysfunction in adriamycin-induced nephropathy in mice.

Effect of atorvastatin on dyslipidemia and carotid intima-media thickness in children with refractory nephrotic syndrome: a randomized controlled trial

BACKGROUND

Dyslipidemia is an important cardiovascular risk factor in steroid-resistant nephrotic syndrome (SRNS). Efficacy of statins for treatment of hyperlipidemia in children with SRNS is unclear.

METHODS

This prospective, randomized, double-blind, placebo-controlled, parallel-group clinical trial enrolled 30 patients with SRNS, aged 5-18 years, with serum low-density lipoprotein cholesterol (LDL-C) levels between 130 and 300 mg/dl, to receive a fixed dose of atorvastatin (n = 15, 10 mg/d) or placebo (n = 15) by block randomization in a 1:1 ratio. Primary outcome was change in serum LDL-C at 12 months. Change in levels of other lipid fractions, carotid intima-media thickness (cIMT), flow-mediated dilation (FMD) of the brachial artery, and adverse events were also evaluated.

RESULTS

At the end of 12 months, atorvastatin was not superior to placebo in reducing plasma LDL-C levels, median percentage reduction 15.8% and 9.5% respectively, in atorvastatin and placebo arms (n = 14 in each; P = 0.40). Apolipoprotein B levels significantly declined with atorvastatin in modified intention-to-treat analysis (P = 0.01) but not in the per-protocol analysis. There was no significant effect on other lipid fractions, cIMT and FMD. Adverse events were similar between groups. Change in serum albumin was negatively associated with change in serum LDL-C, very low-density lipoprotein cholesterol, total cholesterol, triglyceride, and apolipoprotein B (P < 0.001), irrespective of receiving atorvastatin, age, gender, body mass index, and serum creatinine.

CONCLUSIONS

Atorvastatin, administered at a fixed daily dose of 10 mg, was not beneficial in lowering lipid levels in children with SRNS; rise in serum albumin was associated with improvement in dyslipidemia.

[Idiopathic Nephrotic Syndrome: recommendations of the Nephrology Branch of the Chilean Society of Pediatrics. Part two]

Idiopathic nephrotic syndrome is the most common glomerular disease in childhood, affecting 1 to 3 per 100,000 children under the age of 16. It most commonly occurs in ages between 2 and 10. Its cause is unknown, and its histology corresponds to minimal change disease in 90% of cases, or focal segmental glomerulosclerosis. Steroid-resistant nephrotic syndrome represents 10-20% of idiopathic nephrotic syndrome in pediatrics. It has a poor prognosis, and its management is a significant therapeutic challenge. Half of patients evolve to end-stage renal disease within 5 years, and are additionally exposed to complications secondary to persistent NS and to the adverse effects of immunosuppressive therapy. The primary goal of treatment is to achieve complete remission, but even a partial remission is associated with a better renal survival than the lack of response. This paper is the result of the collaborative effort of the Nephrology Branch of the Chilean Society of Pediatrics with aims at helping pediatricians and pediatric nephrologists to treat pediatric idiopathic nephrotic syndrome. In this second part, handling of steroid-resistant nephrotic syndrome as well as nonspecific therapies are discussed.

Genetic testing in nephrotic syndrome--challenges and opportunities

Monogenic nephrotic syndrome (nephrotic syndrome caused by a single gene defect) is responsible for only a small percentage of cases of nephrotic syndrome, but information from studies of the unique cohort of patients with this form of the disease has dramatically improved our understanding of the disease pathogenesis. The use of genetic testing in the management of children and adults with nephrotic syndrome poses unique challenges for clinicians in terms of who to test and how to use the information obtained from testing in the clinical setting. In our view, not enough data exist at present to justify the routine genetic testing of all patients with nephrotic syndrome. Testing is warranted, however, in patients with congenital nephrotic syndrome (onset at 0-3 months), infantile nephrotic syndrome (onset at 3-12 months), a family history of nephrotic syndrome, and those in whom nephrotic syndrome is associated with other congenital malformations. The family and/or the patient should be given complete and unbiased information on the potential benefits and risks associated with therapy, including the reported outcomes of treatment in patients with similar mutations. Based on the data available in the literature so far, intensive immunosuppressive treatment is probably not indicated in monogenic nephrotic syndrome if complete or partial remission has not been achieved within 6 weeks of starting treatment. We advocate that family members of individuals with genetic forms of nephrotic syndrome undergo routine genetic testing prior to living-related kidney transplantation. Prospective, multicentre studies are needed to more completely determine the burden of disease caused by monogenic nephrotic syndrome, and randomized controlled trials are needed to clarify the presence or absence of clinical responses of monogenic nephrotic syndrome to available therapies.

Complications of nephrotic syndrome

Nephrotic syndrome (NS) is one of the most common glomerular diseases that affect children. Renal histology reveals the presence of minimal change nephrotic syndrome (MCNS) in more than 80% of these patients. Most patients with MCNS have favorable outcomes without complications. However, a few of these children have lesions of focal segmental glomerulosclerosis, suffer from severe and prolonged proteinuria, and are at high risk for complications. Complications of NS are divided into two categories: disease-associated and drug-related complications. Disease-associated complications include infections (e.g., peritonitis, sepsis, cellulitis, and chicken pox), thromboembolism (e.g., venous thromboembolism and pulmonary embolism), hypovolemic crisis (e.g., abdominal pain, tachycardia, and hypotension), cardiovascular problems (e.g., hyperlipidemia), acute renal failure, anemia, and others (e.g., hypothyroidism, hypocalcemia, bone disease, and intussusception). The main pathomechanism of disease-associated complications originates from the large loss of plasma proteins in the urine of nephrotic children. The majority of children with MCNS who respond to treatment with corticosteroids or cytotoxic agents have smaller and milder complications than those with steroid-resistant NS. Corticosteroids, alkylating agents, cyclosporin A, and mycophenolate mofetil have often been used to treat NS, and these drugs have treatment-related complications. Early detection and appropriate treatment of these complications will improve outcomes for patients with NS.

Pharmacotherapeutic review and update of idiopathic nephrotic syndrome in children

AIM OF THE REVIEW

The therapeutic management of pediatric idiopathic nephrotic syndrome is still a challenge due to the large number of potentially effective pharmacological alternatives and the insufficient scientific evidence available. A bibliographic review was performed in order to identify the available pharmacological alternatives, as well as their place in therapy, and to analyze whether the treatment algorithm developed by the pediatric nephrology department of our hospital is consistent with the evidence published to date.

METHOD

A literature search was carried out on MEDLINE, through PubMed, using the medical subject heading (MeSH) nephrotic syndrome. The search was limited to review papers, meta-analyses, clinical practice guidelines, and randomized controlled trials performed on pediatric populations up to September 2009.

RESULTS

The treatment algorithm established in our hospital is consistent with the evidence available. Prednisone constitutes the first line treatment with evidence level Ia. When corticosteroids do not achieve remission, there are other therapeutic options that are not clearly positioned yet and further studies that provide more information on their comparative efficacy and safety are needed. These alternative therapeutic options are cyclosporine, mycophenolate mofetil, levamisol, cyclophosphamide and methylprednisolone, as independent strategies or as part of "Mendoza Protocol", tacrolimus and rituximab. Their sequence of introduction in the therapeutic scheme of NS is classified as evidence level IV and grade D recommendation.

CONCLUSION

The wide range of options available for the pharmacotherapeutic management of NS and the lack of evidence about the comparative efficacy and safety of the different therapeutic strategies, make its positioning rather difficult. Therefore each hospital needs to draw up protocols based not only on the small amount of evidence available, but also on the authorized indications, availability of the drugs, clinical experience, associated costs, and patient preferences with regard to the duration of treatment, incidence and type of adverse effects. Development of new randomized controlled trials should be encouraged and setting up national plans for the treatment of this pathology might be a good approach for this problem.

Clinical and laboratory assessment of cardiovascular risk in children: Guidelines for screening, evaluation, and treatment

The early lesions of atherosclerosis begin in childhood and are related to antecedent cardiovascular disease (CVD) risk factors. Environmental and genetic factors (eg, diet, obesity, exercise, and certain inherited dyslipidemias) influence progression of such lesions. Identification of youth at risk for atherosclerosis includes an integrated assessment of these predisposing factors. Treatment starts with a diet low in total and saturated fat and cholesterol, use of water-soluble fiber, plant stanols and plant sterols, weight control, and exercise. Drug therapy, for example, with inhibitors of hydroxymethylglutaryl-CoA reductase, bile acid sequestrants, and cholesterol absorption inhibitors, can be considered in those with a positive family history of premature CVD and low-density lipoprotein cholesterol >160 mg/dL after dietary and hygienic measures. Candidates for drug therapy often include those with familial hypercholesterolemia, familial combined hyperlipidemia, the metabolic syndrome, polycystic ovarian syndrome, type 1 diabetes, and the nephrotic syndrome. Such dietary and drug therapy appears safe and efficacious. Early identification and treatment of youth with CVD risk factors and dyslipidemia are likely to retard the atherosclerotic process. Optimal detection and treatment of high-risk children either from the general population or from families with premature CVD will require a comprehensive universal screening and evaluation program.

Statins benefit outcomes of renal transplant recipients on a sirolimus-cyclosporine regimen

BACKGROUND

Statins offer a strategy to address dyslipidemia commonly experienced by immunosuppressed transplant recipients.

METHODS

This single-center, retrospective study of 325 recipients (mean posttransplant follow-up of over 6 years; 75.0+/-26.0 months) correlated four adverse outcomes-biopsy-confirmed acute rejection episodes, biopsy-confirmed chronic rejection/allograft nephropathy, graft loss, or death-with demographic and posttreatment variables. Patients were treated with a combination of sirolimus (SRL), cyclosporine (CsA), and various durations of steroids. Statins were prescribed for 259/325 (79%) recipients whose serum cholesterol exceeded 240 mg/dL and discontinued when the creatine phosphokinase increased fivefold (3.4%) or the liver function, threefold (3.0%) above normal.

RESULTS

Upon univariate (hazard ratio [HR] 0.16; P<.001) and multivariate analysis (HR 0.38; P=.02), statins were markedly protective against acute rejection episodes. They reduced occurrence of chronic nephropathy/chronic rejection (HR 0.60; P=.03 and HR 0.52; P=.01, respectively). Incidences of graft loss were diminished (HR 0.26; P<.001 and HR 0.49; P=.01, respectively). Finally, the mortality rate was decreased (HR 0.21, P=.001 and HR 0.26, P=.01, respectively). Upon multivariate analysis, a reduced incidence of acute rejection was correlated with greater exposure to SRL (HR 0.78, P=.016) and CsA (HR 0.39; P=.006).

CONCLUSIONS

This study demonstrated compelling effects of statins against all adverse outcomes among patients treated with SRL-based, CsA-containing regimens. The profoundly dyslipidemic properties of SRL may explain these unique findings compared with previous studies on patients treated with CsA-based regimens.

Atorvastatin-induced early-onset rhabdomyolysis in a patient with nephrotic syndrome

PURPOSE

A case of early-onset rhabdomyolysis in a patient treated with atorvastatin is described.

SUMMARY

A 17-year-old Indian boy weighing 55 kg was admitted to the hospital after complaining of facial puffiness and pedal edema for four days. His medical history revealed a diagnosis of nephrotic syndrome when he was 2 years old. He had six relapses, the last of which occurred 10 years ago. He was not taking any medications on admission and had not for the past 9 years. His vital signs were normal on admission (day 1), but anasarca was noticed during general examination. Cardiovascular, respiratory, and abdominal examinations were normal. Relapse of nephrotic syndrome was considered, and his 24-hour urine protein value confirmed the diagnosis. Further laboratory tests revealed that the patient had high total and low-density-lipoprotein cholesterol values (597 and 465 mg/dL, respectively), and atorvastatin 10 mg p.o. once daily was initiated on day 2. Prednisolone 60 mg p.o. once daily was initiated on day 3. On day 6, the patient complained of pain in both thighs and had difficulty walking. His creatine kinase (CK) concentration was then measured and found to be elevated (11,821 IU/L). Prednisolone and atorvastatin were then stopped, as statin-induced myopathy was suspected. The patient received i.v. hydration and sodium bicarbonate, and he began to show improvement by day 9. Follow-up three weeks later revealed a normal CK level and no myopathy-related complaints.

CONCLUSION

Early-onset rhabdomyolysis was reported in a patient with nephrotic syndrome who was treated with atorvastatin. Concomitant use of prednisolone and the patient's underlying renal impairment may have predisposed the patient to this adverse reaction.

Amelioration of steroids and cyclosporine-resistant nephrotic syndrome by pravastatin

We report the case of a girl with steroids and cyclosporine (CsA) resistant focal segmental glomerulosclerosis (FSGS) whose proteinuria and hypoproteinaemia were dramatically resolved by pravastatin. She had been in a nephrotic condition for 6 years. Prednisolone, pulse methylprednisolone therapy, low-density lipoprotein (LDL) apheresis, CsA, cyclophosphamide and mizoribine (MZR) had proved to be ineffective. She was started on pravastatin for her hyperlipidaemia 6 and a half years from onset, in addition to the baseline therapy, which included CsA; remission of the nephrotic syndrome was unexpectedly attained after 10 months of treatment. The baseline therapy has not been changed since the inclusion of pravastatin. This case suggests that, in patients with hyperlipidaemia, the response to CsA could be restored by lowering cholesterol levels with statins. The decrease of cholesterol levels might have improved the pharmacokinetics of CsA in this patient. Furthermore, the anti-inflammatory and immuno-modulatory effects, recently attributed to statins, may also have been involved in the improvement experienced by our patient.

How have the past 5 years of research changed clinical practice in paediatric nephrology?

Clinical practice in paediatric nephrology is continuously evolving to mirror the research output of the 21st century. The management of antenatally diagnosed renal anomalies, urinary tract infections, nephrotic syndrome and hypertension is becoming more evidence based. Obesity and related hypertension is being targeted at primary and secondary care. The evolving field of molecular and cytogenetics is discovering genes that are facilitating clinicians and families with prenatal diagnoses and understanding of disease processes. The progression of chronic kidney disease in childhood to end-stage renal failure (ESRF) can be delayed using medical treatment to reduce proteinuria and treat hypertension. Pre-emptive living-related renal transplantation has become the treatment of choice for children with ESRF, thereby reducing the morbidity and mortality associated with peritoneal and haemodialysis. Although peritoneal dialysis, which is performed in the patient's home, is the preferred modality for children for whom there is no living or deceased donor for transplantation, home nocturnal haemodialysis is becoming a feasible option. Imaging modalities with the use of magnetic resonance and computerised tomography are continuously improving. As mortality for renal and vasculitic diseases improves, the gauntlet is now thrown down to reduce morbidity with secondary prevention of longer-term complications such as atherosclerosis and hyperlipidaemia. Clinical and drug trials in the fields of hypertension, nephrotic syndrome, systemic lupus erythematosus, vasculitis and transplantation are producing more effective treatments, thereby reducing the morbidity resulting from the disease processes and the side effects of drugs.

Treatment of dyslipidemia in children and adolescents

The early lesions of atherosclerosis begin in childhood, and are related to antecedent cardiovascular disease risk factors. Environmental and genetic factors such as diet, obesity, exercise, and certain inherited dyslipidemias influence the progression of such lesions. The identification of youth at risk for atherosclerosis includes an integrated assessment of these predisposing factors. Treatment starts with a diet low in total and saturated fat and cholesterol, the use of water-soluble fiber and plant sterols, weight control, and exercise. Drug therapy, for example, with inhibitors of hydroxymethylglutaryl CoA reductase, bile acid sequestrants, and cholesterol absorption inhibitors, can be considered in those with a positive family history of premature coronary artery disease and a low-density lipoprotein cholesterol above 160 mg/dL, after dietary and hygienic measures. Candidates for drug therapy often include those with familial hypercholesterolemia, familial combined hyperlipidemia, the metabolic syndrome, polycystic ovarian syndrome, type I diabetes, and the nephrotic syndrome. We review the safety and efficacy of dietary and drug therapy, and propose an updated diagnostic and therapeutic algorithm that includes the metabolic syndrome. The early identification and treatment of youth with dyslipidemias is likely to retard the atherosclerotic process.