Rituximab-Resistant Nephrotic Syndrome With Successful Induction of Remission by Low-Density Lipoprotein Apheresis

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.

IPNA clinical practice recommendations for the diagnosis and management of children with steroid-resistant nephrotic syndrome

Idiopathic nephrotic syndrome newly affects 1-3 per 100,000 children per year. Approximately 85% of cases show complete remission of proteinuria following glucocorticoid treatment. Patients who do not achieve complete remission within 4-6 weeks of glucocorticoid treatment have steroid-resistant nephrotic syndrome (SRNS). In 10-30% of steroid-resistant patients, mutations in podocyte-associated genes can be detected, whereas an undefined circulating factor of immune origin is assumed in the remaining ones. Diagnosis and management of SRNS is a great challenge due to its heterogeneous etiology, frequent lack of remission by further immunosuppressive treatment, and severe complications including the development of end-stage kidney disease and recurrence after renal transplantation. A team of experts including pediatric nephrologists and renal geneticists from the International Pediatric Nephrology Association (IPNA), a renal pathologist, and an adult nephrologist have now developed comprehensive clinical practice recommendations on the diagnosis and management of SRNS in children. The team performed a systematic literature review on 9 clinically relevant PICO (Patient or Population covered, Intervention, Comparator, Outcome) questions, formulated recommendations and formally graded them at a consensus meeting, with input from patient representatives and a dietician acting as external advisors and a voting panel of pediatric nephrologists. Research recommendations are also given.

Low-Density Lipoprotein Apheresis in Patients with Acute Kidney Injury Due to Minimal Change Disease Requiring Acute Renal Replacement Therapy

Low-density lipoprotein apheresis (LDL-A) has been developed as a therapy for familial hypercholesterolemia, but LDL-A has also been used as a general treatment for drug-resistant nephrotic syndrome (NS) due to focal segmental glomerulosclerosis (FSGS). The patients with NS due to minimal change disease (MCD) are often difficult to control effective circulating plasma volume, causes acute kidney injury (AKI), and when diuretics are not effective and the respiratory condition of patients worsens, patients require acute renal replacement therapy (ARRT). The effectiveness of LDL-A is not only reduction of serum low-density lipoprotein but also various other benefits. LDL-A might have improved renal hemodynamics by reducing vasoconstrictive eicosanoids and contributed to the therapeutic effect of antiproteinuric drugs such as corticosteroids. We treated a 49-year-old Japanese woman and a 71-year-old Japanese man with AKI caused by NS due to MCD, who required ARRT. Although these patients received ARRT and corticosteroids, their AKI and MCD did not improve sufficiently. We initiated LDL-A treatment for these patients as an additional treatment modality, because their total serum cholesterol levels were high at the time of admission. After the additional LDL-A treatment, both patients were able to discontinue ARRT, because NS and AKI in both patients were improved sufficiently. It is possible that early additional LDL-A is effective for patients with AKI and NS due to MCD who require ARRT, and may help patients discontinue ARRT because of the effect of LDL-A such as improving hypercoagulability and renal hemodynamics and contributing to the therapeutic effect of corticosteroids.

Dyslipidaemia in nephrotic syndrome: mechanisms and treatment

Nephrotic syndrome is a highly prevalent disease that is associated with high morbidity despite notable advances in its treatment. Many of the complications of nephrotic syndrome, including the increased risk of atherosclerosis and thromboembolism, can be linked to dysregulated lipid metabolism and dyslipidaemia. These abnormalities include elevated plasma levels of cholesterol, triglycerides and the apolipoprotein B-containing lipoproteins VLDL and IDL; decreased lipoprotein lipase activity in the endothelium, muscle and adipose tissues; decreased hepatic lipase activity; and increased levels of the enzyme PCSK9. In addition, there is an increase in the plasma levels of immature HDL particles and reduced cholesterol efflux. Studies from the past few years have markedly improved our understanding of the molecular pathogenesis of nephrotic syndrome-associated dyslipidaemia, and also heightened our awareness of the associated exacerbated risks of cardiovascular complications, progressive kidney disease and thromboembolism. Despite the absence of clear guidelines regarding treatment, various strategies are being increasingly utilized, including statins, bile acid sequestrants, fibrates, nicotinic acid and ezetimibe, as well as lipid apheresis, which seem to also induce partial or complete clinical remission of nephrotic syndrome in a substantial percentage of patients. Future potential treatments will likely also include inhibition of PCSK9 using recently-developed anti-PCSK9 monoclonal antibodies and small inhibitory RNAs, as well as targeting newly identified molecular regulators of lipid metabolism that are dysregulated in nephrotic syndrome.