Throwing off the keratin chains: a potential therapy for hereditary podocytopathy

In the current issue, Kuzmuk et al. offer a therapeutic option for patients with NPHS2 R138Q-associated nephrotic syndrome. For the first time in hereditary podocytopathies, this is offered by restoring the membrane targeting of a pathogenic protein. The idea that it is enough to liberate podocin from the trap of keratin 8, a key member of endoplasmic-reticulum-associated protein degradation complex, was brilliantly recognized based on former results obtained in cystic fibrosis.

Nephrotic "full-house" glomerulonephritis successfully treated with antibiotics alone in secondary syphilis: a case report

A Japanese female in her twenties developed general edema with heavy proteinuria, and was referred to our hospital. She exhibited the common clinical manifestation of idiopathic nephrotic syndrome with massive proteinuria (20.37 g/day), hypoalbuminemia (1.8 g/dL), and hypercholesterolemia (300 mg/dL). Routine admission tests were positive results for both the rapid plasma reagin latex agglutination test for syphilis (RPR) and the Treponema pallidum particle agglutination assay (TPHA). As such, we made her a diagnosis of nephrotic syndrome due to secondary syphilis. Renal biopsy revealed "full-house" nephropathy. Following the commencement of penicillin treatment, she developed skin rash, indicating the Jarisch-Herxheimer reaction (JHR). Her nephrotic syndrome responded rapidly and she achieved complete remission with antibiotic therapy alone after 4 weeks. In light of the increasing incidence of syphilis in Japan, clinicians should consider syphilis as a reversible cause of nephrotic syndrome.

A small molecule chaperone rescues keratin-8 mediated trafficking of misfolded podocin to correct genetic Nephrotic Syndrome

Podocin is a key membrane scaffolding protein of the kidney podocyte essential for intact glomerular filtration. Mutations in NPHS2, the podocin-encoding gene, represent the commonest form of inherited nephrotic syndrome (NS), with early, intractable kidney failure. The most frequent podocin gene mutation in European children is R138Q, causing retention of the misfolded protein in the endoplasmic reticulum. Here, we provide evidence that podocin R138Q (but not wild-type podocin) complexes with the intermediate filament protein keratin 8 (K8) thereby preventing its correct trafficking to the plasma membrane. We have also identified a small molecule (c407), a compound that corrects the Cystic Fibrosis Transmembrane Conductance Regulator protein defect, that interrupts this complex and rescues mutant protein mistrafficking. This results in both the correct localization of podocin at the plasma membrane and functional rescue in both human patient R138Q mutant podocyte cell lines, and in a mouse inducible knock-in model of the R138Q mutation. Importantly, complete rescue of proteinuria and histological changes was seen when c407 was administered both via osmotic minipumps or delivered orally prior to induction of disease or crucially via osmotic minipump two weeks after disease induction. Thus, our data constitute a therapeutic option for patients with NS bearing a podocin mutation, with implications for other misfolding protein disorders. Further studies are necessary to confirm our findings.

Lipidomic profiles in serum and urine in children with steroid sensitive nephrotic syndrome

BACKGROUND

Steroid-sensitive nephrotic syndrome (SSNS) accounts for approximately 80% of cases of nephrotic syndrome. The involvement of aberrant lipid metabolism in early SSNS is poorly understood, warranting further investigation. This study aimed to explore alterations in lipid metabolism associated with SSNS pathogenesis.

METHODS

A screening cohort containing serum (50 SSNS, 37 controls) and urine samples (27 SSNS, 26 controls) was analyzed by untargeted lipidomic profiling using UHPLC-QTOF-MS. Then, a validation cohort (20 SSNS, 56 controls) underwent further analysis to check the potential clinical application by ROC curve analysis.

RESULTS

Lipidomic profiling of serum and urine samples revealed significant lipid alterations in SSNS patients, with the alterations in the serum samples being more significant. An elevated concentration of PE and PG and downregulated concentration of FA were observed in SSNS serum. A total of 38 dysregulated lipids and 5 lipid metabolic pathways were identified in the serum samples in SSNS patients. Validation in the second cohort confirmed differential regulation of nine kinds of lipids, including 5 up-regulated substances [SM d33:2 (m/z = 686.5361), SHexCer d34:1 (m/z = 779.521), PI 20:4_22:4 (m/z = 934.5558), Cer_NS d18:1_23:0 (m/z = 635.6216), and GM3 d36:1 (m/z = 1180.7431)], as well as 4 down-regulated substances: [CE 18:1 (m/z = 650.601), PE 38:6 (m/z = 763.5205), PC 17:0_20:4 (m/z = 795.5868) and EtherPC 16:2e_20:4 (m/z = 763.5498)].

CONCLUSIONS

Untargeted lipidomic analysis successfully identified specific lipid class changes in patients with SSNS, providing a deeper understanding of lipid alterations and underlying mechanisms associated with SSNS.

Efficacy and safety of long-term repeated use of rituximab in pediatric patients with nephrotic syndrome

BACKGROUND

We aimed to investigate the efficacy and safety of repeated use of rituximab (RTX) in pediatric patients with nephrotic syndrome (NS).

METHODS

Retrospective review of 50 patients with steroid-dependent NS (SDNS) who had received more than three cycles of RTX was conducted; each consisted of one to four infusions until B lymphocytes were depleted.

RESULTS

The median age of starting the first RTX cycle was 12.4 years (interquartile ranges (IQR) 10.2-14.6). During a median follow-up period of 6.3 (IQR 3.6-8.6) years, patients received a median of 5.0 RTX cycles (IQR 4.0-7.3). The number of relapses decreased from a median of 2.0 relapses per year (IQR 1.0-3.0) to 0.2 relapses per year (IQR 0.0-0.5) after long-term RTX treatments (P < 0.001). Longer relapse-free periods were associated with more than four RTX cycles, longer B-cell depletion, older age at each RTX treatment, and lower cholesterol levels. B lymphocytes recovered to 1% at a median of 5.9 months (95% confidence interval 5.7-6.1) after RTX administration. Factors related to a longer period of B-cell depletion included more than five RTX cycles, a higher dose of RTX, older age at treatment, and concurrent use of antimetabolites. During repeated RTX treatments, 8.0%, 6.0%, and 2.0% of patients developed hypogammaglobulinemia, severe infection, and severe neutropenia, respectively.

CONCLUSIONS

Long-term repeated use of RTX may be effective and safe in pediatric NS patients. Furthermore, the redosing of RTX could be chosen by considering predictive factors for relapse-free and B-cell depletion periods.

Clinicopathological features and outcome of secondary steroid resistant nephrotic syndrome: A retrospective analysis

Objective

To determine the clinico-pathological features and long-term outcome of secondary steroid-resistant nephrotic syndrome treated with steroids and calcineurin inhibitors.

METHODS

The retrospective cohort study was conducted at the Sindh Institute of Urology and Transplant, Karachi, in June and July 2023, and comprised data from January 1, 2008, to December 31, 2020, of children aged 1-18 years who developed steroid resistance after initial sensitivity to steroids with at least 1-year of follow-up. Demographics as well as time taken to secondary steroid response were documented. Renal biopsy of all patients with secondary steroid resistance had been performed. Eventual outcomes after treatment with calcineurin inhibitors based on the degree of proteinuria and serum albumin levels were used to categorise complete remission, partial remission and no response. Kidney function, as determined by estimated glomerular filtration rate, was recorded. Data was analysed using SPSS 22.

RESULTS

Of the 1,000 patients who underwent renal biopsy for steroid resistance, 48(4.8%) had idiopathic steroid-resistant nephrotic syndrome; 32(66.7%) males, 16(33.3%) females and median age of 5 years (interquartile range: 4-7.3 years). Median age at diagnosis of nephrotic syndrome was 5 years (interquartile range: 3.6-7.3 years). The median time from nephrotic syndrome to secondary steroid-resistant nephrotic syndrome was 23 months (interquartile range: 8.75-44.5 months). Biopsy results at diagnosis showed that 27(56.3%) had minimal change disease. The mean follow-up time was 6.1±3.2 years. Of the 43(89.5%) patients who received cyclosporin for 1 year, 29(67%) obtained complete remission, 5(12%) attained partial remission and no response was seen in 9(21%) patients.

Conclusion

Majority of the children had minimal change disease at the time of diagnosis of secondary steroid-resistant nephrotic syndrome. The long-term response with calcineurin inhibitors was favourable at 1 year.

Ofatumumab in Rituximab-Resistant and Rituximab-Intolerant Patients With Primary Membranous Nephropathy: A Case Series

RATIONALE & OBJECTIVE

Rituximab is the first-choice therapy for patients with primary membranous nephropathy (MN) and nephrotic syndrome. However, approximately 30% of patients are treatment-resistant or become treatment-intolerant with hypersensitivity reactions upon repeated drug exposures. We aimed to assess whether ofatumumab, a fully human second-generation anti-CD20 antibody, could be a valuable alternative to rituximab in this population.

STUDY DESIGN

Case series.

SETTING & PARTICIPANTS

7 rituximab-intolerant and 10 rituximab-resistant patients with MN who consented to receive ofatumumab (50-300mg, single intravenous infusion) and were followed at the nephrology unit of Azienda Socio-Sanitaria Territoriale Papa Giovanni XXIII (Bergamo, Italy) between September 2015 and January 2019.

FINDINGS

Over a median (IQR) follow-up of 5.0 (3.0-9.8) months, all 7 rituximab-intolerant and 3 of the 10 rituximab-resistant patients exhibited complete (proteinuria<0.3g/d) or partial (proteinuria<3.5g/d with≥50% reduction vs baseline) remission of nephrotic syndrome. Circulating B cells were similarly depleted in all patients by 1 week, and serum anti-phospholipase A2 receptor antibody concentrations decreased to<2.7 relative units/mL in 3 of 4 rituximab-intolerant and 4 of 8 rituximab-resistant patients with phospholipase A2 receptor-related disease. Ofatumumab significantly reduced 24-hour urinary protein and immunoglobulin G excretion and increased serum albumin and immunoglobulin G levels. These effects were greater in rituximab-intolerant than in rituximab-resistant patients. Measured glomerular filtration rate significantly increased by an average of 13.4% at 24 months compared with baseline (P=0.036) among all patients in the series. There were 14 nonserious infusion-related adverse events in 9 patients that recovered with temporary infusion interruption.

LIMITATIONS

Retrospective design, limited number of patients.

CONCLUSIONS

Ofatumumab may represent an effective and safe treatment for rituximab-intolerant cases of MN. Larger prospective studies will be needed to validate these preliminary findings and explore the effectiveness of other second-generation anti-CD20 antibodies in this clinical setting.

PLAIN-LANGUAGE SUMMARY

Primary membranous nephropathy (MN) is one of the most frequent causes of nephrotic syndrome (NS) in adults. In this case series, we explored the efficacy of ofatumumab, a fully human second-generation anti-CD20 antibody, in 17 patients with MN and NS who were intolerant or unresponsive to rituximab. All 7 rituximab-intolerant patients exhibited complete or partial clinical remission, compared with only 3 of the 10 rituximab-resistant patients. Autoantibody levels decreased in all patients with phospholipase A2 receptor-related disease. Ofatumumab achieved a significant reduction in urinary protein and immunoglobulin G excretion while increasing serum albumin and immunoglobulin G levels. Ofatumumab may be a promising option for patients with MN who are rituximab-intolerant. Further investigations are warranted to validate these preliminary findings.

[Steroid-Dependent Nephrotic Syndrome Due to Minimal Change Glomerulonephritis Treated with Rituximab]

47-year-old woman suffering from minimal lesion glomerulonephritis previously undergone high-dose steroid therapy and subjected to exacerbations of nephrotic syndrome after therapy discontinuation. It was decided to initiate off-label treatment with Rituximab at a dosage of 375 mg/m2 administred at zero-time, one-month and three months with good therapeutic response and resolution of the clinical laboratory picture. The therapy was well tolerated and had no side effects. This scheme could be an alternative to the conventional therapeutic scheme with steroids or other classes of immunosuppressive drugs, especially in order to avoid problems related to prolonged exposure to steroid therapy.

Nystagmus in a child with nephrotic syndrome

We report a child with steroid-dependent nephrotic syndrome presenting with excessive irritability, double vision and inability to walk for 5 days. On examination, the child was irritable with Glasgow coma sccale (GCS of 12/15, had bilateral convergent squint (R>L), vertical nystagmus, ataxia without any focal neurological deficits and normal fundus. MRI brain with venogram showed bilateral symmetric FLAIR hyperintensity in the medial thalamus and periaqueductal grey matter showing diffuse restriction with normal venogram. A possibility of Wernicke encephalopathy (WE) was considered and the child was started on thiamine supplementation, following which he had significant improvement in his symptoms. His irritability reduced with significant improvement in the range of eye movements and vertical nystagmus. At 3-month follow-up, the child is asymptomatic with normal gait. Although WE is uncommon in children with nephrotic syndrome, the possibility has to be kept in mind when a child presents with atypical neurological symptoms.

Urokinase prophylactic anticoagulation in children with nephrotic syndrome: a multicenter retrospective cohort study

OBJECTIVE

To analyze the clinical effect of urokinase on the prevention of thrombosis in children with primary nephrotic syndrome.

METHODS

A total of 370 children diagnosed with primary nephrotic syndrome (PNS) in the Children's Hospital of Soochow University and Zibo Maternal and Child Health Hospital from January 2018 to December 2022 were selected as the research objects. The patients were divided into a urokinase adjuvant therapy group and non-urokinase adjuvant therapy group according to the application of drugs. The clinical data of the children were collected, including sex, age, drug application, bleeding during treatment, and telephone follow-up, to record whether thromboembolism occurred in the acute stage and remission stage. The clinical pattern of PNS, renal biopsy, histopathological type, and related laboratory indexes before and after treatment were recorded.

RESULTS

A total of 313 patients were treated with urokinase and 57 patients were not. More thrombotic events was observed in non-urokinase group compared to the urokinase group(2 versus 0 episodes, p = 0.02). The thrombotic events observed included one patient had pulmonary embolism combined with right ventricular thrombosis, and another had intracranial venous thrombosis. More minor bleeding events occurred in urokinase group compared to the non-urokinase group(7 versus 1 episodes, p = 1.0). No major bleeding events occurred in either group.

CONCLUSION

The rational prophylactic use of urokinase anticoagulation in children with PNS can prevent the formation of thromboembolism and has good safety.

Immunosuppressive agents for frequently relapsing/steroid-dependent nephrotic syndrome in children: a systematic review and network meta-analysis

Aim

This study aimed to systematically compare the efficacy of various immunosuppressive agents in treating pediatric frequently relapsing or steroid-dependent nephrotic syndrome (FRSDNS).

Methods

We conducted systematic searches of PubMed, Embase, the Cochrane Library, and the Web of Science up to May 23, 2023. Outcome measures included relapses within 1 year, mean cumulative exposure to corticosteroids, patients with treatment failure at 1 year, relapse-free survival during 1 year, and adverse events. The quality of the included studies was evaluated using the modified Jadad scale, the Methodological Index for Non-Randomized Studies (MINORS), and the modified Newcastle-Ottawa Scale (NOS).

Results

Rituximab was found to be the most likely (92.44%) to be associated with the fewest relapses within 1 year and was also most likely (99.99%) to result in the lowest mean cumulative exposure to corticosteroids. Rituximab had the highest likelihood (45.98%) of being associated with the smallest number of patients experiencing treatment failure at 1 year. CsA was most likely (57.93%) to achieve the highest relapse-free survival during 1 year, followed by tacrolimus (26.47%) and rituximab (30.48%). Rituximab showed no association with serious side effects and had comparable adverse effects to ofatumumab and tacrolimus.

Conclusion

Rituximab may be the most favorable immunosuppressive agent for treating pediatric FRSDNS. Nephrologists should consider this drug, along with their clinical experience, patient characteristics, and cost considerations, when choosing a treatment approach.

Nephrotic syndrome with acute kidney injury due to combination therapy of immune checkpoint inhibitors: a case report and review of the literature

BACKGROUND

Recent studies have focused on immune checkpoint inhibitors. Renal complications associated with the use of immune checkpoint inhibitors are uncommon compared with other immune-related adverse events. Acute interstitial nephritis accounts for most of these renal complications, with nephrotic syndrome quite rare. We herein report a case of nephrotic syndrome associated with immune checkpoint inhibitors that was more severe than that in previous cases. By comparing this case with previous reports, the possible reasons for the particular severity of this case are discussed.

CASE PRESENTATION

A 75-year-old man developed nephrotic syndrome with acute kidney injury after the first combination therapy of nivolumab and ipilimumab for malignant pleural mesothelioma. The results of a kidney biopsy indicated minimal change disease with mild atherosclerosis, acute interstitial nephritis, and fusion of nearly all podocyte foot processes. Nivolumab and ipilimumab therapy were stopped, and treatment with corticosteroids was initiated. We investigated previously reported cases of nephrotic syndrome using immune checkpoint inhibitors. Seventeen cases of immune checkpoint inhibitor-related nephrotic syndrome, including ours, have been reported. Two of the 17 patients with immune checkpoint inhibitor-related nephrotic syndrome required hemodialysis treatment for acute kidney injury. Unlike many previously reported cases, the present patient was administered two different immune checkpoint inhibitors, which may be one of the reasons for the development of severe nephrotic syndrome.

CONCLUSIONS

In addition to previously reported risk factors, immune checkpoint inhibitor combination therapy can exacerbate nephrotic syndrome compared to immune checkpoint inhibitor monotherapy.

[Incidence of hypogammaglobulinaemia in children with steroid-dependent/frequently relapsing nephrotic syndrome treated with rituximab and its association with severe infections]

Objective: To investigate the incidence and influencing factors of hypogammaglobulinemia (HGG) in children with steroid-dependent/frequently relapsing nephrotic syndrome (SDNS/FRNS) treated with rituximab (RTX), and its relationship with the risk of severe infections. Methods: The clinical data of children with SDNS/FRNS treated with RTX at the Department of Pediatrics of the First Affiliated Hospital of Zhengzhou University from December 2020 to January 2023 were retrospectively analyzed. RTX treatment was performed using a B-cell-guided regimen (a single dose of 375 mg/m2, a maximum of 500 mg/dose, and an additional one dose when reassessment of peripheral blood CD19+B cells≥1%). Patients were divided into HGG and non-HGG groups according to the presence or absence of HGG during the follow-up period. A multivariate logistic regression model was used to analyze the influencing factors of HGG, and the predictive value of each influencing factor on HGG was assessed by plotting the receiver operating characteristic (ROC) curve. Results: A total of 59 SDNS/FRNS children (48 males and 11 females) were included, and aged [M (Q1, Q3)] 9.4 (6.5, 12.2) years at the time of the first RTX treatment, with a median application of 3 (2, 4) doses of RTX. During the follow-up period of 15.5 (9.9, 22.8) months, the HGG was present in 16 (27.1%) children, of which seven persisted for more than 1 year. Compared with non-HGG group, HGG group had a shorter duration of the disease [3.3 (2.1, 3.6) vs 4.6 (2.4, 8.0) years, P=0.030], younger age at the time of the first RTX treatment [6.2 (5.6, 7.4) vs 11.3 (8.8, 13.3) years, P<0.001], and lower serum IgG levels [5.9 (4.9, 6.4) vs 7.5 (6.1, 8.2) g/L, P<0.001]. Multivariate logistic regression analysis showed that young age at the time of the first RTX treatment (OR=0.52, 95%CI: 0.35-0.78, P=0.002) was an influencing factor of HGG. The area under the curve (AUC) for age at first RTX treatment to predict HGG was 0.887 (95%CI: 0.778-0.955, P<0.001), with an optimal cut-off value of 8.3 years. During the follow-up period, six children (10.2%) developed severe infectious, and there was no statistically significant difference in the incidence of serious infections between the HGG and non-HGG groups [12.5% (2/16) vs 9.3% (4/43), P=1.000]. Conclusions: HGG is frequent in children with SDNS/FRNS treated with RTX, and nearly half of HGG persists for more than 1 year. The possibility of HGG is greater in those≤8.3 years at the first RTX treatment, but HGG does not increase the risk of severe infections in children.

Steroid induced ocular complications in idiopathic nephrotic syndrome: a cross sectional single center study

Objective

To screen children receiving steroids to identify ocular complications and their prevalence.

METHODS

The cross-sectional study was conducted at the Paediatric Nephrology and Ophthalmology departments of the Sindh Institute of Urology and Transplantation, Karachi, from May to October 2022, and comprised patients who received at least 1500mg cumulative steroid dose for a minimum of 3 months. They were screened for steroidsensitive or steroid-resistant nephrotic syndrome. Ocular examinations, including visual acuity, intraocular pressure, slit-lamp biomicroscopy, lens examination and fundus evaluation, were performed. Data was analysed using SPSS 22.

RESULTS

Of the 124 subjects with mean age 8.15±2.03 years (range: 6-12 years), 64(51.6%) were boys. Steroidsensitive nephrotic syndrome was present in 97(78%) cases. The mean cumulative steroid dose was 3999.31±1564.22mg. Overall, 36(29%) children developed ocular complications. Blood pressure, number of relapses and the duration of treatment were significantly associated (p<0.05).

Conclusion

Refractive errors were the most frequent side effects/complication seen among children with nephrotic syndrome who received prolonged corticosteroids.

A pilot study of anti-nephrin antibodies in podocytopaties among adults

AIM

Minimal change disease (MCD) and focal segmental glomerulosclerosis (FSGS) are podocytopathies characterized by damage to the glomerular filtration barrier, leading to proteinuria and nephrotic syndrome. The production of anti-podocyte antibodies has been proposed as potential circulating factors contributing to the development of these conditions. The aim of the study is to evaluate the levels of anti-nephrin antibodies in patients with podocytopathies and healthy subjects.

METHODS

In this study, a total of 77 patients with active glomerulopathy and 11 healthy subjects were included. Forty one patients were diagnosed with FSGS, 11 with MCD, and 25 with MN. To measure the levels of anti-nephrin antibodies, enzyme-linked immunosorbent assay was used.

RESULTS

The levels of antibodies to nephrin were significantly higher in patients with MCD 61.2 [28.9-66.3] ng/mL and FSGS 32.5 [17.2-58.4] ng/mL compared to MN 20.3 [14.4-38.4] and healthy individuals 15.3 [12-18.9] ng/mL, p < .05. In patients with primary FSGS, the levels of antibodies to nephrin were significantly higher 45.2 [20-64.3] ng/mL compared to patients with secondary FSGS 26.7 [11.2-44.1] ng/mL, p < .05. There were no significant differences in the remission rate between the anti-nephrin antibodies positive and negative groups (log-rank test: p = .158).

CONCLUSION

The level of anti-nephrin antibodies was found to be significantly higher in patients with MCD and pFSGS compared to those with sFSGS, MN, and healthy subjects. Anti-nephrin antibodies in MCD and primary FSGS may be associated with the severity of podocytopathies, however they did not have an impact on the response to therapy.

Adult survivors of childhood-onset steroid-dependent and steroid-resistant nephrotic syndrome treated with cyclosporine: a long-term single-center experience

BACKGROUND

Although evidence has confirmed that cyclosporine (CS) is efficacious against childhood-onset steroid-dependent and steroid-resistant nephrotic syndrome (SD/SRNS), some patients may continue to relapse during adulthood. However, predictive factors for adult active disease and kidney complications, such as chronic kidney disease (CKD) and hypertension, in this cohort remain unknown.

METHODS

We conducted a retrospective study on the long-term outcomes of 81 young adults with childhood-onset SD/SRNS treated with CS. The primary endpoint was the probability of active disease into adulthood. The secondary endpoint was the probability of developing kidney complications.

RESULTS

At the last follow-up (median age, 23.2 years; median disease duration, 15.8 years), 44 adult patients (54%) continued to have active disease, whereas 16 patients developed CKD or hypertension, respectively. The proportion of patients developing kidney complications was similar between the active disease and long-term remission groups. Young age at NS onset and history of relapse during the initial CS (median, 31 months) were independent predictive factors for active disease. Acute kidney injury at NS onset, focal segmental glomerulosclerosis, and irreversible CS nephrotoxicity were identified as risk factors for the development of CKD, whereas older age was identified as a risk factor for the development of CKD and hypertension.

CONCLUSIONS

More than 50% of adult survivors treated with CS continued to have active disease, and each 20% developed CKD or hypertension. A long-term follow-up is necessary for patients with SD/SRNS to identify the development of kidney complications later in adulthood that can be attributed to prior disease and CS treatment in childhood, irrespective of disease activity. A higher resolution version of the Graphical abstract is available as Supplementary information.

Efficacy and safety of prophylactic anticoagulation in patients with primary nephrotic syndrome: a systematic review and meta-analysis

BACKGROUND AND AIMS

Nephrotic syndrome (NS) is associated with an increased incidence of venous thromboembolism (VTE), approximately 10%. We performed a systematic review to evaluate the efficacy and safety of prophylactic anticoagulation in patients with NS.

METHODS

Studies evaluating prophylactic anticoagulation in NS were identified by an electronic search of MEDLINE and EMBASE databases until December 2021. Weighted mean proportion and 95% confidence intervals (CIs) of thromboembolic and haemorrhagic events were calculated using a fixed-effects and a random-effects model. The differences in the outcomes among groups were estimated as pooled odds ratio (OR) and corresponding 95% CI. Statistical heterogeneity was evaluated using the I2 statistic.

RESULTS

Five cohort studies, for a total of 414 adult patients, were included. Only two studies had a control group. The weighted mean incidence of pulmonary embolism (PE) and deep vein thrombosis in patients who received VTE prophylaxis was 1.8% (95% CI: 0.6-3.5%; I2 : 4.4%) and 0.9% (95% CI: 0.2-2.2%; I2 : 43.4%) respectively. The weighted mean incidence of major bleeding in patients who received VTE prophylaxis was 2.3% (95% CI: 1-4.2%; I2 : 25.4%). Patients with NS that received VTE prophylaxis had a non-significant reduced risk of PE (OR: 0.63 (95% CI: 0.03-14.8; I2 : 64.4%)) and an increased risk of major bleeding (OR: 2.08 (95% CI: 0.41-10.45; I2 : 0%)) compared to patients with NS that did not receive VTE prophylaxis.

CONCLUSIONS

Our findings suggest that prophylactic anticoagulation in adult patients with primary NS may reduce the risk of VTE, even if it may be associated with a not negligible bleeding risk.

Copy number variation analysis in 138 families with steroid-resistant nephrotic syndrome identifies causal homozygous deletions in PLCE1 and NPHS2 in two families

BACKGROUND

Steroid-resistant nephrotic syndrome (SRNS) is the second most common cause of kidney failure in children and adults under the age of 20 years. Previously, we were able to detect by exome sequencing (ES) a known monogenic cause of SRNS in 25-30% of affected families. However, ES falls short of detecting copy number variants (CNV). Therefore, we hypothesized that causal CNVs could be detected in a large SRNS cohort.

METHODS

We performed genome-wide single nucleotide polymorphism (SNP)-based CNV analysis on a cohort of 138 SRNS families, in whom we previously did not identify a genetic cause through ES. We evaluated ES and CNV data for variants in 60 known SRNS genes and in 13 genes in which variants are known to cause a phenocopy of SRNS. We applied previously published, predefined criteria for CNV evaluation.

RESULTS

We detected a novel CNV in two genes in 2 out of 138 families (1.5%). The 9,673 bp homozygous deletion in PLCE1 and the 6,790 bp homozygous deletion in NPHS2 were confirmed across the breakpoints by PCR and Sanger sequencing.

CONCLUSIONS

We confirmed that CNV analysis can identify the genetic cause in SRNS families that remained unsolved after ES. Though the rate of detected CNVs is minor, CNV analysis can be used when there are no other genetic causes identified. Causative CNVs are less common in SRNS than in other monogenic kidney diseases, such as congenital anomalies of the kidneys and urinary tract, where the detection rate was 5.3%. A higher resolution version of the Graphical abstract is available as Supplementary information.

Shear wave elastography of kidneys in children: utility in distinguishing steroid-resistant and steroid-sensitive nephrotic syndrome

PURPOSE

To assess the renal elasticity values using (SWE) and correlate the values with steroid sensitivity to distinguish between steroid-resistant nephrotic syndrome (SRNS) and steroid-sensitive nephrotic syndrome (SSNS) in children.

METHODS

In this IRB-approved cross-sectional study, 83 children (4-14 years) diagnosed with nephrotic syndrome were included from July 2021 to December 2022. SWE measurements were done for each kidney's upper pole, interpolar region, and lower pole. Mean as well as median SWE were calculated. Correlation of the renal stiffness values was done with different laboratory findings (blood urea, serum creatinine, 24 h urine protein, serum albumin, and serum cholesterol), the grayscale findings (cortical echogenicity, and corticomedullary differentiation), and the final diagnosis of SRNS and SSNS. The statistical tests were done at a significance level of α = 0.05.

RESULTS

The median (IQR) overall SWE of kidneys was higher in SRNS group 12.64 (8.4-19.68) kPa than SSNS group 9.87 (8.20-12.56) kPa. The difference was significant (p = 0.004). At a cut-off of ≥ 10.694 kPa (AUROC- 0.641), the overall SWE predicted SRNS group with a sensitivity of 70% and a specificity of 63%. A significant correlation (p < 0.05) was found between the SWE and 24-h urine protein, cortical echogenicity, and corticomedullary differentiation in SSNS, while only between SWE and corticomedullary differentiation in SRNS.

CONCLUSION

The mean SWE was higher in children with SRNS. While SWE has potential to differentiate SSNS from SRNS, a different study design where SWE is performed at presentation is needed for confirmation.

Low-density Lipoprotein Receptor Activities, Lipids, Apolipoprotein, and Clinical Course of Patients with Steroid-resistant Nephrotic Syndrome Treated with Low-density Lipoprotein Apheresis: A Case Series

We herein report three cases of steroid-resistant nephrotic syndrome successfully treated with low-density lipoprotein apheresis (LDL-A). All patients were treated with a combination of steroids, cyclosporine, and LDL-A. In all cases, the serum concentrations of LDL, total and high-density lipoprotein cholesterol, and triglycerides were significantly lowered following LDL-A administration. Furthermore, the estimated LDL receptor activity increased, while both serum LDL and total cholesterol levels decreased, suggesting that LDL-A increases LDL receptor activity by driving changes in serum cholesterol concentration. This case series suggests that LDL-A increases LDL receptor activity, which may improve the intracellular uptake of cyclosporine.

Assessment of medication discrepancy, medication appropriateness, and cost analysis among patients with pediatric nephrotic syndrome: An ambispective cohort observational study

BACKGROUND

Nephrotic syndrome (NS) is a commonly encountered chronic kidney disease in pediatric populations, with South Asian children being at high risk and requiring long-term pharmacological management. Thus, identifying medication discrepancies and evaluating the appropriateness of therapy and its economic burden are vital for inpatient management. The aim of the study was to assess medication reconciliation, medication appropriateness, and cost analysis in NS cases.

METHODS

An ambispective cohort observational study was carried out with 150 NS patients where medication discrepancies were identified retrospectively and prospectively using the best possible medication history and following up patients correspondingly. Further, the Medication Appropriateness Index and cost variation analysis were used to assess the prescribed therapy and cost analysis, respectively.

RESULTS

Out of 150 patients with NS included, 67.3% were male and the mean age was 7.2 years. In total, 36.7% medication discrepancies were found at baseline and 6% discrepancies at follow-up. The majority of discrepancies were unintentional and due to dosing error both at baseline and follow-up. Further, in only 2% of the patients was there inappropriately prescribed medication, and the majority of patients spent between INR (Indian Rupees) 500 and 1000.

CONCLUSION

Chronic conditions like NS require continuous monitoring by the specialist pediatric clinical pharmacist, who can contribute significantly by minimizing the medication discrepancies, by assessing the appropriateness of therapy, and lessening the economic burden.

IgA nephropathy in a boy with frequently relapsing nephrotic syndrome

A Japanese boy developed nephrotic syndrome (NS) and had microscopic hematuria at 8 years old. Renal biopsy was performed. Light microscopy study revealed mesangial proliferation and all immunofluorescent stains (including IgA) were negative, so he was diagnosed with non-IgA diffuse mesangial proliferation (DMP). Complete remission was achieved at 13 days after the initiation of oral prednisolone, and hematuria also disappeared 3 days later, but the patient developed frequently relapsing nephrotic syndrome. Cyclosporine A (CyA) was introduced at 10 years old, and there were no relapses between then and when it was discontinued at 12 years old. A second renal biopsy revealed minimal change without CyA nephrotoxicity. However, there was repeated relapse of NS after discontinuation, so CyA was reintroduced 8 months later, and NS remained in remission thereafter. Microscopic hematuria appeared at 13 years old, however, with gross hematuria appearing at the time of infection. A third renal biopsy revealed mesangial proliferation with IgA-dominant deposition, so the patient was diagnosed with IgA nephropathy. Currently (14 years old), CyA treatment has been discontinued and the patient is undergoing lisinopril therapy for IgA nephropathy, but there are still relapses of NS. To the best of our knowledge, there have been no previous reports of a patient with non-IgA DMP at the onset of NS who had later development of IgA nephropathy. The patient showed non-IgA DMP at the onset, suggesting that NS with non-IgA DMP and IgA nephropathy has some common pathophysiology. Treatment for NS, such as PSL and/or CyA treatment, may suppress the clinical manifestation of late IgA nephropathy.

Chronic thrombotic microangiopathy presenting as acute nephrotic syndrome in a patient with renal cancer receiving tyrosine kinase inhibitor therapy

Thrombotic microangiopathy (TMA) is a rare but serious side effect of tyrosine kinase inhibitor (TKI) therapy. Previous case reports of renal TMA have usually occurred in the first few months of TKI initiation with only very few cases occurring within 2-3 years. We report a case of a patient who was referred to the Nephrology service for nephrotic syndrome and worsening renal function after 8 years of sunitinib therapy for metastatic clear cell carcinoma of the kidney. Renal biopsy showed chronic TMA without another secondary aetiology identified. With discontinuation of sunitinib and pharmacological optimisation of his hypertension, his renal function and proteinuria both significantly improved. No relapse or recurrence of disease activity was noted after a year of follow-up. This case highlights the importance of remaining vigilant for the development of renal TMA even after an extended duration of TKI therapy.

Repeated implants failure in young patient with idiopathic nephrotic syndrome: a case report with brief review of the literature

BACKGROUND

Nephrotic syndrome is a chronic disorder characterized by heavy proteinuria, hypoalbuminemia, hyperlipidemia, and edema. Idiopathic minimal-change disease is the most common form encountered in children. Corticosteroids are the cornerstone for the treatment of idiopathic nephrotic syndrome (INS), with different regimens depending on the response to therapy and frequency of relapses. This case report presents complications after implant treatment in patient with INS.

CASE PRESENTATION

20 years old female patient presented for implant consultation. Medical history includes INS since early childhood, and she is on different medications to control her condition, including long-term steroid use. Dental history revealed that implant treatment was unsuccessful after multiple attempts. She presented with an implant on the area of lower left first mandibular molar, that shows increased mobility and radiolucency on radiographic examination. A diagnosis of implant failure was made, the implant was removed, and the area was cleaned and sutured. The patient decided to replace her missing teeth with fixed partial denture and was referred for prosthodontist. The potential adverse effect of steroid use and the possible underlying mechanism that could affect bone metabolism and implants osseointegration are reviewed.

CONCLUSION

Clinical practice guidelines are needed for the management of dental implants in chronic steroid users.