Clinical features of acute kidney injury in patients with nephrotic syndrome and minimal change disease: a retrospective, cross-sectional study

Risk factors and renal outcomes of AKI in children with secondary steroid-resistant nephrotic syndrome

BACKGROUND

Acute kidney injury (AKI) is increasingly prevalent in children with nephrotic syndrome (NS). It is associated with adverse outcomes in NS, especially steroid-resistant nephrotic syndrome (SRNS). The incidence, risk factors and outcomes of AKI in secondary SRNS remain undefined. The main objectives of this study were to determine the risk factors and prognosis of AKI in hospitalized children with secondary SRNS.

MATERIAL AND METHODS

This retrospective study was conducted from January 2014 to December 2019, involving 172 hospitalizations with secondary SRNS admitted to the First Affiliated Hospital of Sun Yat-sen University. AKI was defined and classified in accordance with the 2012 Kidney Disease Improving Global Outcomes (KDIGO) guidelines.

RESULTS

AKI was found in 67 (39.0%) of 172 hospitalizations with secondary SRNS. Average age of onset in our group is 4.4 (3.1, 6.7) years with AKI and 3.7 (1.8, 5.6) years without AKI. Urea nitrogen level is 5.9 (4.1, 10.0) mmol/L with AKI and 5.1 (3.7, 7.0) mmol/L. Uric acid level is 446.0 (340.0, 567.0) umol/L with AKI and 401.0 (303.0, 496.0) umol/L. 24-h urinary protein level is 4.14 (2.9, 6.5) g with AKI and 2.5 (1.3, 5.3) without AKI. Multivariate logistic regression revealed that infection (OR = 5.287; 95% confidence interval, 2.349 to 11.899; p < 0.001), age at onset (OR = 1.180; 95% confidence interval, 1.032 to 1.349; p = 0.015) and uric acid level (OR = 1.003; 95% confidence interval, 1.000 to 1.006; p = 0.031) were significantly associated with the development of AKI in children with secondary SRNS. Among 72 children with secondary SRNS, six went to end-stage kidney disease (ESKD). Children in the AKI group were more likely to progress to ESKD compared with children in the non-AKI group (p = 0.017) with a median follow-up of 48.5months.

CONCLUSION

AKI occurred in 39.0% of total hospitalizations associated with secondary SRNS. Risk factors including infection, age of onset, and uric acid level are associated with AKI in children with secondary SRNS. Furthermore, AKI was identified as a risk factor for the progression of secondary SRNS to ESKD.

Urinary matrix metalloproteinase-7 is a sensitive biomarker to evaluate renal tubular injury in patients with minimal change disease and focal segmental glomerulosclerosis

Objective

To explore the advantages of urinary matrix metalloproteinase-7 (MMP-7) in evaluating renal tubular injury in minimal change disease (MCD) and focal segmental glomerulosclerosis (FSGS) patients compared with urinary cystatin C (CysC) and retinol-binding protein (RBP).

Methods

Serum and urine samples were collected from 20 healthy volunteers, and 40 MCD and 20 FSGS patients. Serum and urinary MMP-7 levels were measured by enzyme-linked immunosorbent assay. Urinary total protein, CysC and RBP levels were measured by automatic specific protein analyzer and compared with urinary creatinine level for calibration. The renal tissue serial sections were stained by MMP-7 immunohistochemistry and periodic acid-Schiff.

Results

Under light microscopy, MMP-7 granular weak positive expression was showed sporadically in the cytoplasm of a few renal tubular epithelial cells without obvious morphological changes in MCD patients, and MMP-7-positive expression was observed in the cytoplasm of some renal tubular epithelial cells in FSGS patients. There was no significant difference in serum MMP-7 level among the three groups. Compared with the control group, the urinary MMP-7 level in MCD patients was higher, but urinary CysC and RBP levels were not increased significantly. Compared with the control group and MCD patients, urinary MMP-7, CysC and RBP levels in FSGS patients were upregulated significantly.

Conclusions

Urinary MMP-7 could not only evaluate the mild renal tubular epithelial cells injury in MCD patients with massive proteinuria, but also evaluate the continuous renal tubular epithelial cells injury in FSGS patients.

Clinical Profile and Outcomes of Nephrotic Syndrome With Acute Kidney Injury in Adults: A Prospective Cohort Study

BACKGROUND

Nephrotic syndrome (NS) is characterized by various clinicopathological conditions like proteinuria, hypoalbuminemia, and anasarca. Patients with NS are prone to experience associated problems like acute kidney injury (AKI). The present study aimed to investigate the clinical profile and outcomes of NS with AKI in adults.

MATERIALS AND METHODS

This prospective, observational study was conducted over a period of one year. Adult patients with NS diagnosed with AKI were enrolled in the study. Data were collected at baseline and patients were followed up for at least three months.

RESULTS

A total of 60 patients were enrolled. The majority of the patients (78.3%) were aged between 18 and 30 years. Anemia was observed among 96.7% of the patients. A significant improvement was observed in the mean levels of proteinuria (5.80 vs. 1.70 gm/dL; P < 0.001), total cholesterol (270.00 mg/dL vs. 160.00 mg/dL), serum creatinine (2.18 mg/dL vs. 1.68 mg/dL; P < 0.001), and serum albumin (1.86 gm/dL vs. 3.29 gm/dL; P < 0.001) at baseline to three months. Pre-renal AKI was diagnosed in 95% of patients. According to histological classification, 19 patients had minimal change disease, whereas focal segmental glomerulosclerosis was observed in 23 patients. It was observed that 96.7% of the patients did not necessitate the need for renal replacement therapy.

CONCLUSION

The present study successfully examined the clinical profile and outcomes of adults with NS and AKI. The findings provide valuable insights into the characteristics and prognosis of this patient population, contributing to a better understanding of NS with AKI in adults.

Serum IgE levels are a risk factor with prognosis of pediatric minimal change disease

BACKGROUND

Minimal change disease (MCD) is one of the most common primary glomerular disorders with high serum IgE levels. This study was aimed to investigate the clinical features of different serum IgE levels in pediatric MCD and evaluate the prognostic significance of serum IgE levels with regard to remission and relapse in pediatric cohort.

METHODS

This study enrolled 142 new-onset children diagnosed with biopsy-proven MCD from January 2010 to December 2021 at the Jinling Hospital in Nanjing, China. These cases were divided into three groups according to serum IgE levels. MCD patients' demographics, clinical parameters, and follow-up data were collected and analyzed. The primary and secondary outcomes were defined as the time to the first complete remission (CR) and the first relapse.

RESULTS

The results manifested that 85.2% (121/142) of MCD children had high serum IgE levels (IgE > 90.0 IU/ml). A total of 142 patients were divided into the normal-, low-, and high-IgE groups based on the normal reference value level (90.0 IU/ml) and median serum IgE level (597.5 IU/ml). The high-IgE group had a significantly lower cumulative rate of the first CR (log-rank, P = 0.032) and a higher rate of the first relapse (log-rank, P = 0.033) than the normal-IgE and low-IgE groups. Multivariate Cox analysis showed that IgE ≥597.5 IU/ml was independently associated with the delayed first CR [hazard ratio (HR) = 0.566, 95% confidence interval (CI) = 0.330-0.972, P = 0.039] and the early first relapse (HR = 2.767, 95% CI = 1.150-6.660, P = 0.023).

CONCLUSIONS

Serum IgE levels were an independent correlation factor for pediatric MCD-delayed remissions and early relapses.

Non-diabetic urine glucose in idiopathic membranous nephropathy

This study aims to analyze the characteristics of idiopathic membranous nephropathy (iMN) with nondiabetic urine glucose during the follow-up. We retrospectively analyzed the data of 1313 patients who were diagnosed iMN. The prevalence of nondiabetic urine glucose during follow-up was 10.89%. There were significant differences between the patients with nondiabetic urine glucose and those without urine glucose in gender, hypertension ratio, proteinuria, N-acetyl-β-glucosaminidase, retinol binding protein, serum albumin, serum creatinine (Scr), cholesterol, triglyceride and positive anti-phospholipase A2 receptor antibody ratio, glomerular sclerosis ratio, acute and chronic tubular injury lesion at baseline. To exclude the influence of the baseline proteinuria and Scr, case control sampling of urine glucose negative patients was applied according to gender, baseline proteinuria and Scr. The proteinuria nonremission (NR) ratio was 45.83 versus 12.50% of the urine glucose positive group and case control group. Partial remission (PR) ratio of the two groups was 36.46 versus 23.96% and complete remission (CR) ratio was 19.79% versus 63.54%, respectively. Patients with urine glucose had higher risk of 50% estimated glomerular filtration rate (eGFR) reduction. Cox regression showed that urine glucose and baseline Scr were risk factors of 50% reduction of eGFR. Urine glucose remission ratio of the patients with proteinuria NR, PR, and CR was 13.33, 56.25, and 94.73% (p < 0.005). Patients who got urine glucose remission also had better renal survival. In conclusion, non-diabetic urine glucose was closely related to proteinuria. It could be applied as a tubular injury marker to predict renal function.

Acute kidney injury in patients with primary nephrotic syndrome: influencing factors and coping strategies

Background

Acute kidney injury (AKI) is a frequent and serious complication in patients with primary nephrotic syndrome (PNS). We aimed to evaluate the influencing factors of AKI in patients with PNS, to provide implications for the clinical management and nursing care of patients with PNS.

Methods

PNS patients who were treated in the Department of Nephrology in our hospital from January 1, 2020 to July 31, 2021 were included. The clinical characteristics and pathological type of PNS patients were evaluated. Pearson correlation and Logistic regression analysis were performed to analyze the related risk factors of AKI in patients with PNS.

Results

A total of 328 patients with PNS were included, the incidence of AKI in PNS patients was 28.05%. Pearson correlation analysis showed that diabetes(r = 0.688), pulmonary infection (r = 0.614), albumin (r = 0.779), serum creatinine (r = 0.617), uric acid (r = 0.522), blood urea nitrogen (r = 0.616), renal tubular casts (r = 0.707) were correlated with AKI in PNS patients (all P < 0.05). Logistic regression analysis indicated that diabetes (OR2.908, 95%CI1.844 ~ 4.231), pulmonary infection(OR3.755, 95%CI2.831 ~ 4.987), albumin ≤ 24 g/L (OR1.923, 95%CI1.214 ~ 2.355), serum creatinine ≥ 90 μmol/L (OR2.517, 95%CI2.074 ~ 3.182), blood urea nitrogen ≥ 6.5 mmol/L (OR1.686, 95%CI1.208 ~ 2.123), uric acid ≥ 390 μmol/L (OR2.755, 95%CI2.131 ~ 3.371), renal tubular casts(OR1.796, 95%CI1.216 ~ 2.208) were the independently influencing factors of AKI in PNS patients (all P < 0.05).

Conclusions

AKI is common in PNS patients. Actively controlling diabetes and pulmonary infection, strengthening nutrition support and renal function monitoring are essential to reduce the occurrence of AKI in PNS patients.

De Novo Minimal Change Disease following Vaccination with the Pfizer/BioNTech SARS-CoV-2 Vaccine in a Living Kidney Donor

Coronavirus disease 2019 has developed as a pandemic. Immunization with the introduction of vaccines against COVID-19 seems be the only way to end this pandemic. We report on a case of a kidney donor, who developed minimal change disease (MCD) within 4 days post-vaccination with the SARS-CoV-2 BNT162b2 mRNA vaccine (Pfizer/BioNTech). She donated her kidney to her husband 4 years ago. After receiving the 1st vaccine dose, she presented with nephrotic syndrome, with complete remission 5 days later. She proceeded with the second dose of the BNT162b2 vaccine at the appointed time. Two days later, she presented with a relapse of full-blown nephrotic syndrome with preserved renal function. We performed an ultrasound-guided percutaneous kidney biopsy and the final diagnosis was consistent with minimal change disease. Oral prednisolone was promptly initiated at a dosage of 1 mg/kg daily and complete remission was achieved 10 days later. More data about this rare appearance of de novo glomerular diseases after SARS-CoV-2 vaccination are emerging and should be interpreted rigorously.