Pathogenesis and Management of Acute Kidney Injury in Patients with Nephrotic Syndrome Due to Primary Glomerulopathies

Predictors of renal outcomes and mortality in patients with renal vein thrombosis: a retrospective multicenter study

BACKGROUND

Studies on renal vein thrombosis have been conducted as case reports or case series. The renal outcomes and mortality risk of renal vein thrombosis have not been fully established. We aimed to investigate the clinical characteristics, treatment modalities, and predictors of renal outcomes and mortality in patients with renal vein thrombosis in a large multicenter cohort.

METHODS

We retrospectively assessed 182 patients with renal vein thrombosis diagnosed between January 2011 and May 2023 using either Doppler ultrasonography or computed tomography venography. The main outcomes analyzed were all-cause mortality, and worsening kidney function.

RESULTS

We evaluated 182 patients comprising 76 males (41.8%) and 106 females (58.2%). Nephrotic syndrome was the most common cause (51.6%) followed by malignancy (33%) and post-trauma or surgery (11%). Kidney function worsened in 126 patients (69.2%). Acute kidney injury (AKI) was identified in 72 patients (39.6%), whereas 54 patients (29.7%) developed chronic kidney disease (CKD). Multivariate logistic regression showed that declining kidney function was reliably predicted by nephrotic syndrome (Odds ratio (OR): 6.41, P = 0.004), serum albumin (OR: 0.31, P = 0.003), and diabetes mellitus (OR: 14.04, P < 0.001). Eighty-two patients (45.1%) died while being monitored. Sepsis accounted for the majority of deaths (25.3%). Bilateral renal vein thrombosis (Hazard Ratio (HR): 5.61, P < 0.001), malignancy (HR: 6.15, P = 0.004), serum albumin (HR: 0.12, P < 0.001), hemoglobin (Hb) level (HR: 0.102, P < 0.001) and diabetes mellitus (HR: 2.42, P = 0.007) were all reliable predictors of all-cause mortality using multivariate Cox regression.

CONCLUSION

Renal vein thrombosis is associated with a higher risk of mortality and worsening kidney function. It is essential to promptly identify high risk patients and start early treatment to prevent unfavorable outcomes.

[Early identification of acute kidney injury in children with primary nephrotic syndrome]

OBJECTIVES

To investigate the incidence and risk factors for acute kidney injury (AKI) in children with primary nephrotic syndrome (PNS), as well as the role of neutrophil gelatinase-associated lipocalin (NGAL) and kidney injury molecule-1 (KIM-1) in the early identification of AKI in these children.

METHODS

A prospective collection of clinical data from children hospitalized with PNS at the Children's Hospital of the Capital Institute of Pediatrics from January 2021 to October 2022 was conducted. The children were divided into two groups based on the presence of AKI: the AKI group (47 cases) and the non-AKI group (169 cases). The risk factors for AKI in children with PNS were identified by multivariate logistic regression analysis. Urinary KIM-1 and NGAL levels were compared between the AKI and non-AKI groups, as well as among the different stages of AKI.

RESULTS

The incidence of AKI in children with PNS was 21.8%. Multivariate logistic regression analysis revealed that steroid-resistant nephrotic syndrome, gastrointestinal infections, and heavy proteinuria were independent risk factors for AKI in these children with PNS (P<0.05). Urinary KIM-1 and NGAL levels were higher in the AKI group compared to the non-AKI group (P<0.05), and the urinary NGAL and KIM-1 levels in the AKI stage 2 and stage 3 subgroups were higher than those in the AKI stage 1 subgroup (P<0.017).

CONCLUSIONS

KIM-1 and NGAL can serve as biomarkers for the early diagnosis of AKI in children with PNS. Identifying high-risk populations for AKI in children with PNS and strengthening the monitoring of related risk factors is of significant importance.

Serum free fatty acid elevation is related to acute kidney injury in primary nephrotic syndrome

The aim of this research was to examine the clinical characteristics of acute kidney injury (AKI) in primary nephrotic syndrome (NS) and discuss the relationship between serum lipids and AKI. A total of 1028 patients diagnosed with primary NS with renal biopsy results were enrolled in this study. The patients were divided into AKI (n = 81) and non-AKI (n = 947) groups, and their characteristics were compared using a propensity score analysis for the best matching. Serum free fatty acid (FFA) was an independent predictor for AKI in the postmatch samples (p = 0.011). No significant difference in FFA levels was observed among AKI stages or different pathological types in the AKI and non-AKI groups. The AUC (area under the ROC curve) was 0.63 for FFA levels to distinguish AKI. In primary NS, elevated FFA levels tend to be related to a high risk of AKI. FFAs have diagnostic value and may serve as biomarkers for AKI in NS.

Acute Kidney Injury Caused by Renin-Angiotensin System Inhibitors During Minimal Change Disease Treatment

A 76-year-old Japanese man with nephrotic syndrome was admitted to our department for treatment. After his admission, he was administered prednisolone (PSL) at 40 mg/day, and a percutaneous renal biopsy was performed. However, on the first day of admission, his urinary protein decreased from 5.05 g/gCr to 1.85 g/gCr. On the fourth day of admission, his urinary protein further decreased to 0.38 g/gCr and the patient developed acute kidney injury (AKI). Renin-angiotensin system (RAS) inhibitors were suspected to be the cause of AKI; therefore, they were discontinued. After the renal function improved, the urinary protein worsened again to 5.49 g/gCr. Renal pathology suggested minimal change disease (MCD); therefore, PSL was continued. The patient's urinary protein subsequently improved and he had no renal function impairment. Minimal change disease can be complicated by AKI through intravascular volume depletion caused by high urinary protein and hypoalbuminemia. However, when MCD is complicated by RAS inhibitor-associated AKI, the urinary protein may notably decrease, and the patient may present with an atypical course of MCD-associated AKI.

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.

Characteristics of primary glomerular diseases patients with hematuria in Turkey: the data from TSN-GOLD Working Group

PURPOSE

Hematuria is one of the most common laboratory findings in nephrology practice. To date, there is no enough data regarding the clinical and histopathologic characteristics of primary glomerular disease (PGD) patients with hematuria in our country.

METHODS

Data were obtained from national multicenter (47 centers) data entered into the Turkish Society of Nephrology Glomerular Diseases (TSN-GOLD) database between May 2009 and June 2019. The data of all PGD patients over the age of 16 years who were diagnosed with renal biopsy and had hematuria data were included in the study. Demographic characteristics, laboratory and biopsy findings were also recorded.

RESULTS

Data of 3394 PGD patients were included in the study. While 1699 (50.1%) patients had hematuria, 1695 (49.9%) patients did not have hematuria. Patients with hematuria had statistically higher systolic blood pressure, serum blood urea nitrogen, creatinine, albumin, levels and urine pyuria. However, these patients had statistically lower age, body mass index, presence of hypertension and diabetes, eGFR, 24-h proteinuria, serum total, HDL and LDL cholesterol, and C3 levels when compared with patients without hematuria. Hematuria was present 609 of 1733 patients (35.8%) among the patients presenting with nephrotic syndrome, while it was presented in 1090 of 1661 (64.2%) patients in non-nephrotics (p < 0.001).

CONCLUSION

This is the first multicenter national report regarding the demographic and histopathologic data of PGD patients with or without hematuria. Hematuria, a feature of nephritic syndrome, was found at a higher than expected in the PGDs presenting with nephrotic syndrome in our national database.

TLR2 Expression on Select Lymphocyte Subsets as a New Marker in Glomerulonephritis

Toll-like receptor (TLR) signaling may be involved in autoimmune kidney disorders and has been implicated in proliferative and non-proliferative glomerulonephritis (PGN and NPGN). In this study, we investigated the expression of TLR2 on T and B lymphocytes in relation to selected clinical parameters in patients with PGN and NPGN. We collected peripheral blood from the ulnar vein of patients with PGN (n = 15) or NPGN (n = 22) and healthy volunteers (n = 20). The percentage of peripheral blood mononuclear cells expressing TLR2 was determined with flow cytometry. TLR2 expression on T and B lymphocytes was increased in PGN patients compared with NPGN patients and controls (p ≤ 0.001). In patients with PGN, TLR2 expression correlated negatively with the serum concentrations of IgG and albumin and positively with urine protein excretion. Receiver operating characteristic (ROC) analysis indicated that TLR2 expression is a highly specific marker to distinguish PGN patients from NPGN patients and controls, especially on CD4+ T lymphocytes. Its use as a non-invasive marker of disease should be further investigated.