Diagnostic value of N-acetyl-β-D-glucosaminidase for the early prediction of acute kidney injury after percutaneous nephrolithotripsy

Effect of access sheath diameter used in percutaneous nephrolithotomy on renal function: a prospective randomized study

We aimed to determine the effect of the access sheath diameter used in percutaneous nephrolithotomy (PNL) on renal function. We also investigated the predictors of impaired renal function. Data were prospectively collected from patients who underwent PNL from December 2020 to December 2021. The patients were randomized into two groups according to access sheath diameter: Group 1 (22 Fr, n = 44) and Group 2 (28 Fr, n = 44). Relative renal function (RRF) was calculated by technetium-99 m dimercaptosuccinic acid scintigraphy, and glomerular filtration rate (GFR) was calculated by diethylenetriamine pentaacetic acid scintigraphy. A difference of 5% or more in RRF was considered a significant functional change. Preoperative and postoperative Kidney Injury Molecule-1 (KIM-1) levels were measured. Preoperative demographic data and stone characteristics were similar between the groups. There were also no statistically significant differences between the groups in terms of scar development, changes in RRF, GFR, or KIM-1/creatinine (Cr) (p > 0.05). Significant deterioration in RRF was detected in a total of six (6.8%) patients, three in each group. The factors predicting loss of function were analyzed by regrouping the patients without loss of function as Group A (n = 82) and those with loss as Group B (n = 6). Only stone volume was statistically significant in multivariate analysis (p = 0.002). Access sheath diameter had no significant effect on renal function after PNL. However, the stone volume was found to independently correlate to a loss of renal function after PNL.

The effect of standard percutaneous nephrolithotomy, miniaturized percutaneous nephrolithotomy and retrograde intrarenal surgery on biomarkers of renal injury: a randomized clinical trial

Background

Observational studies on the association of endourological procedures with renal parenchymal damage are lacking. This randomized trial examined the effect of standard percutaneous nephrolithotomy (sPCNL) in comparison with miniaturized-PCNL (mini-PCNL) and retrograde intrarenal surgery (RIRS) for nephrolithiasis treatment on novel biomarkers of renal injury.

Methods

Seventy-five patients were randomized in a 1:1:1 ratio to receive sPCNL, mini-PCNL and RIRS for nephrolithiasis. The ratios of neutrophil gelatinase-associated lipocalin (NGAL), kidney injury molecule-1 (KIM-1) and interleukin-18 (IL-18) normalized for urinary creatinine (Cr) were calculated from urine samples collected at baseline (2-h preoperatively) and at 2-, 6-, 24- and 48-h postoperatively. Two-way mixed analysis of variance (ANOVA) for repeated measurements was used to evaluate the effects of type of procedure and time on studied biomarkers.

Results

Between baseline and 2-h postoperatively, no significant differences were observed in NGAL/Cr changes between sPCNL [median (interquartile range) 9.46 (4.82-14.9)], mini-PCNL [12.78 (1.69-25.24)] and RIRS [6.42 (2.61-23.90)] (P = .902). Similarly, no between-group differences were observed for KIM-1/Cr (P = .853) and IL-18 (P = .980) at 2 h, and all biomarkers at any time-point postoperatively. Within-groups, significant increases from baseline were noted for NGAL/Cr (sPCNL, P < .001; mini-PCNL, P < .001; RIRS, P = .001), KIM-1/Cr and IL-18/Cr at 2 h; progressively lower increases from baseline were noted in all groups for KIM-1/Cr and IL-18/Cr at 6-, 24- and 48-h postoperatively. As such, a significant effect of time but not of type of procedure was evidenced with two-way mixed ANOVA. No significant between-group differences were observed in acute kidney injury incidence and complications.

Conclusions

The endourological procedures under study are associated with similar patterns of early tubular injury, detected by novel biomarkers, which is largely reduced within 48 h and no changes in glomerular function.

Combination of Pentoxifylline and Ginko Biloba Nephroprotective Effect in Animal Models with Vancomycin-Induced Nephrotoxicity

Antioxidants have been commonly used in medicine for thousands of years. Clinically, pentoxifylline and Ginkgo biloba have beneficial renal effects. Our study evaluated the nephroprotective effect of Gingko biloba in combination with Pentoxifiln in an experimental model of vancomycin-induced nephrotoxicity. Male Winstar rats were used in 3 groups: CONTROL, VANCO and VANCO+GBI+PTX and each group included 6 rats. Insufficient studies in the literature on the prevention of acute kidney injury by the combination of Ginkgo biloba and pentoxifylline led to the necessity to perform the study. Acute kidney injury was demonstrated by measuring serum values of classical markers such as urea and creatinine but also by measuring the urinary N-acetyl-β-d-glucosaminidase index, a topical marker in modern medicine. The significant decrease of the biochemical parameters in group III (VANCO+GBI+PTX) compared to group II (VANCO) and values similar to group I (CONTROL), demonstrates, the nephroprotective effect of the use in combination of the two substances.

Are endourological procedures for nephrolithiasis treatment associated with renal injury? A review of potential mechanisms and novel diagnostic indexes

Nephrolithiasis is one of the most common urological conditions with a huge socio-economic impact. About 50% of recurrent stone-formers have just one lifetime recurrence and >10% of patients present with a high recurrent disease requiring subsequent and sometimes multiple surgical interventions. The advent of new technology has made endourological procedures the pinnacle of stone treatment, including procedures like percutaneous nephrolithotomy (PCNL), retrograde intrarenal surgery and miniaturized PCNL procedures. Researchers have primarily focused on comparisons with respect to stone-free rates, procedure parameters and post-operative complications. However, the effect of these three procedures on renal function or indexes of renal injury has not been sufficiently examined. This was only reported in a few studies as a secondary objective with the use of common and not the appropriate and detailed renal parameters. This review presents current literature regarding the use of novel and highly predictive biomarkers for diagnosing acute kidney injury, discusses potential mechanisms through which endourological procedures for renal stone treatment may affect renal function and proposes areas with open questions where future research efforts in the field should focus.

Development of a novel ssDNA aptamer targeting neutrophil gelatinase-associated lipocalin and its application in clinical trials

BACKGROUND

Neutrophil gelatinase-associated lipocalin (NGAL) is a promising biomarker of early diagnosis and prediction for acute kidney injury (AKI). However, the current program for NGAL detection is not extensively applied in clinics due to the high expense of antibodies. Nucleic acid aptamers are single-strand DNAs or RNAs which could bind to targets with high specificity and affinity, and they have been widely used in the diagnosis and therapy for multiple diseases. It is valuable for us to develop a new method for NGAL detection using aptamers instead of antibodies to achieve increased efficiency and decreased cost.

METHODS

Nucleic acid aptamers against NGAL were obtained after SELEX process using magnetic beads, and an enzyme-linked aptamer analysis (ELAA), which can be widely used in clinical diagnosis at low cost, were successfully established. The feasibility of ELAA was further validated with urine samples harvested from 43 AKI patients and 30 healthy people.

RESULTS

Three candidate aptamers, including NA36, NA42 and NA53, were obtained after 8 rounds of SELEX process with magnetic beads and verified by quantitative polymerase chain reaction (qPCR), and the Kd value of each aptamer was 43.59, 66.55 and 32.52 nM, respectively. Moreover, the linear relationship was consistent at the range of 125-4000 ng/mL, and the detection limit of ELAA assay was 30.45 ng/mL. We also found that NGAL could be exclusively detected with NA53, and no cross-reaction between NA53 and human albumin or globulin occurred, the coefficient of variation (CV) between inner-plate and inter-plate was less than 15%, and the recovery rate was between 80 and 110%. Moreover, the sensitivity and specificity of ELAA assay in this study are 100% and 90%, respectively. Consistently, these results could also diagnose whether the occurrence of AKI in lots of patients, which has been demonstrated with the ELAA method we established after using NA53.

CONCLUSIONS

Taken together, NA53, the best candidate aptamer targeting NGAL protein, can be applied in clinical testing.

Ulinastatin Protects against Acute Kidney Injury in Infant Piglets Model Undergoing Surgery on Hypothermic Low-Flow Cardiopulmonary Bypass

Objective

Infants are more vulnerable to kidney injuries induced by inflammatory response syndrome and ischemia-reperfusion injury following cardiopulmonary bypass especially with prolonged hypothermic low-flow (HLF). This study aims to evaluate the protective role of ulinastatin, an anti-inflammatory agent, against acute kidney injuries in infant piglets model undergoing surgery on HLF cardiopulmonary bypass.

Methods

Eighteen general-type infant piglets were randomly separated into the ulinastatin group (Group U, n = 6), the control group (Group C, n = 6), and the sham operation group (Group S, n = 6), and anaesthetized. The groups U and C received following experimental procedure: median thoracotomy, routine CPB and HLF, and finally weaned from CPB. The group S only underwent sham median thoracotomy. Ulinastatin at a dose of 5,000 units/kg body weight and a certain volume of saline were administrated to animals of the groups U and C at the beginning of CPB and at aortic declamping, respectively. Venous blood samples were collected at 3 different time points: after anesthesia induction in all experimental groups, 5 minutes, and 120 minutes after CPB in the Groups U and C. Markers for inflammation and acute kidney injury were tested in the collected plasma. N-acetyl-β-D-glucosaminidase (NAG) from urine, markers of oxidative stress injury and TUNEL-positive cells in kidney tissues were also detected.

Results

The expressions of plasma inflammatory markers and acute kidney injury markers increased both in Group U and Group C at 5 min and 120 min after CPB. Also, numbers of TUNEL-positive cells and oxidative stress markers in kidney rose in both groups. At the time point of 120-min after CPB, compared with the Group C, some plasma inflammatory and acute kidney injury markers as well as TUNEL-positive cells and oxidative stress markers in kidney were significantly reduced in the Group U. Histologic analyses showed that HLF promoted acute tubular necrosis and dilatation.

Conclusions

HLF cardiopulmonary bypass surgery could intensify systemic inflammatory responses and oxidative stress on infant piglets, thus causing acute kidney injury. Ulinastatin might reduce such inflammatory response and oxidative stress and the extent of kidney injury.

Urinary netrin-1 and KIM-1 as early biomarkers for septic acute kidney injury

BACKGROUND

Acute kidney injury (AKI) during sepsis is associated with poor outcome. However, diagnosis of AKI with serum creatinine (SCr) level change is neither highly sensitive nor specific. Therefore, identification of novel biomarkers for early diagnosis of AKI is desirable.

AIMS

To evaluate the capacity of combining urinary netrin-1 and human kidney injury molecule type 1 (KIM-1) in the early diagnosis of septic AKI.

METHODS

We prospectively recruited 150 septic patients from Jun 2011 to Jun 2013 at Zhejiang Provincial People's Hospital, China. SCr, urinary netrin-1, and KIM-1 levels were recorded at 0, 1, 3, 6, 24, and 48 h of ICU admission and compared between AKI and non-AKI patients. In addition, we investigated the prognostic value of netrin-1 and KIM-1 between non-survivors and survivors in septic AKI patients.

RESULTS

SCr levels started to show elevation after 24 h of ICU admission. However, netrin-1 levels increased significantly as early as 1 h, peaked at 3-6 h and remained elevated up to 48 h of ICU admission in septic AKI patients. KIM-1 increased significantly by 6 h, peaked at 24 h and remained significantly elevated until 48 h of ICU admission. Furthermore, we observed significant higher urinary KIM-1 levels at 24 h and 48 h in non-survivors compared to survivors in AKI patients.

CONCLUSIONS

Our results suggest that both netrin-1 and KIM-1 are clinically useful as early biomarkers in the diagnosis of septic AKI. In addition, persistent elevation of urinary KIM-1 level may be associated with poor prognosis.