Novel Biomarkers for Early Detection of Acute Kidney Injury and Prediction of Long-Term Kidney Function Decline after Partial Nephrectomy

The efficacy of novel biomarkers for the early detection and management of acute kidney injury: A systematic review

Acute kidney injury (AKI) is a frequent clinical complication lacking early diagnostic tests and effective treatments. Novel biomarkers have shown promise for enabling earlier detection, risk stratification, and guiding management of AKI. We conducted a systematic review to synthesize evidence on the efficacy of novel biomarkers for AKI detection and management. Database searches yielded 17 relevant studies which were critically appraised. Key themes were biomarker efficacy in predicting AKI risk and severity before functional changes; potential to improve clinical management through earlier diagnosis, prognostic enrichment, and guiding interventions; emerging roles as therapeutic targets and prognostic tools; and ongoing challenges requiring further validation. Overall, novel biomarkers like neutrophil gelatinase-associated lipocalin (NGAL), kidney injury molecule-1 (KIM-1), and cell cycle arrest markers ([TIMP-2] •[IGFBP7]) demonstrate capability for very early AKI prediction and accurate risk stratification. Their incorporation has potential to facilitate timely targeted interventions and personalized management. However, factors influencing biomarker performance, optimal cutoffs, cost-effectiveness, and impact on patient outcomes require robust validation across diverse settings before widespread implementation. Addressing these limitations through ongoing research can help translate novel biomarkers into improved detection, prognosis, and management of AKI in clinical practice.

Perioperative Acute Kidney Injury: Diagnosis, Prediction, Prevention, and Treatment

In this review, the authors define acute kidney injury in the perioperative setting, describe the epidemiologic burden, discuss procedure-specific risk factors, detail principles of management, and highlight areas of ongoing controversy and research.

Machine learning models predict the progression of long-term renal insufficiency in patients with renal cancer after radical nephrectomy

BACKGROUND

Chronic Kidney Disease (CKD) is a common severe complication after radical nephrectomy in patients with renal cancer. The timely and accurate prediction of the long-term progression of renal function post-surgery is crucial for early intervention and ultimately improving patient survival rates.

OBJECTIVE

This study aimed to establish a machine learning model to predict the likelihood of long-term renal dysfunction progression after surgery by analyzing patients' general information in depth.

METHODS

We retrospectively collected data of eligible patients from the Affiliated Hospital of Qingdao University. The primary outcome was upgrading of the Chronic Kidney Disease stage between pre- and 3-year post-surgery. We constructed seven different machine-learning models based on Logistic Regression (LR), Support Vector Machine (SVM), Random Forest (RF), Extreme Gradient Boosting (XGBoost), Light Gradient Boosting Machine (Lightgbm), Gaussian Naive Bayes (GaussianNB), and K-Nearest Neighbors (KNN). The performance of all predictive models was evaluated using the area under the receiver operating characteristic curve (AUC), precision-recall curves, confusion matrices, and calibration curves.

RESULTS

Among 360 patients with renal cancer who underwent radical nephrectomy included in this study, 185 (51.3%) experienced an upgrade in Chronic Kidney Disease stage 3-year post-surgery. Eleven predictive variables were selected for further construction of the machine learning models. The logistic regression model provided the most accurate prediction, with the highest AUC (0.8154) and an accuracy of 0.787.

Impact of No-Clamping Partial Nephrectomy on Early Estimated Glomerular Filtration Rate Preservation

Incidences of kidney cancers are steadily increasing. The surgical resection of renal tumors remains the treatment of choice, and different techniques provide similar oncological outcomes. Minimally invasive methods, especially partial nephrectomy (PN), have emerged as the preferred method of tumor resection, both in traditional and robot-assisted laparoscopy. PN may be performed as an open or laparoscopic operation. On-clamp PN is a variant of PN that includes the clamping of renal vessels; off-clamp PN is performed without any ischemia. Objectives: To assess the short-term loss of eGFR after on-clamp and off-clamp PN. Methods: Data from 2021 to 2024 were retrospectively collected from a hospital database. The patients included in the study had a diagnosed kidney tumor that was confirmed by MRI or CT imaging. The patients were divided into two groups depending on the type of treatment they received: on-clamp PN or off-clamp PN. Hematocrit (HCT), hemoglobin (Hb) and eGFR were measured and compared. Results: Both groups had comparable preoperative HTC, Hb, and eGFR. eGFR loss 24 h after the procedure was 35.4% lower in the off-clamp group compared to the on-clamp group (p = 0.027). Conclusions: Off-clamp PN is a safe and viable method for kidney tumor resection, both in traditional and robot-assisted laparoscopy. This technique results in a smaller perioperative loss of eGFR, which relates to better short-term functional outcomes than on-clamp PN.

Mechanism and clinical role of TIMP-2 and IGFBP-7 in cardiac surgery-associated acute kidney injury: A review

Acute kidney injury (AKI) is a common postoperative complication, but there is still a lack of accurate biomarkers. Cardiac surgery-associated AKI is the most common cause of major-surgery-related AKI, and patients requiring renal replacement therapy have high mortality rates. Early diagnosis, intervention, and management are crucial for improving patient prognosis. However, diagnosing AKI based solely on changes in serum creatinine level and urine output is insufficient, as these changes often lag behind actual kidney damage, making early detection challenging. Biomarkers such as tissue inhibitor of metalloproteinases-2 (TIMP-2) and insulin-like growth factor-binding protein-7 (IGFBP-7) have been found to be significant predictors of moderate-to-severe AKI when combined with urine content analysis. This article reviews the mechanism of biomarkers TIMP-2 and IGFBP-7 in AKI and provides a comprehensive overview of the clinical effects of TIMP-2 and IGFBP-7 in cardiac surgery-associated AKI, including prediction, diagnosis, and progression.

Trends and predictors of changes in renal function after radical nephrectomy for renal tumours

BACKGROUND

Chronic kidney disease (CKD) is a common postoperative complication in patients who undergo radical nephrectomy for renal tumours. However, the factors influencing long-term renal function require further investigation.

OBJECTIVE

This study was designed to investigate the trends in renal function changes and risk factors for renal function deterioration in renal tumour patients after radical nephrectomy.

METHODS

We monitored changes in renal function before and after surgery for 3 years. The progression of renal function was determined by the progression and degradation of CKD stages. Univariate and multivariate logistic regression analyses were used to analyse the causes of renal function progression.

RESULTS

We analysed the data of 329 patients with renal tumours who underwent radical nephrectomies between January 2013 and December 2018. In this study, 43.7% of patients had postoperative acute kidney injury (AKI), and 48.3% had CKD at advanced stages. Further research revealed that patients' renal function stabilized 3 months after surgery. Additionally, renal function changes during these 3 months have a substantial impact on the progression of long-term renal function changes in patients.

CONCLUSION

AKI may be an indicator of short-term postoperative changes in renal function. Renal function tests should be performed in patients with AKI after radical nephrectomy to monitor the progression of functional impairment, particularly within the first 3 months after radical nephrectomy.

Comparing Perioperative Complications of Off-Clamp versus On-Clamp Partial Nephrectomy for Renal Cancer Using a Novel Energy Balancing Weights Method

Partial nephrectomy (PN) is the primary surgical method for renal tumor treatment, typically involving clamping the renal artery during tumor removal, leading to warm ischemia and potential renal function impairment. Off-clamp approaches have been explored to mitigate organ damage, yet few results have emerged about the possible effects on hemoglobin loss. Most evidence comes from retrospective studies using propensity score matching, known to be sensitive to PS model misspecification. The energy balancing weights (EBW) method offers an alternative method to address bias by focusing on balancing all the characteristics of covariate distribution. We aimed to compare on- vs. off-clamp techniques in PN using EB-weighted retrospective patient data. Out of 333 consecutive PNs (275/58 on/off-clamp ratio), the EBW method achieved balanced variables, notably tumor anatomy and staging. No significant differences were observed in the operative endpoints between on- and off-clamp techniques, although off-clamp PNs showed slight reductions in hemoglobin loss and renal function decline, albeit with slightly higher perioperative blood loss. Our findings support previous evidence, indicating comparable surgical outcomes between standard and off-clamp procedures, with the EBW method proving effective in balancing baseline variables in observational studies comparing interventions.

Adverse Events of Cabozantinib as a Potential Prognostic Factor in Metastatic Renal Cell Carcinoma Patients: Real-World Experience in a Single-Center Retrospective Study

Cabozantinib, an oral inhibitor targeting MET, AXL, and VEGF receptors, has become a key component of a sequential treatment strategy for clear cell renal cell carcinoma (ccRCC). The purpose of this work is to show that effective management of adverse events (AEs) during cabozantinib treatment and achieving a balance between AEs and treatment efficacy is crucial to achieving therapeutic goals. In this retrospective study, involving seventy-one metastatic RCC (mRCC) patients receiving second or subsequent lines of cabozantinib at the Department of Genitourinary Oncology, Maria Sklodowska-Curie National Research Institute of Oncology, we explored the impact of AEs on overall survival (OS) and progression-free survival (PFS). AEs were observed in 92% of patients. Hypothyroidism during treatment was significantly associated with prolonged OS and PFS (HR: 0.31; p < 0.001 and HR: 0.34; p < 0.001, respectively). The occurrence of hand-foot syndrome (HFS) was also linked to improved OS (HR: 0.46; p = 0.021). Patients experiencing multiple AEs demonstrated superior OS and PFS compared to those with one or no AEs (HR: 0.36; p < 0.001 and HR: 0.30; p < 0.001, respectively). Hypothyroidism and HFS serve as valuable predictive factors during cabozantinib treatment in ccRCC patients, indicating a more favorable prognosis.

Longitudinal changes in renal parenchymal volume and function status after partial nephrectomy: a retrospective cohort study

BACKGROUND

The ipsilateral renal parenchymal volume (RPV) experiences a sharp decrease shortly after partial nephrectomy (PN), mainly due to surgical remove or devascularization of kidney tissue. However, the subsequent change of RPV and its association with glomerular filtration rate (GFR) fast decline remains unknown. Our objective was to investigate the change of ipsilateral RPV and renal function status from new baseline (1-12 months after PN) to latest follow-up (≥1 year) after PN, and to explore factors associated with ipsilateral RPV decrease rate and correlation between RPV decrease and GFR fast decline.

MATERIALS AND METHODS

A retrospective review of 367 patients with PN was conducted. Three-dimensional reconstruction of computed tomography (CT)/MRI images was performed for RPV calculation. Spectrum score was used to assess the degree of acute kidney injury (AKI) in the operated kidney after PN. GFR decline greater than 3 ml/min/1.73 m 2 /year was defined as GFR fast decline. One hundred fourteen patients underwent abdominal surgery was used as control. Predictive factors for subsequent decrease of RPV rate and GFR fast decline were evaluated by linear and logistic regression, respectively.

RESULTS

With a median interval time of 21.1 (interquartile range:13.8-35.5) months, median ipsilateral RPV significantly decreased from 118.7 (interquartile range:100.7-137.1) ml at new baseline to 111.8 (IQR: 92.3-131.3) ml at latest follow-up. The interval time [β: 1.36(0.71-2.01), P <0.001] and spectrum score [β: 5.83 (2.92-8.74), P <0.001] were identified as independent predictors of ipsilateral RPV decrease rate. GFR fast decline was observed in 101 (27.5%) patients. Annual ipsilateral RPV decrease rate [odds ratio:1.67 (1.05-2.67), P =0.03] and overweight [odds ratio:1.63 (1.02-2.60), P =0.04] were independent predictors of GFR fast decline.

CONCLUSIONS

Ipsilateral RPV experienced a moderate but significant decrease during follow-up after PN, especially in those with severer acute kidney injury. The presence of GFR fast decline was found to be associated with reduction of ipsilateral RPV, particularly in overweight individuals.

Currently Used Methods to Evaluate the Efficacy of Therapeutic Drugs and Kidney Safety

Kidney diseases with kidney failure or damage, such as chronic kidney disease (CKD) and acute kidney injury (AKI), are common clinical problems worldwide and have rapidly increased in prevalence, affecting millions of people in recent decades. A series of novel diagnostic or predictive biomarkers have been discovered over the past decade, enhancing the investigation of renal dysfunction in preclinical studies and clinical risk assessment for humans. Since multiple causes lead to renal failure, animal studies have been extensively used to identify specific disease biomarkers for understanding the potential targets and nephropathy events in therapeutic insights into disease progression. Mice are the most commonly used model to investigate the mechanism of human nephropathy, and the current alternative methods, including in vitro and in silico models, can offer quicker, cheaper, and more effective methods to avoid or reduce the unethical procedures of animal usage. This review provides modern approaches, including animal and nonanimal assays, that can be applied to study chronic nonclinical safety. These specific situations could be utilized in nonclinical or clinical drug development to provide information on kidney disease.