Kidney Damage and Stress Biomarkers for Early Identification of Drug-Induced Kidney Injury: A Systematic Review

The role of lncRNAs in AKI and CKD: Molecular mechanisms, biomarkers, and potential therapeutic targets

Exosomes, a type of extracellular vesicle, are commonly found in different body fluids and are rich in nucleic acids (circRNA, lncRNAs, miRNAs, mRNAs, tRNAs, etc.), proteins, and lipids. They are involved in intercellular communication. lncRNAs are responsible for the modulation of gene expression, thus affecting the pathological process of kidney injury. This review summarizes the latest knowledge on the roles of exosome lncRNAs and circulating lncRNAs in the pathogenesis, biomarker discovery, and treatment of chronic kidney disease, renal fibrosis, and acute kidney injury, providing an overview of novel regulatory approaches and lncRNA delivery systems.

New perspectives of drug related kidney diseases and disorders

PURPOSE OF REVIEW

The aim of this review is to provide a discussion of new perspectives for up-to-date definitions, a contemporary classification system, and the potential role of stress and damage biomarkers in the context of drug related kidney diseases and disorders.

RECENT FINDINGS

Acute kidney disease (AKD) is a term recently introduced in the literature describing an abnormality in kidney structure and function that lasts for less than 3 months. Drugs in the context of AKD is described as a new perspective; referred to as drug induced AKD. A framework that includes drugs into the 2X2 classification schema for acute kidney injury (AKI) is provided. Finally, stress and damage biomarkers are examined to assess risk of drug associated AKI (D-AKI), differentiate which drugs cause AKI, differentiate drugs from other etiologies and assess the prognosis of D-AKI.

SUMMARY

Consistent definitions should be adopted with consideration to drug related diseases and disorders. Drug management can be guided using novel biomarkers to isolate a possible drug cause in the presence of more than one nephrotoxin or a nondrug cause, assisting with the diagnosis of pseudo-AKI, and deciding the likelihood AKI recovery. Furthermore, stress and damage kidney biomarkers provide the opportunity to detect subclinical AKI for early intervention in patients at high-risk for severe AKI.

Derivation and Validation of an Optimal Neutrophil Gelatinase-Associated Lipocalin Cutoff to Predict Stage 2/3 Acute Kidney Injury (AKI) in Critically Ill Children

Introduction

Acute kidney injury (AKI) defined by changes in serum creatinine (SCr), or oliguria is associated with increased morbidity and mortality in children who are critically ill. We derived and validated a clinical cutoff value for urine neutrophil gelatinase-associated lipocalin (NGAL), in a prospective multicenter study of children who were critically ill. We report the clinical performance of urine NGAL (uNGAL) to aid in pediatric AKI risk assessment.

Methods

Eligible subjects were aged ≥ 90 days to < 22 years, admitted to an intensive care unit (ICU), and had 1 or more of the following: mechanical ventilation, vasoactive medication administration, solid organ or bone marrow transplantation, or hypotension within 24-hours of admission. uNGAL was assessed within 24-hours of admission. The primary outcome was SCr-based stage 2/3 AKI presence at 48- to 72-hours.

Results

Twenty-five (12.3%) derivation study patients had stage 2/3 AKI at 48- to 72-hours. uNGAL concentration of 125 ng/ml was the optimal cutoff. Forty-seven (9.1%) validation study patients had stage 2/3 AKI at 48- to 72-hours. The area under the curve of a receiver operator characteristics curve (AUC-ROC) for uNGAL performance was 0.83 (95% confidence interval [CI]: 0.77-0.90). Performance characteristics were sensitivity 72.3% (95% CI: 57.4%-84.4%), specificity 86.3% (95% CI: 82.8%-89.3%), positive predictive value 34.7% (95% CI: 28.5%-41.5%), and negative predictive value 96.9% (95% CI: 95.1%-98.0%).

Conclusion

These prospective, pediatric, multicenter studies demonstrate that uNGAL in the first 24-hours performs very well to predict Kidney Disease Improving Global Outcomes (KDIGO) stage 2/3 AKI at 48- to 72-hours into an ICU course. We suggest that a uNGAL cut point of 125 ng/ml can aid in the risk assessment for stage 2/3 AKI persistence or development.

Source Tracing of Kidney Injury via the Multispectral Fingerprint Identified by Machine Learning-Driven Surface-Enhanced Raman Spectroscopic Analysis

Early diagnosis of drug-induced kidney injury (DIKI) is essential for clinical treatment and intervention. However, developing a reliable method to trace kidney injury origins through retrospective studies remains a challenge. In this study, we designed ordered fried-bun-shaped Au nanocone arrays (FBS NCAs) to create microarray chips as a surface-enhanced Raman scattering (SERS) analysis platform. Subsequently, the principal component analysis (PCA)-two-layer nearest neighbor (TLNN) model was constructed to identify and analyze the SERS spectra of exosomes from renal injury induced by cisplatin and gentamycin. The established PCA-TLNN model successfully differentiated the SERS spectra of exosomes from renal injury at different stages and causes, capturing the most significant spectral features for distinguishing these variations. For the SERS spectra of exosomes from renal injury at different induction times, the accuracy of PCA-TLNN reached 97.8% (cisplatin) and 93.3% (gentamicin). For the SERS spectra of exosomes from renal injury caused by different agents, the accuracy of PCA-TLNN reached 100% (7 days) and 96.7% (14 days). This study demonstrates that the combination of label-free exosome SERS and machine learning could serve as an innovative strategy for medical diagnosis and therapeutic intervention.

The protective effect and molecular mechanism of glycyrrhizic acid glycosides against Tripterygium glycosides induced nephrotoxicity based on the RhoA/ROCK1 signalling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Tripterygium glycosides (TG), which are extracted from the traditional Chinese medicine, Tripterygium wilfordii Hook F. (TwHF), has promising applications in the treatment of renal diseases; however, since its active components exerts bidirectional kidney toxicity, its clinical application is severely restricted.

AIM OF THE STUDY

Recent investigations have demonstrated definite toxicity-reducing effects from glycyrrhizic acid glycosides (GA) when combined with TG; however, the mechanism remains unclear. To our knowledge, this is the first study to investigate the specific molecular mechanism by which GA alleviates TG-induced renal toxicity from the perspective of tight junctions.

MATERIALS AND METHODS

Dynamic analyses, which investigated the changes in kidney toxicity biomarkers for different combinations and concentrations of TG and GA, were conducted for three weeks on SD rats and renal tissue structural changes were examined after three weeks of administration. Additionally, the transcription and translation levels of the relevant tight junctions and RhoA/ROCK1/MLC signalling proteins were analysed in HK-2 cells.

RESULTS

Our study showed that TG can cause transient tubulotoxicity at certain doses, and that the combined application of GA and TG can repair tight junction structures by regulating the key factors in the RhoA/ROCK1/MLC signalling pathway, thus reducing TG-induced nephrotoxicity.

CONCLUSIONS

Overall, this study provides a new strategy to reduce TG-induced toxicity by protecting renal tight junctions.

Impact of renal recovery on in-hospital and post-discharge mortality

OBJECTIVE

To verify the impact of renal recovery on mortality in non-critically ill patients with acute kidney injury.

METHOD

A prospective cohort study was carried out in a public hospital in the Federal District with patients with acute kidney injury admitted to a non-critical care unit. Renal recovery was assessed based on the ratio of serum creatinine to baseline creatinine and the patient was followed up for 6 months. Mortality was assessed during hospitalization and after discharge.

RESULTS

Of the 90 patients with hospital-acquired kidney injury, renal recovery was identified in 34.1% to 75% of cases, depending on the time of assessment, considering a follow-up period of up to 6 months. Recovery of renal function during follow-up had an impact on in-hospital mortality [95% CI 0.15 (0.003 - 0.73; p = 0019).

CONCLUSION

Recovery of renal function has been shown to be a protective factor for mortality in patients admitted to the non-critical care unit. Early identification of kidney damage and monitoring of physiological and laboratory variables proved to be fundamental in identifying the severity of the disease and reducing mortality.

Moving toward a contemporary classification of drug-induced kidney disease

Drug-induced kidney disease (DIKD) accounts for about one-fourth of all cases of acute kidney injury (AKI) in hospitalized patients, especially in critically ill setting. There is no standard definition or classification system of DIKD. To address this, a phenotype definition of DIKD using expert consensus was introduced in 2015. Recently, a novel framework for DIKD classification was proposed that incorporated functional change and tissue damage biomarkers. Medications were stratified into four categories, including "dysfunction without damage," "damage without dysfunction," "both dysfunction and damage," and "neither dysfunction nor damage" using this novel framework along with predominant mechanism(s) of nephrotoxicity for drugs and drug classes. Here, we briefly describe mechanisms and provide examples of drugs/drug classes related to the categories in the proposed framework. In addition, the possible movement of a patient's kidney disease between certain categories in specific conditions is considered. Finally, opportunities and barriers to adoption of this framework for DIKD classification in real clinical practice are discussed. This new classification system allows congruencies for DIKD with the proposed categorization of AKI, offering clarity as well as consistency for clinicians and researchers.

Urinary exosomes: a promising biomarker of drug-induced nephrotoxicity

Drug-induced nephrotoxicity (DIN) is a big concern for clinical medication, but the clinical use of certain nephrotoxic drugs is still inevitable. Current testing methods make it hard to detect early renal injury accurately. In addition to understanding the pathogenesis and risk factors of drug-induced nephrotoxicity, it is crucial to identify specific renal injury biomarkers for early detection of DIN. Urine is an ideal sample source for biomarkers related to kidney disease, and urinary exosomes have great potential as biomarkers for predicting DIN, which has attracted the attention of many scholars. In the present paper, we will first introduce the mechanism of DIN and the biogenesis of urinary exosomes. Finally, we will discuss the changes in urinary exosomes in DIN and compare them with other predictive indicators to enrich and boost the development of biomarkers of DIN.

Medication Management in the Critically Ill Patient with Acute Kidney Injury

ABSTRACT

AKI occurs frequently in critically ill patients. Patients with AKI, including those who require KRT, experience multiple pharmacokinetic and pharmacodynamic perturbations that dynamically influence medication effectiveness and safety. Patients with AKI may experience both subtherapeutic drug concentrations, which lead to ineffective therapy, and supratherapeutic drug concentrations, which increase the risk for toxicity. In critically ill patients with AKI not requiring KRT, conventional GFR estimation equations, especially those based on serum creatinine, have several limitations that can limit the accuracy when used for medication dosing. Alternative methods to estimate kidney function may be informative, including use of measured urinary creatinine clearance, kinetic eGFR, and equations that integrate novel kidney biomarkers. For critically ill patients with AKI requiring KRT, physicochemical properties of the drug, the KRT prescription and circuit configuration, and patient-specific factors each contribute to medication clearance. Evidence-based guidance for medication dosing during AKI requiring KRT is often limited. A working knowledge of the basic tenets of drug elimination during KRT can provide a framework for how to approach decision making when the literature is lacking. Iterative re-evaluation of a patient's progress toward therapeutic goals with a medication must occur over the arc of critical illness, including and especially in the setting of dynamic kidney function.

Linalool prevents kidney damage by inhibiting rifampicin-induced oxidative stress and apoptosis

Today, kidney diseases are increasing day by day and life quality is decreasing. In hospitalized patients of all ages, acute kidney injury (AKI) is commonly observed and associated with high rates of morbidity and mortality. Rifampicin (RF) or rifampin is an antibiotic drug from the rifamycin group with a bactericidal effect. RF causes acute kidney injury, often anemia, thrombocytopenia, liver damage and side effect such as cell death. RF causes tissue damage by means of oxidative stress and apoptosis. Thus, in this study, it was examined whether linalool (LN) which had antinociceptive, antimicrobial, antioxidant and anti-inflammatory effects, was beneficial for kidney damage in order to eliminate the side effects of RF. NGAL mRNA, creatinine (Cr), blood urea nitrogen (BUN), Caspase 9 (CAS-9) and nuclear factor-κB (NF-κB) levels increased in the group treated with RF compared to the control group, while the levels of albumin, uric acid and total protein were decreased in the RF-treated group. NGAL mRNA, BUN, Cr, CAS-9 and NF-κB levels decreased significantly in RF+LN administered rats, while it was observed that there was an increase in the levels of albumin, uric acid and total protein. From the results obtained, it was observed that LN was determined to be very effective in preventing tissue damage in kidneys caused by oxidative stress by RF.