Nomenclature and diagnostic criteria for acute kidney injury - 2020 consensus of the Taiwan AKI-task force

GLP-1 receptor agonists' impact on cardio-renal outcomes and mortality in T2D with acute kidney disease

Previous studies have explored the effects of glucagon-like peptide-1 receptor agonists (GLP-1 RAs) in reducing cardiovascular events in type 2 diabetes. Here we show that GLP-1 RAs are associated with lower risks of mortality, major cardiovascular events (MACEs), and major adverse kidney events (MAKEs) in type 2 diabetes patients with acute kidney disease (AKD). Utilizing global data from the TriNetX database (2002/09/01-2022/12/01) and propensity score matching, we compare 7511 GLP-1 RAs users to non-users among 165,860 AKD patients. The most common causes of AKI are sepsis (55.2%) and cardiorenal syndrome (34.2%). After a median follow-up of 2.3 years, GLP-1 RAs users exhibit reduced risks of mortality (adjusted hazard ratio [aHR]: 0.57), MACEs (aHR: 0.88), and MAKEs (aHR: 0.73). External validation in a multicenter dataset of 1245 type 2 diabetes patients with AKD supports the favorable outcomes. These results emphasize the potential of GLP-1 RAs in individualized treatment for this population.

Recovery Dynamics and Prognosis After Dialysis for Acute Kidney Injury

Importance

The interplay among baseline kidney function, severity of acute kidney disease (AKD), and post-AKD kidney function has significant associations with patient outcomes. However, a comprehensive understanding of how these factors are collectively associated with mortality, major adverse cardiac events (MACEs), and end-stage kidney disease (ESKD) in patients with dialysis-requiring acute kidney injury (AKI-D) is yet to be fully explored.

Objective

To investigate the associations of baseline kidney function, AKD severity, and post-AKD kidney function with mortality, MACEs, and ESKD in patients with AKI-D.

Design, Setting, and Participants

This nationwide, population-based cohort study of patients with AKI-D was conducted between January 1, 2015, and December 31, 2018, using data from various health care settings included in the Taiwan nationwide population-based cohort database. Data analysis was conducted from April 28, 2022, to June 30, 2023.

Exposure

Exposure to severe AKI and baseline and post-AKD kidney function.

Main Outcomes and Measures

The primary outcomes were all-cause mortality and incident MACEs, and secondary outcomes were risks of permanent dialysis and readmission.

Results

A total of 6703 of 22 232 patients (mean [SD] age, 68.0 [14.7] years; 3846 [57.4%] male) with AKI-D with post-AKD kidney function follow-up and AKD stage data were enrolled. During a mean (SD) 1.2 (0.9) years of follow-up, the all-cause mortality rate was 28.3% (n = 1899), while the incidence rates of MACEs and ESKD were 11.1% (n = 746) and 16.7% (n = 1119), respectively. After adjusting for known covariates, both post-AKD kidney function and baseline kidney function, but not AKD severity, were independently associated with all-cause mortality, MACEs, ESKD, and readmission. Moreover, worse post-AKD kidney function correlated with progressive and significant increases in the risk of adverse outcomes.

Conclusions and Relevance

In this cohort study of patients with AKI-D, more than one-quarter of patients died after 1.2 years of follow-up. Baseline and post-AKD kidney functions serve as important factors associated with the long-term prognosis of patients with AKI-D. Therefore, concerted efforts to understand the transition from post-AKD to chronic kidney disease are crucial.

Community acquired and hospital acquired AKI - two diseases divided by a common definition

PURPOSE OF REVIEW

Acute kidney injury (AKI) is common across the world. AKI that is acquired in the community (community acquired AKI, CA-AKI) has different risk factors, epidemiological profile, presentation and impact as compared to hospital acquired AKI (HA-AKI). Hence, similar approaches to tackle CA-AKI and HA-AKI might not work. This review highlights the important differences between the two entities that have a bearing on the overall approach to the conditions and how CA-AKI has been overshadowed by HA-AKI in research, diagnosis and treatment recommendations and clinical practice guidelines.

RECENT FINDINGS

The overall burden of AKI is disproportionately more in low and low-middle income countries. The Global Snapshot study of International Society of Nephrology's (ISN) AKI 0by25 program has shown that CA-AKI is the dominant form in these settings. Its profile and outcomes vary with geographical and socio-economic characteristics of the regions where it develops. The current clinical practice guidelines for AKI align more with HA-AKI than CA-AKI, and fail to capture the complete spectrum of CA-AKI as well as its impact. The ISN AKI 0by25 studies have uncovered the circumstantial compulsions in defining and assessing AKI in these settings and shown feasibility of community-based interventions.

SUMMARY

Efforts are needed to better understand CA-AKI in low-resource settings and develop context specific guidance and interventions. A multidisciplinary, collaborative approach with representation from community would be required.

Risk factors and 180-day mortality of acute kidney disease in critically ill patients: A multi-institutional study

Background

Critically ill patients with acute kidney injury (AKI) have a poor prognosis. Recently, the Acute Disease Quality Initiative (ADQI) proposed to define acute kidney disease (AKD) as acute or subacute damage and/or loss of kidney function post AKI. We aimed to identify the risk factors for the occurrence of AKD and to determine the predictive value of AKD for 180-day mortality in critically ill patients.

Methods

We evaluated 11,045 AKI survivors and 5,178 AKD patients without AKI, who were admitted to the intensive care unit between 1 January 2001 and 31 May 2018, from the Chang Gung Research Database in Taiwan. The primary and secondary outcomes were the occurrence of AKD and 180-day mortality.

Results

The incidence rate of AKD among AKI patients who did not receive dialysis or died within 90 days was 34.4% (3,797 of 11,045 patients). Multivariable logistic regression analysis indicated that AKI severity, underlying early CKD, chronic liver disease, malignancy, and use of emergency hemodialysis were independent risk factors of AKD, while male gender, higher lactate levels, use of ECMO, and admission to surgical ICU were negatively correlated with AKD. 180-day mortality was highest among AKD patients without AKI during hospitalization (4.4%, 227 of 5,178 patients), followed by AKI with AKD (2.3%, 88 of 3,797 patients) and AKI without AKD (1.6%, 115 of 7,133 patients). AKI with AKD had a borderline significantly increased risk of 180-day mortality (aOR 1.34, 95% CI 1.00-1.78; p = 0.047), while patients with AKD but no preceding AKI episodes had the highest risk (aOR 2.25, 95% CI 1.71-2.97; p < 0.001).

Conclusion

The occurrence of AKD adds limited additional prognostic information for risk stratification of survivors among critically ill patients with AKI but could predict prognosis in survivors without prior AKI.

Improving awareness of kidney function through electronic urine output monitoring: a comparative study

BACKGROUND

The current classification for acute kidney injury (AKI) according to the Kidney Disease: Improving Global Outcomes (KDIGO) criteria integrates both serum creatinine (SCr) and urine output (UO). Most reports on AKI claim to use KDIGO guidelines but fail to include the UO criterion. It has been shown that patients who had intensive UO monitoring, with or without AKI, had significantly less cumulative fluid volume and fluid overload, reduced vasopressor use, and improved 30-day mortality. We examined whether real-time monitoring of this simple, sensitive, and easy-to-use biomarker in the ICU led to more appropriate intervention by healthcare providers and better outcomes.  METHODS: RenalSense Clarity RMS Consoles were installed in the General ICU at the Hadassah Medical Center, Israel, from December 2019 to November 2020. The Clarity RMS system continuously and electronically monitors UO in real-time. 100 patients were randomly selected from this period as the study group (UO_elec) and compared to a matched control group (UO_manual) from the same period two years earlier. To test whether there was an association between oliguric hours and fluid treatment in each group, the correlation was calculated and analyzed for each of the different UO monitoring methods.

RESULTS

Therapeutic intervention: The correlation of the sum of all oliguric hours on Day 1 and 2 with the sum of any therapeutic intervention (fluid bolus or furosemide) showed a significant correlation for the study group UO_elec (P = 0.017). The matched control group UO_manual showed no such correlation (P = 0.932). Length of Stay (LOS): Median LOS [IQR] in the ICU of UO_elec versus UO_manual was 69.46 [44.7, 125.9] hours and 116.5 [62.46, 281.3] hours, respectively (P = 0.0002).

CONCLUSIONS

The results of our study strongly suggest that ICU patients had more meaningful and better medical intervention, and improved outcomes, with electronic UO monitoring than with manual monitoring.

Machine learning algorithm-based identification and verification of characteristic genes in acute kidney injury

Background

Acute kidney injury is a common renal disease with high incidence and mortality. Early identification of high-risk acute renal injury patients following renal transplant could improve their prognosis, however, no biomarker exists for early detection.

Methods

The GSE139061 dataset was used to identify hub genes in 86 DEGs between acute kidney injury and control samples using three machine learning algorithms (LASSO, random forest, and support vector machine-recursive feature elimination). We used GSEA to identify the related signal pathways of six hub genes. Finally, we validated these potential biomarkers in an in vitro hypoxia/reoxygenation injury cell model using RT-qPCR.

Results

Six hub genes (MDFI, EHBP1L1, FBXW4, MDM4, RALYL, and ESM1) were identified as potentially predictive of an acute kidney injury. The expression of ESM1 and RALYL were markedly increased in control samples, while EHBP1L1, FBXW4, MDFI, and MDM4 were markedly increased in acute kidney injury samples.

Conclusion

We screened six hub genes related to acute kidney injury using three machine learning algorithms and identified genes with potential diagnostic utility. The hub genes identified in this study might play a significant role in the pathophysiology and progression of AKI. As such, they might be useful for the early diagnosis of AKI and provide the possibility of improving the prognosis of AKI patients.

Essential Roles of the Histone Demethylase KDM4C in Renal Development and Acute Kidney Injury

Background: Lysine demethylase 4C (KDM4C) is a nuclear protein that is essential for histone modification and acts as an important regulator of several transcription factors. Previous studies have shown that KDM4C may also play a role in mediating stress responses. The purpose of this study was to examine the roles of KDM4C in kidney development and acute kidney injury (AKI). Methods: The effect of KDM4C on kidney development was assessed by comparing the kidney phenotype between 96 zebrafish embryos treated with kdm4c-morpholino oligonucleotide and 96 untreated zebrafish embryos. We further examined whether KDM4C is essential for maintaining cell survival in AKI. Cultured human renal tubular cells were used for the in vitro study. Wild-type and Kdm4c knockout mice (C57BL/6NTac-Kdm4ctm1a(KOMP)Wtsi) were divided into a sham group and model group, and then subjected to ischemic reperfusion kidney injury (IRI-AKI). Blood samples and kidneys were collected at different time points (day 3, day 7, day 14, and day 28) and were processed for in vivo studies (n = 8 in each group). Results: Kdm4c knockdown significantly decreased zebrafish embryo survival and impaired kidney development. The in vitro study showed that KDM4C inhibition by JIB04 significantly increased cellular apoptosis under oxidative stress conditions. KDM4C knockdown cells had impaired autophagy function under stress conditions. The IRI-AKI mice study showed that KDM4C protein levels dynamically changed and were significantly correlated with HIF-1α levels in AKI. Kdm4c^−/− mice had significantly more severe renal impairment and increased kidney fibrosis than the wild-type mice. Cytokine array results also indicated that the kidneys of Kdm4c^−/− mice had increased inflammation in AKI compared with the wild-type mice. Further RNA sequence analysis revealed that KDM4C may regulate transcription factors related to mitochondrial dynamics and function. Conclusions: Our study suggests that KDM4C may play a critical role in regulating mitochondria, which is related to a protective effect on maintaining cell survival in AKI.

Sepsis and Acute Kidney Injury: A Review Focusing on the Bidirectional Interplay

Although sepsis and acute kidney injury (AKI) have a bidirectional interplay, the pathophysiological mechanisms between AKI and sepsis are not clarified and worthy of a comprehensive and updated review. The primary pathophysiology of sepsis-associated AKI (SA-AKI) includes inflammatory cascade, macrovascular and microvascular dysfunction, cell cycle arrest, and apoptosis. The pathophysiology of sepsis following AKI contains fluid overload, hyperinflammatory state, immunosuppression, and infection associated with kidney replacement therapy and catheter cannulation. The preventive strategies for SA-AKI are non-specific, mainly focusing on infection control and preventing further kidney insults. On the other hand, the preventive strategies for sepsis following AKI might focus on decreasing some metabolites, cytokines, or molecules harmful to our immunity, supplementing vitamin D3 for its immunomodulation effect, and avoiding fluid overload and unnecessary catheter cannulation. To date, several limitations persistently prohibit the understanding of the bidirectional pathophysiologies. Conducting studies, such as the Kidney Precision Medicine Project, to investigate human kidney tissue and establishing parameters or scores better to determine the occurrence timing of sepsis and AKI and the definition of SA-AKI might be the prospects to unveil the mystery and improve the prognoses of AKI patients.