On-line hemodiafiltration did not induce an overproduction of oxidative stress and inflammatory cytokines in intensive care unit-acute kidney injury

Circulating Mitochondrial DNA Stimulates Innate Immune Signaling Pathways to Mediate Acute Kidney Injury

Mitochondrial dysfunction is increasingly considered as a critical contributor to the occurrence and progression of acute kidney injury (AKI). However, the mechanisms by which damaged mitochondria mediate AKI progression are multifactorial and complicated. Mitochondrial DNA (mtDNA) released from damaged mitochondria could serve as a danger-associated molecular pattern (DAMP) and activate the innate immune system through STING, TLR9, NLRP3, and some other adaptors, and further mediate tubular cell inflammation and apoptosis. Accumulating evidence has demonstrated the important role of circulating mtDNA and its related pathways in the progression of AKI, and regulating the proteins involved in these pathways may be an effective strategy to reduce renal tubular injury and alleviate AKI. Here, we aim to provide a comprehensive overview of recent studies on mtDNA-mediated renal pathological events to provide new insights in the setting of AKI.

Intermittent Convective Therapies in Patients with Acute Kidney Injury: A Systematic Review with Meta-Analysis

INTRODUCTION

In critically ill patients requiring intermittent renal replacement therapy (RRT), the benefits of convective versus diffusive clearance remain uncertain. We conducted a systematic review and meta-analysis to determine the safety, clinical efficacy, and clearance efficiency of hemofiltration (HF) and hemodiafiltration (HDF) compared to hemodialysis (HD) in patients with acute kidney injury (AKI) receiving intermittent RRT.

METHOD

We searched Medline, Embase, Cochrane Library, and PROSPERO. We included clinical trials and observational studies that reported the use of intermittent HF or HDF in adult patients with AKI. The following outcomes were included: mortality, renal recovery, clearance efficacy, intradialytic hemodynamic stability, circuit loss, and inflammation modulation.

RESULTS

A total of 3,169 studies were retrieved and screened. Four randomized controlled trials and 4 observational studies were included (n: 615 patients). Compared with conventional HD, intermittent convective therapies had no effect on in-hospital mortality (relative risk, 1.23; 95% confidence interval (CI), 0.76-1.99), renal recovery at 30 days (RR, 0.98; 95% CI, 0.82-1.16), time-to-renal recovery (mean difference [MD], 0.77; 95% CI, -6.56 to 8.10), and number of dialysis sessions until renal recovery (MD, -1.34; 95% CI, -3.39 to 0.72). The overall quality of included studies was low, and dialysis parameters were suboptimal for all included studies.

CONCLUSION

This meta-analysis suggests that there is no significant difference in short-term mortality and renal recovery in patients with severe AKI when treated with intermittent HF or HDF compared to conventional HD. This systematic review emphasizes the need for further trials evaluating optimal convective parameters in AKI patients treated with intermittent dialysis.

Anti-apoptosis mechanism of triptolide based on network pharmacology in focal segmental glomerulosclerosis rats

Triptolide (TPL), the active component of Tripterygium wilfordii, exhibits anti-cancer and antioxidant functions. We aimed to explore the anti-apoptosis mechanism of TPL based on network pharmacology and in vivo and in vitro research validation using a rat model of focal segmental glomerulosclerosis (FSGS). The chemical structures and pharmacological activities of the compounds reported in T. wilfordii were determined and used to perform the network pharmacology analysis. The Traditional Chinese Medicine Systems Pharmacology Database (TCMSP) was then used to identify the network targets for 16 compounds from Tripterygium wilfordii. Our results showed that 47 overlapping genes obtained from the GeneCards and OMIM databases were involved in the occurrence and development of FSGS and used to construct the protein–protein interaction (PPI) network using the STRING database. Hub genes were identified via the MCODE plug-in of the Cytoscape software. IL4 was the target gene of TPL in FSGS and was mainly enriched in the cell apoptosis term and p53 signaling pathway, according to Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses. TPL inhibited FSGS-induced cell apoptosis in rats and regulated IL4, nephrin, podocin, and p53 protein levels via using CCK8, TUNEL, and Western blot assays. The effects of IL4 overexpression, including inhibition of cell viability and promotion of apoptosis, were reversed by TPL. TPL treatment increased the expression of nephrin and podocin and decreased p53 expression in rat podocytes. In conclusion, TPL inhibited podocyte apoptosis by targeting IL4 to alleviate kidney injury in FSGS rats.

Intermittent hemodiafiltration as a down-step transition therapy in patients with acute kidney injury admitted to intensive care unit who initially underwent continuous venovenous hemodiafiltration

BACKGROUND/AIMS

Continuous renal replacement therapies (CRRT) are initially employed in patients with acute kidney injury (AKI) in ICU setting. After the period of serious illness, hemodialysis is usually used as a mode of transition from CRRT. Intermittent hemodiafiltration (HDF) is not commonly applied in this scenario.

OBJECTIVES

To evaluate the feasibility of using HDF as transition therapy after CVVHDF in critically patients with AKI.

METHODS

An observational and prospective pilot study was conducted in ICU patients with dialysis-requiring AKI. Patients were initially treated with CVVHDF and, after medical improvement, those who still needed renal replacement therapy were switched to HDF treatment.

RESULTS

Ten Patients underwent 53 HDF sessions (mean of 5.3 sessions/patient). The main cause of renal dysfunction was sepsis (N = 7; 70%). The APACHE II mean score was 27.6 ± 6.9. During HDF treatment, the urea reduction ratio was 64.5 ± 7.5%, for β-2 microglobulin serum levels the percentage of decrease was 42.0 ± 7.8%, and for Cystatin C was 36.2 ± 6.9%. Five episodes of arterial hypotension occurred (9.4% of sessions). There were 20 episodes of electrolytic disturbance (37.7% of sessions), mainly hypophosphatemia. No pyrogenic or suggestive episode of bacteremia was observed.

CONCLUSION

Hemodiafiltration was safe and efficient to treat critically ill patients with acute kidney injury during the transition phase from continuous to intermittent dialysis modality. Special attention should be paid regarding the occurrence of electrolytic disturbance, mainly hypophosphatemia.

Hemofiltration in Patients with Severe Acute Pancreatitis (Review)

Questions regarding the application of extracorporeal detoxification to patients with severe acute pancreatitis have been considered. Hemodialysis, the historically first method of extracorporeal detoxification for such patients, has been also described in the review. Appropriateness of using renal replacement therapy methods and among them continued renal replacement therapy has been shown. Hemofiltration and hemodiafiltration technologies are described in detail including different modes of their application and the possibility of using various types of filters. Available data on hemofiltration for patients with severe acute pancreatitis have been analyzed. Great attention is paid to the unsolved aspects of hemofiltration in severe acute pancreatitis such as determining renal and extrarenal indices; time of starting hemofiltration; selection of volume replacement modes and a buffer system; procedure duration; anticoagulation measures, defining criteria to assess the adequacy of hemofiltration, state severity, and organ dysfunction degree. Further multicenter investigations are necessary to be able to assess the efficacy of the hemofiltration procedures on the basis of the thoroughly worked out and pathogenically grounded protocol using adequate control methods taking into consideration endogenic intoxication phases and intensity of the multiple organ failure syndrome.

Oxidative Status before and after Renal Replacement Therapy: Differences between Conventional High Flux Hemodialysis and on-Line Hemodiafiltration

Hemodialysis patients experience high oxidative stress because of systemic inflammation and depletion of antioxidants. Little is known about the global oxidative status during dialysis or whether it is linked to the type of dialysis. We investigated the oxidative status before (pre-) and after (post-) one dialysis session in patients subjected to high-flux dialysis (HFD) or on-line hemodiafiltration (OL-HDF). We analyzed carbonyls, oxidized LDL (oxLDL), 8-hydroxy-2′-deoxyguanosine, and xanthine oxidase (XOD) activity as oxidative markers, and total antioxidant capacity (TAC), catalase, and superoxide dismutase activities as measures of antioxidant defense. Indices of oxidative damage (OxyScore) and antioxidant defense (AntioxyScore) were computed and combined into a global DialysisOxyScore. Both dialysis modalities cleared all markers (p < 0.01) except carbonyls, which were unchanged, and oxLDL, which increased post-dialysis (p < 0.01). OxyScore increased post-dialysis (p < 0.001), whereas AntioxyScore decreased (p < 0.001). XOD and catalase activities decreased post-dialysis after OL-HDF (p < 0.01), and catalase activity was higher after OL-HDF than after HFD (p < 0.05). TAC decreased in both dialysis modalities (p < 0.01), but remained higher in OL-HDF than in HFD post-dialysis (p < 0.05), resulting in a lower overall DialysisOxyScore (p < 0.05). Thus, patients on OL-HDF maintain higher levels of antioxidant defense, which might balance the elevated oxidative stress during dialysis, although further longitudinal studies are needed.