Acute kidney injury in patients with chronic liver disease

Literature review of the mechanisms of acute kidney injury secondary to acute liver injury

People exposed to liver ischaemia reperfusion (IR) injury often develop acute kidney injury and the combination is associated with significant morbidity and mortality. Molecular mediators released by the liver in response to IR injury are the likely cause of acute kidney injury (AKI) in this setting, but the mediators have not yet been identified. Identifying the mechanism of injury will allow the identification of therapeutic targets which may modulate both liver IR injury and AKI following liver IR injury.

Urinary neutrophil gelatinase-associated lipocalin: Acute kidney injury in liver cirrhosis

Acute kidney injury (AKI) in liver cirrhosis is associated with poor clinical outcomes including an increased long and short-term mortality. The common type of AKI observed in patients with cirrhosis are prerenal AKI (PRA), hepatorenal syndrome (HRS) and acute tubular necrosis (ATN). Despite the growing knowledge and uniform definition for the diagnosis of AKI, there are several challenges including, early diagnosis and management. Precisely differentiating the type of AKI is critical, as therapies differ significantly. In this review, we summarize AKI in liver cirrhosis, their definition, pathophysiology and deficiencies of using the existing biomarker, serum creatinine. We outline the current clinical evidence on the novel biomarker urinary neutrophil gelatinase-associated lipocalin (uNGAL) and its potential role as a biomarker in the early detection, differentiation and prognostication of AKI. This review also briefly talks about other forthcoming biomarkers which hold promise in the management of AKI in liver cirrhosis.

Liver kidney crosstalk: Hepatorenal syndrome

The dying liver causes the suffocation of the kidneys, which is a simplified way of describing the pathophysiology of hepatorenal syndrome (HRS). HRS is characterized by reversible functional renal impairment due to reduced blood supply and glomerular filtration rate, secondary to increased vasodilators. Over the years, HRS has gained much attention and focus among hepatologists and nephrologists. HRS is a diagnosis of exclusion, and in some cases, it carries a poor prognosis. Different classifications have emerged to better understand, diagnose, and promptly treat this condition. This targeted review aims to provide substantial insight into the epidemiology, pathophysiology, diagnosis, and management of HRS, shed light on the various milestones of this condition, and add to our current understanding.

In-Hospital Mortality in Cirrhotic Patients with End-Stage Renal Disease Treated with Hemodialysis versus Peritoneal Dialysis: A Nationwide Study

Background

Cirrhotic patients often develop end-stage renal disease (ESRD) requiring renal replacement therapy in the form of hemodialysis (HD) or peritoneal dialysis (PD). Studies comparing the outcomes and difference in in-hospital mortality between these 2 groups, particularly among those with ascites, are sparse. We set our objective to determine the dialysis modality with a better in-hospital survival rate among cirrhotic patients with ESRD (ESRD-cirrhosis).

Methods

Data was extracted from the 2005 to 2012 Nationwide Inpatient Sample (NIS). Using propensity score matching, ESRD-cirrhosis patients on PD were matched with patients on HD at a 1:1 ratio. Another subgroup analysis of ESRD-cirrhosis patients with ascites was performed using the same matching algorithm. Analyses were performed using SAS version 9.3 (SAS Institute, Cary, NC, USA).

Results

Among 26,135 cirrhotic patients with incident ESRD, 25,686 (98.3%) and 449 (1.7%) were initiated on HD and PD, respectively, during the hospitalization. There was a nonsignificant mortality difference between the ESRD-cirrhosis patients treated with PD and those treated with HD. In a subgroup analysis of these patients with ascites, 18 patients underwent PD while 1,878 patients required HD. Also, PD had a significantly lower in-hospital mortality compared with HD in this subgroup (0% vs 26.67%, p = 0.03). Mean length of stay for those who received HD was 8.34 days compared with 7.06 days for the PD group ( p < 0.0001). Similarly, mean hospital charges were greater for those who had HD compared with PD ($74,501 vs $57,460; p < 0.001).

Conclusion

Cirrhotic patients with ESRD and ascites who undergo PD have a significantly lower mortality than those who are started on HD. However PD is rarely initiated for ESRD in cirrhotic patients with ascites during hospitalization in the United States. Due to the potential advantages of PD, nephrologists should encourage PD when selecting dialysis modality in this subgroup of patients whenever possible.

C-Reactive Protein in the Prediction of Localization of Gastrointestinal Perforation

AIM

Information regarding the localization of the anatomic site of gastrointestinal (GI) tract perforation is essential for the following surgical procedure. The purpose of this study was to evaluate the significance of C-reactive protein (CRP) and other circulating markers for the prediction of the localization of intra-abdominal hollow organ perforation.

METHODS

Measurements of serum markers were analyzed in 423 patients with GI tract perforations, who were divided according to the intraoperative diagnosis into colorectal and upper GI tract perforation groups.

RESULTS

Levels of CRP were higher in patients with colorectal perforations than in upper GI tract perforations (p < 0.001). Moreover, high levels of CRP were associated with increased mortality of patients with hollow organ perforations (p = 0.009), which was largely driven by the subset of patients with perforations of the upper GI tract (p = 0.001).

CONCLUSION

Increased CRP levels predict worse clinical outcome in patients with intra-abdominal hollow organ perforations and are associated with perforations in the colorectal tract. Thus, CRP might be a useful marker for preoperative risk stratification and prediction of the localization of the perforation site.

Effect of Liver Cirrhosis on the Outcomes of Peritoneal Dialysis

Background:Peritoneal dialysis (PD) has become an increasingly important treatment modality for end-stage renal disease. However, application of PD in patients with liver cirrhosis (LC) and subsequent outcomes have not been thoroughly evaluated.Methods:A total of 1,366 patients (≥ 18 years old) who started PD at 4 tertiary referral centers between January 2000 and December 2015 were initially reviewed. Among them, 45 patients with LC were finally analyzed (LC-PD). Using the multivariate Cox hazard ratio (HR) model, outcomes such as technique failure, infection, and mortality in patients with LC-PD were compared with those in non-LC-PD patients (non-LC-PD) or patients with LC who received hemodialysis (LC-HD). All of the patients were selected by 1:1 matching of age, sex, catheter insertion date, and diabetes mellitus.Results:During the mean follow-up duration of 43 ± 35.8 months, 12 patients with LC-PD experienced technique failure, and this rate was similar to that of non-LC-PD patients. In evaluating infection episodes, the most common causes for peritonitis and exit-site infection were Escherichia coli (5.8%) and Staphylococcus aureus (19.3%), respectively; these event rates of LC-PD did not differ from those of non-LC-PD. The all-cause mortality rate of the LC-PD group was not different from that of the non-LC-PD and LC-HD groups.Conclusion:Dialysis outcomes such as technique failure, infection, and mortality are not affected by the presence of LC. Accordingly, PD therapy is a good option in patients with LC.

Acute kidney injury in children with chronic liver disease

Acute kidney injury (AKI) is a common accompaniment in patients with liver disease. The causes, risk factors, manifestations and management of AKI in these patients vary according to the liver disease in question (acute liver failure, acute-on-chronic liver failure, post-liver transplantation or metabolic liver disease). There are multiple causes of AKI in patients with liver disease-pre-renal, acute tubular necrosis, post-renal, drug-induced renal failure and hepatorenal syndrome (HRS). Definitions of AKI in liver failure are periodically revised and updated, but pediatric definitions have still to see the light of the day. As our understanding of the pathophysiology of liver disease and renal involvement improves, treatment modalities have become more advanced and rationalized. Treatment includes reversing precipitating factors, such as infections and gastrointestinal bleeding, volume expansion, paracentesis and vasoconstrictors. This approach is tried and tested in adults. A pediatric tailored approach is still lacking due to inadequate numbers of patients, differences in causes of AKI and paucity of literature. In this review, we attempt to explore the pathophysiological basis, treatment modalities and controversies in the diagnosis and treatment of AKI in pediatric patients with chronic liver disease and discuss our own personal practice. We recognize that, although it is not a very commonly encountered entity in pediatric population, HRS has specific diagnostic criteria and treatment modalities that differ from other causes of AKI in patients with chronic liver disease; hence among the etiologies of kidney injury in patients with chronic liver disease, we focus here on HRS.

Hepatic damage exacerbates cisplatin-induced acute kidney injury in Sprague-Dawley rats

The objective of this study was to elucidate the effect of hepatic damage on cisplatin (CDDP)-induced acute kidney injury (AKI). Thioacetamide (TAA, 150 mg/kg), a hepatotoxicant, was intraperitoneally (i.p.) injected to male Sprague-Dawley rats for 3 d prior to CDDP (5 mg/kg, i.p.) injection. All animals were sacrificed 5 d after CDDP treatment, and urine or blood was obtained to measure various parameters. No significant changes in serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activity were observed after CDDP treatment. However, pretreatment with TAA significantly elevated ALT and AST activity. Serum blood urea nitrogen and creatinine levels significantly increased in CDDP-treated group compared to control. In addition, urinary excretion of novel protein-based biomarkers such as neutrophil gelatinase-associated lipocalin, vascular endothelial growth factor, kidney injury molecule-1, and tissue inhibitor of metalloproteinase-1 rose markedly in the CDDP-treated group. In particular, pretreatment with TAA markedly elevated CDDP-induced urinary excretion of protein-based nephrotoxic biomarkers compared with CDDP alone. Hematoxylin and eosin staining demonstrated that pretreatment with TAA following CDDP injection led to more severe tubular damage and apoptosis in rats compared with CDDP alone. Antioxidant status was significantly reduced in kidneys following pretreatment with TAA prior to CDDP. These findings indicate that liver injury enhanced the vulnerability of kidney to CDDP-induced AKI and this phenomenon may be associated with severe apoptotic damage.

Urinary and Serum Metabolomics Analyses Uncover That Total Glucosides of Paeony Protect Liver against Acute Injury Potentially via Reprogramming of Multiple Metabolic Pathways

Total glucosides of paeony (TGP) have been confirmed to be hepatoprotective. However, the underlying mechanism is largely unclear. In this study, we investigated the metabolic profiles of urine and serum in rats with carbon tetrachloride- (CCl₄-) induced experimental liver injury and TGP administration by using ultra-performance liquid chromatography-mass spectrometry (UPLC-MS). The vehicle or a single dose of TGP was intragastrically administered to Wistar rats once a day for 14 consecutive days. To induce ALI, 50% CCl₄ was injected intraperitoneally into these rats 2 hours after the last time administration of saline of TGP at the 14th day. The results indicated that TGP administration could protect rats from CCl₄-induced ALI and alanine aminotransferase (ALT) and aspartate aminotransferase (AST) elevation, as well as hepatocyte apoptosis and inflammation. Furthermore, metabolomics analysis showed that TGP treatment significantly attenuated CCl₄-triggered deregulation of multiple metabolites in both urine and serum, including glycine, alanine, proline, and glutamine. Metabolite set enrichment and pathway analyses demonstrated that amino acid cycling and glutathione metabolism were two main pathways involved in CCl₄-induced experimental liver injury and TGP administration. Taken together, these findings revealed that regulation of metabolites potentially plays a pivotal role in the protective effect of TGP on ALI.

Resolvin D1 and E1 alleviate the progress of hepatitis toward liver cancer in long-term concanavalin A-induced mice through inhibition of NF-κB activity

Resolvins, an endogenous lipid mediator derived from eicosapentaenoic acid (EPA) or docosahexaenoic acid (DHA) of fish oil, has been reported to have anti-inflammatory and antitumor effect in various pathogenic processes. However, there are no studies about the effects of resolvin D1 and E1 on concanavalin A-induced hepatitis. Hence, the present study is to illustrate whether resolvin D1 and E1 inhibit concanavalin A-induced liver injury, liver cancer and underlying mechanisms by which they may recover. C57BL/6 mice were pretreated with resolvin D1 and E1 for 4 h, and then injected with concanavalin A for 12 h. Subsequently, blood and liver tissue were collected at 0, 2, 4, 8 and 12 h for different analysis. Analysis of inflammatory cytokines indicated that the inhibition of necrosis factor (TNF)-α, interferon (IFN)-γ, interleukin (IL)-2, IL-1β and IL-6 could be performed by resolvin D1 and E1. Moreover, Toll-like receptor (TLR) 4 expression, NF-κB and AP-1 activity also have been confirmed to have key roles in the development of liver injury. They were significantly suppressed in the treatment group, compared to model. In addition, resolvin D1 and E1 markedly downregulated CD4+ and CD8+ cell infiltration in the liver. A long-term concanavalin A treatment for 32 weeks was performed to analyze the changes of hepatitis to liver cancer and the antitumor effect of resolving D1 and E1. These results indicated that resolvin D1 and E1 prevent concanavalin A-induced liver injury and the changes of hepatitis to liver cancer in mice through inhibition of inflammatory cytokine secretion and NF-κB/AP-1 activity. Thus, they could be novel target to be considered in the process of finding sufficient drug to protect against various forms of hepatitis and liver cancer.