Kidney-liver pathophysiological crosstalk: its characteristics and importance

Human molybdenum exposure risk in industrial regions of China: New critical effect indicators and reference dose

Evidence increasingly suggests molybdenum exposure at environmental levels is still associated with adverse human health, emphasizing the necessity to establish a more protective reference dose (RfD). Herein, we conducted a study measuring 15 urinary metals and 30 clinical health indicators in 2267 participants residing near chemical enterprises across 11 Chinese provinces to investigate their relationships. The kidney and cystatin-C emerged as the most sensitive organ and critical effect indicator of molybdenum exposure, respectively. Odds of cystatin-C-defined chronic kidney disease (CKD) in the highest quantile of molybdenum exposure significantly increased by 133.5% (odds ratio [OR]: 2.34, 95% CI: 1.78, 3.11) and 75.8% (OR: 1.76, 95% CI: 1.24, 2.49) before and after adjusting for urinary 14 metals, respectively. Intriguingly, cystatin-C significantly mediated 15.9-89.5% of molybdenum's impacts on liver and lung function, suggesting nephrotoxicity from molybdenum exposure may trigger hepatotoxicity and pulmonary toxicity. We derived a new RfD for molybdenum exposure (0.87 μg/kg-day) based on cystatin-C-defined estimated glomerular filtration rate by employing Bayesian Benchmark Dose modeling analysis. This RfD is significantly lower than current exposure guidance values (5-30 μg/kg-day). Remarkably, >90% of participants exceeded the new RfD, underscoring the significant health impacts of environmental molybdenum exposure on populations in industrial regions of China.

Screening impacts of Tilmicosin-induced hepatic and renal toxicity in rats: protection by Rhodiola rosea extract through the involvement of oxidative stress, antioxidants, and inflammatory cytokines biomarkers

Tilmicosin (TIL) is a semisynthetic macrolide antibiotic with a broad spectrum of activity derived from tylosin. TIL is effective in the treatment of bovine and ovine respiratory diseases caused by different microbes. In parallel, Rhodiola rosea (RHO) is a popular herbal remedy because of its anti-inflammatory and antioxidant qualities. The experiment lasted for 12 days. Depending on the experimental group, the animals received either distilled water or RHO root extract dissolved in distilled water for 12 days through a stomach tube, and the single subcutaneous injection on day 6 of the experiment of either 500 μL of 0.9% NaCl or TIL dissolved in 500 μL 0.9% NaCl. Samples and blood were collected for serum analysis, gene expression, and immunohistochemistry screening at liver and kidney levels. TIL injection increased serum levels of hepatic and renal markers (ALP, ALT, AST, TC, TG, creatinine, and urea) with decreased total proteins. In parallel, TIL induced hepatic and renal oxidative stress as there was an increase in malondialdehyde levels, with a decrease in catalase and reduced glutathione activities. Of interest, pre-administration of RHO inhibited TIL-induced increase in hepato-renal markers, decreased oxidative stress, and increased liver and kidney antioxidant activities. Quantitative RT-PCR showed that TIL increased the liver's HSP70 (heat shock protein), NFkB, and TNF-α mRNA expression. Moreover, TIL upregulated the expression of desmin, nestin, and vimentin expression in the kidney. The upregulated genes were decreased significantly in the protective group that received RHO. Serum inflammatory cytokines and genes of inflammatory markers were affected in liver tissues (HSP70, NFkB, and TNF-α) and kidney tissues (desmin, nestin, and vimentin)-TIL-induced hepatic vacuolation and congestion together with glomerular atrophy. The immunoreactivity of PCNA and HMGB1 was examined immunohistochemically. At cellular levels, PCNA was decreased while HMGB1 immunoreactivity was increased in TIL-injected rats, which was improved by pre-administration of RHO. RHO administration protected the altered changes in liver and renal histology. Current findings support the possible use of RHO to shield the liver and kidney from the negative effects of tilmicosin.

The Association Between the Albumin-Bilirubin Score and Contrast-Associated Acute Kidney Injury in Patients Undergoing Elective Percutaneous Coronary Intervention

The albumin-bilirubin (ALBI) score is considered an effective and convenient scoring system for assessing liver function. We hypothesized that the ALBI score was predictive of contrast-associated acute kidney injury (CA-AKI) and long-term mortality in patients undergoing elective percutaneous coronary intervention (PCI). We retrospectively observed 5629 patients undergoing elective PCI. Contrast-associated acute kidney injury is defined as a 50% or 0.3 mg/dl increase in baseline serum creatinine levels within 48 h of contrast exposure. The incidence of CA-AKI was 6.2% (n = 350). After adjusting for potential confounding factors, multivariate analysis showed that the ALBI score was an independent predictor of CA-AKI (P = .002). A restricted cubic spline analysis confirmed approximately linear relationships between the ALBI score and risks of CA-AKI. Furthermore, at a median follow-up of 2.8 years, multivariate Cox regression analysis indicated that the ALBI score was an independent risk factor for long-term mortality (P < .001). The ALBI score was closely related to the occurrence of CA-AKI and long-term mortality in patients who underwent elective PCI. This score might be useful for risk stratification in high-risk patient groups to predict CA-AKI.

Clinical factors distinguishing renal infarction from acute pyelonephritis: A randomly matched retrospective case-control study

INTRODUCTION

Renal infarction (RI) is rare but clinically important because the appropriate treatment depends on the time of diagnosis. RI is often misdiagnosed as acute pyelonephritis (APN) because both diseases have nonspecific symptoms such as flank pain and abdominal pain. We identified predictors for distinguishing RI from APN.

METHODS

The data of patients visited the emergency department and diagnosed with RI or APN from March 2016 to May 2020 were prospectively collected and retrospectively analyzed. Patients aged under 18 years, with a history of trauma, or incomplete medical records were excluded. Using a matching ratio of 1:5, RI patients were randomly matched to APN patients. Multivariable logistic regression analysis was performed to identify factors that could distinguish RI from APN. In addition, we constructed a decision tree to identify patterns of risk factors and develop prediction algorithms.

RESULTS

The RI and APN groups included 55 and 275 patients, respectively. Multivariable logistic regression analysis showed that male sex (OR, 6.161; p = 0.009), atrial fibrillation (AF) (OR, 14.303; p = 0.021), costovertebral angle tenderness (CVAT) (OR, 0.106; p < 0.001), aspartate transaminase (AST) level > 21.50 U/L (OR, 19.820; p < 0.001), C-reactive protein (CRP) level < 19.75 mg/L (OR, 10.167; p < 0.001), and pyuria (OR, 0.037; p < 0.001) were significantly associated with RI distinguishing from APN.

CONCLUSION

Male sex, AF, no CVAT, AST level > 21.50 U/L, CRP level < 19.75 mg/L, and no pyuria were significant factors that could distinguish RI from APN.

Protective impacts of Withania somnifera leaf extract from Taif area against diclofenac induced hepato-renal toxicity: role of antioxidants, inflammation, apoptosis, and anti-oxidative stress biomarkers

Current study examined the boosting impacts of Withania somnifera leaf extract from Taif area (high-altitude area) against hepatic and renal toxicity induced by diclofenac in experimental rats. Withania is highly grown on Taif area as environmental herb with multiple functions. Diclofenac is non-steroidal medication used for treatment of pain but over dose has severe side effects. Thirty-two adult Wistar rats of male type were subdivided into 4 groups. The control rats (group 1) received saline. Second group received diclofenac (50 mg/kg BW intraperitoneally) at days 4 and 5. Third group received W. somnifera leaf extract (250 mg /kg body weight) for 6 days. The fourth protective group, received W. somnifera leaf extract plus diclofenac for 6 days as shown in groups 2 and 3. Diclofenac significantly increased serum AST, ALT, and decreased albumin and total proteins levels. It also increased serum concentrations of uric acid and creatinine. In addition, it increased lipid peroxidation, and decreased reduced glutathione and superoxide dismutase levels. Diclofenac increased inflammatory cytokines secretion and up-regulated hepatic oxidative stress genes (HO-1; hemoxygenase-1 and Nrf2nuclear factor erythroid 2-related factor 2 (Nrf2) and renal inflammatory transcriptional markers (TGF-β1; transforming growth factor-beta1 and COX-2; cycloxygenas-2). In parallel, hepatic caspase-3 expression was up-regulated as an apoptotic marker, while Bcl2; (B-cell lymphoma 2) mRNA expression was down regulated as anti-apoptotic marker. W. somnifera pre-administration in the protective group ameliorated the altered parameters induced by diclofenac. In conclusion, W. somnifera leaf extract has the potential to antagonize side effects of diclofenac by regulating the pathways of oxidative stress, inflammation, and apoptosis/antiapoptosis.

Thyroid hormone Beta receptor agonists for treatment of kidney disease: A promising agent?

BACKGROUND

Chronic kidney disease is a common disorder affecting a significant portion of the adult population with high mortality and morbidity. Obesity and hyperlipidemia are prevalent in chronic kidney disease, and they may trigger fat accumulation in renal parenchyma and eventually fatty kidney. Chronic kidney disease and fatty kidney are also strongly associated with nonalcoholic fatty liver disease. Because they both lead to detrimental effects on organ function, they both need to be treated effectively to improve the outcome.

AIM

In this narrative review, we have hypothesized that thyroid hormone beta receptor agonists, a novel drug group, may potentially be beneficial in the management of chronic kidney disease due to its promising outcomes among patients with nonalcoholic fatty liver disease, a condition sharing multiple common underlying pathophysiological mechanisms.

RESULTS AND CONCLUSION

Thyroid hormone beta receptors are abundantly expressed in liver and kidney tissues, while both nonalcoholic fatty liver disease and chronic kidney disease share various similar pathophysiological mechanisms and triggers. Therefore, thyroid hormone beta receptor agonists may become a promising tool in the management of patients with chronic kidney disease.

Effects of Transfusion of Stored Red Blood Cells on Renal Ischemia-Reperfusion–Induced Hepatic Injury in Rats

BACKGROUND

Renal ischemia-reperfusion (IR) injures the liver as well as the kidneys. Transfusion of stored red blood cells (RBCs) triggers inflammatory responses, oxidative stress, and activation of innate immunity. In the present study, we investigated the effect of transfusion of stored RBCs on renal IR-induced hepatic injury.

METHODS

Sprague-Dawley rats were randomly divided into 3 groups based on the following treatments: rats subjected to sham operation (sham group), rats subjected to the induction of renal IR only (RIR group), and rats transfused with stored RBCs 1 hour after the start of reperfusion (RIR-TF group). Renal ischemia was induced for 1 hour, and reperfusion was allowed for 24 hours. After reperfusion, blood and liver tissue samples were obtained.

RESULTS

Serum levels of aspartate and alanine aminotransferase were increased in the RIR-TF group compared with those in the RIR and sham groups. The hepatic mRNA expression levels of heme oxygenase-1 and neutrophil gelatinase-associated lipocalin were increased in the RIR-TF group compared with those in the RIR and sham groups. The mRNA expression level of high mobility group box-1 was also increased in the RIR-TF group compared with that in the RIR group.

CONCLUSION

The transfusion of stored RBCs exacerbates renal IR-induced liver damage. Oxidative stress may be responsible for hepatic injury.

Critical Overview of Hepatic Factors That Link Non-Alcoholic Fatty Liver Disease and Acute Kidney Injury: Physiology and Therapeutic Implications

Non-alcoholic fatty liver disease (NAFLD) is defined as a combination of a group of progressive diseases, presenting different structural features of the liver at different stages of the disease. According to epidemiological surveys, as living standards improve, the global prevalence of NAFLD increases. Acute kidney injury (AKI) is a class of clinical conditions characterized by a rapid decline in kidney function. NAFLD and AKI, as major public health diseases with high prevalence and mortality, respectively, worldwide, place a heavy burden on societal healthcare systems. Clinical observations of patients with NAFLD with AKI suggest a possible association between the two diseases. However, little is known about the pathogenic mechanisms linking NAFLD and AKI, and the combination of the diseases is poorly treated. Previous studies have revealed that liver-derived factors are transported to distal organs via circulation, such as the kidney, where they elicit specific effects. Of note, while NAFLD affects the expression of many hepatic factors, studies on the mechanisms whereby NAFLD mediates the generation of hepatic factors that lead to AKI are lacking. Considering the unique positioning of hepatic factors in coordinating systemic energy metabolism and maintaining energy homeostasis, we hypothesize that the effects of NAFLD are not only limited to the structural and functional changes in the liver but may also involve the entire body via the hepatic factors, e.g., playing an important role in the development of AKI. This raises the question of whether analogs of beneficial hepatic factors or inhibitors of detrimental hepatic factors could be used as a treatment for NAFLD-mediated and hepatic factor-driven AKI or other metabolic disorders. Accordingly, in this review, we describe the systemic effects of several types of hepatic factors, with a particular focus on the possible link between hepatic factors whose expression is altered under NAFLD and AKI. We also summarize the role of some key hepatic factors in metabolic control mechanisms and discuss their possible use as a preventive treatment for the progression of metabolic diseases.

Chronic kidney disease (CKD) and chronic kidney insufficiency (CKI) diagnosing equation in cirrhotic patients

Cirrhotic patients can develop acute kidney injury (AKI), and chronic kidney disease (CKD). Therefore, renal functional evaluation is crucial in cirrhotic patients. However, serum creatinine and urea levels, as well as measured or estimated glomerular filtration rate is not reliable renal functional markers in these patients compared to other patient groups. In the present study, four original equations are designed and tested for screening chronic kidney disease (CKD) and chronic kidney insufficiency (CKI) in stable cirrhotic patients.

MATERIAL & METHOD

estimated GFR (CKD-EPI creatinine and cystatin equations) were recorded in 175 adult stable patients suffering from cirrhosis, and these patients were classified as presenting or not CKD and CKI after evaluation by two independent nephrologists. Based on these data, the variables with the significant discriminating capability to identify CKD and CKI (based on creatinine and cystatin) were detected by applying the Student's t-test for two independent groups, later confirmed by the lambda test of Wilks, in order to obtain the renal function equations.

RESULTS

CKD equation (creatinine) = 7.094238-0.043104 × CKD-EPI creatinine - 0.057537 × haematocrit. CKD equation (cystatin) = 8.375074-0.117218 × CKD-EPI cystatin. CKI equation (creatinine) = 0.428389-0.043214 × CKD-EPI creatinine +0.183051 × Child-Pugh score + 0.050162 × age (in years). CKI equation (cystatin) = 9.169579-0.139319 × CKD-EPI cystatin.

CONCLUSION

Simple and reliable equations have been obtained for screening chronic kidney disease and chronic kidney insufficiency in cirrhotic patients.

Perfusate Enzymes and Platelets Indicate Early Allograft Dysfunction After Transplantation of Normothermically Preserved Livers

BACKGROUND

Normothermic machine perfusion (NMP) has become a clinically established tool to preserve livers in a near-physiological environment. However, little is known about the predictive value of perfusate parameters toward the outcomes after transplantation.

METHODS

Fifty-five consecutive NMP livers between 2018 and 2019 were included. All of the livers were perfused on the OrganOx metra device according to an institutional protocol. Transplant and perfusion data were collected prospectively.

RESULTS

Forty-five livers were transplanted after NMP. Five livers stem from donors after circulatory death and 31 (68.9%) from extended criteria donors. Mean (SD) cold ischemia time was 6.4 (2.3) h; mean (SD) total preservation time was 21.4 (7.1) h. Early allograft dysfunction (EAD) occurred in 13 of 45 (28.9%) patients. Perfusate aspartate aminotransferase (P = 0.008), alanine aminotransferase (P = 0.006), lactate dehydrogenase (P = 0.007) and their development over time, alkaline phosphatase (P = 0.013), and sodium (P = 0.016) correlated with EAD. Number of perfusate platelets correlated with cold ischemia time duration and were indicative for the occurrence of EAD. Moreover, von Willebrand Factor antigen was significantly higher in perfusates of EAD livers (P < 0.001), and Δ von Willebrand factor antigen correlated with EAD. Although perfusate lactate and glucose had no predictive value, EAD was more likely to occur in livers with lower perfusate pH (P = 0.008). ΔPerfusate alkaline phosphatase, Δperfusate aspartate aminotransferase, Δperfusate alanine aminotransferase, and Δperfusate lactate dehydrogenase correlated closely with model for early allograft function but not liver graft assessment following transplantation risk score. Bile parameters correlated with extended criteria donor and donor risk index.

CONCLUSIONS

Biomarker assessment during NMP may help to predict EAD after liver transplantation. The increase of transaminases and lactate dehydrogenase over time as well as platelets and vWF antigen are important factors indicative for EAD.

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.

Association of FIB-4 index and clinical outcomes in critically ill patients with acute kidney injury: a cohort study

Background

The relationship between fibrosis-4 (FIB-4) index and clinical outcomes in patients with acute kidney injury (AKI) is unclear. We aimed to investigate the association between FIB-4 index and all-cause mortality in critically ill patients with AKI.

Methods

We used data from the Multiparameter Intelligent Monitoring in Intensive Care III (MIMIC-III) database (v1.4). The FIB-4 score was calculated using the existing formulas. logistic regression model, and Cox proportional hazards model were used to assessed the relationship between the FIB-4 index and in-hospital,28-day and 90-day mortality, respectively.

Results

A total of 3592 patients with AKI included in the data analysis. 395 (10.99%) patients died during hospitalization and 458 (12.74%) patients died in 28-day. During the 90-day follow-up, 893 (22.54%) patients were dead. An elevated FIB-4 value was significantly associated with increased in-hospital mortality when used as a continuous variable (odds ratio [OR] 1.183, 95% confidence interval [CI] 1.072–1.305, P = 0.002) and as a quartile variable (OR of Q2 to Q4 1.216–1.744, with Q1 as reference). FIB-4 was positively associated with 28-day mortality of AKI patients with hazard ratio (HR) of 1.097 (95% CI 1.008, 1.194) and 1.098 (95% 1.032, 1.167) for 90-day mortality, respectively.

Conclusion

This study demonstrated the FIB-4 index is associated with clinical outcomes in critically ill patients with acute kidney injury.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12876-021-02071-2.

Non-Alcoholic Fatty Liver Disease Is Associated With Reduced Glomerular Filtration Rate in Patients With Chronic Plaque Psoriasis

BACKGROUND

Chronic plaque psoriasis has been associated with metabolic comorbidities, including non-alcoholic fatty liver disease (NAFLD). A causal relationship between NAFLD and chronic kidney disease (CKD) is debated.

OBJECTIVES

To assess whether NAFLD is associated with impaired renal function in patients with psoriasis.

METHODS

A multicenter, retrospective, observational study including 337 patients with moderate-to-severe chronic plaque psoriasis, who had no history of excessive alcohol consumption or other secondary causes of chronic liver and renal diseases was conducted. NAFLD was diagnosed by ultrasonography, and CKD stage ≥2 or stage ≥3 were defined by an estimated glomerular filtration rate (e-GFR) of <90 ml min^-1 1.73 m^-2 or <60 ml min^-1 1.73 m^-2, respectively. Logistic and linear regression analyses were undertaken to assess the independent association of NAFLD with CKD or eGFR levels.

RESULTS

Patients with NAFLD (n = 212, 62.9% of total) had significantly lower e-GFR levels (83.4 ± 18.0 vs. 93.5 ± 15.8 ml min^-1 1.73 m^-2, P<.001) and a remarkably higher prevalence of both CKD stage ≥2 (56.1% vs. 30.4%, P<.0001) and CKD stage ≥3 (10.4% vs. 3.2%, P<.0001) compared with their counterparts without NAFLD. Multivariable logistic regression analysis showed that NAFLD was associated with a nearly 2.5-fold increased risk of prevalent CKD stage ≥2 (adjusted-odds ratio= 2.60 95% confidence intervals 1.4-4.8, P=.02), independently of components of metabolic syndrome, psoriasis severity, and psoriatic arthritis.

CONCLUSIONS

Ultrasound-diagnosed NAFLD is strongly associated with a reduced eGFR in patients with moderate-to-severe psoriasis, independently of cardiometabolic risk factors and psoriasis-related variables.

Early Hypertransaminasemia after Kidney Transplantation: Significance and Evolution According to Donor Type

Early hypertransaminasemia after kidney transplantation (KT) is frequent. It has been associated with the crosstalk produced between the liver and the kidney in ischemia-reperfusion situations. However, the influence of the donor type has not been evaluated. We present a retrospective study analyzing the increase in serum aspartate aminotransferase/alanine aminotransferase (AST/ALT) during the first three months post-KT in 151 recipients who received thymoglobulin as induction therapy, either from brain-death donors (DBD, n = 75), controlled circulatory death donors (cDCD, n = 33), or uncontrolled DCD (uDCD, n = 43). Eighty-five KT recipients from DBD who received basiliximab were included as controls. From KT recipients who received thymoglobulin, 33.6/43.4% presented with an increase in AST/ALT at 72 h post-KT, respectively. Regarding donor type, the percentage of recipients who experienced 72 h post-KT hypertransaminasemia was higher in uDCD group (65.1/83.7% vs. 20.3/26% in DBD and 20.7/27.6% in cDCD, p < 0.001). Within the control group, 9.4/12.9% of patients presented with AST/ALT elevation. One month after transplant, AST/ALT values returned to baseline in all groups. The multivariate analysis showed that uDCD recipients had 6- to 12-fold higher risk of developing early post-KT hypertransaminasemia. Early post-KT hypertransaminasemia is a frequent and transient event related to the kidney donor type, being more frequent in uDCD recipients.

Therapeutic implications of shared mechanisms in non-alcoholic fatty liver disease and chronic kidney disease

The most common cause of liver disease worldwide is now non-alcoholic fatty liver disease (NAFLD). NAFLD refers to a spectrum of disease ranging from steatosis to non-alcoholic steatohepatitis, causing cirrhosis, and ultimately hepatocellular carcinoma. However, the impact of NAFLD is not limited to the liver. NAFLD has extra-hepatic consequences, most notably, cardiovascular and renal disease. NAFLD and chronic kidney disease share pathogenic mechanisms including insulin resistance, lipotoxicity, inflammation and oxidative stress. Not surprisingly, there has been a recent surge in efforts to manage NAFLD in an integrated way that not only protects the liver but also delays comorbidities such as chronic kidney disease. This concept of simultaneously addressing the main disease target and comorbidities is key to improve outcomes, as recently demonstrated by clinical trials of SGLT2 inhibitors and GLP1 receptor agonists in diabetes. HIF activators, already marketed in China, also have the potential to protect both liver and kidney, as suggested by preclinical data. This review concisely discusses efforts at identifying common pathogenic pathways between NAFLD and chronic kidney disease with an emphasis on potential paradigm shifts in diagnostic workup and therapeutic management.