Predictive Role of Serum Cytokine Profiles in Acute Kidney Injury after Living Donor Liver Transplantation

Impact of Paired Remote Ischemic Preconditioning on Postreperfusion Syndrome in Living-Donor Liver Transplantation: A Propensity-Score Matching Analysis

Background and Objectives: Postreperfusion syndrome (PRS) is a significant challenge in liver transplantation (LT), leading to severe circulatory and metabolic complications. Ischemic preconditioning (IPC), including remote IPC (RIPC), can mitigate ischemia-reperfusion injury, although its efficacy in LT remains unclear. This study evaluated the impact of paired RIPC, involving the application of RIPC to both the recipient and the living donor, on the incidence of PRS and the need for rescue epinephrine during living-donor LT (LDLT). Materials and Methods: This retrospective observational cohort analysis included 676 adult patients who had undergone elective LDLT between September 2012 and September 2022. After applying exclusion criteria and propensity score matching (PSM), 664 patients were categorized into the paired RIPC and non-RIPC groups. The primary outcomes were the occurrence of PRS and the need for rescue epinephrine during reperfusion. Results: The incidence of PRS and the need for rescue epinephrine were significantly lower in the paired RIPC group than in the non-RIPC group. Furthermore, the incidence of postoperative acute kidney injury was lower in the paired RIPC group. Multivariable logistic regression adjusted for propensity scores indicated that paired RIPC was significantly associated with a reduced occurrence of PRS (odds ratio: 0.672, 95% confidence interval: 0.479-0.953, p = 0.021). Conclusions: Paired RIPC, involving both the recipient and the living donor, effectively reduces the occurrence of PRS and the need for rescue epinephrine during LDLT. These findings suggest that paired RIPC protects against ischemia-reperfusion injury in LDLT. Future randomized controlled trials are needed to verify our results and to explore the underlying mechanisms of the protective effects of RIPC.

Predictive Role of the D-Dimer Level in Acute Kidney Injury in Living Donor Liver Transplantation: A Retrospective Observational Cohort Study

This study aimed to determine the association between serum D-dimer levels and the risk of acute kidney injury (AKI) in patients undergoing living donor liver transplantation (LDLT). Clinical data of 675 patients undergoing LDLT were retrospectively analyzed. The exclusion criteria included a history of kidney dysfunction, emergency cases, and missing data. The final study population of 617 patients was divided into the normal and high D-dimer groups (cutoff: 0.5 mg/L). After LDLT, 145 patients (23.5%) developed AKI. A high D-dimer level (>0.5 mg/L) was an independent predictor of postoperative development of AKI in the multivariate analysis when combined with diabetes mellitus [DM], platelet count, and hourly urine output. AKI was significantly higher in the high D-dimer group than in the normal D-dimer group (odds ratio [OR], 2.792; 95% confidence interval [CI], 1.227-6.353). Patients with a high D-dimer exhibited a higher incidence of early allograft dysfunction, longer intensive care unit stay, and a higher mortality rate. These results could improve the risk stratification of postoperative AKI development by encouraging the determination of preoperative D-dimer levels in patients undergoing LDLT.

Mineralocorticoid receptor blockade with spironolactone has no direct effect on plasma IL-17A and injury markers in urine from kidney transplant patients

Kidney transplantation is associated with increased risk of cardiovascular morbidity. Interleukin-17A (IL-17A) mediates kidney injury. Aldosterone promotes T-helper-17 (Th-17) lymphocyte differentiation and IL-17A production through the mineralocorticoid receptor (MR). In this exploratory, post-hoc substudy, it was hypothesized that 1-year intervention with the MR antagonist spironolactone lowers IL-17A and related cytokines and reduces epithelial injury in kidney transplant recipients. Plasma and urine samples were obtained from kidney transplant recipients from a double-blind randomized clinical trial testing spironolactone (n=39) versus placebo (n=41). Plasma concentrations of cytokines IFN-γ, IL-17A, TNF-α, IL-6, IL-1β, and IL-10 were determined before and after 1-year treatment. Urine calbindin, clusterin, KIM-1, osteoactivin, TFF3, and VEGF/creatinine ratios were analyzed. Blood pressure and plasma aldosterone concentration at inclusion did not relate to plasma cytokines and injury markers. None of the cytokines changed in plasma after spironolactone intervention. Plasma IL-17A increased in the placebo group. Spironolactone induced an increase in plasma K⁺ (0.4 ± 0.4 mmol/L). This increase did not correlate with plasma IL-17A or urine calbindin and TFF3 changes. Ongoing treatment at inclusion with angiotensin-converting-enzyme inhibitor and/or angiotensin II receptor blockers was not associated with changed levels of IL-17A and injury markers and had no effect on the response to spironolactone. Urinary calbindin and TFF3 decreased in the spironolactone group with no difference in between-group analyses. In conclusion, irrespective of ongoing ANGII inhibition, spironolactone has no effect on plasma IL-17A and related cytokines or urinary injury markers in kidney transplant recipients.

RORC gene polymorphism is associated with acute kidney injury following cardiac surgery

BACKGROUND

Acute kidney injury (AKI) is a common complication of cardiopulmonary bypass (CPB), associated with increased mortality in surgical patients. It is well-proven that Th17 and its hallmark cytokine, IL-17, contribute to AKI development. Since the RAR-related orphan receptor C (RORC) gene is a master regulator of the Th17 differentiation, we aimed to evaluate the association between its polymorphisms, CPB-AKI and plasma IL-17 levels among Iranian patients undergoing CPB.

METHOD

Totally, 138 patients undergoing CPB in Bandar Abbas, Iran, were enrolled. The allele and genotype frequencies of the selected SNPs were determined using PCR-SSP. IL-17 serum level was determined using an enzyme-linked immunosorbent assay.

RESULTS

Rs9017 GG genotype and G allele were associated with increased risk of CPB-AKI (OR = 3, 95% CI = 1.4-6.6 and OR = 2.3, 95% CI = 1.3-3.9, respectively) while A allele was protective against the disease (OR = 0.4, 95% CI = 0.3-0.7, p = .02). There was not a statistically significant interaction between the three genotypes of rs9017 and AKI disease with IL-17 serum level before (p = .9) and after (p = .6) the operation. The IL-17 serum level before surgery was significantly higher in patients carrying GG genotype compared to GA genotype (p = .017).

CONCLUSION

Our results showed that the rs9017 GG genotype was associated with an increased level of IL-17 and risk of CBP-AKI in the Iranian population. Our current results suggest that the rs9017 GG genotype could be a probable predictor of AKI after cardiac surgery.

Cytokines in Liver Transplantation

Cytokines, soluble mediators of the immune system, play a critical role in the pathogenesis of autoimmune, allergic and infectious diseases. They are also implicated in the initiation and development of allograft rejection. During recent years, there have been considerable advances in generating novel anti-cytokine agents with promoted efficacy and safety, which could be administrated for managing dysregulated cytokine secretion; besides, gene therapy for overexpression of immunomodulatory cytokines has shown substantial improvements. Liver transplantation has been established as a life-saving treatment for end-stage hepatic diseases but the growing number of recipients urge for improved post-transplant care including tolerance induction, infection control and resolving immunosuppressant drugs adverse effects. Cytokines with a wide range of proinflammatory and regulatory properties might be considered as potential therapeutic targets for selective suppression or enhancement of the immune responses in recipients. In the present review, we aimed to summarize the positive and negative effects of cytokines on liver allograft in addition to their prognostic and therapeutic values.

Low Preoperative Antithrombin III Level Is Associated with Postoperative Acute Kidney Injury after Liver Transplantation

We aimed to determine the association between the preoperative antithrombin III (ATIII) level and postoperative acute kidney injury (AKI) after LT (post-LT AKI). We retrospectively evaluated 2395 LT recipients between 2010 and 2018 whose data of perioperative ATIII levels were available. Patients were divided into two groups based on the preoperative level of ATIII (ATIII < 50% vs. ATIII ≥ 50%). Multivariable regression analysis was performed to assess the risk factors for post-LT AKI. The mean preoperative ATIII levels were 30.2 ± 11.8% in the ATIII < 50% group and 67.2 ± 13.2% in the ATIII ≥ 50% group. The incidence of post-LT AKI was significantly lower in the ATIII ≥ 50% group compared to that in the ATIII < 50% group (54.7% vs. 75.5%, p < 0.001); odds ratio (OR, per 10% increase in ATIII level) 0.86, 95% confidence interval (CI) 0.81–0.92; p < 0.001. After a backward stepwise regression model, female sex, high body mass index, low albumin, deceased donor LT, longer duration of surgery, and high red blood cell transfusion remained significantly associated with post-LT AKI. A low preoperative ATIII level is associated with post-LT AKI, suggesting that preoperative ATIII might be a prognostic factor for predicting post-LT AKI.

Predictive utility of fibrinogen in acute kidney injury in living donor liver transplantation: A propensity score-matching analysis

BACKGROUND

This study investigated the association between the fibrinogen level and the risk of acute kidney injury (AKI) in patients who have undergone living donor liver transplantation (LDLT).

PATIENTS AND METHODS

A total of 676 patients who underwent LDLT were analyzed retrospectively. Exclusion criteria included a history of severe kidney dysfunction, emergency operation, deceased donor, ABO-incompatible transplantation, and missing data. The study population was divided into low and normal fibrinogen groups. A 1:1 propensity score (PS) matching analysis was used to evaluate the association between a low fibrinogen level (< 160 mg/dL) and postoperative development of AKI.

RESULTS

In total, 142 patients (23.1%) developed AKI after LDLT. The PS matching analysis showed that the probability of AKI was two-fold higher in the low fibrinogen group than in the normal fibrinogen group. In addition, patients with AKI had poorer postoperative outcomes such as longer hospitalization, longer ICU stay, and higher mortality than patients without AKI.

CONCLUSIONS

The preoperative fibrinogen level may be useful for risk stratification of patients undergoing LDLT in terms postoperative development of AKI.

Inflammatory stress in SARS-COV-2 associated Acute Kidney Injury

Increasing clinical evidence shows that acute kidney injury (AKI) is a common and severe complication in critically ill COVID-19 patients. The older age, the severity of COVID-19 infection, the ethnicity, and the history of smoking, diabetes, hypertension, and cardiovascular disease are the risk factor for AKI in COVID-19 patients. Of them, inflammation may be a key player in the pathogenesis of AKI in patients with COVID-19. It is highly possible that SARS-COV-2 infection may trigger the activation of multiple inflammatory pathways including angiotensin II, cytokine storm such as interleukin-6 (IL-6), C-reactive protein (CRP), TGF-β signaling, complement activation, and lung-kidney crosstalk to cause AKI. Thus, treatments by targeting these inflammatory molecules and pathways with a monoclonal antibody against IL-6 (Tocilizumab), C3 inhibitor AMY-101, anti-C5 antibody, anti-TGF-β OT-101, and the use of CRRT in critically ill patients may represent as novel and specific therapies for AKI in COVID-19 patients.

Sequential Use of Normothermic Regional and Ex Situ Machine Perfusion in Donation After Circulatory Death Liver Transplant

In Italy, 20 minutes of a continuous flat line on an electrocardiogram are required for declaration of death. In the setting of donation after circulatory death (DCD), prolonged warm ischemia time prompted the introduction of abdominal normothermic regional perfusion (NRP) followed by postprocurement ex situ machine perfusion (MP). This is a retrospective review of DCD liver transplantations (LTs) performed at 2 centers using sequential NRP and ex situ MP. From January 2018 to April 2019, 34 DCD donors were evaluated. Three (8.8%) were discarded before NRP, and 11 (32.4%) were discarded based on NRP parameters (n = 1, 3.0%), liver macroscopic appearance at procurement and/or biopsy results (n = 9, 26.5%), or severe macroangiopathy at back-table evaluation (n = 1, 3.0%). A total of 20 grafts (58.8%; 11 uncontrolled DCDs, 9 controlled DCDs) were considered eligible for LT, procured and perfused ex situ (9 normothermic and 11 dual hypothermic MPs). In total, 18 (52.9%; 11 uncontrolled) livers were eventually transplanted. Median (interquartile range) no-flow time was 32.5 (30-39) minutes, whereas median functional warm ischemia time was 52.5 (47-74) minutes (controlled DCD), and median low-flow time was 112 minutes (105-129 minutes; uncontrolled DCD). There was no primary nonfunction, while postreperfusion syndrome occurred in 8 (44%) recipients. Early allograft dysfunction happened in 5 (28%) patients, while acute kidney injury occurred in 5 (28%). After a median follow-up of 15.1 (9.5-22.3) months, 1 case of ischemic-type biliary lesions and 1 patient death were reported. DCD LT is feasible even with the 20-minute no-touch rule. Strict NRP and ex situ MP selection criteria are needed to optimize postoperative results.

Predictive Utility of Antithrombin III in Acute Kidney Injury in Living-Donor Liver Transplantation: A Retrospective Observational Cohort Study

INTRODUCTION

This study was performed to determine the association between the serum level of antithrombin III (ATIII) level and the risk of acute kidney injury (AKI) in patients undergoing living-donor liver transplantation (LDLT).

PATIENTS AND METHODS

A total of 591 patients undergoing LDLT were retrospectively investigated and 14 patients were excluded because of a history of kidney dysfunction or missing data; 577 patients were finally enrolled in the study. The study population was divided into normal and low ATIII groups. Data on all laboratory variables, including ATIII, were collected on the day before surgery.

RESULTS

After LDLT, 143 patients developed AKI (24.8%). A lower ATIII was independently associated with postoperative AKI along with preoperative (diabetes mellitus) and intraoperative (mean heart rate, hourly urine output) factors. Based on the standard cutoff for normal ATIII (<70%), the probability of AKI was 2.8-fold higher in the low ATIII group than in the normal ATIII group. In addition, patients with low ATIII received blood transfusion products during the operation and underwent longer duration mechanical ventilation.

CONCLUSIONS

Preoperative ATIII measurement will help improve risk stratification for postoperative AKI development in patients undergoing LDLT.

Predictive role of vitamin B12 in acute kidney injury in living donor liver transplantation: a propensity score matching analysis

OBJECTIVES

We examine the association between vitamin B₁₂ level and risk for acute kidney injury (AKI) in patients undergoing living donor liver transplantation (LDLT).

DESIGN

Retrospective observational cohort study.

SETTING

University hospital, from January 2009 to December 2018.

PARTICIPANTS

A total of 591 patients who underwent elective LDLT were analysed in this study. Those with a preoperative history of kidney dysfunction, vitamin B₁₂ supplementation due to alcoholism, low vitamin B₁₂ (<200 pg/mL) or missing laboratory data were excluded.

PRIMARY AND SECONDARY OUTCOME MEASURES

The population was classified into AKI and non-AKI groups according to Kidney Disease Improving Global Outcomes (KDIGO) criteria, and associations between perioperative factors and AKI were analysed. After 1:1 propensity score (PS) matching, the association between high vitamin B₁₂ (>900 pg/mL) and postoperative AKI was evaluated.

RESULTS

Preoperative vitamin B₁₂ was higher in the AKI group. Potentially significant perioperative factors from univariate analyses were entered into multivariate analyses, including preoperative factors (vitamin B₁₂, diabetes), intraoperative factors (hourly urine output) and donor graft fatty change in LDLT patients. PS matching analyses with adjustment using PS revealed that high serum vitamin B₁₂ (>900 pg/mL) was associated with risk for AKI, and the risk was 2.8-fold higher in patients with high vitamin B₁₂ than in those with normal vitamin B₁₂. Higher vitamin B₁₂ was also related to a higher AKI stage. In addition, inflammatory factors (C reactive protein, white blood cells and albumin) were associated with vitamin B₁₂ level.

CONCLUSIONS

Our study may improve the accuracy of predicting postoperative AKI by introducing preoperative vitamin B₁₂ into risk assessments for patients undergoing LDLT.

Role of thrombocytopenia in risk stratification for acute kidney injury after living donor liver transplantation

The aim of our study was to investigate pre and intraoperative clinical factors, including platelet count, which could inform risk stratification of early acute kidney injury (AKI) after living donor liver transplantation (LDLT). Additionally, the impact of severe thrombocytopenia on AKI risk was assessed using a propensity score (PS)-matched analysis. In total, 591 adult patients who underwent LDLT between January 2009 and December 2018 at our hospital were retrospectively analyzed. Early postoperative AKI was determined based on the KDIGO criteria, and 149 patients (25.2%) developed AKI immediately after surgery. In a multivariate analysis, a lower preoperative platelet count was significantly associated with early postoperative AKI, together with diabetes mellitus, lower hourly urine output, and longer graft ischemic time; furthermore, a decrease in platelet count was correlated with AKI severity. After adjusting for the PS, the probability of AKI was significantly (1.9-fold) higher in patients with severe thrombocytopenia than in those without severe thrombocytopenia. Patients with thrombocytopenia showed a higher postoperative incidence of AKI and a higher requirement for dialysis than those without thrombocytopenia. The platelet count can easily be obtained via regular blood analysis of patients scheduled for LDLT and can be used to identify patients at risk for AKI.

Tocilizumab in transplantation

PURPOSE

Tocilizumab, a monoclonal antibody directed against the IL-6 receptor, might block detrimental effects of IL-6 on transplantation. IL-6 plays a considerable role in cytokine storm after stem cell transplantation as well as graft versus host disease, and it has also been shown to be involved in solid organ allograft rejection; therefore, tocilizumab is expected to promote graft survival. Nonetheless, due to the small number of studies and disparate methods of drug administration and outcome evaluation, for which types of transplantation, at which stages, and to what extent tocilizumab could be applied remains to be defined.

METHODS

The Pubmed, SCOPUS and Google Scholar search engines were used to collect data. The keywords were determined by Pubmed MeSH. No time limitation was set and all types of articles were allowed.  RESULTS: According to the potential of Tocilozumab in controlling both cellular and humoral immunity it could be considered as a promising agent in tolerance induction; however, blocking IL-6 signaling might result in augmented infection rate in recipients.

CONCLUSION

The need for providing effective and safe immunosuppressive agents to protect transplanted cells and organs against allo-reactivity urges the collection and discussion of all available findings about inhibition of determining immune components including cytokines; herein, we have summarized the clinical consequences of blocking IL-6 by tocilizumab in stem cell and solid organ transplantations.

Notoginsenoside R1 Suppresses Inflammatory Signaling and Rescues Renal Ischemia-Reperfusion Injury in Experimental Rats

Background

Notoginsenoside R1 (NR) is a major dynamic constituent of Panax notoginseng found to possess anti-inflammatory activity against various inflammatory diseases. However, its protective effects against renal ischemia-reperfusion (I/R) injury have not been elucidated. In male Wistar rats, we induced I/R under general anesthesia by occluding the renal artery for 60 min, followed by reperfusion and right nephrectomy.

Material/Methods

Rats were randomized to 4 groups: a sham group, an I/R group, an NR-pretreated (50 mg/kg) before I/R induction group, and an NR control group. All animals were killed at 72 h after I/R induction. Blood and renal tissues were collected, and histological and basic renal function parameters were assessed. In addition, levels of various kidney markers and proinflammatory cytokines were measured using RT-PCR, ELISA, and immunohistochemistry analysis.

Results

After I/R induction, the onset of renal dysfunction was shown by the elevated levels of serum urea, creatinine levels, and histological evaluation, showing a 2-fold increase in the renal failure markers kim-1 and NGAL compared to control rats. Rats pretreated with NR before I/R induction had significantly better renal functions, with attenuated levels of oxidative markers, restored levels of inflammatory cytokines such as tumor necrosis factor-α (TNF-α), tumor growth factor-β1 (TGF-β1), INF-γ, and IL-6, and increased anti-inflammatory cytokine levels (IL-10) compared to I/R-induced rats.

Conclusions

NR suppressed I/R-induced inflammatory cytokines production by suppressing oxidative stress and kidney markers, suggesting that NR is a promising drug candidate for prevention, progression, and treatment of renal dysfunction.