Acute Kidney Injury after Cardiac Surgery: Risk Factors and Novel Biomarkers

Predictive value of perioperative NT-proBNP levels for acute kidney injury in patients with compromised renal function undergoing cardiac surgery: a case control study

BACKGROUND

Acute kidney injury (AKI) significantly increases morbidity and mortality following cardiac surgery, especially in patients with pre-existing renal impairments. N-terminal pro-B-type natriuretic peptide (NT-proBNP) is a marker of cardiac stress and dysfunction, conditions often exacerbated during cardiac surgery and prevalent in chronic kidney disease (CKD) patients. Elevated NT-proBNP levels can indicate underlying cardiac strain, hemodynamic instability and volume overload. This study evaluated the association between perioperative changes in NT-proBNP levels and the incidence of AKI in this particular patient group.

METHODS

This retrospective study involved patients with impaired renal function (eGFR 15-60 ml/min/1.73 m²) who underwent cardiac surgery from July to December 2022. It analyzed the association between the ratio of preoperative and ICU admittance post-surgery NT-proBNP levels and the development of AKI and AKI stage 2-3, based on KDIGO criteria, using multivariate logistic regression models. Restricted cubic spline analysis assessed non-linear associations between NT-proBNP and endpoints. Subgroup analysis was performed to assess the heterogeneity of the association between NT-proBNP and endpoints in subgroups.

RESULTS

Among the 199 participants, 116 developed postoperative AKI and 16 required renal replacement therapy. Patients with AKI showed significantly higher postoperative NT-proBNP levels compared to those without AKI. Decreased baseline eGFR and increased post/preoperative NT-proBNP ratios were associated with higher AKI risk. Specifically, the highest quantile post/preoperative NT-proBNP ratio indicated an approximately seven-fold increase in AKI risk and a ninefold increase in AKI stage 2-3 risk compared to the lowest quantile. The area under the receiver operating characteristic curve for predicting AKI and AKI stage 2-3 using NT-proBNP were 0.63 and 0.71, respectively, demonstrating moderate accuracy. Subgroup analysis demonstrated that the positive association between endpoints and logarithmic transformed post/preoperative NT-proBNP levels was consistently robust in subgroup analyses stratified by age, sex, surgery, CPB application, hypertension, diabetes status and fluid balance.

CONCLUSION

Perioperative NT-proBNP level changes are predictive of postoperative AKI in patients with pre-existing renal deficiencies undergoing cardiac surgery, aiding in risk assessment and patient management.

Metabolic change in monocytes and postoperative morbidity after major abdominal surgery in elderly patients: A prospective cohort study

Background

Postoperative complications in aging patients remain a significant cause of increased costs, hospital length of stay, and patient distress. Although alterations in energy metabolism have been closely linked to aging process and surgery, it is still unclear whether metabolic changes during surgery is associated with postoperative complications in elderly patients. This study was conducted to investigate whether metabolic changes during surgery predicts postoperative complications in elderly patients.

Methods

We conducted a prospective single-center observational cohort study. 244 adults (aged ≥65 years) who were scheduled for elective major non-cardiac surgery were recruited. Blood samples for each patient were taken before and after surgery. All patients were randomly divided into two groups (122 in each group), then oxygen consumption rate (OCR) or extracellular acidification rate (ECAR) was measured on isolated monocytes in each group.

Results

14 of 110 (12.7%) patients went through OCR measurement and 15 of 122 patients (12.3%) went through ECAR measurement experienced moderate to severe complications. Overall, there was an intensification of glycolysis in monocytes after surgery. Among all variables, only the change (preoperative -postoperative) of glycolytic reserve (GR)/glycolysis (G) and GR/non-glycolytic acidification (NG) were predictors of moderate to severe complications (AUC = 0.70; 95% CI, 0.56-0.81; P = 0.019 and AUC = 0.67; 95% CI, 0.55-0.80; P = 0.031). Decreased postoperative GR/G were associated with worse postoperative complications (RR = 9.08; 95% CI, 1.23-66.81; P = 0.024).

Conclusions

Compared with mitochondria function, the change of glycolytic function in monocyte was more valuable in predicting postoperative complications after major abdominal surgery. Our study gave us a new insight into identifying patients at high risk in aging patients.

Comparison of the effect of surgical versus transcatheter aortic valve replacement on the development of postoperative acute kidney injury

Acute kidney injury (AKI) frequently occurs after cardiac surgery. Recently, transcatheter aortic valve implantation (TAVI), a less invasive option for aortic stenosis (AS), has been increasingly performed, particularly in elderly patients. We retrospectively investigated and compared the incidence and risk factors of postoperative AKI in patients who underwent surgical aortic valve replacement (SAVR) and TAVI. This was a retrospective single-center study. Seven days postoperatively, data were obtained from medical records. Patients were classified into SAVR and TAVI groups based on age, according to the policy of the Japanese Circulation Society. A total of 155 patients underwent surgery for AS between January 2020 and December 2021. Variables included age, sex, risk score, preoperative left ventricular ejection fraction, hypertension, and renal dysfunction. AKI was defined in accordance with the Kidney Disease: Improving Global Outcomes criteria. A total of 33 SAVR and 79 TAVI procedures were included in this study. The incidences of AKI in the SAVR and TAVI groups were 45.5% and 43.0%, respectively. No significant differences existed between the two groups. Weight (p = 0.0392) and pre-renal dysfunction (p = 0.0308) affected the incidence of AKI in the SAVR group, whereas no such variables were identified in the TAVI group. Within the current age-based treatment selection criteria for AS, no significant difference in the incidence of AKI was observed between the two procedures.Although preoperative renal function may be associated with postoperative AKI, further studies are required to select the optimal surgical procedure for patients with renal dysfunction.

Association between triglyceride-glucose index and AKI in ICU patients based on MIMICIV database: a cross-sectional study

BACKGROUND

Methods for early prediction of the occurrence of acute kidney injury (AKI) were limited. The relationship between triglyceride glucose index (TyG) and the incidence of acute kidney injury in ICU patients is unclear. This study aims to explore the relationship between the two.

METHODS

Based on their TyG index, participants from the Intensive Care Medical Information Market IV (MIMIC-IV) were divided into quartiles. A logistic regression model was constructed based on the risk of acute kidney injury as the main outcome, in order to detect a potential relationship that may exist between the TyG index and acute kidney injury in ICU patients. Finally, in order to confirm the relationship existing between the TyG index and the results, a restricted cubic spline model was used.

RESULTS

In total, 54,263 patients were involved in our present study, of whom 48.2% were male. The occurrence of acute kidney injury was 25.1%. An independent relationship was observed between the TyG index and an increased risk of acute kidney injury through multivariate logistic regression analysis (OR, 1.28 [95% CI 1.22-1.35] p < 0.001). Q4 (5.344-9.911) of the TyG index quartiles was independently associated with an increase in the risk of acute kidney injury (OR, 1.43 [95% CI (1.32-1.54)] p < 0.001). Through the restricted cubic spline regression model, the risk of acute kidney injury was also demonstrated to increase linearly with an increase in the TyG index.

CONCLUSION

The triglyceride glucose index is related to the risk of acute kidney injury in ICU patients. In the future, in order to further validate this finding, larger prospective studies are needed.

Postoperative acute kidney injury after on-pump cardiac surgery in patients with connective tissue disease

Objective

Patients with connective tissue disease have a poor prognosis after receiving cardiac surgery. This study described the clinical scenarios and investigated factors correlated with acute kidney injury (AKI) after on-pump cardiac surgery in patients with systemic lupus erythematosus (SLE) or vasculitis.

Methods

Patients with SLE or vasculitis who underwent on-pump cardiac surgery from March 2002 to March 2022 were enrolled, while patients with preoperative renal dysfunction were excluded. AKI was defined according to the Kidney Disease: Improving Global Outcomes (KDIGO) criteria. Uni- and multivariable analyses were performed to identify potential factors associated with postoperative AKI.

Results

Among 123 patients enrolled, 39 (31.7%) developed AKI within seven days after receiving on-pump cardiac surgery. Four patients died in the hospital, resulting in an overall in-hospital mortality of 3.3%, and all deaths occurred in the AKI group. Patients in the AKI group also had longer ICU stays (median difference 3.0 day, 95% CI: 1.0-4.0, P < 0.001) and extubation time (median difference 1.0 days, 95% CI: 0-2.0, P < 0.001) than those in the non-AKI group. Multivariable logistic regression revealed that BMI over 24 kg/m2 (OR: 3.00, 95% CI: 1.24-7.28) and comorbid SLE (OR: 4.73, 95% CI: 1.73-12.93) were independently correlated with postoperative AKI.

Conclusion

Factors potentially correlated with AKI following on-pump cardiac surgery in patients with connective tissue disease were explored. Clinicians should pay more attention to preoperative evaluation and intraoperative management in patients with risk factors.

Is pre-operative monocyte count-high-density lipoprotein ratio associated with postoperative acute kidney injury in isolated coronary artery bypass grafting?

OBJECTIVE

Monocyte-to-high-density lipoprotein cholesterol ratio has emerged as an indicator of inflammation and oxidative stress in recent years. The aim of this study was to evaluate the association of monocyte-to-high-density lipoprotein ratio with postoperative acute kidney injury in isolated coronary artery bypass grafting.

METHODS

A total of 954 patients (672 males, mean age 60.8 ± 8.2 years), operated on between June 2014 and June 2022, at the same centre by the same team, for isolated coronary artery bypass grafting with cardiopulmonary bypass, whose preoperative serum creatinine level was < 1.5 mg/dl, were enrolled in the study. Patients were placed in group 1 if they had acute kidney injury in the early postoperative period (n = 161) and group 2 comprised those without (n = 793). Univariate and subsequent multivariate logistic regression analysis were done to determine significant clinical factors, and independent predictors of acute kidney injury.

RESULTS

Pre-operative monocyte count (p = 0.0001), monocyte count-high-density lipoprotein cholesterol ratio (p = 0.0001), C-reactive protein (p = 0.0001), erythrocyte sedimentation rate (p = 0.0001), mean platelet volume (p = 0.0001) and postoperative first- and third-day C-reactive protein levels (p = 0.0001) were significantly increased in group 1. Multivariate logistic regression analysis revealed that pre-operative elevated monocyte count (p = 0.0001), monocyte-high-density lipoprotein ratio (p = 0.0001), erythrocyte sedimentation rate (p = 0.0001), postoperative first-day C-reactive protein level (p = 0.0001), postoperative first-third day erythrocyte sedimentation rate (p = 0.002, p = 0.004, respectively) and mean platelet volume (p = 0.02, p = 0.0001, respectively) were independent predictors of early postoperative acute kidney injury in patients who had undergone isolated coronary artery bypass grafting.

CONCLUSIONS

Pre-operative monocyte-high-density lipoprotein cholesterol ratio was found to be an independent predictor of acute kidney injury in the early postoperative period of isolated coronary artery bypass grafting.

Association of intraoperative cerebral and somatic tissue oxygen saturation with postoperative acute kidney injury in adult patients undergoing multiple valve surgery

BACKGROUND

The association between tissue oxygenation with postoperative acute kidney injury (AKI) in adult patients undergoing multiple valve surgery has not been specifically studied.

METHODS

In this prospective exploratory cohort study, 99 patients were enrolled. The left forehead, the left forearm, the left upper thigh, and the left renal region tissue oxygen saturation using near-infrared spectroscopy were monitored. The association between each threshold and AKI was assessed. The relative and absolute thresholds were < 70%, < 75%, < 80%, < 85%, < 90%, < 95%, and < 100% baseline, and baseline-standard deviation (SD), -1.5 SD, -2 SD, -2.5 SD, and -3 SD. Multivariate logistic regression analysis was adopted to explore the association.

RESULTS

AKI occurred in 53 (54%) patients. The absolute value-based SrrO2 thresholds associated with AKI were baseline-3 SD (odds ratio [OR], 4.629; 95% confidence interval [CI], 1.238-17.314; P = 0.023) and baseline-2.5 SD (OR, 2.842; 95% CI, 1.025-7.881; P = 0.045) after adjusting for the potential confounders, those are renal region tissue oxygen saturation of 55% and 60%, but not statistically significant after correcting for multiple testing (corrected P = 0.114 and 0.179, respectively).

CONCLUSION

The SrrO2 desaturation, defined as < baseline - 2.5 SD or < baseline - 3 SD, may be associated with AKI. The thresholds need to be verified in future large-scale studies.

TRIAL REGISTRATIONS

The study was registered at ClinicalTrials.gov, first trial registration: 26/10/2017, identifier: NCT03323203.

The Review of Current Knowledge on Neutrophil Gelatinase-Associated Lipocalin (NGAL)

Neutrophil gelatinase-associated lipocalin (NGAL) is a 25-kDa protein that is secreted mostly by immune cells such as neutrophils, macrophages, and dendritic cells. Its production is stimulated in response to inflammation. The concentrations of NGAL can be measured in plasma, urine, and biological fluids such as peritoneal effluent. NGAL is known mainly as a biomarker of acute kidney injury and is released after tubular damage and during renal regeneration processes. NGAL is also elevated in chronic kidney disease and dialysis patients. It may play a role as a predictor of the progression of renal function decreases with complications and mortality due to kidney failure. NGAL is also useful in the diagnostic processes of cardiovascular diseases. It is highly expressed in injured heart tissue and atherosclerostic plaque; its serum concentrations correlate with the severity of heart failure and coronary artery disease. NGAL increases inflammatory states and its levels rise in arterial hypertension, obesity, diabetes, and metabolic complications such as insulin resistance, and is also involved in carcinogenesis. In this review, we present the current knowledge on NGAL and its involvement in different pathologies, especially its role in renal and cardiovascular diseases.

Acute Kidney Injury and Renal Replacement Therapy: A Review and Update for the Perioperative Physician

Post-operative acute kidney injury is a devastating complication with significant morbidity and mortality associated with it. The perioperative anesthesiologist is in a unique position to potentially mitigate the risk of postoperative AKI, however, understanding the pathophysiology, risk factors and preventative strategies is paramount. There are also certain clinical scenarios, where renal replacement therapy may be indicated intraoperatively including severe electrolyte abnormalities, metabolic acidosis and massive volume overload. A multidisciplinary approach including the nephrologist, critical care physician, surgeon and anesthesiologist is necessary to determine the optimal management of these critically ill patients.

Serum procalcitonin, C-reactive protein, and neutrophil gelatinase-associated lipocalin in early diagnosis of acute kidney injury after upper urinary tract calculi

Objective

To investigate the value of serum procalcitonin(PCT), C-reactive protein(CRP), and neutrophil gelatinase-associated lipocalin(NGAL) in the early diagnosis of acute kidney injury(AKI) after upper urinary tract calculi(UUTC).

Methods

The clinical data of 86 patients who underwent UUTC surgery in our hospital from March 2020 to April 2021 were analyzed retrospectively(Approval number: 20211205L, Date: 2021-12-21). Patients were divided into an AKI group (AKI≥7 days after the operation) and a Non-AKI group. PCT, CRP, and NGAL concentrations were compared before and two hours after the operation. Multivariate logistic regression analysis was used to identify risk factors affecting the early occurrence of AKI post-operation. The receiver operating characteristic curve evaluated PCT, CRP, and NGAL in the early AKI diagnosis.

Results

A total of 86 patients (30 with AKI and 56 with Non-AKI) were included. Kidney injury molecule-1(KIM-1) and urinary microalbumin(mAlb) concentrations were significantly higher in the AKI group (P<0.05). PCT, CRP, and NGAL concentrations were significantly higher two hours after the operation than before the operation (P<0.05). KIM-1 levels and elevated PCT, CRP and NGAL concentrations affected the establishment of AKI after UUTC. The sensitivity of PCT, CRP, and NGAL in evaluating AKI after UUTC were 81.17%, 84.42%, and 79.02%; the specificity was 62.31%, 71.48%, and 73.32%; and the AUC was 0.812, 0.885 and 0.804 respectively.

Conclusions

PCT, CRP, and NGAL concentrations in patients with AKI after UUTC were significantly increased two hours after the operation, which can be used for the early diagnosis of AKI after UUTC operation.

Postoperative Lactate Predicts In-Hospital Death in Patients with Acute Type A Aortic Dissection

Several studies have found that lactate correlates with surgical outcomes in patients with heart disease. However, the prognostic value of postoperative lactate in patients with acute type A aortic dissection (AAAD) remains unclear. This study aimed to investigate the relationship between postoperative lactate and in-hospital mortality in patients with AAAD. Patients who underwent AAAD surgery at Fujian Cardiac Medical Center from February 2020 to January 2022 were enrolled in this retrospective study. Correlations between in-hospital mortality and various parameters, including lactate, were investigated. A total of 357 patients were included in this study, 58 of which died. Multivariate logistic regression analysis revealed that body mass index (BMI) (odds ratio [OR] = 1.099, 95% confidence interval [CI]: 1.017-1.188, P = 0.017), cardiopulmonary bypass (CPB) time (OR = 1.005; 95% CI: 1.000-1.010, P = 0.039), and lactate (OR = 1.291, 95% CI: 1.182-1.409, P < 0.001) were independent risk factors for in-hospital mortality in AAAD patients. Receiver operating characteristic (ROC) curve analysis showed that lactate had a moderate power for in-hospital mortality (area under the curve [AUC] = 0.729, 95% CI: 0.647-0.810, P < 0.001). Furthermore, the combination of lactate, BMI, and CPB time showed better performance (AUC = 0.780; 95% CI: 0.706-0.854, P < 0.001) in predicting in-hospital mortality than in using these variables independently. Among patients undergoing AAAD surgery, postoperative lactate was significantly associated with in-hospital mortality. Lactate can be used as a potential predictor of in-hospital mortality. The combination of lactate, BMI, and CPB time showed better performance in predicting in-hospital mortality than using single one.

Development and validation of a nomogram for predicting overall survival in cirrhotic patients with acute kidney injury

BACKGROUND

Acute kidney injury (AKI) is a common and severe complication in patients with cirrhosis, and is associated with poor prognosis. Therefore, identifying cirrhotic patients with AKI who are at high risk of mortality is very important and may be helpful for providing timely medical interventions to improve the prognosis of these patients. However, studies focused on investigating the risk factors for the mortality of cirrhotic patients with AKI were scarce.

AIM

To identify risk factors for mortality and establish a nomogram for predicting the prognosis of these patients.

METHODS

Two hundred fifty consecutive patients with cirrhosis and AKI were recruited and randomly divided into training cohort (n = 173) and validation cohort (n = 77). In the training cohort, potential risk factors for death were identified by performing a Cox regression analysis, and a nomogram was established. The predictive performance of the nomogram was internally and externally validated by calculating the area under the receiver operating characteristic curve (AUROC), constructing a calibration curve and performing decision curve analysis.

RESULTS

The serum sodium level, international normalized ratio, peak serum creatinine level > 1.5 mg/dL, the presence of hepatic encephalopathy and diabetes were potential risk factors for mortality of cirrhotic patients with AKI in the training dataset. A prognostic nomogram incorporating these variables was established for predicting the overall survival of these patients. Compared with Child-Turcotte-Pugh, the model for end-stage liver disease (MELD) and the MELD-Na scores, the nomogram in predicting 90- and 180-d mortality exhibited better discriminatory power with AUROCs of 0.792 and 0.801 for the training dataset and 0.817 and 0.862 for the validation dataset, respectively. With a nomogram score of 98, patients were divided into low- and high-risk groups, and high-risk patients had a higher mortality rate.

CONCLUSION

A prognostic nomogram displayed good performance for predicting the overall survival of cirrhotic patients with AKI, and will assist clinicians in evaluating the prognosis of these patients.

Preoperative Glucose-to-Lymphocyte Ratio is an Independent Predictor for Acute Kidney Injury After Cardiac Surgery in Patients in Intensive Care Unit

Background

We aimed to investigate the association between preoperative glucose-to-lymphocyte ratio (GLR) and cardiac surgery associated with acute kidney injury (CSA-AKI) in patients in the intensive care unit (ICU).

Methods

The Medical Information Mart for Intensive Care IV (MIMIC-IV version 1.0) database was used to identify adults' patients who performed cardiac surgery during ICU stay. The primary outcome was the development of AKI based on the KDIGO criteria. Multivariable logistic regression was applied to investigate the association between GLR and clinical outcomes, and propensity score matching (PSM) and inverse probability of treatment weighting (IPTW) were also used to validate our findings.

Results

The optimal cut-off value for GLR was 1.28. Among the 7181 patients who conducted cardiac surgery, 2072 high-GLR group (≥1.28) patients and 2072 low-GLR group (<1.28) patients, had similar propensity scores were included in this study. After matching, the high-GLR group had a significantly higher incidence of AKI (odds ratio, OR, 3.28, 95% confidence index, 95% CI, 2.81-3.84, P <0.001) even after adjustment for confounding factors. Moreover, the performance of GLR was superior to that of SOFA scores and GLR plus clinical model could add more net benefit for CSA-AKI than clinical model alone.

Conclusion

Preoperative GLR could serve as a good predictor for CSA-AKI in patients in ICU.

Kidney Injury Molecule 1 (KIM-1): a Multifunctional Glycoprotein and Biological Marker (Review)

KIM-1 (kidney injury molecule 1) is a transmembrane glycoprotein also known as HAVcr-1 and TIM-1 belongs to the T-cell immunoglobulin and mucin domain family (TIM) of proteins. TIM glycoproteins are presented on the immune cells and participate in the regulation of immune reactions. KIM-1 differs from other members of its family in that it is expressed not only by immunocompetent cells but epithelial cells as well. Cellular and humoral effects mediated by KIM-1 are involved in a variety of physiological and pathophysiological processes.

Current understanding of the mechanisms determining the participation of KIM-1 in viral invasion, the immune response regulation, adaptive reactions of the kidney epithelium to acute ischemic or toxic injury, in progression of chronic renal diseases, and kidney cancer development have been presented in this review. Data of clinical researches demonstrating the association of KIM-1 with viral diseases and immune disorders have also been analyzed. Potential application of KIM-1 as urinary or serological marker in renal and cardiovascular diseases has been considered.

Correlation and Diagnostic Value of Serum Cys-C, RBP4, and NGAL with the Condition of Patients with Traumatic Acute Kidney Injury

There is a lack of targeted biomarkers that can diagnose Acute Kidney Injury (AKI) early and accurately, which leads to deterioration of renal function and even death in patients who do not receive timely and effective treatment. In recent years, an increasing number of studies have shown that AKI-related markers such as cystatin C (Cys-C) and retinol-binding protein (RBP) can be used for early diagnosis of AKI to a certain extent. A total of 262 subjects were included in this study, of which 132 patients with traumatic AKI were enrolled in one group and named as the AKI group; 130 healthy subjects were enrolled in another group and named as the healthy group. AKI patients with different conditions were classified into AKI phase I, II, and III according to the KDIGO AKI diagnostic criteria, with 45, 59, and 28 in each group. In this study, we examined and compared serum Cys-C, RBP4, and neutrophil gelatinase-associated lipid transport protein (NGAL) levels between the AKI and healthy groups and between patients with AKI of different conditions, and the correlation and diagnostic value of three serum markers with the condition of traumatic AKI patients were also analyzed. The results showed that serum Cys-C, RBP4, and NGAL were significantly higher in the AKI group compared with the healthy group (P < 0.05), and the mean concentrations of the three serum markers increased as the severity of the disease increased, while correlation analysis showed that all three serum markers were positively correlated with serum Scr levels (P < 0.001). Further ROC curve analysis was performed, and the diagnostic values of serum Cys C, RBP4, and NGAL alone and in combination for traumatic AKI were 0.769, 0.741, 0.771, and 0.905, respectively. In short, serum Cys C, RBP4, NGAL have important value for the assessment and diagnosis of traumatic AKI patients.

Evaluating the Effect of Acetazolamide on the Prevention of Post-operative Acute Kidney Injury after Coronary Artery Bypass Grafting Surgery: A Randomized, Open-labeled Clinical Trial

Acute kidney injury (AKI) is a common complication after coronary artery bypass grafting (CABG) surgery and can be linked to the increased morbidity and mortality. Therefore, in the present study, the effect of preoperative administration of acetazolamide was evaluated to investigate whether it could prevent occurrence of post-operative AKI after CABG surgery. In this randomized controlled clinical trial, 130 patients who were candidates to undergo elective CABG surgery from January 21, 2020 to February 8, 2021 were randomly allocated to intervention group (receiving 500 mg of acetazolamide orally 2 h preoperatively) and control group. The patients were evaluated for AKI based on the kidney disease- improving global outcomes (KDIGO) criteria based on their serum creatinine (SCr) level and urine output until 7 days postoperatively. There was no significant difference in baseline demographics between the two groups. The total incidence of AKI was measured as 43%. Analysis of post-operative AKI incidence showed no statistically significant difference between the two groups (P = 0.860). Mean post-operative SCr level on day 1 was significantly higher in the acetazolamide group (P = 0.036). A significant difference was found in length of hospitalization stay between the groups, which was higher in the control group (P = 0.006). Our results did not demonstrate a significant protective effect of acetazolamide on incidence of post-operative AKI in the patients undergone elective on-pump CABG surgery.

Interleukin -17 Serum Levels and Polymorphisms in Acute Kidney Injury Patients

BACKGROUND

Cardiopulmonary bypass (CPB) has been demonstrated to provoke a systemic inflammatory response believed to be responsible for some of the serious postoperative complications such as renal dysfunction. Therefore, we tested the hypothesis suggesting that the serum levels of IL- 17A (IL-17), as an inflammatory cytokine, and its gene variants are associated with acute kidney injury after CPB (AKI-CPB).

METHODS

A total of 135 Iranian patients undergoing cardiopulmonary bypass were included in this study, of whom 65 (48.1%) developed AKI. Blood specimens were collected preoperatively and at 12 hours postoperatively. The IL-17 gene polymorphisms (rs2275913 and rs3819024) were determined using sequence-specific primers (PCR-SSP) technique.Pre- and postoperative IL-17 levels were measured and analyzed in relation to polymorphisms.

RESULTS

IL-17 concentrations in CBP subjects, were increased after cardiopulmonary bypass (P<0.00001)but there were no statistically significant differences in IL-17 serum level between AKI and non-AKI groups. Different genotypes of IL-17 rs2275913 SNP (G→A) were associated with different circulating IL-17 levels before bypass and also after AKI development. There were no associations between gene polymorphisms (rs2275913and rs3819024) and incidence of AKI- CPB. There was an association between thers2275913 SNP and the severity of AKI.

CONCLUSION

This study clarified that the rs2275913 SNP to some extent determines plasma IL-17 concentrations in CPB patients. No significant association was found between IL-17 levels or gene polymorphisms (rs2275913and rs3819024) and incidence of AKI-CPB. Our results suggest that there is an association between rs2275913 and the severity of AKI- CPB.

Fish oils protects against cecal ligation and puncture‑induced septic acute kidney injury via the regulation of inflammation, oxidative stress and apoptosis

Septic acute kidney injury (AKI) is usually caused by sepsis. ω3 fatty acid has been reported to suppress sepsis-induced organ dysfunction to a certain degree. The present study aimed to investigate the effects of ω3 fatty acid in septic renal injury. Sprague Dawley rats were used to establish a cecal ligation and puncture (CLP) model in order to mimic the development of septic injury. The rats were treated with dexamethasone and fish oils (FOs) for 4 days prior to CLP. Alterations in the morphology of the tissues, the renal function and the induction of inflammation, oxidative stress and apoptosis were evaluated. The effects of FOs on nuclear factor-κB (NF-κB), JAK2/STAT3 and p38-MAPK were determined. The rats of the CLP model group exhibited low survival rates and increased expression of serum creatine, blood urea nitrogen, neutrophil gelatinase-associated lipocalin, kidney injury molecule-1 and of proinflammatory cytokines. In addition, the levels of the markers of oxidative injury and apoptosis were increased. The induction of renal injury was notably reversed by administration of dexamethasone and FOs. The expression levels of the protein markers involved in inflammation and apoptosis were measured and the results indicated that FOs inhibited JAK/STAT3 and p-38MAPK signaling, while they concomitantly increased the expression of NF-κB. The present study highlighted that FOs improve CLP-induced mortality and renal injury by inhibiting inflammation, oxidative stress and apoptosis.