Antithrombin Ⅲ is a Novel Predictor for Contrast Induced Nephropathy After Coronary Angiography

The Rise and Fall of Antithrombin Supplementation in Cardiac Surgery

Various cohort studies, both retrospective and prospective, showed that low antithrombin levels after cardiac surgery (at the arrival in the intensive care unit and during the next days) were associated with a number of adverse outcomes, including surgical reexploration and thromboembolic events, eventually leading to prolonged stay in the intensive care. Values lower than 58% to 64% of antithrombin activity were indicative of this higher morbidity with good sensitivity and specificity. The scenario generated the hypothesis that low antithrombin levels needed to be corrected by supplementation to improve postoperative outcome. However, randomized controlled studies run to test this idea failed to demonstrate any benefit of antithrombin supplementation, showing no effects on outcome, neither as preemptive preoperative strategy nor for treating postoperative low antithrombin values. In addition, randomized trials highlighted that those patients who received antithrombin experienced significantly higher incidence of acute kidney injury with a pooled odds ratio of 4.41 (95% CI, 1.90-10.23; P = .001). A strongly decreased thrombin activity after antithrombin correction may eventually affect the efficiency of the glomerular filtration and cause the deterioration of kidney function, but underlying biological mechanisms remain unclear. In conclusion, low levels of antithrombin activity after cardiac surgery should be considered as a marker of greater severity of the patient's conditions and/or of the complexity of the surgical procedure. There are no indications for antithrombin supplementation in cardiac surgery unless for correcting heparin resistance.

Contrast-induced acute kidney injury in patients submitted to coronary angioplasty: prospective cohort

OBJECTIVE

To analyze the incidence, risk factors, and associations of clinical outcomes for contrast-induced acute kidney injury (CI-AKI) in patients with acute coronary syndrome (ACS) after coronary angioplasty.

METHOD

Prospective cohort of 182 patients followed for three months after undergoing angioplasty, from July 2020 to June 2021. The analyzed variables were sociodemographic, clinical, and those related to the procedure.

RESULTS

The incidence of CI-AKI was 35.7% (n = 65) and was associated with old age, diabetes mellitus, and chronic kidney disease (p = 0.004, p < 0.001, and p = 0.009, respectively). Out of the 17 patients who died within 90 days, 76.5% had CI-AKI (n = 13), the odds ratio between death and CI-AKI was approximately 7.2 times (95% confidence interval (CI), [2.41;26.36]; p = 0.001). The decrease of one unit in the patient's baseline hemoglobin showed a 6.5% increase for CI-AKI (95% CI, [-0.089; -0.040]; p < 0.0001).

CONCLUSION

CI-AKI is prevalent in patients with ACS after angioplasty and is related to diabetes mellitus and chronic kidney disease, showing high mortality rates.

Lesão renal aguda induzida por contraste em pacientes submetidos à angioplastia coronariana: coorte prospectiva

RESUMO Objetivo: Analisar a incidência, os fatores de risco e as associações dos desfechos clínicos para Lesão Renal Aguda Induzida Por Contraste (LRA-IC) em pacientes com Síndrome Coronariana Aguda (SCA) após angioplastia coronariana. Método: Coorte prospectivo de 182 pacientes seguidos por três meses após angioplastia, entre julho de 2020 e junho de 2021. As variáveis foram sociodemográficas, clínicas e relacionadas ao procedimento. Resultados: A incidência de LRA-IC foi de 35,7% (n = 65) e esteve associada à idade avançada, diabetes mellitus e doença renal crônica (respectivamente p = 0,004, p < 0,001 e p = 0,009). Dos 17 pacientes que faleceram em até 90 dias, 76,5% tiveram LRA-IC (n = 13), a razão de chances entre óbito e LRA-IC foi de aproximadamente 7,2 vezes (intervalo de confiança (IC) 95%, [2,41;26,36]; p = 0.001). A diminuição de uma unidade na hemoglobina basal do paciente demonstrou um aumento de 6,5% para LRA-IC (IC 95%, [–0,089; –0,040]; p < 0,0001). Conclusão: Em pacientes com SCA após angioplastia, a LRA-IC tem alta incidência e está relacionada com diabetes mellitus e doença renal crônica, apresentando altos índices de mortalidade.

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.

Genetic Susceptibility to Acute Kidney Injury

Acute kidney injury (AKI) is a widely held concern related to a substantial burden of morbidity, mortality and expenditure in the healthcare system. AKI is not a simple illness but a complex conglomeration of syndromes that often occurs as part of other syndromes in its wide clinical spectrum of the disease. Genetic factors have been suggested as potentially responsible for its susceptibility and severity. As there is no current cure nor an effective treatment other than generally accepted supportive measures and renal replacement therapy, updated knowledge of the genetic implications may serve as a strategic tactic to counteract its dire consequences. Further understanding of the genetics that predispose AKI may shed light on novel approaches for the prevention and treatment of this condition. This review attempts to address the role of key genes in the appearance and development of AKI, providing not only a comprehensive update of the intertwined process involved but also identifying specific markers that could serve as precise targets for further AKI therapies.

Biochemical Markers in the Prediction of Contrast-induced Acute Kidney Injury

For many years clinicians have been searching for "kidney troponin"- a simple diagnostic tool to assess the risk of acute kidney injury (AKI). Recently, the rise in the variety of contrast-related procedures (contrast computed tomography (CT), percutaneous coronary intervention (PCI) and angiography) has resulted in the increased number of contrast-induced acute kidney injuries (CI-AKI). CIAKI remains an important cause of overall mortality, prolonged hospitalisation and it increases the total costs of therapy. The consequences of kidney dysfunction affect the quality of life and they may lead to disability as well. Despite extensive worldwide research, there are no sensitive and reliable methods of CI-AKI prediction. Kidney Injury Molecule 1 (KIM-1) and Neutrophil Gelatinase Lipocalin (NGAL) have been considered as kidney-specific molecules. High concentrations of these substances before the implementation of contrast-related procedures have been suggested to enable the estimation of kidney vulnerability to CI-AKI and they seem to have the predictive potential for cardiovascular events and overall mortality. According to other authors, routine determination of known inflammation factors (e.g., CRP, WBC, and neutrophil count) may be helpful in the prediction of CIAKI. However, the results of clinical trials provide contrasting results. The pathomechanism of contrast- induced nephropathy remains unclear. Due to its prevalence, the evaluation of the risk of acute kidney injury remains a serious problem to be solved. This paper reviews pathophysiology and suggested optimal markers facilitating the prediction of contrast-induced acute kidney injury.

Heat Shock Protein 27 Is an Emerging Predictor of Contrast-Induced Acute Kidney Injury on Patients Subjected to Percutaneous Coronary Interventions

Contrast-induced acute kidney injury (CI-AKI) is a serious complication associated with considerable morbidity and mortality. Heat-shock protein 27 (HSP27) plays a role in the defense of the kidney tissue against various forms of cellular stress, including hypoxia and oxydative stress, both features associated with CI-AKI. The aim of our study was to evaluate a potential predictive value of HSP27 for CI-AKI in patients subjected to percutaneous coronary interventions (PCI). Included were 343 selected patients subjected to PCI. Exclusion criteria were conditions that potentially might influence HSP27 levels. HSP27 serum levels were evaluated prior to PCI, together with serum creatinine, the concentration of which was also evaluated twice at 48 and 72 h post PCI. CI-AKI was diagnosed in 9.3% of patients. Patients in whom CI-AKI was diagnosed were older (p < 0.001), were more often females (p = 0.021), had higher prevalence of diabetes (p = 0.011), hypotension during PCI (p < 0.001), albuminuria (p = 0.004) as well as multivessel disease (p = 0.002), received higher contrast volume (p = 0.006), more often received contrast volume (CV) above the maximum allowed contrast dose (MACD) (p < 0.001), and had lower HSP27 level (p < 0.001). On multivariate analysis, CV > MACD (OR 1.23, p = 0.001), number of diseased vessels (OR 1.27, p = 0.006), and HSP27 (OR 0.81, p = 0.001) remained independent predictors of CI-AKI. Low concentration of HSP27 is an emerging, strong and independent predictor of CI-AKI in patients subjected to PCI.

The Effect of Urine pH and Urinary Uric Acid Levels on the Development of Contrast Nephropathy

BACKGROUND

Hyperuricemia may cause acute kidney injury by activating inflammatory, pro-oxidative and vasoconstrictive pathways. In addition, radiocontrast causes an acute uricosuria, potentially leading to crystal formation. We therefore aimed to investigate the effect of urine acidity and urine uric acid level on the development of contrast-induced nephropathy (CIN) in patients undergoing elective coronary angiography.

METHODS

We enrolled 175 patients who underwent elective coronary angiography. CIN was defined as a >25% increase in the serum creatinine levels relative to basal values 48-72 h after contrast use. Prior to coronary angiography and 48-72 h later, serum uric acid, urea, creatinine, bicarbonate levels, and spot uric acid to creatinine ratio (UACR) were measured.

RESULTS

Of the 175 subjects included, 29 (16.6%) developed CIN. Those who developed CIN had a higher prevalence of diabetes, higher UACR (0.60 vs. 0.44, p = 0.014), higher contrast volume, and lower serum sodium level. With univariate analysis of a logistic regression model, the risk of CIN was found to be associated with diabetes (p = 0.0016, OR = 3.8 [95% CI: 1.7-8.7]), urine UACR (p = 0.0027, OR = 9.6 [95% CI: 2.2-42.2]), serum sodium (p = 0.0079, OR = 0.8 [95% CI: 0.77-0.96]), and contrast volume (p = 0.0385, OR = 1.8 [95% CI: 1.03-3.09]). In a multiple logistic regression model with stepwise method of selection, diabetes (p = 0.0120, OR = 3.2 [95% CI: 1.3-8.1]) and UACR (p = 0.0163, OR = 6.9 [95% CI: 1.4-33.4]) were the 2 risk factors finally identified.

CONCLUSIONS

We have demonstrated that higher urine UACR is associated with the development of CIN in patients undergoing elective coronary angiography.

Two Novel Mutations Cause Hereditary Antithrombin Deficiency in a Chinese Family

OBJECTIVE

To study the molecular basis of hereditary antithrombin (AT) deficiency in a Chinese family. It will help us understand the pathogenesis of this type of disease.

METHOD

AT activity (AT:A) and the AT antigen (AT:Ag) level were tested by chromogenic substrate and immunoturbidimetry, respectively. To identify the novel mutations, SERPINC1 gene sequencing was carried out. The possible impact of the mutations was analyzed by model and bioinformatic analyses.

RESULTS

AT:A and the AT:Ag level of the proband were 43% and 113 mg/L (normal range: 98-119% and 250-360 mg/L), respectively. Sequencing analysis revealed compound heterozygous mutations, including a frameshift mutation (c.318_319insT) resulting in Asn75stop and a missense mutation (c.922G>T) resulting in Gly276Cys. The bioinformatic and model analyses indicated that these mutations may disrupt the function and structure of the AT protein.

CONCLUSION

We detected 2 novel heterozygous mutations (c.318_319insT and c.922G>T) in the proband, and these were associated with decreased AT:A.

3,3'‑Diindolylmethane mitigates lipopolysaccharide‑induced acute kidney injury in mice by inhibiting NOX‑mediated oxidative stress and the apoptosis of renal tubular epithelial cells

3,3′-Diindolylmethane (DIM) is a naturally derived indole compound found in the Brassica family of vegetables. DIM has several beneficial effects, including anti-cancer, anti-inflammatory and anti-angiogenic functions. However, the effects of DIM on acute kidney injury (AKI) stimulated by lipopolysaccharide (LPS) are poorly studied. In this present study, male BALB/c mouse models of AKI were established using intraperitoneal injections of 10 mg/kg LPS. DIM (40 mg/kg) was administered intraperitoneally 24 and 2 h before LPS exposure. The results indicated that DIM significantly mitigated histopathological changes in the kidneys and improved the levels of blood urea nitrogen and serum creatinine. DIM also suppressed the LPS-induced production of reactive oxygen species and cell apoptosis. Furthermore, DIM treatment significantly decreased the expression of NADPH oxidase 2 (NOX2) and NOX4 in LPS-treated mice. Therefore, DIM may exert its renoprotective actions by inhibiting NOX-mediated oxidative stress and the apoptosis of renal tubular epithelial cells.

Effects of Serum Cytochrome c on Contrast-Induced Nephropathy in Patients with ST-Elevation Myocardial Infarction Undergoing Percutaneous Coronary Intervention

Background and Aims

Contrast-induced nephropathy (CIN) is a relatively infrequent complication after percutaneous coronary intervention (PCI) in patients with ST-elevation myocardial infarction (STEMI). However, little is known about the association between cytochrome c (cyt c) and increased risk of CIN. We conducted this study to explore the impact of serum cyt c on the occurrence of CIN.

Methods

We prospectively examined cyt c levels before undergoing PCI in 240 patients with STEMI. The logistic regression was performed to identify the independent risk factors for the occurrence of CIN. The receiver operating characteristic (ROC) analysis was employed to evaluate the predictive value of cyt c for the occurrence of CIN.

Results

29 patients (12.1%) had developed CIN after the PCI procedure. The cyt c levels at baseline were significantly higher in patients who developed CIN than those in non-CIN group (0.65±0.08 versus 0.58±0.1; P = 0.001). The multivariate logistic regression showed that cyt c was an independent risk factor for the occurrence of CIN (OR, 7.421; 95% CI, 6.471–20.741; P = 0.034) after adjusting for age, history of hypertension and diabetes mellitus, levels of creatinine, uric acid, and glucose. The ROC curve analysis showed that the area under the curve of cyt c was 0.697 (95% CI, 0.611–0.783; P = 0.001), and cyt c > 0.605 ng/mL predicted CIN with sensitivity of 79.3% and specificity of 56.9%.

Conclusion

Our results show that a higher cyt c level was significantly associated with the occurrence of CIN after PCI in STEMI patients. This study has been registered in the Chinese Clinical Trial Registry. The clinical trial registration number is ChiCTR1800019368.

Association between inflammatory-response gene polymorphisms and risk of acute kidney injury in children

In the present study, we investigated the association of 12 polymorphisms in six inflammatory-response genes (TNF, IL6, IL10, IL18, NFKB1 and NFKBIA) with risk of acute kidney injury (AKI) in children. The polymorphisms were genotyped in 1138 children with AKI and 1382 non-AKI controls. Logistic regression analysis was performed to calculate the odds ratio for estimating the risk association. After accounting for Bonferroni correction and adjustment for potential confounders, significant association was observed for NFKB1 rs28362491, NFKBIA rs2233406 and NFKBIA rs696 polymorphisms (P < 0.004). All three polymorphisms were associated with a reduced risk of AKI. For rs28362491 polymorphism, the OR for ID vs. II comparison was 0.75 (95% CI = 0.58-0.83) while that for DD vs. II was 0.44 (95% CI = 0.30-0.67). For rs2233406 polymorphism, the CT vs. CC comparison showed an OR of 0.90 (95% CI = 0.39-0.99), while the TT vs. CC comparison showed an OR of 0.43 (95% CI = 0.33-0.80). For rs696 polymorphism, the OR for AG vs. AA comparison was 0.71 (95% CI = 0.43-0.89), while the GG vs. AA comparison showed an OR of 0.39 (95% CI = 0.21-0.71). In conclusion, NFKB1 rs28362491, NFKBIA rs2233406 and NFKBIA rs696 polymorphisms may serve as biomarkers for predicting risk of AKI in children.

IL-6 receptor blockade ameliorates diabetic nephropathy via inhibiting inflammasome in mice

BACKGROUND AND OBJECTIVE

Interleukin 6 (IL-6) has been identified as a key mediator in inflammation, immune responses and glucose metabolism. In this study, we assessed the effects of an IL-6 receptor antibody on diabetic nephropathy in a mouse model of type 2 diabetes mellitus.

METHODS

Twelve week old male db/db mice were treated with Tocilizumab (an IL-6 receptor antibody), normal IgG1 control antibody, insulin or normal saline for 12 weeks. Renal injury, inflammation and insulin resistance were assessed.

RESULTS

Db/db mice treated with Tocilizumab exhibited reduced proteinuria and glomerular mesangial matrix accumulation compared to db/db + IgG controls. Additionally, Tocilizumab suppressed inflammatory response, oxidative stress and the IL-6 signaling pathway in the diabetic kidneys. It is noteworthy that blockade of IL-6 receptor blunted the activation of NLRP3 inflammasome partly through inhibition of IL-17A. Furthermore, insulin resistance assessed by glucose tolerance test, was ameliorated by Tocilizumab treatment.

CONCLUSIONS

The protective effects of an IL-6 receptor blockade against diabetic renal injury may be due to decreased insulin resistance and inhibition of the inflammasome.