Plasma Cell-Free DNA and Caspase-3 Levels in Patients with Chronic Kidney Disease.

BACKGROUND: Cell-free plasma DNA (cfDNA) is circulating extracellular DNA arising from cell death mechanisms (apoptosis, necrosis, etc.). It is commonly existent in healthy individuals, but its ranks increase in diverse clinical circumstances, such as kidney disease, sepsis, myocardial infarction, trauma and cancer. In patients with advanced chronic kidney disease, cfDNA is connected to inflammation, and it has been associated with higher mortality. Caspase-3 plays a dominant role in apoptosis, a mechanism of programmed cell death involved in the pathogenesis and progression of chronic kidney disease (CKD). The aim of this pilot study was the evaluation of cfDNA levels and caspase-3 concentrations in patients with chronic kidney disease, in order to investigate the potential role of these molecules, deriving from inflammatory and apoptotic mechanisms, in the progression of renal damage. METHODS: We compared cfDNA and caspase-3 levels in 25 CKD patients and in 10 healthy subjects, evaluating their levels based on CKD stage. We also explored correlations between cfDNA and caspase-3 levels in CKD patients and between cfDNA and caspase-3 levels and serum creatinine and urea in this population. RESULTS: We observed that cfDNA and caspase-3 levels were higher in patients with CKD compared to healthy subjects, in particular in patients with advanced renal disease (CKD stage 5). A positive correlation between cfDNA and caspase-3 levels and between cfDNA and caspase-3 and creatinine and urea were also noticed. CONCLUSIONS: Patients with chronic kidney disease show higher levels of cfDNA and caspase-3 levels compared to the control group. Based on these preliminary results, we speculated that the worsening of renal damage and the increase in uremic toxin concentration could be associated with higher levels of cfDNA and caspase-3 levels, thus reflecting the potential role of inflammation and apoptosis in the progression of CKD. Future studies should focus on the validation of these promising preliminary results.

The Role of Cell-Free Plasma DNA in Patients with Cardiorenal Syndrome Type 1.

BACKGROUND: Recent research highlighted the potential role of circulating cell-free DNA (cfDNA), resulted by apoptosis or cell necrosis, as a prognostic marker in the setting of different clinical conditions. Cardiorenal syndrome type 1 (CRS type 1) is characterized by a rapid worsening of cardiac function leading to acute kidney injury (AKI). Apoptosis of renal epithelial cells is proposed as a mechanism involved in CRS type 1. In this study, we investigated cfDNA levels in patients with acute heart failure (AHF) and CRS type 1 and the possible correlation between cfDNA levels and inflammatory and apoptotic parameters. METHODS: We enrolled 17 AHF patients and 15 CRS type 1 who exhibited AKI at the time of admission (caused by AHF) or developed AKI during the first 48 h from admission. cfDNA was extracted from plasma and quantified by real-time polymerase chain reaction. Plasma levels of NGAL, tumor necrosis factor-α, interleukin (IL)-6, IL-18, and caspase-3 were measured. RESULTS: We observed significantly higher levels of cfDNA in patients with CRS type 1 than patients with AHF. Caspase-3, IL-6, IL-18, and NGAL levels resulted significantly increased in patients with CRS type 1. Moreover, a positive correlation between cfDNA levels and caspase-3 levels was found, as well as between cfDNA levels and IL-6 and renal parameters. CONCLUSION: Our study explores the premise of cfDNA as a marker for apoptosis and inflammation in CRS type 1 patients. cfDNA could potentially serve as an index for noninvasive monitoring of tissue damage and apoptosis in patients with AKI induced by AHF.

Presepsin and Procalcitonin Levels as Markers of Adverse Postoperative Complications and Mortality in Cardiac Surgery Patients.

Backgound: This study was aimed at evaluating the presepsin and procalcitonin levels to predict adverse postoperative complications and mortality in cardiac surgery patients. METHODS: A total of 122 cardiac surgery patients were enrolled for the study. Presepsin and procalcitonin levels were measured 48 h after the procedure. The primary endpoints were adverse renal, respiratory, and cardiovascular outcomes and mortality. RESULTS: Presepsin and procalcitonin levels were significantly higher in patients with adverse renal and respiratory outcome (p < 0.001 and 0.0081). The presepsin levels were significantly higher in patients with adverse cardiovascular outcome (p = 0.023) and the procalcitonin values in patients with sepsis (p = 0.0013). Presepsin levels were significantly higher in patients who died during hospitalization (382 pg/mL, interquartile range [IQR] 243-717.5 vs. 1,848 pg/mL, IQR 998-5,451.5, p = 0.049). In addition, the predictive value for in-hospital, 30-days, and 6-months mortality was higher for presepsin, with a significant difference between the 2 biomarkers (p = 0.025, p = 0.035, p = 0.003; respectively). Presepsin and procalcitonin seem to have comparable predictive value for adverse renal, cardiovascular, and respiratory outcome in cardiac surgery patients. Although a positive trend was notable for presepsin and adverse renal outcome (area under the ROC [receiver operating characteristic] curves [AUC] of 0.760, 95% CI 0.673-0.833 versus procalcitonin: AUC 0.692; 95% CI 0.601-0.773): no statistically significant difference was evident between the AUC of the 2 biomarkers (p = 0.25). CONCLUSIONS: Presepsin and -procalcitonin seem to have comparable predictive value for -adverse renal, cardiovascular, and respiratory outcome in cardiac surgery patients. Also, presepsin possesses a better predictive value for in-hospital, 30-days, and 6-months mortality.

Ultrasound and color Doppler applications in chronic kidney disease.

Chronic kidney disease (CKD) includes all clinical features and complications during the progression of various kidney conditions towards end-stage renal disease (ESRD). These conditions include immune and inflammatory disease such as: primary and hepatitis C virus (HCV)-related glomerulonephritis; infectious disease such as pyelonephritis with or without reflux and tuberculosis; vascular disease such as chronic ischemic nephropathy; hereditary and congenital disease such as polycystic disease and congenital cystic dysplasia; metabolic disease including diabetes and hyperuricemia; and systemic disease (collagen disease, vasculitis, myeloma). During the progression of CKD, ultrasound imaging and color Doppler imaging (US-CDI) can differentiate the etiology of the renal damage in only 50-70% of cases. Indeed, the end-stage kidney appears shrunken, reduced in volume (Ø < 9 cm), unstructured, amorphous, and with acquired cystic degeneration (small and multiple cysts involving the cortex and medulla) or nephrocalcinosis, but there are rare exceptions, such as polycystic kidney disease, diabetic nephropathy, and secondary inflammatory nephropathies. The main difficulties in the differential diagnosis are encountered in multifactorial CKD, which is commonly presented to the nephrologist at stage 4-5, when the kidney is shrunken, unstructured and amorphous. As in acute renal injury and despite the lack of sensitivity, US-CDI is essential for assessing the progression of renal damage and related complications, and for evaluating all conditions that increase the risk of CKD, such as lithiasis, recurrent urinary tract infections, vesicoureteral reflux, polycystic kidney disease and obstructive nephropathy. The timing and frequency of ultrasound scans in CKD patients should be evaluated case by case. In this review, we will consider the morpho-functional features of the kidney in all nephropathies that may lead to progressive CKD.

Procalcitonin and Interleukin-6 Levels: Are They Useful Biomarkers in Cardiac Surgery Patients?

BACKGROUND/AIM: Cardiac surgery-associated acute kidney injury is an independent predictor of chronic renal disease and mortality. The scope of this study was to determine the utility of procalcitonin (PCT) and plasma interleukin-6 (IL-6) levels in predicting renal outcome and mortality in these patients. METHODS: PCT and plasma IL-6 levels of 122 cardiac surgery patients were measured at 48 h after the surgical procedure. Primary endpoints were adverse renal outcome and mortality. Secondary endpoints were length of stay, bleeding, and number of transfusions. RESULTS: PCT was found to be a better predictor of adverse renal outcome than IL-6. IL-6 seemed to be a better predictor of both 30-day and overall mortality than PCT. Neither PCT nor IL-6 levels were found to be good predictors of intensive care unit stay and bleeding. CONCLUSION: PCT may be considered a good predictor of adverse renal outcome in cardiac surgery patients, whereas IL-6 seems to possess a good predictive value for mortality in this population of patients.

The Role of Cell-Free Plasma DNA in Critically Ill Patients with Sepsis.

BACKGROUND: The identification of highly reliable outcome predictors in severe sepsis is important to define disease severity, predict bedside prognosis and monitor response to treatment. Cell-free plasma DNA (cfDNA) has been recently proposed as a possible prognostic marker of clinical outcome in septic patients. In this study, we investigated the prognostic value of cfDNA in patients with sepsis and its possible correlation with caspase-3, IL-6 and IL-18 levels. METHODS: We enrolled 34 patients admitted to the intensive care unit (ICU). Out of these 34, 27 patients were septic and 7 were non-septic. cfDNA was extracted from plasma and quantified by real time PCR. Plasma levels of caspase-3, IL-6 and IL-18 were measured by ELISA. RESULTS: We observed significantly higher levels of cfDNA in septic patients. No significant differences were found between cfDNA levels in patients with Gram+, Gram- and fungal infections. Out of the 27 septic patients, 12 developed acute kidney injury (AKI) requiring continuous renal replacement therapy (CRRT), and cfDNA levels resulted to be higher in this group. Out of the 27 septic patients, 11 had a negative outcome during the ICU stay. The cfDNA concentrations at admission were higher in non-survivors than in survivors. Caspase-3, IL-6 and IL-18 levels were significantly higher in septic patients when compared to these levels in non-septic patients and correlated with cfDNA levels. CONCLUSION: cfDNA can be considered a good prognostic marker of clinical outcome in septic patients. Its levels increase in case of AKI complicating sepsis, in particular if CRRT is needed, and are associated with poor outcome. Caspase-3, IL-6 and IL-18 levels are higher in septic patients and correlate to cfDNA concentrations.

Oxidative stress: dual pathway induction in cardiorenal syndrome type 1 pathogenesis.

Cardiorenal Syndrome Type 1 (Type 1) is a specific condition which is characterized by a rapid worsening of cardiac function leading to acute kidney injury (AKI). Even though its pathophysiology is complex and not still completely understood, oxidative stress seems to play a pivotal role. In this study, we examined the putative role of oxidative stress in the pathogenesis of CRS Type 1. Twenty-three patients with acute heart failure (AHF) were included in the study. Subsequently, 11 patients who developed AKI due to AHF were classified as CRS Type 1. Quantitative determinations for IL-6, myeloperoxidase (MPO), nitric oxide (NO), copper/zinc superoxide dismutase (Cu/ZnSOD), and endogenous peroxidase activity (EPA) were performed. CRS Type 1 patients displayed significant augmentation in circulating ROS and RNS, as well as expression of IL-6. Quantitative analysis of all oxidative stress markers showed significantly lower oxidative stress levels in controls and AHF compared to CRS Type 1 patients (P < 0.05). This pilot study demonstrates the significantly heightened presence of dual oxidative stress pathway induction in CRS Type 1 compared to AHF patients. Our findings indicate that oxidative stress is a potential therapeutic target, as it promotes inflammation by ROS/RNS-linked pathogenesis.

Secondary amyloidosis in a patient carrying mutations in the familial Mediterranean fever (FMF) and tumour necrosis factor receptor-1 syndrome (TRAPS) genes.

Secondary amyloidosis (AA) is characterized by the extracellular tissue deposition of fibrils composed of fragments of an acute-phase reactant protein, serum amyloid A (SAA), due to chronic inflammatory diseases, infections and several neoplasms. AA amyloidosis may also complicate several hereditary diseases, where genetic factors play a pivotal role in the expression of amyloidosis. Familial Mediterranean fever (FMF) and tumour necrosis factor receptor-1 syndrome (TRAPS) are the most frequently involved. We describe a case of a 21-year-old Romanian woman who presented at the 35th week of gestation with acute abdominal pain, nausea and vomiting. The laboratory workup performed after delivery showed proteinuria in the nephrotic range and increased SAA protein. Kidney amyloid deposits were detected and genetic testing for secondary amyloidosis was performed identifying two mutations, one involving the gene of FMF (MEFV), and the other involving the tumour necrosis factor receptor-1 gene (TNFRSF1A). To our knowledge, this is the first case in the literature where secondary amyloidosis develops in a patient carrying mutations involving the genes of both FMF and TRAPS.

Genomics and biological activity of neutrophil gelatinase-associated lipocalin in several clinical settings.

Recent literature has shown that neutrophil gelatinase-associated lipocalin (NGAL) is one of the most interesting and promising biomarkers in case of acute kidney injury. However, several studies indicated that this protein may be applied beyond the boundaries of renal pathophysiology and may be used in other pathophysiological settings since it is also expressed in neutrophils, and respiratory, bowel and prostate epithelia. In this review, we report NGAL genomics and biology and its possible use in several clinical settings. In particular, we review the genomic organization of the NGAL gene, the lipocalin family structure, the interaction between NGAL and ligands, and the induction and expression of NGAL in different conditions.

[Ultrasound assessment in renal infections]. / L'ecografia nelle infezioni del rene.

Urinary tract infections (UTIs) are a common clinical problem, especially among women. Ultrasound assessment is indicated in case of complicated UTIs, in particular in children, pregnant women and patients with chronic kidney disease. Even though B-mode imaging alone is rarely diagnostic in case of particular kidney infections such as focal and multifocal acute pyelonephritis, Doppler and power-Doppler (PD) techniques are able to increase its sensitivity. Contrast-enhanced ultrasound (CEUS) further improves the signal-to-noise ratio, thus increasing the diagnostic accuracy of ultrasound in case of renal infectious disease. Recent studies performed on kidney transplant recipients have indeed demonstrated the high sensitivity and specificity of CEUS in diagnosing acute pyelonephritis. Moreover, ultrasonography is a useful diagnostic tool in case of kidney abscesses, emphysematous pyelonephritis, early phases of pyonephrosis, and in the evaluation and monitoring of echinococcal cysts. Ultrasound imaging is less specific in diagnosing xanthogranulomatous pyelonephritis, malacoplakia and renal tuberculosis. Finally, several authors recommend routine ultrasound assessment in HIV patients, given the high incidence of renal complications in this population of patients.

Evaluation of a new polysulfone hemofilter for continuous renal replacement therapy.

New strategies using continuous renal replacement therapy as a tool to achieve immunomodulation in septic acute kidney injury have been proposed. The hypothesis is based on the possibility to remove inflammatory mediators and oxidants in a wide spectrum of molecular weights, thanks to new, highly permeable synthetic membranes. A new polysulfone hemofilter with high permeability and a sharp high cut-off membrane (CUREFLO™; Asahi Kasei Kuraray Medical Co., Ltd., Tokyo, Japan) has been evaluated in this study to assess IL-6 and advanced oxidation protein product removal in critically ill patients undergoing continuous renal replacement therapy. Unit performance, sieving coefficients and clearances were evaluated in fourteen patients undergoing continuous veno-venous hemofiltration and continuous veno-venous hemodialysis.

Cisplatin-induced kidney injury in the rat: L-carnitine modulates the relationship between MMP-9 and TIMP-3.

Renal interstitial fibrosis is a major complication of cisplatin treatment, due to the increased accumulation of extracellular matrix (ECM) proteins whose remodeling is important for the development of normal tissues; indeed, its malfunction might play a role in the etiology of various diseases. Biopharmacological evaluations suggest that L-carnitine can prevent cardiac metabolic damage caused by doxorubicin, as well as can inhibit cisplatin-induced injury in the kidney and in the small intestine, without any interference with the drug's antitumoral properties. Since the glomerular basement membrane and the mesangial matrix constitute the ECM of the renal glomerulus, we examined the localization and expression of MMP-9 and TIMP-3 in normal rat kidney and the changes in their expression over a period of time by treatment with cisplatin, with and without L-carnitine. MMP-9 immunoreaction in cisplatin-treated rat kidney tissue suggests an involution of the basal membrane, an alteration of ECM components and low glomerular function, due to the increased thickness of the mesangium. Our results suggest that the matrix remodeling by MMP-9 and TIMP-3, in the later stages, can play an important role in the development of glomerular sclerosis and interstitial fibrosis after cisplatin treatment. It can also be postulated that L-carnitine protects from cisplatin injury, by modulating the relationship between MMP-9 and TIMP-3.

Supplementation of L-arginine prevents glucocorticoid-induced reduction of bone growth and bone turnover abnormalities in a growing rat model.

The present study was designed to evaluate the effects of glucocorticoid (GC) treatment on bone turnover and bone mineral density in the growing rat. Because of the recent evidence that nitric oxide (NO) can counteract prednisolone-induced bone loss in mature rats, we examined the effect on bone of the NO donor L: -arginine in young male rats, in which bone mass is increased by the same biological mechanism as in children and adolescents. Thirty-six 10-week-old Sprague-Dawley male rats were assigned to six groups of six animals each, and treated for 4 weeks with either vehicle (once a week subcutaneous injection of 100 microl of sesame oil); prednisolone sodium succinate, 5 mg/kg, 5 days per week by intramuscular injection (i.m.); L-arginine, 10 mg/kg intraperitoneally (i.p.) once a day; N(G)-nitro-L-arginine methylester (L-NAME), 50 mg/kg subcutaneously once a day; prednisolone sodium succinate 5 mg/kg, 5 days per week i.m. +L-arginine 10 mg/kg i.p. once a day; or prednisolone sodium succinate, 5 mg/kg, 5 days per week i.m. +L-NAME 50 mg/kg subcutaneously once a day. Serum calcium, alkaline phosphatase (ALP), osteocalcin, and the C-terminal telopeptides of type I collagen (RatLaps) were measured at baseline conditions and after 2 and 4 weeks. Prior to treatment, and after 2 and 4 weeks, the whole body, vertebral, pelvic, and femoral bone mineral density (BMD) was measured by dual-energy X-ray absorptiometry (DXA) scanning. Prednisolone and prednisolone+L-NAME treated rats had significantly lower ALP and osteocalcin levels than controls at 2 and 4 weeks, and significantly higher levels of Rat-Laps than controls at 4 weeks. Prednisolone, L-NAME, and prednisolone+L-NAME produced a significant inhibition of bone accumulation and bone growth at all sites measured. Supplementation with L-arginine appeared to prevent the inhibition of bone growth and increase in bone resorption induced by prednisolone. These data would suggest, for the first time, that supplementation with an NO donor could be considered as a treatment for steroid-induced osteoporosis in the developing skeleton.