Acute kidney injury in Turkey: epidemiological characteristics, etiology, clinical course, and prognosis.

BACKGROUND: This study aimed to evaluate the etiologies, comorbidities, and outcomes of acute kidney injury (AKI) in Turkey and determine any potential differences among different geographical parts of the country. METHODS: This prospective observational study was conducted by the Acute Kidney Injury Working Group of the Turkish Society of Nephrology. Demographical and clinical data of patients with AKI at the time of diagnosis and at the 1st week and 1st, 3rd, and 6th months of diagnosis were evaluated to determine patient and renal survival and factors associated with patient prognosis. RESULTS: A total of 776 patients were included (54.7% male, median age: 67 years). Prerenal etiologies, including dehydration, heart failure, and sepsis, were more frequent than other etiologies. 58.9% of the patients had at least one renal etiology, with nephrotoxic agent exposure as the most common etiology. The etiologic factors were mostly similar throughout the country. 33.6% of the patients needed kidney replacement therapy. At the 6th month of diagnosis, 29.5% of the patients had complete recovery; 34.1% had partial recovery; 9.5% developed end-stage kidney disease; and 24.1% died. The mortality rate was higher in the patients from the Eastern Anatolian region; those admitted to the intensive care unit; those with prerenal, renal, and postrenal etiologies together, stage 3 AKI, sepsis, cirrhosis, heart failure, and malignancy; those who need kidney replacement therapy; and those without chronic kidney disease than in the other patients. CONCLUSION: Physicians managing patients with AKI should be alert against dehydration, heart failure, sepsis, and nephrotoxic agent exposure. Understanding the characteristics and outcomes of patients with AKI in their countries would help prevent AKI and improve treatment strategies.

Neutrophil gelatinase-associated lipocalin is a better biomarker than cystatin C for the prediction of imminent acute kidney injury in critically ill patients.

Aims The prevention of acute kidney injury can be lifesaving for the intensive care unit patients. However, conventional methods are not sufficient for the prediction of the risk of future acute kidney injury. In this study, the promising biomarker, neutrophil gelatinase-associated lipocalin, was compared with cystatin C as an indicator for the risk of future acute kidney injury. Methods One hundred and eighty-three adult patients without chronic kidney disease or renal replacement therapy were included in this study. The plasma and urine concentrations of neutrophil gelatinase-associated lipocalin and cystatin C were assessed on the second day after intensive care unit admission and were followed for seven days to monitor the development of acute kidney injury. Acute kidney injury diagnosis was based on the risk, injury, failure, loss, end-stage renal failure criteria. Results Thirty-four per cent of the patients had acute kidney injury; 17 patients who did not fulfil criteria at the beginning, developed acute kidney injury from days 3 to 7 after admission. The mean serum creatinine on admission did not significantly differ between this and control groups (0.72 ± 0.20 and 0.83 ± 0.21; P = 0.060); however, the serum and urinary neutrophil gelatinase-associated lipocalin concentrations on the second day were significantly different (median: 75.69 [54.18-91.18] and 123.68 [90.89-166.31], P = 0.001; and median: 17.60 [8.56-34.04] and 61.37 [24.59-96.63], P = 0.001). Notably, the 48-h serum cystatin C concentration did not differ. Conclusion Neutrophil gelatinase-associated lipocalin concentrations in the urine and serum on the second day of intensive care unit admission could be used to predict the development of acute kidney injury in the following three to seven days in the intensive care unit; however, the cystatin C concentration did not have predictive value.

Neutrophil gelatinase-associated lipocalin levels during the first 48 hours of intensive care may indicate upcoming acute kidney injury.

PURPOSE: The recognition of acute kidney injury (AKI) as early as possible is important in the intensive care unit. This study proposes that serum and urine levels of neutrophil gelatinase-associated lipocalin (NGAL) may be used for this purpose. METHODS: One hundred and seven critically ill adult patients with no previous renal failure were included. NGAL levels were measured during the first 48 hours after admission; NGAL levels were followed for 7 days and classified based on Risk, Injury, Failure, Loss, and End-Stage Renal Failure criteria. RESULTS: The AKI incidence was 35.5%, and serum NGAL (sNGAL) and urinary NGAL (uNGAL) levels were higher in the AKI group. The area under the receiver operating characteristic curve was 0.76 (P<.001) for sNGAL and 0.75 (P<.001) for uNGAL. Seventy-one percent of AKI cases were observed within 48 hours, with 11 additional cases in the ensuing 7 days. The mean serum creatinine levels in the 11 patients were not different from non-AKI levels (P=.197), but the NGAL values were different, and the area under the receiver operating characteristic curve for sNGAL uNGAL was 1.00 (P=.014) and 0.93 (P=.02), respectively. CONCLUSIONS: Most AKI cases were diagnosed within the first 48 hours after admission, and NGAL was useful for predicting upcoming AKI.

Comparative Proteome Analysis of hAT-MSCs Isolated from Chronic Renal Failure Patients with Differences in Their Bone Turnover Status.

The relationship between the stem cells and the bone turnover in uremic bone disease due to chronic renal failure (CRF) is not described. The aim of this study was to investigate the effect of bone turnover status on stem cell properties. To search for the presence of such link and shed some light on stem-cell relevant mechanisms of bone turnover, we carried out a study with mesenchymal stem cells. Tissue biopsies were taken from the abdominal subcutaneous adipose tissue of a CRF patient with secondary hyperparathyroidism with the high turnover bone disease. This patient underwent parathyroidectomy operation (PTX) and another sample was taken from this patient after PTX. A CRF patient with adynamic bone disease with low turnover and a healthy control were also included. Mesenchymal stem cells isolated from the subjects were analyzed using proteomic and molecular approaches. Except ALP activity, the bone turnover status did not affect common stem cell properties. However, detailed proteome analysis revealed the presence of regulated protein spots. A total of 32 protein spots were identified following 2D gel electrophoresis and MALDI-TOF/TOF analyzes. The identified proteins were classified into seven distinct groups and their potential relationship to bone turnover were discussed. Distinct protein expression patterns emerged in relation to the bone turnover status indicate a possible link between the stem cells and bone turnover in uremic bone disease due to CRF.

ANCA Associated Vasculitis and Renal Failure Related to Propylthiouracil and Hyperthyroidism Induced Cholestasis in the Same Case.

Introduction. Liver involvement due to hyperthyroidism and also ANCA positive vasculitis related renal failure cases were reported separately several times before. However, to our knowledge, these two complications together in the same case had never been observed before. Case Presentation. The case of an ANCA positive 71-year-old Caucasian male with renal failure and lung involvement, subclinical hyperthyroidism, and intrahepatic cholestatic jaundice was presented in this paper. After exclusion of all of the other possibilities, cholestatic hepatitis was explained by subclinical hyperthyroidism; renal failure and lung involvement were interpreted as ANCA related vasculitis which might be a side effect of propylthiouracil use. Conclusion. The coexistence of these rare conditions in the same patient deserves emphasis and it is worth reporting. This case demonstrates that following the clinical course of the patient is essential after prescribing any medications to see whether any complication occurs or not. If the complications of this case were noticed earlier, it would be possible to treat and to prevent the permanent damages.

Evaluation of sepsis/systemic inflammatory response syndrome, acute kidney injury, and RIFLE criteria in two tertiary hospital intensive care units in Turkey.

Sepsis is a common cause of acute renal failure in intensive care units (ICU) with mortality rates as high as 60%. In this study, the clinical and laboratory predictors of acute kidney injury (AKI) in critically ill Turkish patients with sepsis/systemic inflammatory response syndrome were identified. We studied 139 (67 females/72 males) patients admitted to our ICUs with sepsis/systemic inflammatory response syndrome without renal failure. The clinical and laboratory parameters and treatments were recorded. Patients were classified as those without AKI (n = 60; 43.20%) and those with AKI (n = 79; 56.80%) based on the RIFLE (Risk, Injury, Failure, Loss, End-stage renal disease) criteria. Those with AKI were further classified as: risk in 27 (19%), injury in 25 (17.9%), failure in 25 (17.9%), and loss in 2 (1.4%). We found that the mortality rate increased with the severity of renal involvement: 56% in risk, 68% in injury, 72% in failure, and 100% in loss categories. Patients with AKI had a more positive fluid balance, higher central venous pressure, more vasopressor use, and lower systolic blood pressure. In multivariate analysis, the sequential organ failure assessment score, blood pressure, serum creatinine, and fluid balance were risk factors for the development of AKI. In this population, the incidence of AKI was higher and contrary to previous knowledge. A positive fluid balance also carries a risk for AKI and mortality in septic ICU patients. The RIFLE criteria were found to be applicable to our ICU population.

Citrobacter freundii peritonitis and tunnel infection in a patient on continuous ambulatory peritoneal dialysis.

The clinical course of a patient on continuous ambulatory peritoneal dialysis who developed peritonitis and tunnel infection due to an unusual pathogen, Citrobacter freundii, is described. The patient did not respond well to antibiogram-based therapy (intravenous meropenem and intraperitoneal gentamicin) and removal of the catheter was required.

Relationship between fluid status and its management on acute renal failure (ARF) in intensive care unit (ICU) patients with sepsis: a prospective analysis.

BACKGROUND: Sepsis carries a high morbidity and mortality, further enhanced by acute renal failure (ARF). Although fluid loading can prevent ARF in dehydrated patients, this approach could be risky in septic patients, since it can deteriorate oxygenation. This study evaluates the relationship between fluid status and management and ARF development in septic patients. METHODS AND PATIENTS: Patients admitted to the ICU between 1 January 2001 and 31 December 2001 were included if serum creatinine (Cr) was <2 mg% on admission, and if they developed sepsis. ARF was determined as a doubling of serum Cr, an increase of serum Cr >2 mg%, or oliguria <500 ml/24 hr. RESULTS: 257 out of 2442 patients, admitted to the intensive care unit (ICU), developed sepsis, 29 developed ARF, 13 needed a renal replacement. ARF vs. non-ARF patients were older (65.2 +/- 13.3 vs. 55.1 +/- 17.4, p=0.002), had a higher central venous pressure (CVP) at day 1 (9.6 +/- 4.3 vs. 5.2 +/- 3.6 mmHg, p<0.001), and at day 2 (7.1 +/- 5.1 vs. 5.1 +/- 4.0 mmHg, p=0.03), a higher colloid fluid loading for the first 3 days (2037 +/- 1681 vs. 1116 +/- 1220 mL, p<0.03), a higher serum Cr (1.25 +/- 0.39 vs. 0.96 +/- 0.33 mg/dL, p=0.009) and an increase vs. a decrease in serum Cr during the first 24 hr (+0.30 +/- 0.58 vs. -0.31 +/- 0.45 mg/dL, p=0.02), a lower diuresis (1347 +/- 649 vs. 1849 +/- 916 mL, p=0.005). There was no difference in APACHE II scores (19.2 +/- 7.2 vs. 17.2 +/- 6.6, p=0.1), or MAP (64.5 +/- 12.4 vs. 67.9 +/- 12.4, p=0.18). The fraction of inspired oxygen (FiO2) need in the ARF group increased from 40.4 +/- 11.5 to 65.6 +/- 24.2% from day 1 to day 2 (p=0.04), where it remained unchanged in the non-ARF group. The use of diuretics was higher in the ARF group (21/29 vs. 43/228, p=0.001). CONCLUSION: Septic patients developing ARF have an elevated CVP at day 1 of sepsis, indicating cardiodepression or intrarenal causes for hypoperfusion. These patients develop ARF despite further fluid loading. Respiratory function deteriorated in patients with ARF. Persistent fluid challenges should be avoided if they do not lead to an improvement in renal function, or if oxygenation deteriorates.

Clinical characteristics of patients developing ARF due to sepsis/systemic inflammatory response syndrome: results of a prospective study.

BACKGROUND: Acute renal failure (ARF) in patients with sepsis provokes high mortality and financial cost. In this prospective study, we collected characteristics of patients in the intensive care unit (ICU) who developed sepsis/systemic inflammatory response syndrome (SIRS) to analyze differences between those who subsequently did or did not develop ARF. METHODS: All patients admitted to the ICU of the University Hospital Gent, Belgium, between January 1, 2001, and December 31, 2001, who developed sepsis/SIRS were included if they had a serum creatinine level less than 2 mg/dL (<177 micromol/L). RESULTS: Of 2,442 patients admitted to the ICU, 257 patients developed sepsis/SIRS. Of those, 29 patients (11%) developed ARF. In a univariate analysis, age, central venous pressure (CVP), and serum creatinine and blood urea nitrogen levels were greater (P = 0.003, P = 0.006, P < 0.001, and P < 0.001, respectively), whereas mean arterial and diastolic blood pressures, 24-hour urinary output, arterial pH, bicarbonate level, thrombocyte count, albumin level, and prothrombin time were lower (P = 0.05, P = 0.004, P = 0.005, P = 0.03, P = 0.009, P = 0.037, P = 0.05, and P = 0.006, respectively) in the ARF group. Prevalence of diabetes, sex, and need for ventilation were not different between the ARF and no-ARF groups, but in the ARF group, diuretic use, vasopressor use, and presence of primary hepatic failure were more prevalent (P = 0.001 for each). In a multivariate analysis, age, serum creatinine level, CVP, and presence of liver failure significantly contributed to a logistic regression model for ARF. CONCLUSION: Several parameters already were disturbed at the first day of SIRS/sepsis in patients who later developed ARF. Older age, elevated serum creatinine level despite elevated CVP, and presence of hepatic failure are predictive for ARF in septic patients.

Renoprotective effects of valsartan and enalapril in STZ-induced diabetes in rats.

Effects of the angiotensin II type 1 (AT1) receptor antagonist valsartan and the angiotensin-converting enzyme (ACE) inhibitor enalapril were studied in streptozotocine (STZ)-induced diabetes in rats on the basis of microalbuminuria (Ma) and renal morphology. Five groups of Wistar rats were used, one group was the non-diabetic control, one group consisted of untreated STZ-diabetics and 3 groups of STZ-diabetics were treated with either enalapril and/or valsartan for 30 days. Blood glucose (BG) and Ma levels, body and kidney weight and glomerular size were measured. Immunohistochemical staining with an anti-transforming growth factor-beta1 (TGF-beta1) antibody was performed as well. In STZ-diabetics, BG and Ma levels were significantly increased when compared with the non-diabetic group. Although Ma levels in the valsartan-treated group was found to be higher than those in the non-diabetics group after 15 days of treatment, in all treated diabetic groups Ma levels were significantly decreased as compared with STZ-diabetics at the end of the experiment. Thickening of the glomerular and tubular basement membranes, increased mesangial matrix and glomerular size were found in the untreated diabetic group. All these changes were less in the treated groups. A significant increase in TGF-beta1 immunoreactivity was found in glomeruli of untreated STZ-diabetics as compared with non-diabetics. Again, TGF-beta1 expression was decreased in the treated groups as compared with untreated STZ-diabetics. We conclude that valsartan and enalapril have renoprotective effects in diabetic nephropathy. A combined therapy has an advantage because lower dosages of these drugs can be used. Their beneficial effects are related to a blockade of the renin-angiotensin system (RAS) and a decrease in TGF-beta1 expression in glomeruli.