Early Detection Of Renal Dysfunction Research Articles

Nefrotoxicidade por lítio

Lithium has been widely used in the treatment of bipolar disorder. Its renal toxicity includes impaired urinary concentrating ability and natriuresis, renal tubular acidosis, tubulointerstitial nephritis progressing to chronic kidney disease and hypercalcemia. The most common adverse effect is nephrogenic diabetes insipidus, which affects 20-40% of patients within weeks of lithium initiation. Chronic nephropathy correlates with duration of lithium therapy. Early detection of renal dysfunction should be achieved by rigorous monitoring of patients and close collaboration between psychiatrists and nephrologists. Recent experimental and clinical studies begin to clarify the mechanisms by which lithium induces changes in renal function. The aim of this study was to review the pathogenesis, clinical presentation, histopathological aspects and treatment of lithium-induced nephrotoxicity.

Serum cystatin C level is a good prognostic marker in patients with cirrhotic ascites and normal serum creatinine levels

Serum creatinine (Cr) is not a reliable marker for early detection of renal dysfunction in patients with cirrhotic ascites. Several reports have suggested that cystatin C (CysC) is more sensitive than Cr for detecting reduced renal function in these patients. This study evaluated the clinical significance of CysC in patients with cirrhotic ascites and a normal serum Cr level. We enrolled patients with ascites and a normal serum Cr level (<1.2 mg/dl). Liver function tests, international normalized ratio (INR) and serum Cr and CysC levels were measured on the same day for all patients. CysC levels were measured using the automated latex-enhanced immunonephelometric method. The endpoint of follow-up was the development of hepatorenal syndrome (HRS) or mortality. Seventy-eight patients with cirrhotic ascites were enrolled in the study (58 men and 30 women; age, 53+/-11 years). The underlying liver diseases in these patients were chronic hepatitis B (37%), chronic hepatitis C (4%), alcoholic liver disease (53%) and others (6%). Forty-six (59%) and 32 (41%) patients were in Child-Pugh classes B and C respectively. HRS developed in 14 patients during the follow-up period (349+/-241 days), with cumulative incidences of 10.2% and 20.4% at 6 and 12 months respectively. The CysC level was the only independent predictive factor for HRS. Twenty-three patients died during the follow-up period. CysC level and INR were independent factors for predicting mortality. Serum CysC level is a good marker for predicting HRS and survival in patients with cirrhotic ascites and a normal Cr level.

Insufficient therapeutic management of hypertensive patients with renal failure in France

Hypertension is both the cause and consequence of chronic renal failure (CRF). The prevalence of CRF, which itself is a cardiovascular risk factor, is not well known in France. To estimate the prevalence of renal dysfunction among hypertensive patients who were seen by general practitioners (GP); to assess the drug management of hypertension in these patients according to their renal status. A transversal observational study among patients of both genders aged 18 or more, with arterial blood pressure greater than 130/80 mmHg (i.e., over CRF-recommended blood pressure) or under antihypertensive drugs who were recruited in France by GP. Among the 2315 included patients, 1908 could be analyzed for their renal function. Of these, 70.5% had an estimated glomerular filtration rate (GFR) of 89 ml/min per 1.73 m(2) or lower. One third of these patients (31.4%) were suffering from renal failure (GFR<or=59 ml/min per 1.73 m(2)). CRF was moderate in 27.9% of patients, severe in 2.20% and terminal (GFR<15 ml/min per 1.73 m(2)) in 1.26%. At least one antihypertensive drug was taken by 1952 patients (84.3%), regardless of the patient's renal status. Hypertensive patients who are seen by GP have a high level of renal disturbances and many of them do not reach recommended blood pressure values. This highlights the importance of an early detection of renal dysfunction avoiding progression towards end-stage renal failure and an adapted antihypertensive drugs prescription, such as angiotensin-converting enzyme inhibitors and angiotensin receptor blocker, acting as renal protectors.

RENAL INVOLVEMENT IN CHILDREN WITH GLYCOGEN-STORAGE DISEASE

INTRODUCTION: Long-term complications of glycogen-storage diseases (GSDs) include delayed puberty, hepatic adenomata, and renal disease. OBJECTIVE: In this study, our aim was to detect renal involvement in children with GSD and to determine the most accurate laboratory test to be the gold standard for early detection of this renal dysfunction. METHODS: Twenty-seven children known to have GSD were included in this study. Fifteen healthy age- and gender-matched children were also included as controls. Routine urine analysis and measurement of urinary β2-microglobulin and microalbumin levels were performed for all patients and controls. Renal-function tests, measurement of serum electrolyte, alkaline phosphatase, urinary calcium, blood, and urine pH levels, creation of a urinary and plasma aminogram, calculation of the glomerular filtration rate, bone radiography to detect rachitic manifestations, and abdominal ultrasound to measure renal size were performed for all patients. RESULTS: Twenty-one patients had ≥1 renal abnormality. The most common was increased urinary β2-microglobulin level (15 of 21) followed by an abnormal glomerular filtration rate, whether low or high (8 of 21), and microalbuminuria (6 of 21). Sonographically, there was nephrocalcinosis in 1 case and renal stone in another. The area under the receiver operating characteristic curve for β2-microglobulin was 0.86 (P = .01) and 0.7 for the urinary microalbumin/creatinine ratio (P = .15). The best cutoff level for predicting renal abnormality for urinary β2-microglobulin was 0.22 mg/L with 70% sensitivity and 100% specificity, and the best cutoff value for the urinary microalbumin/creatinine ratio was 4.5 with 86% sensitivity and 50% specificity. CONCLUSIONS: Renal abnormalities are common in patients with GSD. Urinary B2-microglobulin level can be considered the gold standard for early detection of renal dysfunction in these patients.

Cystatin C Does Not Detect Acute Changes in Glomerular Filtration Rate in Early Diabetic Nephropathy

Background. The measurement of renal functional reserve (acute change in glomerular filtration rate [GFR] after protein load) allows the detection of sub-clinical renal dysfunction and has prognostic implications in diabetes. Our aim was to test cystatin C as an index of GFR and renal functional reserve. Methods. GFR was measured by CSinistrin at baseline and after protein load in 28 diabetic patients with serum creatinine <1.2 mg/dL. The CSinistrin was compared with cystatin C, serum creatinine, creatinine clearance, and Cockcroft-Gault formula. Results. Baseline CSinistrin ranged from 67–172 mL/min. Regression analysis showed an overall low relationship between CSinistrin and the indirect markers of GFR. The highest correlation with CSinistrin was obtained for cystatin C clearance (R2 = 0.58, r = 0.76, p < 0.001), the 1/serum cystatin C (R2 = 0.58, r = 0.76, p < 0.001), and serum cystatin C (R2 = 0.52, r = 0.72, p < 0.001). Renal functional reserve was preserved in 6 of 28 patients. There was no significant change in cystatin C in response to protein load. Conclusion. Wide variation in baseline GFR emphasizes the need for the early detection of renal dysfunction. Cystatin C correlated best with CSinistrin at baseline, but did not detect renal functional reserve.

How to monitor renal function in pediatric solid organ transplant recipients

The aim is to review the tools for early detection of renal dysfunction after pediatric solid organ transplantation. Currently, the most widely used marker for detection of renal dysfunction involves measurement of GFR. Inulin clearance forms the "gold standard" method for measuring GFR; however, nuclear medicine methods ((51)Cr EDTA and (99)Tc DTPA isotope clearance studies) have replaced inulin clearance. The measurement of serum creatinine has a low sensitivity for the early detection of renal damage. The Schwartz formula using patient height and serum creatinine requires center-specific constants and has limitations associated with creatinine determination. These limitations may be overcome using a cystatin C-based GFR estimation. In diabetic nephropathy, and more recently in hemolytic uremic syndrome, microalbuminuria has been established as a useful screening tool for renal damage, while its predictive value in the transplantation setting needs to be established. All transplant recipients should be screened for hypertension. Early referral for ambulatory 24-h blood pressure monitoring and involvement of pediatric nephrologists should be considered. All pediatric solid organ transplant recipients receiving CNI should be screened regularly for high blood pressure and early evidence of renal damage using either GFR scans or cystatin C-based GFR estimations.

Determination of renal function in long-term heart transplant patients by measurement of urinary retinol-binding protein levels

Significant improvements have been noted in heart transplantation with the advent of cyclosporine. However, cyclosporine use is associated with significant side effects, such as chronic renal failure. We were interested in evaluating the incidence of long-term renal dysfunction in heart transplant recipients. Fifty-three heart transplant recipients were enrolled in the study. Forty-three patients completed the entire evaluation and follow-up. Glomerular (serum creatinine, creatinine clearance measured, and creatinine clearance calculated) and tubular functions (urinary retinol-binding protein, uRBP) were re-analyzed after 18 months. At the enrollment time, the prevalence of renal failure ranged from 37.7 to 54% according to criteria used to define it (serum creatinine > or = 1.5 mg/dL and creatinine clearance <60 mL/min). Mean serum creatinine was 1.61 +/- 1.31 mg/dL (range 0.7 to 9.8 mg/dL) and calculated and measured creatinine clearances were 67.7 +/- 25.9 and 61.18 +/- 25.04 mL min-1 (1.73 m(2))-1, respectively. Sixteen of the 43 patients who completed the follow-up (37.2%) had tubular dysfunction detected by increased levels of uRBP (median 1.06, 0.412-6.396 mg/dL). Eleven of the 16 patients (68.7%) with elevated uRBP had poorer renal function after 18 months of follow-up, compared with only eight of the 27 patients (29.6%) with normal uRBP (RR = 3.47, P = 0.0095). Interestingly, cyclosporine trough levels were not different between patients with or without tubular and glomerular dysfunction. Renal function impairment is common after heart transplantation. Tubular dysfunction, assessed by uRBP, correlates with a worsening of glomerular filtration and can be a useful tool for early detection of renal dysfunction.

Estimation of glomerular filtration rates after orthotopic liver transplantation: Evaluation of cystatin C–based equations

Early detection of renal dysfunction in patients after orthotopic liver transplantation is important. Creatinine-based equations to estimate glomerular filtration rate (GFR) were found to be less accurate in liver transplant recipients than in their original populations. Since cystatin C (CysC) is independent from muscle mass and hepatic biosynthesis, we evaluated the diagnostic accuracy of 3 CysC-based equations (Larson, Hoek, and Filler formulae) that are based on the same CysC method as that of our center in comparison to the abbreviated creatinine-based modification of diet in renal disease (MDRD) formula in 59 liver transplant recipients. "True GFR" was measured by 99mTc-diethylene triamine pentaacetic acid ((99m)Tc-DTPA) clearance. Neither correlation with the GFR (correlation coefficients: 0.594-0.640) nor precision (root mean square error: 15.7-18.17 mL/min/1.73 m(2)) differed significantly between the tested formulae. The biases of the Hoek and Larsson formulae were significantly smaller than those of the MDRD and Filler equations (-0.1 and -2.3 vs. 10.1 and 7.9 mL/min/1.73 m(2), respectively; P </= 0.0023). Mean estimates of MDRD (61.9 +/- 21.4 mL/min/1.73 m(2)) and Filler (61.2 +/- 22.1 mL/min/1.73 m(2)) differed significantly from the measured GFR (52.3 +/- 17.5 mL/min/1.73 m(2); P < 0.005), whereas Larsson and Hoek did not (49.5 +/- 20.2 and 51.4 +/- 17.9 mL/min/1.73 m(2), respectively). Accuracy within 30% and 50% of the true GFR was best for the Hoek (76.3% and 93.2%) formula, albeit not significantly different from MDRD (64.4% and 83.1%). Taken together, these data show the best overall performance for GFR estimates derived from the Hoek equation with respect to bias, precision, and accuracy.

Renal dysfunction in hepatic disease: early identification with renal duplex Doppler US in patients who undergo liver transplantation.

To improve early detection of renal dysfunction in patients who undergo liver transplantation, a prospective study was performed with intrarenal duplex Doppler sonography before and after liver transplantation in 42 patients. The duplex Doppler findings were compared with multiple clinical and laboratory findings; patients were grouped on the basis of preoperative renal resistive index (RI) and serum creatinine level. The mean initial renal RI was elevated (.73 +/- .07 [standard deviation]); after transplantation, it was lower (.60 +/- .06) (P less than .001). Thirty-six patients had a normal serum creatinine level at the preoperative Doppler examination. Patients with an elevated renal RI (n = 19) had a greater chance of subsequent renal dysfunction (P less than .001), hemodialysis (P less than .01), longer stays in the intensive care unit (P less than .05), and longer hospital stays after surgery (P less than .05) than those with a normal renal RI (n = 17). In 34 patients the RI fell 10% or more after surgery and none died, whereas five of eight patients (62%) whose RI fell less than 10% died. Doppler analysis enabled identification of patients without azotemia whose course of disease before and after surgery was similar to that of patients with clinically recognized renal disease.

Assessment of renal function in the patient receiving chemotherapy

With foresight, knowledge, and an awareness of the problem, nephrotoxicity associated with chemotherapy can be prevented or minimized, thereby avoiding irreversible renal failure or death. Careful assessment of those patients at risk for renal damage and the identification of early signs/symptoms of renal impairment are key steps in the prevention and early detection of renal dysfunction. The purpose of this article is to describe the clinical and laboratory manifestations of renal toxicity, as well as the nurse's role in the assessment of nephrotoxicity.

Early detection of renal dysfunction: practical recommendations

Test programmes for early detection of renal dysfunction are urgently needed. They should be adapted to the population under investigation, whether the general population or an occupationally or medically exposed population. At present, there is no clinically relevant definition of renal dysfunction on the basis of pathological test results. Due to the complex function and structure of the kidney, measurement of a single parameter is not sufficient for early detection of renal dysfunction. However, any prophylactic and prospective protocol should take into account the sensitivity and specificity of the applied tests, the amount of work involved and the possible positive effects for the population at risk.