Parathyroid hormone as a marker for the differential diagnosis of acute and chronic renal failure

It is often difficult to distinguish acute renal failure clinically from chronic renal failure, especially in patients who do not have records of their medical history. We investigated the magnitude of iPTH increase in ARF and the potential role of iPTH as a marker for differential diagnosis of ARF and CRF in new patients referred to our renal unit. We prospectively analyzed 122 (ARF n = 64, CRF n = 58) patients referred to our renal unit with serum creatinine higher than 2 mg/dL. ROC curve analysis was performed to investigate role of iPTH for differentiating ARF from CRF. The sensitivity, specificity, and positive predictive value of iPTH in discrimination of ARF and CRF were calculated. There was no statistically significant difference regarding the means of age, sex distribution, and serum chemistry between patients with ARF or CRF. But serum iPTH (p < 0.0001) levels were lower in patients with ARF than in those with CRF. A cutoff, set at 170 pg/mL for iPTH to discriminate patients with CRF, yielded a sensitivity of 88% and a specificity of 89%. This study confirms that the iPTH measurement is of clinical value in differentiating acute from chronic renal failure.     

Kinetics of carbamylated haemoglobin in acute renal failure.

BACKGROUND: Carbamylation of proteins by isocyanic acid, the reactive form of cyanate derived from urea, is increased in uraemia and may contribute to uraemic toxicity. Kinetics of carbamylation that may reflect uraemic toxicity is not clearly defined in acute renal failure (ARF). METHODS: Twenty-eight patients with ARF and 13 with chronic renal failure (CRF) were included in the study in order to determine changes in carbamylated haemoglobin concentration (CarHb) in ARF. The usefulness of this parameter for differentiating ARF from CRF was also investigated. CarHb was measured by high-performance liquid chromatography after acid hydrolysis. RESULTS: Mean CarHb level (expressed as microg carbamyl valine per gram (CV/g) Hb) was significantly higher in ARF (54.3+/-5.2) than in normal subjects (31.6+/-1.3). On admission, CarHb level was correlated with duration of ARF prior to hospitalization in the intensive care unit (r(2)=0.723, P<0.001). CarHb was significantly higher at recovery in the subgroup of patients requiring haemodialysis than in the subgroup not requiring haemodialysis (82. 4+/-11.3 vs 46.7+/-5.2, P<0.01). Similarly dialysis patients lost more weight (8.6+/-1.4 vs 2.7+/-0.5 kg, P<0.005) and had higher averaged blood urea levels in the 20 days prior to recovery (17. 6+/-1.9 vs 11.3+/-1.8 mol/l, P<0.05). After recovery, CarHb level decreased at a rate of 0.219 microg CV/g Hb per day in patients with reversible renal insufficiency. CarHb concentration was higher in patients with CRF. A cut-off CarHb value of 100 microg CV/g Hb had a sensitivity of 94% and a positive predictive value of 94% for differentiating ARF from CRF. CONCLUSIONS: Kinetics of CarHb showed a near normal red blood cell life span in ARF. Changes in CarHb enabled, with a good sensitivity, the distinction to be made between patients who recovered from ARF and those with sustained renal impairment, whether due to prior CRF or resulting from parenchymal sequelae. Measurement of CarHb is valuable at clinical presentation of ARF in patients with an unknown medical history of renal disease.     

Validation of Liano score in acute renal failure: a prospective study in Indian patients

Aim  To validate Liano score as a prognostic scoring system in acute renal failure (ARF): a prospective study in Indian patients. Patients and methods  Prospective study including 100 patients over a period of 1 year, from March 2006 to July 2007. Inclusion criteria were patients with no previous renal disease or any systemic disease known to affect the kidney and who presented with acute rise (hours to days) in serum creatinine. Exclusion criteria were patients with preexisting chronic renal failure, age younger than 12 years and ultrasound of the abdomen showing contracted kidneys. Results and conclusions  In this study there were 68 males and 32 females. Peak incidence by age was in the fifth decade. There was no increased mortality in any age group (p = 0.278). A total of 19 patients had pre-renal ARF, 74 patients had intrinsic ARF, of which 46 were acute tubular necrosis (ATN); 7 patients had obstructive ARF. A total of 21 patients had Liano score greater than 0.9, of which 18 patients died and 3 were discharged against medical advice in a critical condition (and died later at home). Calculated sensitivity was 62.1%, specificity was 100% and positive predictive value was 100%. Sensitivity and specificity when calculated separately for intrinsic renal ARF (after excluding post renal ARF) were 60.7% and 100%, respectively. There was statistically significant correlation between Liano score and mortality (p < 0.001).     

High incidence of renal failure in patients with aortic aneurysms.

BACKGROUND: Renal failure (RF) is a well-recognized complication of aortic aneurysms (AA) although its incidence has been poorly documented previously. The purpose of this study is to examine the incidence of RF in patients with AA and prognosis of AA patients with RF. METHODS: Renal function, complications and prognosis of AA patients with RF were retrospectively reviewed in 350 AA patients (median age 69.8+/-10.7 years) in the International Medical Center of Japan from 1989 to 1999. RESULTS: Among 350 patients with AA, 90 patients (25.7%) had chronic renal failure (CRF) at the initiation of follow-up. The number of CRF patients increased to 117 (33.4%) at 30 months of follow-up. Forty-four out of 160 patients (27.5%) who had aortic surgery developed postoperative acute renal failure (ARF). Stepwise logistic regression analysis revealed that age (>or=65 years), hypertension and multiple aneurysms were independent risk factors for CRF, whereas dissecting aneurysms, preoperative serum creatinine (sCr) levels and duration of surgery were independent risk factors for postoperative ARF in AA patients. In the 5-year follow-up of AA patients with CRF, the mean slopes of 1/serum-creatinine did not significantly differ between conservative treatment and surgical treatment. The survival rates were 49.5% in the conservative treatment group and 67.3% in the surgical treatment group. CONCLUSION: Our data suggest that the management of renal function including blood pressure from an early stage in AA patients is important since CRF is highly prevalent in AA patients and affects their prognosis and mortality.     

Importance of serum ferritin levels in patients with renal failure

Study results on acute phase reactants of renal failure patients are controversial. In this study, we enrolled 39 patients and divided them into 2 groups: acute renal failure (ARF), and chronic renal failure (CRF) patients. As opposed to CRF patients, the patients with ARF had higher serum ferritin levels that were independent of anemia parameters and other acute phase reactants.     

Acute Renal Failure Complicating Severe Acute Pancreatitis

The records of 563 patients admitted to the hospital with diagnosis of acute pancreatitis have been studied retrospectively. The aim of the study was to investigate the prevalence of acute renal failure (ARF) in these patients, and to evaluate the most important risk factors for ARF development and mortality. The prevalence of ARF in studied population was 14%, but only 3.8% of ARF patients with acute pancreatitis had isolated renal failure. Other patients had additional failure of other organ systems, 68.4% of whom had multiorgan failure (MOF) before the onset of ARF. In only 8.9% of ARF patients was the renal system the first organ system to fail. Patients with ARF were significantly older, had more preexisting chronic diseases (including chronic renal failure), usually had MOF, and local pancreatic complications relative to these in the group with normal renal function. The development of ARF was directly influenced by severity of acute pancreatitis. The mortality rate in ARF patients was 74.7%, compared to an 7.4% mortality of patients with acute pancreatitis and normal renal function. Preexisting chronic disease, the presence of MOF and their number, local pancreatic complications, and older age of the patients increased mortality in ARF patients. The prognosis of patients with oliguric ARF requiring renal replacement therapy was extremely poor, indicating the importance of prevention of ARF in the patients with acute pancreatitis.     

Urinary excretion of urodilatin in healthy children and children with renal disease

Urodilatin (URO) is a natriuretic peptide isolated from human urine which is thought to be produced by distal tubular cells. We measured urinary URO excretion in 50 healthy children and 23 children with acute (ARF), chronic renal failure (CRF), or hereditary tubular disorders, using a specific radioimmunoassay. The mean URO excreted in these four groups was 56, 45, 94, and 121 fmol/min per 1.73 m², respectively (differences between first three groups not significant). The variation in URO excretion was larger in patients with kidney disease than in controls. There were significant correlations between urinary URO and sodium excretion in controls and CRF, but not in ARF. URO excretion also correlated with urine flow rate in CRF. Although no correlation was found between URO excretion and creatinine clearance, urinary URO was increased in some patients with advanced CRF, which suggests stimulated tubular production to compensate for reduced sodium excretion. In view of the therapeutic potential of URO in renal insufficiency, further study of the renal handling of URO is warranted. Received December 4, 1996; received in revised form and accepted June 13, 1997     

The safety of gadolinium in patients with stage 3 and 4 renal failure.

BACKGROUND: Although there is a well-documented risk of acute renal failure (ARF) with the iodinated contrast agents, intravenous gadolinium-based contrast agents are considered non-nephrotoxic and have been widely used for magnetic resonance imaging (MRI). However, debate continues regarding the safety issue of gadolinium, especially in patients with kidney failure. Therefore, we aimed to evaluate the safety of gadolinium in patients with stage 3 and 4 renal failure as well as risk factors for nephrotoxicity. METHOD: We retrospectively analysed 473 patients with chronic renal failure who underwent angiographic MRI procedures in our centre from February 1999 to March 2005 in whom gadolinium was used as the sole contrast agent at a dose of 0.2 ml/kg. Among them, 91 patients with stage 3 or 4 renal failure according to K/DOQI definition, who had available data in their files, were enrolled in the study. The ARF was defined as an increase of at least 0.5 mg/dl in serum creatinine level over baseline after using gadolinium. RESULTS: Eleven of 91 (52 males, 39 females; median age 59 years; median estimated glomerular filtration rate (eGFR) 33 ml/min/1.73 m2) patients developed ARF (12.1%). The median eGFR was lower in patients with ARF than in those who did not develop ARF. The risk factors for ARF were baseline eGFR, older age, diabetic nephropathy and low baseline haemoglobin and albumin levels. Baseline eGFR and diabetic nephropathy were determined as the independent risk factors in regression analysis. CONCLUSIONS: An ARF can occur after gadolinium-based contrast agents in patients with moderate to severe chronic renal failure. Risk factors for ARF after gadolinium toxicity include diabetic nephropathy and low GFR.     

Acute renal failure and hyperkalaemia associated with cyclooxygenase-2 inhibitors.

BACKGROUND: The renal effects of cyclooxygenase-2 (COX-2) inhibitors have been incompletely elucidated, and acute renal failure (ARF) due to COX-2 inhibitors has been reported. METHODS: In order to determine the causes of ARF and hyperkalaemia in five patients during COX-2 inhibitor therapy, we carefully analysed case studies of consecutive in-patients or out-patients referred to our Renal Division over a 6-month period for ARF and hyperkalaemia who had recently received COX-2 inhibitors. RESULTS: ARF developed 2-3 weeks after COX-2 inhibitor therapy in five patients. The ARF was consistent with pre-renal azotaemia from renal hypoperfusion. Four patients were receiving the loop diuretic, furosemide. Four patients developed hyperkalaemia and decreased serum bicarbonate despite diuretic therapy, and one patient had changes in plasma renin activity and aldosterone levels consistent with reversible hyporeninaemic hypoaldosteronism. Renal failure was reversible after discontinuation of diuretics and COX-2 inhibitors. CONCLUSIONS: COX-2 inhibitors may cause reversible ARF and hyperkalaemia in patients with oedematous conditions treated with low sodium diets and loop diuretics.     

IGF-binding protein-3 fragments in plasma of a child with acute renal failure

The insulin-like growth factors (IGF) -I and -II promote cellular growth and differentiation of various organs. Their growth-stimulating effects are modulated by a family of six IGF-binding proteins (IGFBPs). Altered patterns of intact and fragmented IGFBPs have been reported in serum and urine of children with chronic renal failure (CRF), and it has been suggested that this may contribute to the growth failure observed in these patients. In the present study, a rapid and comprehensive method is presented to analyze IGFBPs and IGFBP fragments in the plasma of a child with acute renal failure (ARF) who had undergone plasmapheresis. The plasma IGF-I and IGFBP-3 levels were drastically reduced. Plasmapheresis filtrate (3 l) was fractionated by cation-exchange chromatography and reversed-phase high-performance liquid chromatography. The fractions obtained were tested by ligand and immunoblotting. In addition to IGFBP-1 and -4 fragments, the majority of IGF-binding polypeptides were IGFBP-3 immunoreactive. N-terminal sequence analysis of a 17-kDa polypeptide revealed the isolation of a C-terminal fragment of IGFBP-3 starting with Lys 160. The IGF-II-binding polypeptide pattern in the ARF plasma resembles the pattern in hemofiltrate from CRF patients, suggesting that similar or identical proteases are involved in IGFBP-3 fragmentation and common mechanisms may lead to the accumulation of the fragments in both diseases.     

Acute renal failure in patients with pre-existing renal dysfunction following coronary artery bypass grafting

BACKGROUND: Pre-existing renal dysfunction predisposes to acute renal failure (ARF) in patients undergoing coronary artery bypass grafting. We assessed the incidence and impact of the development of ARF in this patient population in our unit. METHODS: One-hundred and six patients had a preoperative serum creatinine of >or=0.13 mmol/L and underwent coronary artery bypass grafting in the year 2000. The incidence of ARF (as defined by a >or=50% rise in postoperative serum creatinine), hospitalization days, dialysis requirement, in-hospital and 1-year mortality, and potential risk factors for ARF were recorded. RESULTS: Of the patients recorded, 43/104 (41.35%) developed ARF following coronary artery bypass grafting. Patients with ARF stayed in hospital longer (P < 0.02). Ten out of forty-three patients required some form of dialysis and the in-hospital mortality of the renal failure group was 23% compared to 3.1% in the other group (P < 0.002). One year postoperatively, the group with renal failure had significantly worse survival (71.8% vs 98%P < 0.0001). CONCLUSION: For patients undergoing coronary artery bypass grafting, pre-existing renal dysfunction predisposes to the development of ARF, this is associated with prolonged hospitalization and increased mortality.     

急性肾衰竭患者血清胆碱酯酶变化的意义

目的通过观察急性肾衰竭（ARF）患者血清胆碱酯酶（CHE）的变化，探讨血清CHE与ARF预后的关系，并分析其临床意义。方法将68例ARF患者分为存活组（A组）及死亡组（B组），检测其治疗前后血清CHE，并与40例肾功能正常的原发肾小球疾病患者（M组）和30例健康体检者（N组）比较。结果A组和B组患者血清CHE均较M组和N组降低；而M组与N组间无显著性差异；A组患者治疗后血清CHE恢复，与治疗前CHE相比差异有统计学意义；B组患者治疗后血清CHE持续降低。结论血清CHE可作为ARF的检测物之一，对ARF患者的病情监测和预后判断具有重要的临床意义。     

慢性肾炎致慢性肾衰竭患者心衰发生相关危险因素分析

目的：了解慢性肾炎致慢性肾衰竭患者血压、血红蛋白、血清白蛋白、血脂、血肌酐、电解质及尿素氮、胱抑素C、同型半胱氨酸及高敏C反应蛋白等指标与心力衰竭发生之间的关系,分析并探讨相关危险因素。方法：回顾性分析我院343例慢性肾炎致慢性肾衰竭患者心衰发生及其同期血压等指标变化情况,了解其规律及相互关系。结果：（1）343例患者有77例合并发生心衰（22．4％）,其中19岁～39岁占20．5％,40岁～59岁占22．8％,〉60岁占33．3％;合并发生心衰多为CKD5期患者（97．4％）。（2）血压、血红蛋白、CO2CP、血肌酐、高敏C反应蛋白在有无心衰发生组存在统计学差异（P〈0．01）,其中血压、血肌酐、光抑素C、高敏C反应蛋白等与心衰发生呈负相关（P〈0．05）,而年龄、钙磷、血清白蛋白及血脂、尿素氮、同型半胱氨酸组间无统计学差异。结论：慢性肾炎致慢性肾衰竭患者心力衰竭发生率很高,其发生可能与高血压、贫血、酸中毒、血肌酐及微炎症状态等因素有关。     

Aetiology and outcome of acute and chronic renal failure in infants.

BACKGROUND: The aetiology and outcome of acute (ARF) and chronic renal failure (CRF) in infants were analysed in a retrospective study. METHODS: Between January 1997 and April 2004 all children <1 year of age with a serum creatinine >100 mumol/l at Hannover Medical School were followed up for up to 6 years. One hundred and nineteen children with a serum creatinine >100 mumol/l were identified, 70 infants suffering from ARF and 49 from chronic kidney disease (CKD), stages 3-5. RESULTS: Renal failure was caused in 49/119 (41%) by congenital and in 70/119 (59%) by acquired diseases. The aetiology of ARF (n = 70) included cardiac (27%), prematurity (27%), septic (10%), hepatic (9%), renal (9%) and other (18%) causes. Twelve infants needed transient dialysis treatment. Renal function recovered in all surviving children. The mortality rate was 37%. Causes of death were unrelated to kidney function. Twenty-one of 49 infants with CKD were dialyzed with a median age of 65 days at the start of dialysis, and 23/49 children received a kidney transplant (RTx). The 5-year patient and graft survival for RTx-children of 95.5% was not different from older children. The 5-year patient survival rate of 26 children with CKD without RTx was 63%. The causes of death were parental refusal of therapy in neonates (n = 4) and life-threatening extra-renal comorbidity (n = 3). CONCLUSION: Renal replacement therapy offers good chances of survival in infants without life-threatening comorbidity. Patient survival of infants treated for CKD in the first year of life was comparable to that of older children.     

Differentiation of acute renal failure and chronic renal failure by 2-dimensional analysis of urinary dipeptidase versus serum creatinine

The differential diagnosis of acute renal failure (ARF) and chronic renal failure (CRF) may be possible by measuring urinary dipeptidase (Udpase) activity and serum creatinine (Scr) concentration. When the mass test of 246 individuals was examined on a 2-dimensional plot of Udpase (y-axis) versus Scr (x-axis) with the data obtained from healthy volunteers (n = 189), ARF (n = 19) and CRF (n = 38) patients, the characteristic distribution of each group was obvious. It is summarized by the mean values of healthy volunteers (1.44 +/- 0.39 mg/dL, 1.19 (0.59 mU/mL), ARF (6.04 +/- 5.04 mg/dL, 0.12 +/- 0.08 mU/mL), and CRF patients (8.72 +/- 2.93 mg/dL, 0.81 +/- 0.44 mU/mL). The healthy volunteers are distributed along the y-axis and the ARF patients the x-axis, thus separating the two groups 90 degrees apart. The CRF patients are scattered away from both x-, and y-axis. This 2-dimensional approach is thought to be very useful for the differential diagnosis of ARF suggesting Udpase as a new member of the marker enzymes of renal disease.     

Early Prognostic Factors in Patients with Acute Renal Failure Requiring Dialysis

Purpose. Despite improvements in renal therapy and technology, the mortality rate of patients with acute renal failure (ARF) remains high. Because ARF is a heterogeneous syndrome, occurring in patients with diverse etiologies and comorbid conditions, predicting its outcome is difficult. This study aims to identify early clinical and laboratory prognostic factors, including acute-phase reactants such as C-reactive protein (CRP), fibrinogen, and albumin, in ARF patients requiring dialysis. Material and methods. From June 2002 to March 2004, 61 patients with ARF requiring dialysis at Chang Gung Memorial Hospital, Chiayi, were prospectively analyzed. For each patient, the worst values of prognostic variables 24 hr before starting dialysis were prospectively assessed. Results. Oliguria, low plasma fibrinogen levels, hypotension, cardiac disease, and neoplastic disease were statistically significant in predicting hospital mortality. Using Youden's index, the best cut-off value for plasma fibrinogen in predicting mortality was 300 mg/dL with a sensitivity and specificity of 61% and 96%, respectively. Serum CRP and serum albumin were not predictive of hospital mortality. Conclusion. Early prognostic factors in predicting mortality for patients with ARF requiring dialysis identified by multivariate logistic regression were oliguria, low plasma fibrinogen, hypotension, cardiac disease, and neoplastic disease. Serum CRP and albumin were not predictive of hospital mortality, whereas a plasma fibrinogen level ≤300 mg/dL had 61% sensitivity and 96% specificity in predicting mortality.     

Plasma leptin concentration in patients with acute renal failure

BACKGROUND: Acute renal failure (ARF) is characterized by impaired excretory, endocrine, homeostatic and metabolic function of the kidneys. It is well-known that leptin is an adipose-derived polypeptide hormone which is predominantly biodegraded by the kidneys. Therefore, plasma leptin concentration is increased in chronic renal failure (CRF). However, its' concentrations in patients with ARF were not investigated until now. The aim of the present study was to evaluate plasma leptin concentration in patients with ARF. PATIENTS AND METHODS: 27 patients with ARF (age 44 +/- 4 years, BMI 26.0 +/- 0.9 kg/m2, means +/- SEM, 17 patients 15 M, 2 F recovered kidney function and 10 patients 7 M, 3 F died during the anuric phase), 27 hemodialysis patients (22 M, 5 F; age 45 +/- 2 years; BMI 26.2 +/- 0.8 kg/m2) with chronic renal failure (CRF) and 27 healthy subjects (HS) (22 M, 5 F; age 42 +/- 3 years; BMI 25.9 +/- 0.6 kg/m2) were examined. In patients with ARF, blood samples for plasma leptin and routinely assessed biochemical parameters were withdrawn before the first HD session (I), and in patients who survived a second time 5 days later during the anuric/oliguric phase (II), and a third one during the polyuric phase before discharge of the patient from hospital (III). In patients with CRF all examined parameters were estimated only once before a subsequent HD session. RESULTS: Patients with ARF (before the first HD session) and CRF did not differ significantly with respect to BMI, serum creatinine and blood hydrogen ion concentrations. Plasma leptin level in patients with ARF before the first HD session was similar to values obtained in HS, but significantly lower (p < 0.01) than in patients with CRF (2.5 (1.9 - 8.2) vs. 3.4 (2.5 - 8.3) vs. 8.4 (2.9 - 16.9) ng/ml in ARF, HS and CRF, respectively). There was no significant difference in leptinemia between patients with ARF who survived and who died. In patients with ARF who survived, improvement ofrenal function was accompanied by a slightly (not significant) declining tendency in plasma leptin concentration (5.6 +/- 2.2 vs. 4.8 +/- 1.7 vs. 4.5 +/- 1.3 ng/ml; I, II, III phases of ARF, respectively). CONCLUSIONS: In contrast to hemodialysis patients with chronic renal failure, patients with acute renal failure are characterized by normal plasma leptin concentration. Thus, difference in leptinemia between patients with chronic and acute renal failure seems to be due to preservation of large amounts of active renal parenchyma in ARF patients.     

慢性肾衰竭患者血浆NT—proBNP水平的研究

目的探讨慢性肾衰竭患者血浆脑钠肽前体N末端片段（N—terminal-pro—brain natriuretic prptide，NT-proBNP）水平与慢性肾功能不全之间的关系。方法选择临床诊断慢性肾衰竭患者59例，根据肾小球滤过率将患者分为氮质血症期25例、肾衰竭期20例、尿毒症期14例，对照组20例。检测血浆NT—proBNP水平、测量超声心动图并收集患者临床资料。对比不同肾功能状态患者的血浆NT—proBNP水平差异及其与肾功能损害等临床指标及心脏结构功能改变之间的相关性。结果慢性肾衰竭各期患者血浆NT-proBNP水平明显升高，且与左心室后壁厚度、血磷水平正相关，与左室射血分数呈负相关。结论慢性肾衰竭患者血浆NT-proBNP水平升高，其浓度与患者心脏结构和功能的改变以及肾功能下降有关。血浆NT-proBNP水平可作为慢性肾衰竭患者心血管疾病的生化指标。     

Acute renal failure in patients with acute pancreatitis: prevalence, risk factors, and outcome

A total of 267 consecutive patients presenting with acute pancreatitiswere studied restrospectively. We analysed the collected datato determine the prevalence of acute renal failure (ARF), andfactors significantly predisposing to its occurrence and outcome.The prevalence of ARF in our patients was 16%. Only 2% had isolatedARF. Seventy-three percent of patients with additional organsystem failure suffered ARF after the onset of other organ failure.The number of organ system failure was significantly greaterbefore, compared to after, the development of ARF. Using multiplelogistic regression we found that pre-existing chronic diseaseand cardiovascular and haematological failure were independentrisk factors positively related to the development of ARF, whereassystemic infection was not. Overall mortality from ARF was 81%.Chronic disease, local complications and the presence of additionalorgan system failure and their number significantly increasedmortality in ARF patients. No patients requiring renal replacementtherapy survived. ARF is a common complication of severe acute pancreatitis, butoccurs late in the disease course, and mostly preceded by otherorgan system failure. The prognosis of patients with ARF isextremely poor, indicating that more emphasis should be placedon prevention of ARF.