Effective elimination of high-dose methotrexate by repeated hemodiafiltration and high-flux hemodialysis in patients with acute kidney injury.

INTRODUCTION: Acute kidney injury (AKI) after high dose methotrexate (HD-MTX) is associated with delayed MTX-excretion and life-threatening toxicity. Glucapridase, the recommended therapy, is expensive and not always available. CASE SERIES: We describe 3 cases (69, 67, 73 years) with diffuse large B-cell lymphoma who developed AKI and early-onset severely delayed MTX elimination after HD-MTX. MTX serum concentrations were 101 and 69 µmol/L at 24 h after administration in two patients and 34 µmol/L at 32 h in the third. MANAGEMENT AND OUTCOME: Since glucarpidase was unavailable, we performed daily high-flux hemodialysis (HF-HD) or online hemodiafiltration (HDF) sessions (median duration, 6 h). The median serum MTX elimination half-life during HDF/HF-HD sessions was similar in all patients (median, 4.4 h; IQR, 3.8-5.3 h), but serum MTX concentrations rebounded after each dialysis by a median of 40% of the trough concentrations. The three patients underwent multiple dialysis sessions, until MTX serum concentrations remained sufficiently low to be neutralized by leucovorin. Only 1 patient developed severe pancytopenia, and renal function normalized in all patients after 3-6 weeks. DISCUSSION: In conclusion, when glucarpidase is unavailable or delayed, early, repeated and prolonged HDF/HF-HD effectively enhance MTX elimination and prevent toxicity in patients with AKI and severely delayed MTX elimination after HD-MTX.

[HEMODIALYSIS: PRESENT INNOVATIONS FOR PATIENTS' FUTURE].

INTRODUCTION: End-stage renal disease (ESRD) is a major cause of morbidity and mortality worldwide. Survival of ESRD patients depends on renal replacement therapies, such as kidney transplantation and dialysis. Due to the shortage of potential kidney donors and patients' comorbidities, dialysis is the major therapeutic option offered to such patients. In this review, recent advances in hemodialysis and hemodiafiltration, and their potential impact on improving patient survival will be discussed.

The syndrome of inappropriate antidiuretic hormone secretion: Distribution and characterization according to etiologies.

PURPOSE: To determine the distribution of etiologies for the syndrome of inappropriate antidiuretic hormone secretion (SIADH) in hospitalized patients and to characterize patients according to the different etiologies. METHODS: A single-center retrospective study including all patients diagnosed with SIADH in a large community hospital and tertiary center between 1.1.2007 and 1.1.2013. Two physicians reviewed every patient's medical file for predetermined relevant clinical data. RESULTS: The study cohort included 555 patients. The most common etiologies were malignancies and medication-induced SIADH, followed by idiopathic SIADH, pulmonary infections, pain and nausea, and central nervous system (CNS) disorders. Subgroup analysis according to etiology showed that CNS disorders were associated with more severe episodes of SIADH. Patients with idiopathic SIADH were older than patients with a specific diagnosis, had a lower urine osmolality, and required less treatment with hypertonic saline. Long-term survival was determined primarily by SIADH etiology rather than hyponatremia severity, with hazard ratios for death of up to 7.31 (95% CI 4.93-10.82, p<0.001) for patients with malignancy-associated SIADH as compared to patients with idiopathic SIADH. Hyponatremia grade at short-term follow-up was also predictive for long-term survival (HR 1.42 per grade, 95% CI 1.21-1.66, p<0.001). CONCLUSIONS: Patients with SIADH have different characteristics and a different prognosis according to SIADH etiology. Serum sodium concentration at short-term follow-up is predictive of long-term survival. These findings might have diagnostic and treatment-related implications.

GFR in Patients with ß-Thalassemia Major.

BACKGROUND AND OBJECTIVES: Patients with ß-thalassemia major (TM) may have tubular dysfunction and glomerular dysfunction, primarily hyperfiltration, based on eGFR. Assessment of GFR based on serum creatinine concentration may overestimate GFR in these patients. This study sought to determine GFR by using inulin clearance and compare it with measured creatinine clearance (Ccr) and eGFR. DESIGN, SETTING, PARTICIPANTS & MEASUREMENTS: Patients followed up in an Israeli thalassemia clinic who had been regularly transfused for years and treated with deferasirox were included in the study. They were studied by inulin clearance, Ccr, the CKD Epidemiology Collaboration and the Modification of Diet in Renal Disease equations for eGFR, and the Cockcroft-Gault estimation for Ccr. Expected creatinine excretion rate and tubular creatinine secretion rate were calculated. RESULTS: Nine white patients were studied. Results, given as medians, were as follows: serum creatinine was 0.59 mg/dl (below normal limits); GFR was low (76.6 ml/min per 1.73 m(2)) and reached the level of CKD; Ccr was 134.9 ml/min per 1.73 m(2), higher than the GFR because of a tubular creatinine secretion rate of 30.3 ml/min per 1.73 m(2) (this accounted for 40% of the Ccr); and eGFR calculated by the CKD Epidemiology Collaboration and Modification of Diet in Renal Disease equations and Cockcroft-Gault-estimated Ccr were 133, 141, and 168 ml/min per 1.73 m(2), respectively. These latter values were significantly higher than the GFR, reaching the hyperfiltration range, and indicated that the estimation techniques were clinically unacceptable as a method for measuring kidney function compared with the GFR according to Bland and Altman analyses. CONCLUSIONS: Contrary to previous reports, patients in this study with TM had normal or reduced GFR. The estimating methods showed erroneous overestimation of GFR and were clinically unacceptable for GFR measurements in patients with TM by Bland and Altman analysis. Therefore, more accurate methods should be used for early detection of reduced GFR and prevention of its further decline toward CKD in these patients.

A longitudinal assessment of the natural rate of decline in renal function with age.

BACKGROUND: Cross-sectional studies have long suggested that renal function declines with age. Longitudinal studies regarding this issue are limited. METHODS: We retrospectively analyzed a database of subjects attending a screening center in Israel between the years 2000-2012. Only subjects with normal estimated glomerular filtration rate (eGFR) were included. eGFR was assessed consequently at 5 or more yearly visits. The rate of decline in GFR with age was assessed in healthy subjects and in subjects with comorbidities. RESULTS: The cohort included 2693 healthy subjects and 230 subjects with different comorbidities. Mean (±standard error) annual rate of decline in eGFR in healthy subjects was 0.97 ± 0.02 ml/min/year/1.73 m(2). This decline increased significantly from 0.82 ± 0.22 in age-group 20-30 years to 0.84 ± 0.08, 1.07 ± 0.08 and 1.15 ± 0.12 ml/min/year/1.73 m(2) in age groups 31-40, 41-50 and 50 years and older respectively (p < 0.001). No correlation was found between the annual decline in eGFR and body mass index. In subjects with hypertension, diabetes mellitus, impaired fasting glucose or combined comorbidity the decline in eGFR was 1.12 ± 0.12, 0.77 ± 0.16, 0.85 ± 0.17, and 1.18 ± 0.26 ml/min/year/1.73 m(2) respectively. CONCLUSIONS: This large longitudinal study provides new data on the decrease in eGFR with age. Accurate prediction of the natural rate of GFR decline might be used to distinguish between normally aging kidneys and those with chronic disease. This approach could avoid unnecessary diagnostic procedures in the former and facilitate appropriate treatment in the latter.

Association between the body mass index and chronic kidney disease in men and women. A population-based study from Israel.

BACKGROUND: Any association between the body mass index (BMI) and chronic kidney disease (CKD) has so far proved inconclusive. Most studies have estimated glomerular filtration rate (eGFR) using the Modification of Diet in Renal Disease (MDRD) equation. This has recently been replaced by the more accurate Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation. METHODS: In a cross-sectional study, data from a screening centre in Israel, n = 21880 (32% women) were used to assess the prevalence of CKD defined as eGFR < 60 mL/min/1.73 m(2) in relation to BMI categories. The CKD-EPI equation was used to assess the eGFR. RESULTS: CKD was found in 167 men and 45 women. Subjects with a BMI of 25-29.9 kg/m(2), compared with those with a BMI of <25 kg/m(2), had an odds ratio (OR; 95% confidence intervals) for CKD of 1.8 (1.2-2.7) and 3.4 (1.5-7.7) for men and women, respectively. Subjects with a BMI of 30-35 kg/m(2) had an OR of 2.5 (1.6-4.0) and 4.5 (1.7-11.7) for men and women, respectively. In comparable data, for subjects with a BMI > 35 kg/m(2) the OR was 2.7 (1.3-5.5) and 15.4 (6.4-36.7) for men and women, respectively. After multivariate adjustment for age, hypertension and diabetes mellitus, no association was found in men yet it persisted for women. This correlation in women, between the BMI and CKD, was attributed to the subcategory of severely obese women with a BMI of >35 kg/m(2). CONCLUSIONS: Our study is the first to suggest that morbid obesity may be an independent factor related to CKD in women.

Proximal tubular hypertrophy and enlarged glomerular and proximal tubular urinary space in obese subjects with proteinuria.

BACKGROUND: Obesity is associated with glomerular hyperfiltration, increased proximal tubular sodium reabsorption, glomerular enlargement and renal hypertrophy. A single experimental study reported an increased glomerular urinary space in obese dogs. Whether proximal tubular volume is increased in obese subjects and whether their glomerular and tubular urinary spaces are enlarged is unknown. OBJECTIVE: To determine whether proximal tubules and glomerular and tubular urinary space are enlarged in obese subjects with proteinuria and glomerular hyperfiltration. METHODS: Kidney biopsies from 11 non-diabetic obese with proteinuria and 14 non-diabetic lean patients with a creatinine clearance above 50 ml/min and with mild or no interstitial fibrosis were retrospectively analyzed using morphometric methods. The cross-sectional area of the proximal tubular epithelium and lumen, the volume of the glomerular tuft and of Bowman's space and the nuclei number per tubular profile were estimated. RESULTS: Creatinine clearance was higher in the obese than in the lean group (P=0.03). Proteinuria was similarly increased in both groups. Compared to the lean group, the obese group displayed a 104% higher glomerular tuft volume (P=0.001), a 94% higher Bowman's space volume (P=0.003), a 33% higher cross-sectional area of the proximal tubular epithelium (P=0.02) and a 54% higher cross-sectional area of the proximal tubular lumen (P=0.01). The nuclei number per proximal tubular profile was similar in both groups, suggesting that the increase in tubular volume is due to hypertrophy and not to hyperplasia. CONCLUSIONS: Obesity-related glomerular hyperfiltration is associated with proximal tubular epithelial hypertrophy and increased glomerular and tubular urinary space volume in subjects with proteinuria. The expanded glomerular and urinary space is probably a direct consequence of glomerular hyperfiltration. These effects may be involved in the pathogenesis of obesity-related renal disease.

The effect of cardiac angiography timing, contrast media dose, and preoperative renal function on acute renal failure after coronary artery bypass grafting.

OBJECTIVE: Our objective was to assess the effect of the timing of cardiac angiography, contrast media dose, and preoperative renal function on the prevalence of acute renal failure after cardiac surgery. METHODS: Data on 395 consecutive patients who underwent coronary artery bypass grafting were prospectively collected. Creatinine clearance was estimated by the Cockcroft-Gault equation. Patients were divided into 3 groups according to the time between cardiac angiography and surgery (group A, < or = 1 day; group B, > 1 day and < or = 5 days; group C, > 5 days). Patients who underwent a salvage operation or were receiving dialysis before surgery were excluded. Acute renal failure was defined as 25% decrease from baseline of estimated creatinine clearance and estimated creatinine clearance of 60 mL/min or less on postoperative day 3. Owing to differences in preoperative characteristics between groups, propensity score analysis was used to adjust those differences. RESULTS: Acute renal failure developed in 13.6% of patients. Hospital mortality was 3.3% and was higher in patients in whom acute renal failure developed (22%) versus those in whom it did not (0.3%; P < .001). Multivariable analysis identified preoperative estimated creatinine clearance of 60 mL/min or less (odds ratio [OR], 7.1), operation within 24 hours of catheterization (OR = 3.7), use of more than 1.4 mL/kg of contrast media (OR = 3.4), lower hemoglobin level (OR = 1.3), older age (OR = 1.1), and lower weight (OR = 0.95) as independent predictors of postoperative acute renal failure. Analysis of interaction between contrast dose and time of surgery revealed that high contrast dose (>1.4 mL/kg) predicted acute renal failure if surgery was performed up to 5 days after angiography. CONCLUSIONS: Whenever possible, coronary bypass grafting should be delayed for at least 5 days in patients who received a high contrast dose, especially if they also have preoperative reduced renal function.

Three-day vs longer duration of antibiotic treatment for cystitis in women: systematic review and meta-analysis.

PURPOSE: We performed a meta-analysis to ascertain the efficacy and safety of the currently practiced 3-day antibiotic therapy for cystitis versus prolonged therapy (5 days or longer) to relieve symptoms and to achieve bacteriological cure. METHODS: The Cochrane Library, the Cochrane Renal Group's Register of trials, EMBASE and MEDLINE were searched to identify all randomized controlled trials comparing 3-day oral antibiotic therapy with prolonged therapy (5 days and longer) for uncomplicated cystitis in adult non-pregnant women. Two reviewers independently applied selection criteria, performed quality assessment, and extracted data. Relative risks (RR) with their 95% confidence intervals (CI) were estimated; a fixed effect model was used. An intention-to-treat analysis was performed whenever possible. RESULTS: Thirty-two trials and 9605 patients met inclusion criteria. For symptomatic failure rates no difference between 3-day and prolonged antibiotic regimens was found at short term (RR 1.16, 95% CI: 0.96-1.41) and long-term follow-up (RR 1.17, 95% CI: 0.99-1.38). Three-day treatment was less effective than prolonged therapy in preventing bacteriological failure, relative risk 1.37 (95% CI: 1.07-1.74) for short-term follow-up, and 1.47 (95% CI: 1.22-1.77) for long-term follow-up. Adverse effects were more common in the prolonged therapy group (RR 0.83, 95% CI: 0.79-0.91). The results were consistent for subgroup and sensitivity analyses. CONCLUSION: Antibiotic therapy for 3 days is similar to prolonged therapy in achieving symptomatic cure for cystitis, while the prolonged treatment is more effective in obtaining bacteriological cure.

Spontaneous DNA repair in human peripheral blood mononuclear cells.

DNA molecules are constantly damaged during mitosis and by oxygen-free radicals produced by either cellular metabolism or by external factors. Populations at risk include patients with cancer-prone disease, patients under enhanced oxidative stress, and those treated with immunosuppressive/cytotoxic therapy. The DNA repair process is crucial in maintaining the genomal DNA integrity. The aim of this study was to evaluate spontaneous DNA repair capacity of peripheral blood mononuclear cells (PBMC) from normal blood donors. PBMC DNA repair ability represents DNA repair by other tissues as well. It is shown in the present study that in vitro incorporation of [3H]thymidine in non-stimulated PBMC expresses the ability of the cells to repair DNA damage. This method was validated by double-stranded DNA measurements. Both catalase and Fe2+ increased DNA repair, the former by preventing re-breakage of newly repaired DNA and the latter by introducing additional DNA damage, which enhanced DNA repair. Better understanding of DNA repair processes will enable to minimize DNA damage induced by oxidative stress.