Renal sonography in bipolar patients on long-term lithium treatment.

PURPOSE: The aim of the study was to analyze sonographic (US) renal findings in lithium-treated bipolar patients and to correlate them with renal function. METHODS: Renal US and renal function tests were performed on 120 patients with bipolar disorder. Ninety patients (30 males, 60 females), aged 36-82 years, had received lithium therapy for an average of 16 years, whereas 30 patients (10 males, 20 females), aged 35-85 years, who had never been exposed to lithium, served as controls. RESULTS: In the lithium-treated group, patients with macrocysts (22%) had poorer renal function with higher creatinine serum concentrations, lower estimated glomerular filtration rates, and lower urine specific gravity, compared with the patients without macrocysts. The US changes characteristic for lithium nephropathy (punctate hyperechoic foci, microcysts < 2 mm, and increased echogenicity) were seen in three patients. These patients had been treated with lithium for more than 20 years and had impaired renal function. Sixteen percent of patients in the control group had macrocysts; however, no correlation between their presence and impaired renal function was found. CONCLUSIONS: The presence of macrocysts in the kidneys of lithium-treated bipolar patients is associated with impaired renal function. The US changes characteristic for lithium nephropathy are rare, and in our study, were only found in patients treated with lithium for 20 years or more. © 2016 Wiley Periodicals, Inc. J Clin Ultrasound 44:354-359, 2016.

The association of glycogen synthase kinase-3beta (GSK-3ß) gene polymorphism with kidney function in long-term lithium-treated bipolar patients.

BACKGROUND: Most bipolar patients experience a reduction in urinary concentrating ability within a few weeks of starting lithium treatment. This phenomenon may be connected with the effect of lithium on the glycogen synthase kinase-3beta (GSK-3ß) present in the renal tubules. The GSK-3ß gene is located on chromosome 3q13 and possesses a functional -50 C/T polymorphism. In the present study, we estimated this polymorphism in a group of long-term lithium-treated patients and assessed its association with various parameters of kidney function, including novel markers of kidney injury such as serum neutrophil gelatinase-associated lipocalin (NGAL) and urinary beta2-microglobulin (ß2-MG). METHODS: The study comprised 78 patients with bipolar mood disorder (25 males, 53 females), aged 36 to 82 (60 ± 11) years. The mean duration of bipolar illness was 6 to 50 (24 ± 10) years, and the patients have been receiving lithium for 5 to 38 (16 ± 9) years. All the patients had the following features, regarded as the phenotypes of kidney functions measured: urine examination for specific gravity evaluation, serum creatinine concentration, and estimated glomerular filtration rate (eGFR) evaluation, as well as the serum concentrations of NGAL and urinary ß2-MG. Genotyping of GSK-3ß gene -50 C/T polymorphism was done by polymerase chain reaction analysis. RESULTS AND DISCUSSION: Thirty-four patients (6 males, 28 females) had the T/T genotype, 37 patients (16 males, 21 females) had the T/C genotype, and 7 patients (3 males, 4 females) had the C/C genotype. Patients homozygous for C allele had significantly higher urine specific gravities (1.019 ± 0.008) compared to the remaining genotypes (1.013 ± 0.007) (p = 0.035), with no influence of the duration of lithium treatment. Other parameters of kidney function (serum creatinine, eGFR, serum NGAL, and urinary ß2-MG levels) were not different between genotypes and, again, were not affected by the duration of lithium treatment. There was no correlation between urine specific gravity and other kidney function parameters. The results of our study indicate that the GSK-3ß genotype may be connected with lithium-induced impairment of renal concentrating ability in long-term lithium-treated bipolar patients. Limitations of the study include small size of the sample, small number of C/C genotype patients, and a lack of multiple testing analysis of genotypic differences in various measures of kidney function.

Novel markers of kidney injury in bipolar patients on long-term lithium treatment.

OBJECTIVES: We assessed kidney function in long-term lithium-treated bipolar patients compared with age-matched patients not taking lithium, including novel markers of kidney injury such as plasma neutrophil gelatinase-associated lipocalin (NGAL) and urinary beta-2 microglobulin (ß2-MG) METHODS: The study comprised 120 patients with bipolar disorder of which 90 (30 males and 60 females) have been receiving lithium for 5-38 (mean 16) years, and 30 (10 males and 20 females) have never been exposed to lithium. RESULTS: Lithium-treated patients, both men and women, showed significantly higher plasma NGAL and urinary ß2-MG and lower urine specific gravity and estimated glomerular filtration rate (eGFR), compared with patients not taking lithium. In these patients, serum NGAL did not correlate with any clinical feature or other parameter of kidney function. Urinary ß2-MG correlated with serum creatinine and eGFR in the whole group of lithium-treated patients and in addition, in males, with duration of illness, duration of lithium treatment, and urine specific gravity. CONCLUSIONS: Lithium treatment causes an impairment of kidney function reflected also by abnormal levels of novel markers of kidney injury. Of these, urinary ß2-MG, as a marker of tubular function seems to be better predictor than serum NGAL in lithium-treated patients because it shows multiple clinical and biochemical correlations, especially in men.

[The effect of long-term lithium treatment on kidney function]. / Wplyw dlugotrwalego podawania litu na czynnosc nerek.

In 1963 it was first demonstrated that long-term lithium administration exerts a "mood-stabilising" effect, preventing recurrences of mania and depression in bipolar affective disorder. Despite the introduction of many other drugs having mood-stabilising effect, lithium still remains the first choice drug for the prophylaxis of affective episodes in mood disorder. Lithium is eliminated nearly exclusively by the kidneys: lithium clearance is proportional to creatinine clearance and is influenced by natriuretic and antinatriuretic factors. Nowadays, nearly 40-year experience with long-term lithium treatment point to a possibility of nephrotoxic effects of this ion. Impaired urinary concentrating ability, which, in a few patients can reach an intensity of diabetes insipidus, can occur after several weeks of lithium administration. Favourable results in the treatment of diabetes insipidus have been obtained with amiloride, the drug which block epithelial sodium channel. However, after 10-20 years of treatment, lithium-induced interstitial nephropathy may be demonstrated in some patients, which, in small proportion of the latter may lead to end-stage renal disease. Lithium-induced hipercalcemia and nephrotic syndrome are rare complications of lithium therapy. In patients on long-term lithium therapy periodic monitoring of kidney function by measuring serum creatinine concentration and glomerular filtration rate is necessary. In case of detecting nephropathy, a discontinuation of lithium sho uld be considered. The patient in whom lithium was discontinued due to nephropathy should remain in nephrological treatment.

Screening for the markers of kidney damage in men and women on long-term lithium treatment.

BACKGROUND: Lithium is the most effective therapeutic modality for the prevention of recurrences in bipolar disorder. An important adverse effect of lithium, especially with long-term treatment, is a possibility of a toxic effect on kidney function. Therefore, the aim of the study was to assess kidney function in a group of long-term lithium-treated patients. MATERIAL/METHODS: The study comprised 80 patients with bipolar mood disorder (26 male, 54 female), aged 60 ± 11 years. They had been receiving lithium for 5-38 (16 ± 9) years. Random urine sample was examined for albumin and creatinine excretion, and urinary albumin to creatinine ratio (UACR) was calculated. Specific gravity of the urine sample was recorded. Serum concentration of creatinine was measured and estimated glomerular filtration rate (eGFR) was calculated. Serum concentration of albumin was also measured. RESULTS: Decreased eGFR values <60 ml/min/1.73 m² were found in 23% of patients, significantly more frequently in men that in women (38% vs. 16%, p=0.04). Elevated UACR values (>30 mg/g) were found in 25% of men and 12% of women, respectively. Serum albumin concentration >52 g/l was detected in 19% of patients (17% of men and 20% of women). Specific gravity of the urine, equal to or below 1.005, was recorded in 21% of men and 14% of women. CONCLUSIONS: The results confirm the opinion that screening for the markers of kidney damage should be performed in long-term lithium-treated patients for identification of persons with impaired kidney function. Male sex seems to be the risk factor for the development of kidney damage during long-term lithium treatment.

Pregnancy in diabetic woman with coexisting hypothyroidism, coronary artery disease and with early onset nephrotic syndrome--a case report.

We present a case of pregnancy in 28-years old nulliparous woman with an over 20-years long history of diabetes, hypothyroidism, diabetic nephropathy with nephrotic syndrome, retinopathy and coronary artery disease treated with PCA prior the pregnancy (class H diabetes, according to White classification).

Urinary excretion of soluble tumour necrosis factor receptor 1 as a marker of increased risk of progressive kidney function deterioration in patients with primary chronic glomerulonephritis.

BACKGROUND: The effects of tumor necrosis factor α (TNF α), a potent proinflammatory cytokine, in the kidneys are mediated by two membrane receptors (TNFR), TNFR1 and TNFR2. The expression of both TNF and TNFRs increases in several kidney diseases and is associated with the shedding of the receptors out of the cell membranes. In an experimental model of glomerulonephritis (GN), elevated concentrations of TNFRs in serum and TNFRs excretion in urine were demonstrated. The aim of this study was evaluation of urinary excretion of TNFR1 and its relationship with the clinical markers of kidney injury in patients with GN. The value of basal urinary TNFR1 excretion as a prognostic indicator of the progression of kidney function impairment was also assessed. MATERIAL AND METHODS: Fifty-five patients with newly diagnosed, biopsy-proven primary GN were included in the study. In all patients, and in 20 healthy subjects, UTNFR1 was measured using an ELISA . In the patients, risk factors of the progression of impairment of kidney function (reduced eCcr, nephrotic syndrome, hypertension and intensity of morphological lesions in the kidneys) were evaluated. The appropriate treatment was then introduced and the patients were in follow-up for 4 years. The progression of kidney function impairment was defined as a reduction of eCcr > 5 mL/min/1.73 m2 /year during follow-up. The association of basal TNFR1 excretion with the progression was evaluated. RESULTS: Urinary excretion of TNFR1 in the patients with GN (4039.2 ± 3801.5 pg/mgCr) was greater than in the healthy subjects (1358.9 ± 927.8 pg/mgCr, P < 0,00002). A significant negative correlation between TNFR1 excretion and eCcr (Sr=0.464, P < 0.01) and a positive correlation between TNFR1 excretion and proteinuria (Sr = 0,463, P < 0.01) were found. In 13 patients, a marked reduction of eCcr was observed during follow-up. Logistic regression analysis revealed that TNFR1 excretion > 3863.3 pg/mgCr predicts progression of renal function impairment along with advanced interstitial fibrosis in the kidney biopsy specimens at presentation. CONCLUSION: Markedly elevated urinary TNFR1 excretion may be considered as a good marker of an activated TNFα-pathway in patients with newly diagnosed GN and as a potentially modifiable risk factor of progressive kidney function impairment.

Elevated urinary fibronectin excretion predicts poor outcome in patients with primary chronic glomerulonephritis.

BACKGROUND/AIMS: Fibronectin (FN) is one of the major matrix proteins in the kidney. The accumulation of FN fragments in inflamed glomeruli could contribute to the progression of renal injury. In the present study, the urinary FN excretion (UFN) was measured for evaluation of its possible role as a prognostic marker in patients with newly diagnosed chronic glomerulonephritis (GN). METHODS: In 55 patients with newly diagnosed biopsy-proven chronic GN, UFN was measured using an enzyme-immunossay kit. The progression of kidney disease was defined as a reduction of the estimated glomerular filtration rate (eGFR) >or=5 ml/min/year during the 4-year follow-up. RESULTS: The mean UFN in patients with GN (245.0 +/- 229.2 ng/mmol creatinine) was higher than in the 19 healthy subjects (100.7 +/- 87.3 ng/mmol creatinine; p < 0.002). No correlations between the initial UFN and eGFR and proteinuria were found. We did not find any association between UFN and the severity of glomerular sclerosis or the intensity of interstitial fibrosis. The progressive fall of eGFR was recorded in 13 patients (progressors). The mean initial UFN was significantly higher in progressors than in nonprogressors (p < 0.01). In logistic regression analysis, the initial high UFN was identified as independent factor predicting kidney function deterioration. CONCLUSION: These results indicate that UFN measured before treatment could serve as an additional prognostic marker of a poor outcome in patients with newly diagnosed primary GN.

Therapeutic equivalence of epoetin zeta and alfa, administered subcutaneously, for maintenance treatment of renal anemia.

INTRODUCTION: The primary objective of the trial was to prove the therapeutic equivalence of epoetin zeta to epoetin alfa when administered subcutaneously for maintaining target hemoglobin (Hb) in patients with renal anemia on chronic hemodialysis. Additional information was provided on the safety and tolerability of epoetin zeta with particular focus on the formation of anti-erythropoietin antibodies. METHODS: A total of 462 patients were randomized to either epoetin zeta or alfa for 28 weeks after an open period of dose adjustment of 12-16 weeks with only epoetin zeta. The aim of treatment was to maintain Hb between 10.0-12.0 g/dL with constant epoetin dosage. Primary endpoints were the mean Hb level and the mean weekly epoetin dosage during the last 4 weeks of treatment. Safety endpoints were the occurrence of anti-erythropoietin antibodies, incidence of Hb levels above 13 g/dL, ratings of tolerability, and adverse events (AEs). RESULTS: The mean Hb level (+/-SD) during the last 4 weeks of treatment was 10.94+/-0.84 g/dL (epoetin zeta) and 11.02+/-0.94 g/dL (epoetin alfa). The 95% confidence interval (CI) (''C0.28 g/dL to 0.12 g/dL) was entirely within the predefined equivalence range (+/-0.5 g/dL). The mean weekly epoetin dosage per body weight over the last 4 weeks of treatment was 97.0+/-94.3 IU/kg/week (epoetin zeta) and 86.0+/-78.0 IU/kg/week (epoetin alfa). The 95% CI (''C8.06 IU/kg/week to 29.96 IU/kg/week) was also within the predefined equivalence range of +/-45 IU/kg/week. The most common AEs were infections and infestations (15.1% of patients on epoetin zeta and 14.8% of patients on epoetin alfa). None of the patients developed anti-erythropoietin antibodies. CONCLUSIONS: Epoetin zeta, administered subcutaneously, is equivalent to epoetin alfa in respect of its clinical efficacy. The safety profile of both products is similar: no unexpected AEs were observed, no patients developed anti-erythropoietin antibodies, and both epoetin preparations were well tolerated.

Effects of bicarbonate/lactate dialysis solution on the inflammatory response of spontaneous peritonitis in rats undergoing chronic peritoneal dialysis.

BACKGROUND: We evaluated the incidence of spontaneous peritonitis as well as the local inflammatory response and macroscopic changes in the peritoneum during the use of a bicarbonate/lactate-buffered (P) solution in comparison to conventional (D) solutions in rats on chronic peritoneal dialysis. METHODS: Sixty-three male Wistar rats were implanted with peritoneal catheters. After 7 days, the animals were randomly divided into 2 experimental groups (32 rats in D, 31 rats in P) and infused twice daily over the following 4 weeks. RESULTS: After 14 and 23 days, rats dialyzed with D had a higher peritonitis rate than those dialyzed with P. The median number of days until peritonitis occurred was 22 days for the rats in the D group and 29 days for the rats in the P group. Spontaneously infected rats dialyzed with the D solution had higher scores for adhesion formation. CONCLUSIONS: In this animal model, dialysis with P delayed the time to the 1st infection, reduced the overall peritonitis rate and reduced peritonitis-associated peritoneal adhesion formation during chronic peritoneal dialysis.

[Nephrological care in Wielkopolska-region of Poland in 2009--realization of the united idea]. / Opieka nefrologiczna w Wielkopolsce w 2009 r.--realizacja spójnej koncepcji.

The establishment of net of the dialysis centers within the distance of 50 km each other, created the basis for realization of united idea for organization of nephrological care in the Wielkopolska-region of Poland. Nephrological care consists of both an integrated methods of the renal replacement therapy: hemodialysis, peritoneal dialysis and kidney transplantation and the screening for chronic kidney disease, its early diagnosis and effective treatment which slow-down the progression of the disease. The nephrological ambulatory, associated with dialysis centers and the nephrological departments with dialysis center and ambulatory play an important role in the integrated nephrological care. As the result of an accessibility of nephrological consultation in the ambulatory located about 25-30 km from the patients home, the nephrological care in Wielkopolska region constantly improves.

Effect of intradialytic intravenous administration of omega-3 fatty acids on nutritional status and inflammatory response in hemodialysis patients: a pilot study.

OBJECTIVE: Because omega-3 polyunsaturated fatty acids (PUFAs) may have anti-inflammatory properties, we tested the hypothesis that intradialytic, intravenous omega-3 PUFA treatment, combined with dietary supplementation, can modify the inflammatory response to dialysis, and influence the nutritional status of hemodialysis (HD) patients. METHODS: Twenty HD patients with serum albumin at <39g/L received 100mL of 10% omega-3 PUFA emulsion during 11 consecutive HD sessions. Body mass index (BMI), serum albumin, transferrin, and lipids were measured before and after treatment. Serum interleukin-6 (IL-6) and high-sensitivity C-reactive protein (hsCRP) levels were determined before and after the HD session at baseline and after 4 weeks of treatment. RESULTS: No adverse events were evident during the study. There were no significant changes in BMI, serum albumin, transferin, total and low-density lipoprotein cholesterol, and triglycerides. Predialysis hsCRP and IL-6 did not change. There was a significant increase in hsCRP (P=.01) and a tendency of IL-6 concentration to increase during the HD session before treatment (P=.067). In contrast, neither hsCRP (P=.21) nor IL-6 (P=.26) changed during the final HD session. Neither urea reduction ratio nor Kt/V changed significantly during the study, but the normalized protein catabolic ratio increased after treatment (P=.003). CONCLUSIONS: Short-term parenteral administration of omega-3 PUFA is safe and well-tolerated by HD patients. The intervention does not significantly influence markers of inflammation or change the nutritional status of chronic HD patients, but it may attenuate the inflammatory response to HD sessions.

Early detection of chronic kidney disease: results of the PolNef study.

BACKGROUND: Continuous increase in the number of patients with end-stage renal disease demands early detection of chronic kidney disease (CKD). The aim of the present study was to diagnose CKD in its earliest stages in a randomly selected population using a diagnostic algorithm developed by the working group. METHODS: An algorithm for the diagnostic procedure was created to identify patients with CKD requiring further nephrological care. Randomly chosen adult inhabitants of a city with a population of 60,000 were invited to participate in this study. Screening procedures included a microalbuminuria dipstick test accompanied by blood pressure measurement and medical questionnaire. In further diagnosis of CKD, estimated glomerular filtration rate (eGFR), albumin concentration in urine, urinalysis and ultrasound examination were used according to the algorithm. Multivariate logistic regression was performed to identify associations between participants' characteristics and albuminuria. RESULTS: Out of 9,700 invited subjects, 2,471 individuals participated in the PolNef study. Albuminuria was detected in 15.6% of the investigated population using the dipstick test and thereafter confirmed in 11.9% by the turbidimetric method. The modeling of multivariate logistic regression indicated the following independent predictors of albuminuria: male sex, diabetes, nocturia and hypertension. For people without diabetes and without hypertension, nocturia independently predicted detection of albuminuria. 481 people received a consultation with a nephrologist, and 96% of them were recognized as having CKD. At least 9% of patients with CKD had eGFR by MDRD <60 ml/min/1.73 m(2). Six persons were referred for further treatment because of newly diagnosed kidney tumor. CONCLUSIONS: CKD in early stages occurs frequently in the studied population. The proposed diagnostic algorithm seems to be a powerful tool to identify subjects at risk of CKD. The role of nocturia as an independent predictor of albuminuria, both in the general population and in people without diabetes or hypertension, should be further examined.

Effect of membrane permeability on survival of hemodialysis patients.

The effect of high-flux hemodialysis membranes on patient survival has not been unequivocally determined. In this prospective, randomized clinical trial, we enrolled 738 incident hemodialysis patients, stratified them by serum albumin < or = 4 and >4 g/dl, and assigned them to either low-flux or high-flux membranes. We followed patients for 3 to 7.5 yr. Kaplan-Meier survival analysis showed no significant difference between high-flux and low-flux membranes, and a Cox proportional hazards model concurred. Patients with serum albumin < or = 4 g/dl had significantly higher survival rates in the high-flux group compared with the low-flux group (P = 0.032). In addition, a secondary analysis revealed that high-flux membranes may significantly improve survival of patients with diabetes. Among those with serum albumin < or = 4 g/dl, slightly different effects among patients with and without diabetes suggested a potential interaction between diabetes status and low serum albumin in the reduction of risk conferred by high-flux membranes. In summary, we did not detect a significant survival benefit with either high-flux or low-flux membranes in the population overall, but the use of high-flux membranes conferred a significant survival benefit among patients with serum albumin < or = 4 g/dl. The apparent survival benefit among patients who have diabetes and are treated with high-flux membranes requires confirmation given the post hoc nature of our analysis.

The Comparison of the Podocyte Expression of Synaptopodin, CR1 and Neprilysin in Human Glomerulonephritis: Could the Expression of CR1 be Clinically Relevant?

Podocytes are considered as the most important cells that determine loss of structure and function of the glomerular filter. We compared the expression of three podocyte markers, i.e.: synaptopodin (SYN), CR1 and neprilysin (NEP) in 107 patients with different forms of glomerulonephritis (GN) and 5 normal kidneys (NK). A quantitative immunohistochemistry was applied to evaluate the expression of podocyte proteins. The results were related with serum creatinine (Scr), estimated glomerular filtration rate (eGFR) and urinary protein. We observed the reduction in the podocyte expression of NEP, SYN and CR1 in proliferative and non-proliferative forms of GN. Interestingly, in mesangial proliferative GN (MesPGN), the expression of SYN and CR1 was lower in IgA-MesPGN than in non-IgA-MesPGN (p<0.005 and p<0.02, respectively). In all the patients, the expression of NEP and SYN was positively related (r=0.53, p=0.02) as that of NEP and CR1 (r=0.39, p=0.04). Yet, clinical correlations with Scr (r=-0.33, p=0.03) and eGFR (r=0.26, p=0.05) were obtained only with respect to CR1. In conclusion, SYN, CR1 and NEP may be used as markers of podocyte loss in patients with GN. However, in agreement with previous studies, the clinical relevance draws a special attention to the expression of CR1.

CD52 gene polymorphism and its potential effect on the response to alemtuzumab in renal transplant recipients.

CD52 is a small glycopeptide leukocyte antigen present on selected subpopulations of human cells. From the clinical point of view this protein is an important target for therapeutic interventions aimed at leukocyte depletion in hematological malignancies and post-transplant immunosuppression. Recently, two variants of CD52--rs1071849 (A119G; Asn40Ser) and rs17645 (A123G; I1e41Met)--were discovered. We now report on the distribution of these variants in kidney graft recipients and controls. Our bioinformatics findings suggest that CD52 polymorphism may affect the efficiency of GPI anchor formation and thus may indirectly alter the response to anti-CD52 agents.

Comparison of the therapeutic effects of epoetin zeta and epoetin alpha in the correction of renal anaemia.

OBJECTIVE: To assess the therapeutic equivalence of epoetin zeta and epoetin alpha for correction of haemoglobin (Hb) concentration in patients with anaemia and chronic kidney disease (CKD) stage 5 maintained on haemodialysis. STUDY DESIGN: In total, 609 patients with CKD and anaemia (Hb < 9 g/dL) were randomly assigned to receive either epoetin zeta or epoetin alpha intravenously, one to three times per week for 24 weeks. Dosing was titrated individually to achieve a stable, target Hb concentration of 11-12 g/dL. Primary endpoints were the mean weekly dose of epoetin per kilogram of body weight and mean Hb concentration during the last 4 weeks of treatment. Safety endpoints were the occurrence of anti-erythropoietin antibodies, ratings of tolerability and adverse events (AEs). RESULTS: Mean (+/- standard deviation [SD]) Hb concentration over the last 4 weeks of treatment was 11.61 +/- 1.27 g/dL for patients receiving epoetin zeta, compared with 11.63 +/- 1.37 g/dL for patients receiving epoetin alpha (95% confidence interval [CI]: -0.25 to 0.20 g/dL). Mean (+/- SD) epoetin zeta weekly dose over the last 4 weeks of treatment was 182.20 +/- 118.11 IU/kg/wk, compared with 166.14 +/- 109.85 IU/kg/wk for epoetin alpha (95% CI: -3.21 to 35.34 IU/kg/wk). The most commonly reported AEs (> 5% of patients) were infections and infestations (12.5% and 12.8% of patients treated with epoetin zeta and epoetin alpha, respectively) and vascular disorders (8.5% and 8.9%, respectively). No patients developed neutralizing anti-erythropoietin antibodies. CONCLUSIONS: Epoetin zeta, administered intravenously, is therapeutically equivalent to epoetin alpha in the correction of low Hb concentration in patients with CKD undergoing haemodialysis. No unexpected AEs were seen and both epoetin zeta and epoetin alpha were well tolerated.

The MPO Study: just a European HEMO Study or something very different?

Although results from observational and epidemiological studies suggested a survival benefit associated with high-flux hemodialysis, conclusive evidence from prospective randomized clinical trials has been lacking. Both the HEMO Study in the USA and the Membrane Permeability Outcome Study (MPO Study) in Europe are randomized studies investigating the effect of high- and low-flux hemodialysis on patient outcomes, even though there were some significant differences in the design of the two studies. An earlier randomized clinical trial could not show differences on patient survival between patient groups being treated with membranes of different material and permeability, but this trial was not designed specifically to examine this particular endpoint. Based on these previous experiences, the MPO Study addressed a hemodialysis patient population which was considered to be more susceptible to the intervention with high-flux dialysis. To identify these patients with an elevated risk, low serum albumin levels were chosen as an indicator; low serum albumin is associated with malnutrition, inflammation, atherosclerosis, and with increased risk of morbidity and mortality. Together with low serum albumin, patients had to be new to dialysis to be selected for the MPO Study. These particular considerations on patient selection, together with additional methodological refinements in the study design allow the conclusion that the MPO Study is valid on its own rather than being a European version of the HEMO Study.

Effect of preload reduction on sonographic myocardial integrated backscatter.

PURPOSE: Sonographic myocardial tissue characterization with integrated backscatter (IBS) is affected by both structural and functional properties of the myocardium. The aim of the present study was to investigate the effect of preload reduction by hemodialysis (HD) on IBS measurements. METHODS: Fifty-two patients on maintenance HD underwent echocardiography before and after a routine HD session. Measurements included the variation of IBS during the cardiac cycle (CV-IBS) and calibrated IBS (cal-IBS). RESULTS: After HD, there were significant reductions in left ventricular end-diastolic and end-systolic dimensions and left atrial diameter. There was a reduction in stroke volume and LV ejection fraction consistent with a reduction in preload. Furthermore, CV-IBS was significantly lower after HD (7.9 +/- 2.2 versus 6.9 +/- 1.8 dB, 7.0 +/- 2.1 versus 6.2 +/- 1.9 dB, and 9.0 +/- 2.6 versus 8.1 +/- 2.0 dB [p < 0.01], respectively, in the left anterior, lateral, and inferior wall of the ventricle). Cal-IBS remained unchanged after dialysis compared with baseline. CV-IBS and ultrafiltration volume were significantly correlated. CONCLUSION: HD leads to a decrease in CV-IBS that appears to be preload-dependent. This finding is in concordance with diminished left ventricular performance during HD.