Impaired vascular function contributes to exercise intolerance in chronic kidney disease.

BACKGROUND: Exercise intolerance is an important feature in patients with chronic kidney disease (CKD) and is prognostic for both increased morbidity and mortality. Little is known about the underlying mechanisms in predialysis CKD. This study aimed to gain more insight into the role of vascular dysfunction in the exercise intolerance of predialysis CKD. In addition, vascular-related microRNAs (miRNAs)-as epigenetic regulators of exercise capacity-were analysed. METHODS: Sixty-three patients with CKD stages 1-5 and 18 healthy controls were included. Peak oxygen consumption (VO2peak) was determined by cardiopulmonary exercise testing, endothelial function by flow-mediated dilation (FMD) and arterial stiffness by carotid-femoral pulse wave velocity (PWV). Plasma miRNA levels (miR-21, miR-126, miR-146a, miR-150 and miR-210) were quantified by quantitative RT-PCR. RESULTS: VO2peak was already impaired in mild CKD (stages 1-3A) and significantly correlated with estimated glomerular filtration rate (eGFR; r = 0.525, P < 0.001). Likewise, both FMD and PWV were significantly correlated with eGFR (r = 0.319, P = 0.007 and r = -0.365, P = 0.001, respectively). In multiple regression analysis, PWV remained one of the strongest independent determinants of VO2peak (ß = -0.301, P = 0.01). Of the studied miRNA, circulating levels of miR-146a and miR-150 correlated with eGFR, PWV and VO2peak, but the association with the latter was lost when correcting for PWV. CONCLUSIONS: Arterial stiffness contributes to the observed reduced aerobic capacity in predialysis CKD, independent of age, haemoglobin levels and endothelial function and represents a promising therapeutic target for improving exercise capacity in this population. Future work is required to elucidate why higher circulating levels of miR-146a and miR-150 are associated with impaired renal function and increased arterial stiffness.

Plasma levels of microRNA in chronic kidney disease: patterns in acute and chronic exercise.

Exercise training is an effective way to improve exercise capacity in chronic kidney disease (CKD), but the underlying mechanisms are only partly understood. In healthy subjects (HS), microRNA (miRNA or miR) are dynamically regulated following exercise and have, therefore, been suggested as regulators of cardiovascular adaptation to exercise. However, these effects were not studied in CKD before. The effect of acute exercise (i.e., an acute exercise bout) was assessed in 32 patients with CKD and 12 age- and sex-matched HS (study 1). miRNA expression in response to chronic exercise (i.e., a 3-mo exercise training program) was evaluated in 40 CKD patients (study 2). In a subgroup of study 2, the acute-exercise induced effect was evaluated at baseline and at follow-up. Plasma levels of a preselected panel miRNA, involved in exercise adaptation processes such as angiogenesis (miR-126, miR-210), inflammation (miR-21, miR-146a), hypoxia/ischemia (miR-21, miR-210), and progenitor cells (miR-150), were quantified by RT-PCR. Additionally, seven miRNA involved in similar biological processes were quantified in the subgroup of study 2. Baseline, studied miRNA were comparable in CKD and HS. Following acute exercise, miR-150 levels increased in both CKD (fold change 2.12 ± 0.39, P = 0.002; and HS: fold change 2.41 ± 0.48 P = 0.018, P for interaction > 0.05). miR-146a acutely decreased in CKD (fold change 0.92 ± 0.13, P = 0.024), whereas it remained unchanged in HS. Levels of miR-21, miR-126, and miR-210 remained unaltered. Chronic exercise did not elicit a significant change in the studied miRNA levels. However, an acute exercise-induced decrease in miR-210 was observed in CKD patients, only after training (fold change 0.76 ± 0.15). The differential expression in circulating miRNA in response to acute and chronic exercise may point toward a physiological role in cardiovascular adaptation to exercise, also in CKD.

Effect of Moderate Aerobic Exercise Training on Endothelial Function and Arterial Stiffness in CKD Stages 3-4: A Randomized Controlled Trial.

BACKGROUND: Evidence of a beneficial effect of exercise training on mediators of vascular disease is accumulating in chronic kidney disease (CKD), but its effect on vascular function in vivo still has to be established. The present study was designed to investigate whether a formal aerobic exercise training program improves peripheral endothelial function in patients with CKD stages 3 to 4. STUDY DESIGN: Randomized controlled trial with a parallel-group design. SETTING & PARTICIPANTS: 48 patients with CKD stages 3 to 4 without established cardiovascular disease were randomly assigned to either an exercise training program or usual care. 40 patients completed the study (exercise training, 19; usual care, 21). INTERVENTION: The 3-month home-based aerobic training program consisted of 4 daily cycling sessions of 10 minutes each at a target heart rate, calculated as 90% of the heart rate achieved at the anaerobic threshold. Patients in the usual-care group were given standard therapy. OUTCOMES: The primary outcome was peripheral endothelial function. Secondary outcomes were aerobic capacity, arterial stiffness, numbers of endothelial (EPCs) and osteogenic progenitor cells (OPCs), migratory function of circulatory angiogenic cells, and health-related quality of life. MEASUREMENTS: Endothelial function was assessed with flow-mediated dilation of the brachial artery, aerobic capacity by peak oxygen uptake (VO(2peak)), arterial stiffness by carotid-femoral pulse wave velocity, numbers of EPCs and OPCs by flow cytometry, circulatory angiogenic cell function by an in vitro migratory assay, and quality of life by the Kidney Disease Quality of Life-Short Form questionnaire. RESULTS: Exercise training significantly improved VO(2peak) and quality of life, but not in vivo vascular function (flow-mediated dilation and carotid-femoral pulse wave velocity) or cellular markers for vascular function (EPC and OPC count and circulatory angiogenic cell migratory function). LIMITATIONS: Short duration and intermittent nature of the exercise intervention. CONCLUSIONS: In patients with CKD stages 3 to 4 without overt cardiovascular disease, 3 months of aerobic exercise training improved VO(2peak) and quality of life, without altering endothelial function or arterial stiffness.

Magnesium loss in cyclosporine-treated patients is related to renal epidermal growth factor downregulation.

BACKGROUND: Cyclosporine (CsA) treatment is associated with hypomagnesaemia due to a renal Mg(2+) leak. In animal studies a role for the Mg(2+) channel TRPM6 localized in the distal convoluted tubule and stimulated by epidermal growth factor (EGF) is suggested. We hypothesize that CsA-induced hypomagnesaemia is due to a renal magnesium leak, also in patients, resulting from a downregulation of the renal EGF production, thereby inhibiting the activation of TRPM6. METHODS: Renal transplant patients treated with CsA (n = 55) and 35 chronic kidney disease (CKD) patients were included. At three time points, with an interval of at least 1 month, blood and urine samples were taken to determine creatinine, Mg(2+), sodium and EGF. RESULTS: Serum Mg(2+) was significantly lower in the CsA group versus the CKD group with significantly more CsA-treated patients developing hypomagnesaemia. Although the fractional excretion (FE) Mg(2+) did not differ significantly between the two groups, subanalysis of the patients with hypomagnesaemia showed a significantly higher FE Mg(2+) in CsA-treated patients compared with CKD patients (P = 0.05). The urinary EGF excretion was significantly decreased in the CsA group and was a predictor of the FE Mg(2+) in the two groups. Serum sodium was significantly decreased in the CsA group simultaneously with an increased FE Na(+). CONCLUSIONS: In CsA-treated patients, the association of a low urinary EGF excretion and a decreased renal Mg(2+) reabsorption is in accordance with in vitro and animal studies. In the whole study population, log urinary EGF excretion is an independent predictor of the FE Mg(2+), supporting the role of EGF in magnesium reabsorption.

Acute exercise-induced response of monocyte subtypes in chronic heart and renal failure.

PURPOSE: Monocytes (Mon1-2-3) play a substantial role in low-grade inflammation associated with high cardiovascular morbidity and mortality of patients with chronic kidney disease (CKD) and chronic heart failure (CHF). The effect of an acute exercise bout on monocyte subsets in the setting of systemic inflammation is currently unknown. This study aims (1) to evaluate baseline distribution of monocyte subsets in CHF and CKD versus healthy subjects (HS) and (2) to evaluate the effect of an acute exercise bout. Exercise-induced IL-6 and MCP-1 release are related to the Mon1-2-3 response. METHODS: Twenty CHF patients, 20 CKD patients, and 15 HS were included. Before and after a maximal cardiopulmonary exercise test, monocyte subsets were quantified by flow cytometry: CD14(++)CD16(-)CCR2(+) (Mon1), CD14(++)CD16(+)CCR2(+) (Mon2), and CD14(+)CD16(++)CCR2(-) (Mon3). Serum levels of IL-6 and MCP-1 were determined by ELISA. RESULTS: Baseline distribution of Mon1-2-3 was comparable between the 3 groups. Following acute exercise, %Mon2 and %Mon3 increased significantly at the expense of a decrease in %Mon1 in HS and in CKD. This response was significantly attenuated in CHF (P < 0.05). In HS only, MCP-1 levels increased following exercise; IL-6 levels were unchanged. Circulatory power was a strong and independent predictor of the changes in Mon1 (ß = -0.461, P < 0.001) and Mon3 (ß = 0.449, P < 0.001); and baseline LVEF of the change in Mon2 (ß = 0.441, P < 0.001). CONCLUSION: The response of monocytes to acute exercise is characterized by an increase in proangiogenic and proinflammatory Mon2 and Mon3 at the expense of phagocytic Mon1. This exercise-induced monocyte subset response is mainly driven by hemodynamic changes and not by preexistent low-grade inflammation.

Determining factors predictive of CD34+ cell collection efficiency in an effort to avoid extended and repeated apheresis sessions.

INTRODUCTION: Collection efficiency (CE) is a reflection of the proportion of cells passing through a cell separator that is harvested. The aim of our study was to evaluate which factors influence CE independently in order to find ways to improve CE and therefore minimize the costs and risks of leukapheresis and graft processing. MATERIALS AND METHODS: A total of 206 consecutive apheresis procedures performed on 128 donors/patients were studied retrospectively. We explored the association between CE and the following factors: age, sex, weight, mobilization (granulocyte-colony-stimulating factor with or without chemotherapy), collection type (autologous versus allogeneic), venous access (peripheral versus central), total processed blood volume (TPV), hematocrit, white blood cell (WBC) count, thrombocyte count, and peripheral blood CD34+ cell concentration (PBCD34+). RESULTS: Stepwise multiple regression analysis showed WBC count to be the single best predictor of CE, accompanied by TPV. When performing subgroup analysis for autologous apheresis procedures, the inverse correlation of WBC count and TPV with CE becomes stronger (r = -0.563 with P < 0.001 and r = -0.198 with P = 0.020 respectively), whereas those correlations disappear when analyzing only allogeneic apheresis procedures. CONCLUSION: The negative correlation between TPV and CE present only in autologous collection procedures can be explained by the limited intra-apheresis recruitment of CD34+ cells into the blood which is negatively influenced by extensive pre-treatment. As a result of this study we decided to limit TPV to a maximum of three times the patient's blood volume in autologous apheresis procedures at our center.

Maximal conservative therapy of calcific uremic ateriolopathy.

We present the case of a 61-year- old female patient in long-term hemodialysis who developed calcific uremic arteriolopathy (CUA) upon administration of the oral calcimimetic agent cinacalcet for treatment of secondary hyperparathyroidism. In May 2009, the baseline serum values were parathormone (PTH) 310 pg/ml, calcium 9.1 mg/dl and phosphorous 6.9 mg/dl. Necrotic wounds in the suprapubic fat tissue were successfully treated first, by correcting the calcium phosphorous product; second, through treatment with sodium thiosulfate and third, through intensive wound care with hyperbaric oxygen therapy and vacuum-assisted closure therapy, with no need for parathyroidectomy. Multiple factors have been described to play a role in the development of CUA. Based on the findings of this case, the treatment of CUA should be aimed at correcting different causes simultaneously.

The evolution of hypertension treatment in Belgium, a pharmacoepidemiological study.

OBJECTIVES: The aim of this paper is to study the number of patients treated for hypertension and the evolution in usage of different classes of antihypertensive medication. METHODS: Data from 1997 to 2009 was extracted from Pharmanet, a nation-wide database of prescriptions of reimbursed medication in Belgium. RESULTS: In 2009, 25% of women and 20% of men were prescribed at least one antihypertensive drug. Prescription rates rose with age but already 25% of the population aged between 41 and 60 years were treated. More than 50% of the Belgians above 60 years took antihypertensive medication. From 1997 to 2009, a rise in absolute prescription rate was observed for all antihypertensive drug classes. Diuretics and beta blockers remain by far the most frequently delivered drugs with stable prescription rates of 30% over this period. The largest rise is observed for angiotensin II receptor blockers (ARBs), which were only sporadically prescribed in 1997 and now account for 10.5% of the delivered antihypertensive drugs. A small rise is also noted for angiotensin-converting enzyme inhibitors (ACE-inhibitors) (12.3% in 1997 vs 15.6% in 2009). Their success comes at the expense of calcium antagonists, of which the delivered amount declined from 19.8% in 1997 tot 14.1% in 2009. A progressive rise in the prescription of fixed combination products is observed (from 15% in 1997 to 21% in 2009), and can probably be attributed to their growing availability but also to the recent guidelines, promoting their usage. CONCLUSION: Above age 60, the majority of the Belgians are treated with antihypertensive medication. There is a growing tendency for the use of renin angiotensin aldosterone system (RAAS) blockers and fixed combination products.

Expression of renal distal tubule transporters TRPM6 and NCC in a rat model of cyclosporine nephrotoxicity and effect of EGF treatment.

Renal magnesium (Mg(2+)) and sodium (Na(+)) loss are well-known side effects of cyclosporine (CsA) treatment in humans, but the underlying mechanisms still remain unclear. Recently, it was shown that epidermal growth factor (EGF) stimulates Mg(2+) reabsorption in the distal convoluted tubule (DCT) via TRPM6 (Thébault S, Alexander RT, Tiel Groenestege WM, Hoenderop JG, Bindels RJ. J Am Soc Nephrol 20: 78-85, 2009). In the DCT, the final adjustment of renal sodium excretion is regulated by the thiazide-sensitive Na(+)-Cl(-) cotransporter (NCC), which is activated by the renin-angiotensin-aldosterone system (RAAS). The aim of this study was to gain more insight into the molecular mechanisms of CsA-induced hypomagnesemia and hyponatremia. Therefore, the renal expression of TRPM6, TRPM7, EGF, EGF receptor, claudin-16, claudin-19, and the NCC, and the effect of the RAAS on NCC expression, were analyzed in vivo in a rat model of CsA nephrotoxicity. Also, the effect of EGF administration on these parameters was studied. CsA significantly decreased the renal expression of TRPM6, TRPM7, NCC, and EGF, but not that of claudin-16 and claudin-19. Serum aldosterone was significantly lower in CsA-treated rats. In control rats treated with EGF, an increased renal expression of TRPM6 together with a decreased fractional excretion of Mg(2+) (FE Mg(2+)) was demonstrated. EGF did not show this beneficial effect on TRPM6 and FE Mg(2+) in CsA-treated rats. These data suggest that CsA treatment affects Mg(2+) homeostasis via the downregulation of TRPM6 in the DCT. Furthermore, CsA downregulates the NCC in the DCT, associated with an inactivation of the RAAS, resulting in renal sodium loss.

Epidermal growth factor as a potential prognostic and predictive biomarker of response to platinum-based chemotherapy.

In this study, we investigated serum epidermal growth factor (EGF) in an oncological population of head- and neck and pulmonary neoplasms and whether serum EGF could serve as a prognostic marker of survival and as a predictive marker for treatment response to platinum-based chemotherapy. A total of 59 oncological patients and a control group of age- and sex-matched healthy volunteers were included in this study. Pre-treatment serum EGF from both groups was determined. Patient's and tumour characteristics and mortality were recorded during a 5-year follow up period. Baseline serum EGF significantly differed between the oncological patients and the healthy volunteers (p<0.001). Serum EGF was associated with lymph node metastasis (p = 0.004) but not with sex (p = 0.753), age (p = 1.00), TNM stage (p = 0.191) or tumour size (p = 0.077). Neither serum EGF (p = 0.81) nor age (p = 0.55) showed an effect on the patient's survival. Tumour location was significantly associated with overall 5-year survival (p = 0.003). The predictive capacity of serum EGF of response to chemotherapy was limited (AUC = 0.606), a sensitivity of 80% and a specificity of 56% was observed resulting in a likelihood ratio of a positive and negative test equal to 1.81 and 0.36, respectively. In conclusion, serum EGF levels are 5.5 times higher in an oncological population compared to a control group. Within the oncological population, low serum EGF values are associated with the presence of lymph node metastasis. Further investigation is necessary to determine if the serum EGF levels could serve as a diagnostic biomarker.

Chronic allograft nephropathy: what have we learned from protocol biopsies?

Chronic allograft nephropathy, characterized by interstitial fibrosis and tubular atrophy, is still a major cause of graft loss after kidney transplantation. The complex pathophysiology of chronic allograft nephropathy is still poorly understood, and could be clarified by a more systematic performance of implantation and protocol biopsies of the renal allograft. This review highlights the contribution of implantation and protocol biopsies to our current knowledge of the complex interaction of multiple processes, ultimately leading to the development of interstitial fibrosis and tubular atrophy in the transplanted kidney. In addition, the safety and the limitations of protocol biopsies are discussed, as well as potential future directions for clinical practice and clinical research.

Exposure of the elderly to potential nephrotoxic drug combinations in Belgium.

PURPOSE: To count in the Belgian ambulatory prescription database Pharmanet, the number of elderly people treated with ACE inhibitors (ACEI) and/or angiotensine receptor blockers (ARB) (+/-diuretics +/- beta-blockers) who eventually also received a prescription of non-steroidal anti-inflammatory drugs (NSAID) or spironolactone. METHOD: All prescriptions dispensed in community pharmacies are collected in the Pharmanet database. The data of 2005 were used. Two age groups were studied: 65-79 years (label 1) and 80+ years (label 2). The following chronic treatments (subgroups) were studied: (A) ACEI/ARB; (B) ACEI/ARB + diuretics; (C) ACEI/ARB + spironolactone; (D) ACEI/ARB + beta-blocker + diuretic and (E) ACEI/ARB + beta-blocker + spironolactone. RESULTS: In 2005, 7.3% of Belgian population was chronically treated with ACEI/ARB. Twenty-five per cent of 65-79 year-old-patients (subgroup A1) and 36.15% of 80+ year-old-patients (subgroup A2) received ACEI/ARB. At least one package of NSAID or spironolactone was prescribed to subgroup A1 in 25.44 and 5.80%, respectively, and to subgroup A2 in 22.04 and 9.89%, respectively. In all studied subgroups and age categories, NSAID were coprecribed in more than 20-35% of cases. CONCLUSIONS: NSAID are frequently prescribed in elderly patients treated with ACEI or ARB in combination with diuretics. Severe renal adverse effects may result in this high-risk population.

Longitudinal Study of the Role of Epidermal Growth Factor on the Fractional Excretion of Magnesium in Children: Effect of Calcineurin Inhibitors.

BACKGROUND: It was shown in animal models and adults that the epidermal growth factor (EGF) is involved in the pathophysiology of calcineurin inhibitor (CNI) induced renal magnesium loss. In children, however, the exact mechanism remains unclear, which was set as the purpose of the present study. METHODS: Children with nephrotic syndrome and renal transplant children treated with CNI (n = 50) and non-CNI treated children (n = 46) were included in this study. Urine and serum samples were collected at three time points to determine magnesium, creatinine, and EGF. The magnesium intake was calculated from a food frequency questionnaire. RESULTS: Serum Mg2+ and urinary EGF/creatinine were significantly lower in the CNI treated children, with significantly more CNI-treated children developing hypomagnesaemia. In the latter patients, the fractional excretion of magnesium (FE Mg2+) was significantly higher. Urinary EGF, age, renal function, and serum magnesium were independent predictors of the FE Mg2+. Only 29% of the children reached the recommended daily intake of magnesium. The magnesium intake did not differ between hypomagnesemic and normomagnesemic patients and was not a predictor of the FE Mg2+. CONCLUSIONS: In CNI-treated children who developed hypomagnesemia, the FE Mg2+ was increased. The urinary EGF concentration, age, and renal function are independent predictors of the FE Mg2+.

Conversion from cyclosporine to sirolimus in stable renal transplant recipients.

BACKGROUND: Conversion from cyclosporine (CsA) to sirolimus (SRL) has mainly been done in clinical conditions warranting calcineurin inhibitor discontinuation. Little is known about the clinical outcome of conversion in renal transplant recipients without transplant dysfunction. METHODS: This prospective, open-label, multicentric pilot study evaluates the safety and efficacy of converting patients with stable renal function from CsA to SRL. RESULTS: Forty stable patients on CsA, mycophenolate mofetil (MMF) (1.5 g/day), and steroids (ST) were converted at 7.6+/-1.4 months after renal transplantation. At 1 year, graft and patient survival was 100% and the incidence of acute rejection 5%. Calculated glomerular filtration rate (GFR) increased from 54+/-18 to 66+/-16 ml/min (P<0.0001). Blood pressure remained unchanged. A gradual increase in the incidence and severity of proteinuria was observed from month 6 onwards with de novo proteinuria in 30% of the patients at 1 year. Protein excretion was below 1 g/day in 12.5%, between 1 and 3 g/day in 17.5% and above 3 g/day in 7.5% of the proteinuric cohort (P=0.0043, compared to baseline). No predictors could be identified for the development of proteinuria. All patients had a reduction in protein excretion following renin-angiotensin blockade and were continued on SRL. CONCLUSION: Conversion of stable renal transplant recipients from a CsA-MMF-ST to a SRL-MMF-ST regimen is safe and results in improved renal function but is associated with the development of proteinuria in 30% of the patients requiring renin-angiotensin blockade.

Induction of cytomegalovirus-specific T cell responses in healthy volunteers and allogeneic stem cell recipients using vaccination with messenger RNA-transfected dendritic cells.

BACKGROUND: Infection with human cytomegalovirus (CMV) is a significant cause of morbidity and mortality in solid organ and hematopoietic stem cell transplant (HSCT) recipients. METHODS: The present study explored the safety, feasibility, and immunogenicity of CMV pp65 messenger RNA-loaded autologous monocyte-derived dendritic cells (DC) as a cellular vaccine for active immunization in healthy volunteers and allogeneic HSCT recipients. Four CMV-seronegative healthy volunteers and three allogeneic HSCT recipients were included in the study. Four clinical-grade autologous monocyte-derived DC vaccines were prepared after a single leukapheresis procedure and administered intradermally at a weekly interval. RESULTS: De novo induction of CMV-specific T-cell responses was detected in three of four healthy volunteers without serious adverse events. Of the HSCT recipients, none developed CMV disease and one of two patients displayed a remarkable threefold increase in CMV pp65-specific T cells on completion of the DC vaccination trial. CONCLUSION: In conclusion, our DC vaccination strategy induced or expanded a CMV-specific cellular response in four of six efficacy-evaluable study subjects, providing a base for its further exploration in larger cohorts.

Trends in therapeutic plasma exchange: a single-center evaluation.

PURPOSE: The quality of evidence supporting the use of therapeutic plasma exchange (TPE) in the treatment of individual diseases and disorders is often limited. Since we have experienced a growing variety of indications in our center we decided to make an inventory of our TPE population. METHODS: Single-center retrospective inventory of adult TPE-patients during a 7-year period to determine the evolution of indications for TPE, the response to treatment, and the existing evidence supporting TPE in specified settings. RESULTS: During a period of 84 months, 72 patients underwent 638 sessions of TPE in 91 episodes. There was no shift in frequency of TPE or level of indication. Our population consisted of 69 patients. A level I indication was seen in 41 patients (59.4%), while 14 (20.3%) had a level II indication, 8 (11.6%) had a level III indication, one had a level IV indication (1.4%) and 5 patients suffered from a condition not mentioned in the guidelines (7.2%). The response rate was inversely correlated with the level of evidence after exclusion of these 5 patients (category I 97.6%, category II 71.4%, category III 50%, category IV 0% response, p<0.01). CONCLUSIONS: There was no shift in frequency of TPE or level of indication in our center. Controversial indications should be carefully evaluated on an individual basis and a trial of TPE cannot be solely ruled out because of lack of evidence.

Complement factor H mutation associated with membranoproliferative glomerulonephritis with transformation to atypical haemolytic uraemic syndrome.

A patient with a history of haemolytic anaemia and membranoproliferative glomerulonephritis type 1 since childhood developed relapsing atypical haemolytic uraemic syndrome (aHUS) at the age of 18. Despite several episodes of relapsing aHUS, she was successfully treated with plasmapheresis. aHUS is strongly associated with disorders of the complement pathway. Diagnostic work-up of the patient revealed normal serum values of complement factor H, I, B and membrane cofactor protein (MCP). Genetic analysis showed a homozygous mutation in the factor H gene. Extraordinarily, the homozygous mutation in this patient causes a normal amount but hypothetically functionally defective factor H in the plasma.

Six-day postoperative impact of a standardized nurse observation and escalation protocol: a preintervention and postintervention study.

PURPOSE: The purpose of the study is to determine the impact of a standardized nurse observation and escalation protocol on observation frequency, the measurement of vital signs, and the incidence of in-hospital mortality and resurgery. METHODS: This is a preintervention and postintervention study by analysis of patient records for a 6-day postoperative period of all adult patients hospitalized in 4 hospital wards after surgery during a preintervention (November 2010 to March 2011; n = 2359) and postintervention (November 2011 to March 2012; n = 1888) period implementing a standardized nurse observation and escalation protocol including the Modified Early Warning Score. RESULTS: The mean patient observation frequency per nursing shift increased from 0.9076 (95% confidence interval [CI], 0.8921-0.9231) preintervention to 0.9940 (95% CI, 0.9708-1.0172; P < .001) postintervention and was lower in case of 6-day postoperative mortality (0.6686 [95% CI, 0.4984-0.8388] vs other patients 0.9475 [95% CI, 0.9340-0.9610]; P = .003) or resurgery (0.8402 [95% CI, 0.7894-0.8909] vs other patients 0.9564 [95% CI, 0.9378-0.9657]; P = .003). The mean number of vital signs measured per observation episode increased from a mean of 1.81 (95% CI, 1.79-1.83) preintervention to 2.45 (95% CI, 2.39-2.51; P < .001) postintervention. The relative risk reduction was 73.7% (95% CI, 22.8-91.0; P = .015) for 6-day postoperative in-hospital mortality and 30.9% (95% CI, 9.5-47.2; P = .007) for 6-day postoperative resurgery.

The TRPM6/EGF pathway is downregulated in a rat model of cisplatin nephrotoxicity.

Cisplatin-induced hypomagnesemia is described in humans and rats, but the underlying mechanisms are still unclear. Recent studies have shown that epidermal growth factor (EGF) stimulates Mg(2+) re-absorption in the distal convoluted tubule via the Mg(2+) channel TRPM6. This study investigates the role of TRPM Mg(2+) channels, claudines, and EGF in the Mg(2+) homeostasis in a rat model of cisplatin-induced nephrotoxicity. Wistar rats were given 2.5 mg/kg cisplatin per week for 3 weeks and were euthanized 4 or 9 weeks after the first administration. The cisplatin treatment significantly increased the fractional excretion of Mg(2+). Real-time RT-PCR and/or Western blots were performed to assess the renal expression TRPM6, TRPM7, claudin-16, claudin-19, EGF, EGF receptor (EGFR) and EGFR-pathway components. The renal mRNA expression of TRPM6 and EGF showed a significant decrease after cisplatin treatment, while the TRPM7, claudin-16 and EGFR expressions remained stable. The claudin-19 mRNA expression was significantly upregulated after cisplatin treatment. Western blotting confirmed the mRNA expression data for the claudins, but an showed upregulation of EGFR only at week 9. The role of the EGFR pathway, involving Pi3-AKT-Rac1, in cisplatin-induced nephropathy, could not be substantiated in further detail. This study shows that cisplatin treatment results in EGF and TRPM6 downregulation in the rat kidney, causing renal Mg(2+) loss. Our results are in line with the hypothesis that EGF influences the renal expression or activation of TRPM6 and plays a significant role in Mg(2+) loss in medication-induced nephropathy.

Immunogenicity and safety of an investigational AS02(v)-adjuvanted hepatitis B vaccine in patients with renal insufficiency who failed to respond or to maintain antibody levels after prior vaccination: results of two open, randomized, comparative trials.

An investigational AS02(v)-adjuvanted hepatitis B (HB-AS02) was compared with a licensed conventional recombinant hepatitis B vaccine (HBVAXPRO™; Sanofi Pasteur MSD, Lyon, France) in pre-dialysis, peritoneal dialysis and hemodialysis patients aged ≥18 years who had failed either to respond to prior vaccination with a conventional hepatitis B vaccine (Study A; n=251) or to maintain protective antibody concentrations after prior hepatitis B vaccination (Study B; n=181). These were open, randomized, comparative trials. Mean (range) age was 65.9 (31-92) and 64.6 (29-92) years in the two studies, respectively. In Study A, two doses of HB-AS02 given one month apart were found to be superior to two doses of the licensed vaccine in terms of seroprotection rate (76.9% versus 37.6%) and anti-HBs geometric mean antibody concentration (GMC; 139.3 versus 6.9mIU/ml), with antibody concentrations ≥100mIU/ml in 61.1% and 15.4% of subjects in the two groups, respectively. In Study B, one month after administration of a single booster dose, seroprotection rates were 89.0% in the HB-AS02 group and 90.8% in the licensed vaccine group, 81.3% and 60.9% of subjects had antibody concentrations ≥100mIU/ml, and anti-HBs GMCs were 1726.8 and 189.5mIU/ml. HB-AS02 was found to be more reactogenic than the licensed vaccine. In summary, the investigational HB-AS02 vaccine induced higher seroprotection rates and anti-HBs GMCs than a licensed conventional hepatitis B vaccine in uremic patients who had failed to respond or to maintain protective antibody titers after prior hepatitis B vaccination.