Prevention of tunneled cuffed catheter dysfunction with prophylactic use of a taurolidine urokinase lock: A randomized double-blind trial.

BACKGROUND: The efficacy and cost-effectiveness of prophylactic thrombolytic locks in hemodialysis patients at high-risk of thrombotic dialysis catheter dysfunction is uncertain. We investigated this question in a double-blinded randomized controlled study. METHODS: Prevalent hemodialysis patients from 8 Belgian hemodialysis units, with ≥2 separate episodes of thrombotic dysfunction of their tunneled cuffed catheter during the 6 months before inclusion, were randomized to either: taurolidine heparin locks thrice weekly (control arm) or the same locks twice a week combined with taurolidine urokinase locks once a week before the longest interval without HD (TaurolockU arm). The primary efficacy outcome was the incidence rate of catheter thrombotic dysfunction requiring thrombolytic locks to restore function. RESULTS: 68 hemodialysis patients (32 controls, 36 urokinase) were followed during 9875 catheter days between May 2015 and June 2017. Incidence rate of thrombotic catheter dysfunction was 4.8 in TaurolockU vs 12.1/1000 catheter days in control group (rate ratio 0.39; 95%CI 0.23-0.64). 15/36 (42%) catheters in the treatment group required at least one therapeutic urokinase lock vs 23/32 (72%) in the control group (P = 0.012). The two groups did not differ significantly in catheter-related bloodstream infection and combined cost of prophylactic and therapeutic catheter locks. The TaurolockU group had a numerically higher number of episodes of refractory thrombosis. CONCLUSIONS: Prophylactic use of urokinase locks is highly effective in reducing the number of thrombotic catheter dysfunctions in catheters with a history of recurring dysfunction. Prophylactic use of urokinase locks did not reduce the overall costs associated with catheter locks and was associated with a numerically higher number of episodes of refractory thrombosis. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02036255.

Hemodialysis Does Not Induce Detectable Activation of the Contact System of Coagulation.

INTRODUCTION: Systemic anticoagulation is administered during hemodialysis to prevent clotting of the extracorporeal circuit. The role of contact system activation in thrombin generation during hemodialysis using current era dialyzer membranes is unknown. METHODS: We performed a single-center randomized crossover study. Ten patients treated with hemodialysis underwent 3 standardized hemodialysis sessions. For every patient, each session was performed with a different type of dialyzer membrane (polyphenylene [PP], polymethylmetacrylate [PMMA], polyethylenimine-coated polyacrylonitrile [AN69ST]). Blood samples were collected before and 5, 15, 30, 90, and 240 minutes after blood pump start to evaluate coagulation activation (thrombin-antithrombin complex [TAT], prothrombin fragment 1+2 [PF1+2], activated factor XII [FXIIa], kallikrein, activated factor XI [FXIa]). Plasma of healthy volunteers (n = 20) was used as a reference. RESULTS: Baseline TAT and PF1+2 levels were higher in hemodialysis patients compared to healthy controls (median [interquartile range] for TAT: 3.3 [2.9-4.2] vs. 2.4 [2.3-2.5] µg/l [P = 0.0002] and for PF1+2: 647 [478-737] vs. 138 [125-254] pmol/l [P < 0.0002]). Despite the use of systemic anticoagulation, TAT further increased during treatment, with the increase starting after 30 minutes (median TAT at t240: 9.0 µg/l (PP), 5.5 µg/l (PMMA), and 7.2 µg/l (AN69ST), all P < 0.05 vs. baseline). Contact system markers FXIIa and kallikrein did not differ significantly between dialysis patients and healthy controls, whereas baseline FXIa levels were significantly lower in dialysis patients compared to healthy controls (P = 0.001). Levels of all contact system markers remained unchanged during hemodialysis with all types of dialyzer membranes. CONCLUSION: Routine hemodialysis using systemic heparin anticoagulation induces coagulation activation without measurable contact system activation.

Serum phosphate optimal timing and range associated with patients survival in haemodialysis: the COSMOS study.

BACKGROUND: Serum phosphate is a key parameter in the management of chronic kidney disease-mineral and bone disorder (CKD-MBD). The timing of phosphate measurement is not standardized in the current guidelines. Since the optimal range of these biomarkers may vary depending on the duration of the interdialytic interval, in this analysis of the Current management of secondary hyperparathyroidism: a multicentre observational study (COSMOS), we assessed the influence of a 2- (midweek) or 3-day (post-weekend) dialysis interval for blood withdrawal on serum levels of CKD-MBD biomarkers and their association with mortality risk. METHODS: The COSMOS cohort (6797 patients, CKD Stage 5D) was divided into two groups depending upon midweek or post-weekend blood collection. Univariate and multivariate Cox's models adjusted hazard ratios (HRs) by demographics and comorbidities, treatments and biochemical parameters from a patient/centre database collected at baseline and every 6 months for 3 years. RESULTS: There were no differences in serum calcium or parathyroid hormone levels between midweek and post-weekend patients. However, in post-weekend patients, the mean serum phosphate levels were higher compared with midweek patients (5.5 ± 1.4 versus 5.2 ± 1.4 mg/dL, P < 0.001). Also, the range of serum phosphate with the lowest mortality risk [HR ≤ 1.1; midweek: 3.5-4.9 mg/dL (95% confidence interval, CI: 2.9-5.2 mg/dL); post-weekend: 3.8-5.7 mg/dL (95% CI: 3.0-6.4 mg/dL)] showed significant differences in the upper limit (P = 0.021). CONCLUSION: Midweek and post-weekend serum phosphate levels and their target ranges associated with the lowest mortality risk differ. Thus, clinical guidelines should consider the timing of blood withdrawal when recommending optimal target ranges for serum phosphate and therapeutic strategies for phosphate control.

Efficacy of urokinase lock to treat thrombotic dysfunction of tunneled hemodialysis catheters: A retrospective cohort study.

BACKGROUND:: There are few data to inform decisions about the optimal management of occluded tunneled cuffed hemodialysis catheters with thrombolytic locking solutions. The effect of dose, dwell-time, and number of administrations remains controversial. METHODS:: In this retrospective single-center review of tunneled cuffed catheters used between 2010 and 2014, restoration of blood flow as well as pre- and post-pump pressures after either short (30 min) or prolonged (48-72 h) administration of 100,000 IU of urokinase locking solution was evaluated in all thrombotic dysfunctions. We also assessed if multiple urokinase locks for the same thrombotic dysfunction event were more efficient to restore catheter performance than single administration. RESULTS:: Data on 773 thrombotic events in 148 patients (236 catheters) were collected during observation period. After urokinase treatment, blood flow and pre-pump pressure improved (median of 50 mL/min and 20 mmHg) whereas post-pump pressure decreased (median of 15 mmHg) (all P < 0.0001). The short thrombolytic procedure, used in more severely dysfunctional catheters, resulted in significantly larger improvements in catheter function than the long procedure. Multiple administrations for the same thrombotic event further improved access function in case of persisting dysfunction after first lock but had no added beneficial effect if blood flow and/or pump pressures were normalized after first urokinase lock. CONCLUSION:: Both short and prolonged administration of urokinase locks were efficient in restoring blood flow and pre- and post-pump pressures in dialysis catheters with thrombotic dysfunction. Multiple urokinase locks provide added benefit on these outcomes only in case of persisting dysfunction after the first lock.

Urokinase-containing locking solution in the prevention of dialysis catheter dysfunction: a double blind randomized controlled trial.

INTRODUCTION: The prophylactic use of recombinant tissue plasminogen activator once weekly reduces the incidence rate of tunneled cuffed catheter (TCC) malfunction and bacteremia as compared to the exclusive use of heparin as locking solution. Restricting the use of prophylactic thrombolytic agents to patients with a history of thrombotic TCC malfunction could be more cost effective. We conduct a multicenter, double-blind, randomized controlled trial and test the hypothesis that weekly use of urokinase lock will reduce the incidence of thrombotic malfunction by 50% in prevalent hemodialysis patients with a history of thrombotic malfunction. METHODS: Patients with a history of at least two separate TCC thrombotic dysfunctions treated with urokinase lock during the 6 months preceding inclusion are recruited in eight Belgian dialysis units. Patients are randomized in two groups: the control group receiving Taurolock™-HEP500 (heparin 500 IU/mL, taurolidine, citrate 4%) after each hemodialysis session and the treatment group receiving Taurolock-U 25,000 (urokinase 25,000, taurolidine, citrate 4%) once a week and the standard Taurolock-HEP500 at the end of the two others sessions. The primary outcome is the incidence rate of TCC thrombotic dysfunction defined by the use of urokinase. The secondary outcomes are the incidence rate of TCC removal and systemic thrombolysis. For the study, both patients and healthcare staff are blinded to treatment allocation. CONCLUSIONS: The present trial is the first to investigate the effect of Taurolock-U 25,000 catheter lock once a week as secondary prevention in hemodialysis patients with the highest risk of TCC-related thrombotic dysfunction. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02036255.

Isonatric Dialysis Biofeedback in Hemodiafiltration with Online Regeneration of Ultrafiltrate in Hypertensive Hemodialysis Patients: A Randomized Controlled Study.

UNLABELLED: Dialysis biofeedback in hemodiafiltration with online regeneration of ultrafiltrate (HFR) could help to improve arterial hypertension. We evaluated the impact of isonatric HFR (HFR-iso) on hypertension control compared to conventional HFR. Forty-seven hemodialysis patients were included and randomized (ratio 2/1) HFR-iso versus HFR during 24 dialysis sessions. In the HFR-iso group (32 patients, 768 dialysis sessions), the predialytic systolic blood pressure (BP) decreased from S1 to S24 of 9 ± 20 mm Hg and increased of 5 ± 24 mm Hg in the HFR group (15 patients, 360 dialysis sessions), variation that differed between the 2 groups (x0394;S1-S24, p = 0.035; interaction group*time, p = 0.012). The diastolic BP (HFR-iso -3 ± 14 mm Hg vs. HFR 5 ± 13 mm Hg; p = 0.088), the DDD of antihypertensive treatment and the dry weight did not vary significantly during the study. Number of sessions complicated by symptomatic hypotension was similar in the 2 groups. HFR-iso improved BP control without increasing dialysis hypotension episodes. SHORT SUMMARY: In this multicenter, open-label, controlled, randomized study, we evaluated the impact of dialysis biofeedback in HFR on arterial hypertension compared to conventional HFR. We observed that HFR-iso improved arterial BP control without increasing dialysis hypotension episodes.

Avoidance of systemic anticoagulation during intermittent haemodialysis with heparin-grafted polyacrilonitrile membrane and citrate-enriched dialysate: a retrospective cohort study.

BACKGROUND: Since October 2010, the combination of a heparin-grafted polyacrilonitrile (AN69ST) membrane with a 0.80 mmol/L citric acid-containing dialysate is routinely used in our centre for intermittent haemodialysis, without systemic anticoagulation, in critically ill patients with increased bleeding risk. The primary outcome of this retrospective cohort study was to assess the development of circuit clotting during these dialysis procedures. Secondly, we assessed the impact of clotting on treatment duration, the incidence rate of coagulation-induced retransfusion failure and the association of patient and dialysis characteristics with the occurrence of clotting. METHODS: Dialysis and patient data on consecutive intermittent haemodialysis procedures, performed at the Intensive Care Unit of Universitair Ziekenhuis Brussel between October 2010 and March 2012, were retrospectively reviewed. We used descriptive statistics as well as a random effects logit model with patient identity as a panel variable to assess associations. RESULTS: Of a total of 309 treatments combining a heparin-grafted AN69ST membrane and a 0.8 mmol/L citric acid-enriched dialysate in 94 patients, circuit clotting was reported in 17.5% (95% CI 13.2% to 21.7%; N = 54), and in 19% (95% CI 13.6% to 24.4%; N = 40) of sessions with prescribed treatment time ≥ 4 hours (N = 210). Clotting shortened treatment time in 15.2% (95% CI 11.4% to 19.7%; N = 47) of sessions by a median of 55 (IQR 20 to 80) minutes. Complete clotting of the circuit with inability for retransfusion occurred in 4.2% (95% CI 2.2% to 7.0%; N = 13) of sessions. Circuit coagulation was not associated with APACHE II score, patient age, gender, number of treatments, type of vascular access or ultrafiltration rate. CONCLUSION: Intermittent haemodialysis without systemic anticoagulation combining a heparin-grafted AN69ST dialyzer with a citrate-enriched dialysate favourably compares as to clotting complications with the published outcomes of anticoagulation-free intermittent haemodialysis strategies using saline flushes, heparin-coated dialyzer in combination with regular dialysate or regional citrate anticoagulation with calcium supplemented dialysate. The incidence of circuit clotting in our cohort appears to be higher than previously reported for regional citrate anticoagulation with a calcium-free dialysate.

Influence of body mass index on the association of weight changes with mortality in hemodialysis patients.

BACKGROUND AND OBJECTIVES: A high body mass index (BMI) is associated with lower mortality in patients undergoing hemodialysis. Short-term weight gains and losses are also related to lower and higher mortality risk, respectively. The implications of weight gain or loss may, however, differ between obese individuals and their nonobese counterparts. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: The Current Management of Secondary Hyperparathyroidism: A Multicenter Observational Study (COSMOS) is an observational study including 6797 European hemodialysis patients recruited between February 2005 and July 2007, with prospective data collection every 6 months for 3 years. Time-dependent Cox proportional hazard regressions assessed the effect of BMI and weight changes on mortality. Analyses were performed after patient stratification according to their starting BMI. RESULTS: Among 6296 patients with complete data, 1643 died. At study entry, 42% of patients had a normal weight (BMI, 20-25 kg/m(2)), 11% were underweight, 31% were overweight, and 16% were obese (BMI ≥ 30 kg/m(2)). Weight loss or gain (<1% or >1% of body weight) was strongly associated with higher rates of mortality or survival, respectively. After stratification by BMI categories, this was true in nonobese categories and especially in underweight patients. In obese patients, however, the association between weight loss and mortality was attenuated (hazard ratio, 1.28 [95% confidence interval (CI), 0.74 to 2.14]), and no survival benefit of gaining weight was seen (hazard ratio, 0.98 [95% CI, 0.59 to 1.62]). CONCLUSIONS: Assuming that these weight changes were unintentional, our study brings attention to rapid weight variations as a clinical sign of health monitoring in hemodialysis patients. In addition, a patient's BMI modifies the strength of the association between weight changes with mortality.

Use of phosphate-binding agents is associated with a lower risk of mortality.

Hyperphosphatemia has been associated with higher mortality risk in CKD 5 patients receiving dialysis. Here, we determined the association between the use of single and combined phosphate-binding agents and survival in 6797 patients of the COSMOS study: a 3-year follow-up, multicenter, open-cohort, observational prospective study carried out in 227 dialysis centers from 20 European countries. Patient phosphate-binding agent prescriptions (time-varying) and the case-mix-adjusted facility percentage of phosphate-binding agent prescriptions (instrumental variable) were used as predictors of the relative all-cause and cardiovascular mortality using Cox proportional hazard regression models. Three different multivariate models that included up to 24 variables were used for adjustments. After multivariate analysis, patients prescribed phosphate-binding agents showed a 29 and 22% lower all-cause and cardiovascular mortality risk, respectively. The survival advantage of phosphate-binding agent prescription remained statistically significant after propensity score matching analysis. A decrease of 8% in the relative risk of mortality was found for every 10% increase in the case-mix-adjusted facility prescription of phosphate-binding agents. All single and combined therapies with phosphate-binding agents, except aluminum salts, showed a beneficial association with survival. The findings made in the present association study need to be confirmed by randomized controlled trials to prove the observed beneficial effect of phosphate-binding agents on mortality.

COSMOS: the dialysis scenario of CKD-MBD in Europe.

BACKGROUND: Chronic kidney disease-mineral and bone disorders (CKD-MBD) are important complications of CKD5D patients that are associated with mortality. METHODS: COSMOS is a multicentre, open cohort, prospective, observational 3-year study carried out in haemodialysis patients from 20 European countries during 2005-07. The present article describes the main characteristics of the European dialysis population, the current practice for the prevention, diagnosis and treatment of secondary hyperparathyroidism and the differences across different European regions. RESULTS: The haemodialysis population in Europe is an aged population (mean age 64.8±14.2 years) with a high prevalence of diabetes (29.5%) and cardiovascular disease (76.0%), and 28.7% of patients have been on haemodialysis more than 5 years. Patients from the former Eastern countries are younger (59.3±14.3 versus 66.0±13.9), having a lower proportion of diabetics (24.1 versus 30.7%). There were relevant differences in the frequency of measurement of the main CKD-MBD biochemical parameters [Ca, P and parathyroid hormone (PTH)] and the Eastern countries showed a poorer control of these biochemical parameters (K/DOQI and K/DIGO targets). Overall, 48.0% of the haemodialysis patients received active vitamin D treatment. Calcitriol use doubled that of alfacalcidiol in the Mediterranean countries, whereas the opposite was found in the non-Mediterranean countries. The criteria followed to perform parathyroidectomy were different across Europe. In the Mediterranean countries, the level of serum PTH considered to perform parathyroidectomy was higher than in non-Mediterranean countries; as a result, in the latter, more parathyroidectomies were performed in the year previous to inclusion to COSMOS. CONCLUSIONS: The COSMOS baseline results show important differences across Europe in the management of CKD-MBD.

Effect of a plasma sodium biofeedback system applied to HFR on the intradialytic cardiovascular stability. Results from a randomized controlled study.

BACKGROUND: Intradialytic hypotension (IDH) is still a major clinical problem for haemodialysis (HD) patients. Haemodiafiltration (HDF) has been shown to be able to reduce the incidence of IDH. METHODS: Fifty patients were enrolled in a prospective, randomized, crossover international study focussed on a variant of traditional HDF, haemofiltration with endogenous reinfusion (HFR). After a 1-month run-in period on HFR, the patients were randomized to two treatments of 2 months duration: HFR (Period A) or HFR-Aequilibrium (Period B), followed by a 1-month HFR wash-out period and then switched to the other treatment. HFR-Aequilibrium (HFR-Aeq) is an evolution of the haemofiltration with endogenous reinfusion (HFR) dialysis therapy, with dialysate sodium concentration and ultrafiltration rate profiles elaborated by an automated procedure. The primary end point was the frequency of IDH. RESULTS: Symptomatic hypotension episodes were significantly lower on HFR-Aeq versus HFR (23 ± 3 versus 31 ± 4% of sessions, respectively, P l= l0.03), as was the per cent of clinical interventions (17 ± 3% of sessions with almost one intervention on HFR-Aeq versus 22 ± 2% on HFR, P <0.01). In a post-hoc analysis, the effect of HFR-Aeq was greater on more unstable patients (35 ± 3% of sessions with hypotension on HFR-Aeq versus 71 ± 3% on HFR, P <0.001). No clinical or biochemical signs of Na/water overload were registered during the treatment with HFR-Aeq. CONCLUSIONS: HFR-Aeq, a profiled dialysis supported by the Natrium sensor for the pre-dialysis Na(+) measure, can significantly reduce the burden of IDH. This could have an important impact in every day dialysis practice.

Anti-HBs antibody persistence following primary vaccination with an investigational AS02(v)-adjuvanted hepatitis B vaccine in patients with renal insufficiency.

BACKGROUND: Three doses of the investigational AS02(v)-adjuvanted hepatitis B virus (HBV) vaccine HB-AS02 have been shown to induce more rapid seroprotection and higher anti-HBs antibody concentrations in patients with renal insufficiency than four doses of FENDrix™ (HB-AS04), an adjuvanted HBV vaccine licensed in Europe for use in this population. This study evaluated persistence of immune response up to 36 months after primary vaccination. METHODS: In this open, international, Phase III follow-up study, 151 pre-dialysis, peritoneal dialysis and hemodialysis patients ≥15 years of age received HB-AS02 at 0, 1, 6 months and 149 received HB-AS04 at 0, 1, 2, 6 months. Of these, 99 and 80 returned at Month 36, 76 and 62 of whom were eligible for inclusion in the Long-Term According-To-Protocol (LT-ATP) cohort for descriptive analysis of antibody persistence (mean age: 65.6 years). RESULTS: At Month 36, 89.5% of subjects in the HB-AS02 group and 72.6% of those in the HB-AS04 group had anti-HBs antibody concentrations ≥10 mIU/ml. Anti-HBs antibody concentrations were ≥100 mIU/ml in 82.9% and 35.5% of subjects, respectively. Anti-HBs geometric mean antibody concentrations were higher in the HB-AS02 group over the 36 months of follow-up. An exploratory "time to boost" analysis confirmed that subjects who received HB-AS02 were 2.54 times more likely than those who received HB-AS04 to have anti-HBs antibody concentrations ≥10 mIU/ml at Month 36 (p=0.013 [95% CI: 1.22, 5.31]). CONCLUSION: HB-AS02 candidate vaccine induces high and persistent anti-HBs antibody levels in pre-dialysis, peritoneal dialysis and hemodialysis patients, potentially reducing the need for booster doses in this population.

Alkaline-encrusted pyelitis and cystitis: an easily missed and life-threatening urinary infection.

Alkaline-encrusted pyelitis is a urinary infection characterised by encrustations in the wall of the urinary tract. It is caused by fastidious growing urea splitting microorganisms mainly Corynebacterium group D2. The diagnosis is easily missed and should be evoked on basis of sterile pyuria, alkaline urine pH and calcifications of the urinary excretion ways on the CT scan and then confirmed by prolonged culture on appropriate media. The authors report here the case of a patient who died after a delayed diagnosis from recurrent septic urinary infections.

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.

Rapid, enhanced, and persistent protection of patients with renal insufficiency by AS02(V)-adjuvanted hepatitis B vaccine.

The adjuvanted hepatitis B vaccine, HB-AS04, elicits more rapid and persistent protective antibody concentrations than double doses of conventional recombinant vaccines in patients with renal insufficiency. We compared the immunogenicity, reactogenicity, and safety of the AS02(V)-adjuvanted hepatitis B vaccine HB-AS02 with that of HB-AS04. In this phase III, open, randomized study, 151 hepatitis B vaccine-naïve pre-dialysis, peritoneal dialysis, and hemodialysis patients aged 15 years and older received three doses of HB-AS02 at 0, 1, and 6 months. Another 149 similar patients received four doses of HB-AS04 at 0, 1, 2, and 6 months, and all were followed up for 12 months. HB-AS02 elicited more rapid and persistent seroprotection than HB-AS04, with rates of 77 and 39%, respectively, 1 month after the second vaccine dose, and 94 and 79%, respectively, at 12 months. Superiority of HB-AS02 over HB-AS04 in anti-hepatitis B geometric mean concentrations was found at all time points. HB-AS02 was more reactogenic than HB-AS04, but adverse events were mainly transient, of mild to moderate intensity with no reportable vaccine-related serious events. We conclude that a three-dose primary course of HB-AS02 induced more rapid, enhanced, and persistent protection in patients with renal insufficiency than the licensed four-dose primary schedule of HB-AS04. This adjuvanted vaccine affords greater protection with reduced need for booster doses in patients at high risk of hepatitis B infection.

Cytotoxicity of mononuclear cells as induced by peritoneal dialysis fluids: insight into mechanisms that regulate osmotic stress-related apoptosis.

OBJECTIVE: High glucose content of peritoneal dialysis fluids (PDFs) has been shown to contribute to loss of peritoneal function during long-term peritoneal dialysis. However, hyperosmolality and hypertonicity of PDF are usually seen as similar stress events inducing osmotic stress-induced programmed cell death. In this study, we examined the impact of various osmotic agents on apoptosis induced by hyperosmolar PDFs, focusing on the mechanisms underlying the lethal effects of PDFs on peripheral blood mononuclear cells (PBMCs). METHODS: We assessed apoptosis and necrosis by annexin V-propidium iodide (PI) labeling, and caspase-3 activity by fluorescence assay. F-actin remodeling was measured using fluorescent phalloidin labeling. RESULTS: Hyperosmolality does not cause the cytotoxicity observed with PDF, but exposure to agents incapable of permeating cell membranes results in a significant increase in the percentage of apoptotic PBMCs by annexin V-PI labeling, which is confirmed by the increase in caspase-3 activity. Interestingly, inhibition of caspase-3 by Z-VAD-FMK did not suppress apoptosis. Extracellular hypertonicity produced polymerization of filamentous actin and cell shrinkage, which displayed similar time courses. Cell shrinkage was blocked by cytochalasin D, indicating an active role for actin cytoskeleton in hypertonicity-induced cell shrinkage. F-actin polymerization was related to an increase in intracellular ionic strength. Finally, we excluded a direct role for actin remodeling in osmotic stress-induced programmed cell death. CONCLUSIONS: Exposure to osmolytes that cannot penetrate cell membranes results in a hypertonicity-induced apoptosis that cannot be blocked by the broad-spectrum caspase inhibitor Z-VAD-FMK. In addition, extracellular hypertonicity induced by impermeant solutes produces F-actin polymerization through an increase in intracellular ionic strength. The remodeling of the cytoskeleton does not modulate apoptosis but participates in cell shrinkage.

Current management of secondary hyperparathyroidism: a multicenter observational study (COSMOS).

STUDY AIMS: To survey bone mineral disturbances in the hemodialysis (HD) population in Europe and current clinical practice in Europe for the prevention, diagnosis and treatment of secondary hyperparathyroidism (SHPT) in HD patients. PRIMARY OBJECTIVES: First, to estimate the prevalence of Kidney Disease Outcomes Quality Initiative (K/DOQI) guideline achievement in a representative sample of European hemodialysis subjects. As part of this objective, we will investigate the prevalence of achievement by type of dialysis, type of center and time on dialysis (less than or greater than 1 year). Among new dialysis subjects (less than 1 year), we will evaluate prevalence of K/DOQI target achievement until the end of the study. The study will run for 3 years. Second, to estimate the association of bone mineral markers (parathyroid hormone [PTH], calcium [Ca], serum phosphorus [P] and calcium phosphate product [CaxP]) classified by achievement of K/DOQI targets with mortality and overall cardiovascular hospitalization. Third, to characterize the longitudinal changes in bone mineral markers. As part of this objective, we will describe the patterns and predictors of bone mineral markers and achievement, with K/DOQI targets, using repeated measurements on individuals over time. SECONDARY OBJECTIVES: First, To estimate the association of bone mineral markers (PTH, Ca, P and CaxP) classified by achievement of K/DOQI targets with specific cardiovascular outcomes, parathyroidectomy, manifest bone disease (including incidence of symptomatic bone fractures), hospitalizations and vascular access. Second, to evaluate the additional value of albumin and hemoglobin levels in conjunction with bone mineral markers in the prediction of mortality and clinical events.

Pathochemical toxicity of perfluorocarbon-5070, a liquid test performance fluid previously used in dialyzer manufacturing, confirmed in animal experiment.

In the light of clustered deaths in late 2001 associated with hemodialysis (HD), this article analyzes the pathochemical toxicity of the perfluorocarbon-5070 (PF-5070), a liquid used as test performance fluid for detecting capillary leaks during dialyzer manufacturing. Residual PF-5070 in some Athane dialyzers of the involved brands was infused in the injured patients during hemodialysis. The clinical presentation was in contrast with other previously described severe reactions to HD. Foam material was discovered in the right ventricle and caval vein of the patients who underwent postmortem examination. Deaths were attributed to gas embolism without the external causes identified. To explore the pathochemical toxicity of the inert liquid PF-5070, an animal model was developed. In a rabbit model, single slug intravenous injections as bolus of increasing doses of PF-5070 were performed. In a first set of experiments, three groups of three rabbits were administered increasing doses of PF-5070 at 4, 40, or 160 microl/kg. After intravenous injection, the animals were observed for clinical signs of adverse effects and underwent autopsy after death. Doses were normalized to animal body weight to allow comparison with supposed patient exposure. Five of nine rabbits died soon after PF-5070 dosing: One rabbit died within 4 h in the 4 microl/kg group, one rabbit died within 30 min in the 40 microl/kg group, and three rabbits died within 30 min in the 160 mul/kg group. In a second set of experiments, six rabbits were injected with a lethal dose of PF-5070 to analyze clinical symptoms and pathophysiology. All rabbits died on the day of dosing and displayed neurologic disorders (paralysis, nystagmus, rigidity, convulsions), then breathing abnormalities (rapid breathing, salivation, dark mucous membrane), and fatal collapse. Autopsy of rabbits showed evidence of gas retention in the lung tissue and gas bubbles in the right cardiac cavities. Histologic findings included alveolar hemorrhage with pulmonary edema, cerebellum, and cortex patchy areas of infarction. Single-dose intravenous administration of PF-5070 reproduced in a rabbit model the pathophysiologic effects observed in the hemodialysis patients. Severity of the symptoms observed in the animals was dose-dependent. Clinical and pathologic findings can be explained by the capacity of perfluorocarbon to emulsify blood at body temperature, to increase partial pressure in the pulmonary capillary bed, and to form bubbles in the pulmonary capillary circulation, thus blocking lung and visceral perfusion. Such experimental findings indicate the toxicity of PF-5070 administered intravenously and make the pathochemical toxicity link with the hemodialysis-related deaths caused by the presence of residues of PF-5070 in the Althane dialyzers. We conclude, in light of this outbreak and the subsequent investigations, that liquid PF-5070 is a highly toxic compound when administered intravenously because of its emulsifying properties. The use of PF-5070 or any liquid fluorocarbon compounds in medical devices with blood contact and particularly in the dialyzer manufacturing should be considered with caution.