Chien-Hsing Wu

Effects of AST-120 on blood concentrations of protein-bound uremic toxins and biomarkers of cardiovascular risk in chronic dialysis patients.

Background: Removal of protein-bound uremic toxins by dialysis therapy is limited. The effect of oral adsorbent AST-120 in chronic dialysis patients has rarely been investigated. Methods: AST-120 was administered 6.0 g/day for 3 months in 69 chronic dialysis patients. The blood concentrations of indoxyl sulfate, p-cresol sulfate and biomarkers of cardiovascular risk were determined before and after AST-120 treatment. Results: AST-120 significantly decreased both the total and free forms of indoxyl sulfate and p-cresol sulfate ranging from 21.9 to 58.3%. There were significant simultaneous changes of the soluble tumor necrosis factor-like weak inducer of apoptosis (sTWEAK, 24% increase), malondialdehyde (14% decrease) and interleukin-6 (19% decrease). A significant association between the decrease of indoxyl sulfate and changes of sTWEAK and interleukin-6 was noted. Conclusions: AST-120 effectively decreased indoxyl sulfate and p-cresol sulfate levels in both total and free forms. AST-120 also improved the profile of cardiovascular biomarkers.

Biomarkers associated with vascular and valvular calcification in chronic hemodialysis patients

Background: Cardiovascular calcification, including arterial intimal and medial calcification (AIC and AMC) and valvular calcification (VC) are important predictors of outcome in chronic dialysis patients. We aimed to compare their prevalence and analyze respective risk factors in hemodialysis (HD) patients. Methods: A total of 81 HD patients were enrolled. Vascular calcification was assessed by plain film radiography of the pelvis and VC was diagnosed by echocardiography. Demographic data was reviewed and serum levels of calcification-relevant biomarkers were determined. Patients with and without calcification were then compared. Results: The prevalence study indicated that 36 patients had AIC (44.4%), 17 had AMC (21%) and 60 (74.1%) had VC. Patients with vascular calcification were older, and had a higher prevalence of diabetes. Their IL-6, osteoprotegerin, and uric acid levels were higher. Serum fetuin-A was lower in patients with VC. Logistic regression analysis revealed age, uric acid and diabetes to be independently associated with AIC; uric acid, diabetes and osteoprotegerin with AMC. Fetuin-A was the sole associate of VC. Conclusions: It is concluded that the prevalence of cardiovascular calcification in chronic HD patients was high with cardiac valve involvement more frequent. Factors associated with different type of calcification were not identical. Changes in biomarkers may represent clinical clues for assessment of cardiovascular calcification in HD patients.

Albuminuria, proteinuria, and urinary albumin to protein ratio in chronic kidney disease.

Both albuminuria and proteinuria are important disease markers of chronic kidney disease (CKD). Their relationship and the ratio between urinary albumin and protein in patients with CKD have not been investigated. Whether clinical features can affect these measurements is not clear.

Discrepancy between effects of carbapenems and flomoxef in treating nosocomial hemodialysis access-related bacteremia secondary to extended spectrum beta-lactamase producing Klebsiella pneumoniae in patients on maintenance hemodialysis.

BackgroundHemodialysis (HD) patients are susceptible to extended spectrum beta-lactamase (ESBL)-producing bacterial infections. Because the optimal treatment and clinical significance of ESBL-producing Klebsiella pneumoniae (ESBL-Kp) HD access-related bacteremia remain unclear, we conducted this retrospective study to determine the clinical outcomes of patients treated with either flomoxef or a carbapenem.MethodsThe eligibility criterion was fistula or graft- or catheter- related ESBL-Kp bacteremia in patients on maintenance HD. The clinical characteristics and antibiotic management were analyzed. Outcome was determined by mortality resulting from bacteremia during the 14‐day period after the first positive blood culture for flomoxef-susceptible ESBL-Kp.ResultsThe 57 patients studied were predominantly elderly, malnourished, with a history of severe illnesses and broad-spectrum antibiotic use before the onset of bacteremia, and with severe septicemia as determined by the Pitt bacteremia score (PBS). The study population comprised 7 fistula, 8 graft, and 42 HD catheter-related bacteremia (CRB) cases, and the mortality rate was high (36/57, 63.2%) in these 57 patients. Of 42 patients with CRB, those in the deceased group (27/42, 64.3%) had significantly lower levels of serum albumin, longer prior hospital stay and duration of catheter-dependent HD, and higher PBS than patients in the survived group. Failure to receive effective antibiotics (flomoxef or a carbapenem) within 5 days after onset of bacteremia and treatment with flomoxef both significantly contributed to higher mortality. Multivariate analyses revealed that flomoxef use, PBS, and catheter-dependent HD >30 days were independently associated with increased mortality (OR, 3.52; 95% CI, 1.19–58.17, OR, 2.92; 95% CI, 1.36–6.26 and OR, 5.73; 95% CI, 1.21–63.2, respectively).ConclusionsConsidering the high mortality rate, ESBL-Kp should be recognized as a possible pathogen in patients on maintenance HD at high risk of acquiring HD access infections associated with ESBL-producing bacteria. Carbapenems rather than flomoxef should be the therapy of choice in these critically vulnerable patients.

Calcification of the Aortic Arch Predicts Cardiovascular and All-Cause Mortality in Chronic Hemodialysis Patients

Background: Cardiovascular calcification represents a marker of cardiovascular risk in chronic dialysis patients. In the general population, aortic arch calcification (AAC) can predict cardiovascular mortality. We conducted a prospective study to investigate factors associated with AAC in hemodialysis patients and examined its prognostic value in long-term outcome. Methods: A total of 712 hemodialysis patients were enrolled. AAC was identified on postero-anterior chest X-ray films and classified as grade (Gr.) 0, 1, 2 or 3. Demographic data including age, gender, dialysis vintage, co-morbidity and biochemical data were reviewed and recorded. The patients were followed for 10 years. Results: AAC was present in 164 patients (23%) as Gr. 1, in 116 patients (16.3%) as Gr. 2 and in 126 patients (17.7%) as Gr. 3. An increase in the severity of calcification was associated with older patients who had lower albumin, higher calcium and glucose levels. During the follow-up period of 10 years, we found that the grade of AAC was directly related to cardiovascular mortality (Gr. 0: 5.3%; Gr. 1: 12.7%; Gr. 2: 18.9%, and Gr. 3: 24.4%; p < 0.05) and all-cause mortality (Gr. 0: 19.9%; Gr. 1: 31.1%; Gr. 2: 44.8%, and Gr. 3: 53.2%; p < 0.001). Multivariate Cox proportional hazards analysis revealed that high-grade calcification was associated with cardiovascular and all-cause mortality. Patients with AAC were associated with a worse outcome in survival analysis. The severity of AAC also influenced their survival. Conclusion: Calcification of the aortic arch detected in plain chest radiography was an important determinant of cardiovascular as well as all-cause mortality in chronic hemodialysis patients. The presence and severity of AAC predicted long-term survival.

Relationship between Kt/V urea-based dialysis adequacy and nutritional status and their effect on the components of the quality of life in incident peritoneal dialysis patients

BackgroundIt is well known that the quality of life of patients with chronic kidney disease can be improved by dialysis. While previous studies have used retrospective designs and adhered to a standard target prescribed by clinical guidelines, our study prospectively investigates the association between the adequacy of peritoneal dialysis (PD) and measures of nutritional status on quality-of-life domains in a cohort of incident PD patients.MethodsIt was a prospective 6-month observational study. Eighty incident PD participants who were treated in a hospital-based PD center were enrolled. The period of enrollment was January 2009–June 2010; follow-up continued until December 2010. PD adequacy indices, including Kt/V urea, weekly Ccr (WCcr), measures of nutritional status (albumin, BMI), and nPCR were measured at 1 month and 6 months after PD initiation. SF-36 health survey questionnaires were used to measure the quality of life. The outcomes were used to measure the changes in the domains of the SF-36 after 6 months of PD therapy.ResultsSeventy-seven incident patients who underwent PD for 6 months were included in the study. The mean age was 47.3 years, and the male-to-female ratio was 38:39. A peritoneal Kt/V urea value of 1.2, which was also the baseline cutoff value, was found to have the highest influence on SF-36 domains. Patients with baseline peritoneal Kt/V urea value of <1.2 showed improvement in the physical functioning and role limitation of physical functioning components after 6 months of PD. In contrast, patients with baseline peritoneal Kt/V urea values of ≥1.2 showed remarkable improvement in the general health, physical functioning, role limitation caused by physical problems, and bodily pain components. However, the trend of improvement decreased in patients with baseline nPCR of <1.2. Baseline renal WCcr did not influence the improvement in the SF-36 domains.LimitationsA small cohort and a short observation period.ConclusionsThe baseline level of peritoneal Kt/V urea affected the components of the quality of life after PD initiation. In contrast, a lower baseline nPCR level was associated with deterioration in the quality of life after PD therapy.

Lack of modulatory effect of simvastatin on indoxyl sulfate-induced activation of cultured endothelial cells

AIMS Endothelial dysfunction is a common manifestation of chronic kidney disease (CKD). The protein-bound uremic toxins have emerged as important factors associated with cardiovascular disease and the outcome of CKD. The effect of indoxyl sulfate (IS) on endothelial cells remains unclear. MAIN METHODS Human umbilical endothelial cells (HUVEC) were incubated using IS at two concentrations: 100 μM and 1000 μM over two periods of time: 16 and 48 h. HUVEC were also pre-treated with simvastatin to examine its effect. RT-PCR was used to assess changes in the gene expression of intracellular cell adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), Monocyte chemotactic protein-1 (MCP-1), E-selectin, and angiotensin receptor type 1 (AT1R). Protein abundance of the investigated molecules was assessed by immunoblotting. KEY FINDINGS Treatment with 100 μM IS for 16 h induced a 2-fold increase in the expression of ICAM-1, VCAM-1, and MCP-1. At a concentration of 1000 μM, there was a 2-3-fold increase. An extended treatment period at low concentrations was associated with a 2-3 fold increase and the increase of ICAM-1 and VCAM-1 was more prominent under high concentration. Results of immunoblotting confirmed an increase in the abundance of ICAM-1, VCAM-1 and MCP-1. No significant change was noted in E-selectin and AT1R according to concentration or treatment duration. Pre-treatment with simvastatin did not alter IS-induced changes. SIGNIFICANCE IS increased the expression of adhesion molecules of endothelial cells exhibiting a concentration and duration dependent pattern. Simvastatin did not demonstrate any effect on IS-associated endothelial activation.

A Quality and Cost-Benefit Analysis of Dialyzer Reuse in Hemodialysis Patients

Background. To evaluate the benefits of dialyzer reuse for hemodialysis (HD) patients, including the cost of HD treatment and patients survival, a comparison was made regarding the standard practice of single-use dialysis. Methods. From January 1, 2005, to December 31, 2005, a total of 128,232 successive HD treatments in 822 patients in Chang Gung Memorial Hospital-Kaohsiung Medical Center were included in this study. Results. Approximately 54.25% (446/822) of patients reused dialyzers. The average times of dialyzer reuse was 2.54. The annual hollow fiber cost is reduced by

Nosocomial extended-spectrum beta-lactamase-producing Klebsiella pneumoniae bacteremia in hemodialysis patients and the implications for antibiotic therapy.

241,054.08 U.S. dollars (NT

Free p-cresol sulfate is associated with survival and function of vascular access in chronic hemodialysis patients.

7,834,257.60). The annual cost of hollow fiber was reduced by