High Ferritin Level and Malnutrition Predict High Risk of Infection-Related Hospitalization in Incident Dialysis Patients: A Japanese Prospective Cohort Study.

AIMS: The aim of the study was to clarify the relationship between serum ferritin and infectious risks. METHODS: We evaluated all hospital admissions due to infections, clinical biomarkers and nutrition status in 129 incident Japanese dialysis patients during a median follow-up of 38 months. RESULTS: Kaplan-Meier analysis revealed that the period without infections requiring hospitalization was significantly shorter in ferritin > median (82.0 ng/ml) group than in the ferritin < median group (log-rank test 4.44, p = 0.035). High ferritin was associated with significantly increased relative risk of hospitalization for infection (Cox hazard model 1.52, 95% CI 1.06-2.17). The number of hospitalization days was gradually longer in patients with high ferritin levels and malnutrition. CONCLUSION: Although serum ferritin levels were low, and doses of iron administered to dialysis patients in Japan are generally lower than in Western countries, an elevated ferritin level was associated with increased risk of infection, particularly in patients with poor nutritional status.

Development and validation of a short-version checklist for patients undergoing hemodialysis based on the International Classification of Functioning, Disability and Health.

BACKGROUND: In 2009, we developed a "100-category checklist" for patients undergoing hemodialysis (HD) based on the International Classification of Functioning, Disability and Health, and we confirmed its validity. However, we found that for patients' daily assessment, 100 categories were too many. The purpose of the present study was to develop and validate a short version of the "100-category checklist." METHODS: A total of 100 outpatients undergoing HD were recruited. They were interviewed using the "100-category checklist" and asked whether they had experienced problems after starting HD. From the "100-category checklist," we extracted categories that had greater than a 50 % rate of "yes" responses. Content validity was evaluated using the frequency of patients who had a problem in each category. Criterion validity was evaluated based on the correlation of the score from the "short-version checklist" categories with that from the Kidney Disease Quality of Life (KDQOL™) questionnaire. Construct validity was evaluated using Spearman correlation coefficients between the number of problem categories and the presence of HD-related complications. Cronbach's coefficient alpha was calculated to evaluate internal consistency. RESULTS: Twenty-two categories were identified as problem categories. Criterion validity showed that 12 categories were significantly correlated with subscales of the KDQOL™. Construct validity showed that the presence of complications contributed to an increased number of problems associated with HD. Cronbach's coefficient alpha of this checklist was 0.79. CONCLUSION: The "short-version checklist" had a certain degree of validity, suggesting its usefulness in a simplified assessment of patients undergoing HD.

Neutrophil/lymphocyte ratio as a predictor of cardiovascular events in incident dialysis patients: a Japanese prospective cohort study.

BACKGROUND: Previous studies have suggested that high neutrophil/lymphocyte ratios are related to worse outcome in patients with cardiovascular diseases. Patients with end-stage renal disease, especially those with inflammation, are at an increased risk of premature mortality, primarily because of cardiovascular disease. We aimed to clarify if high neutrophil/lymphocyte ratio is associated with increasing cardiovascular events in Japanese patients with end-stage renal disease. METHODS: We enrolled 86 incident Japanese dialysis patients (58 men, age 58 ± 11 years) in a prospective cohort study. The median follow-up was for 38.7 months. The association between neutrophil/lymphocyte ratio at the start of dialysis therapy and clinical biomarkers was investigated. Relative risks and cumulative cardiovascular disease events were calculated. RESULTS: The median neutrophil/lymphocyte ratio reported was 3.72. The duration from the start of the dialysis therapy to the first cardiovascular disease event was significantly shorter as a neutrophil/lymphocyte ratio increased (log-rank test, P = 0.003). The relative risk of cardiovascular disease events in patients with neutrophil/lymphocyte ratio > median to cardiovascular events in patients with the ratio < median as a reference was 3.02 (95 % CI 1.32-8.00) in a Cox proportional hazard model. The cumulative cardiovascular disease events during the observational period was higher in patients with neutrophil/lymphocyte ratio > median (23.0 events 100 person-years) than in patients with the ratio < median (6.8 events 100 person-years). CONCLUSIONS: A higher neutrophil/lymphocyte ratio is associated with increased risk of cardiovascular disease events and is a stronger predictor of future events.

Polymorphism of Nrf2, an antioxidative gene, is associated with blood pressure and cardiovascular mortality in hemodialysis patients.

OBJECTIVE: Nrf2 is a transcription factor that regulates the expression of antioxidant genes. This study aimed to investigate the association of Nrf2 gene single nucleotide polymorphisms (SNPs), rs35652124 (-653A/G) and rs6721961 (-617C/A), with laboratory data and mortality in hemodialysis (HD) patients. METHODS: Blood samples were obtained from 216 HD patients (119 males and 97 females; 60 diabetics and 156 non-diabetics) with mean age of 60.3±13.3 (SD) years, and mean HD duration of 9.10±8.28 years. Genotyping was performed using polymerase chain reaction with confronting two-pair primers (PCR-CTPP) assay. RESULTS: As for rs35652124, diastolic blood pressure (BP) was significantly high in total AA carriers. ß2-microglobulin was significantly low in male AA carriers. Systolic BP, diastolic BP and albumin were significantly high in female AA carriers. As for 6721961, systolic BP and diastolic BP were significantly high in female AA carriers. Cox proportional hazard analysis adjusted for age, HD duration, diabetes and Kt/V demonstrated that rs35652124 AA carriers showed higher cardiovascular mortality than (GG+GA) carriers. CONCLUSION: Nrf2 SNPs were associated with BP in Japanese HD patients. More notably, rs35652124 was associated with cardiovascular mortality in these patients.

Effect of chitosan chewing gum on reducing serum phosphorus in hemodialysis patients: a multi-center, randomized, double-blind, placebo-controlled trial.

BACKGROUND: HS219 (40 mg chitosan-loaded chewing gum) is designed to bind salivary phosphorus as an add-on to available phosphorus binders. We performed a randomized, placebo-controlled, double-blind study to evaluate the efficacy and safety of HS219 in hemodialysis (HD) patients with hyperphosphatemia as an add-on to phosphorus binders. METHODS: Sixty-eight HD patients who were maintained on calcium carbonate (n=33) or sevelamer hydrochloride (n=35) were enrolled. The primary end point was a change in serum phosphorus levels. Secondary end points included changes in levels of salivary phosphorus, serum calcium, parathyroid hormone (PTH), and intact fibroblast growth factor (iFGF) 23. RESULTS: Sixty-three patients chewed either HS219 (n=35) or placebo (n=28) for 30 min, three times a day, for 3 weeks. HS219 was well tolerated and safe. However, HS219 was not superior to placebo with additional reduction of serum phosphorus with respect to phosphorus binders at the end of the chewing period. There were no significant effects of HS219 on reduction of salivary phosphorus, serum calcium, iPTH, or iFGF23 levels. CONCLUSIONS: The chitosan-loaded chewing gum HS219 does not affect serum and salivary phosphorus levels in Japanese HD patients with hyperphosphatemia. Our findings do not support previous findings that 20 mg of chitosan-loaded chewing gum reduces serum and salivary phosphorus levels. TRIAL REGISTRATION: [corrected] ClinicalTrials.gov NCT01039428, 24 December, 2009.

Protein-bound uremic toxins in hemodialysis patients measured by liquid chromatography/tandem mass spectrometry and their effects on endothelial ROS production.

Cardiovascular disease (CVD) is prevalent in patients with chronic kidney disease (CKD). In hemodialysis (HD) patients, some protein-bound uremic toxins are considered to be associated with CVD. However, it is not yet known which uremic toxins are important in terms of endothelial toxicity. Serum samples were obtained from 45 HD patients before and after HD. Total and free serum concentrations of indoxyl sulfate, indoxyl glucuronide, indoleacetic acid, p-cresyl sulfate, p-cresyl glucuronide, phenyl sulfate, phenyl glucuronide, phenylacetic acid, phenylacetyl glutamine, hippuric acid, 4-ethylphenyl sulfate, and 3-carboxy-4-methyl-5-propyl-2-furanpropionic acid (CMPF) were simultaneously measured by liquid chromatography/electrospray ionization-mass spectrometry/mass spectrometry (LC/ESI-MS/MS). The effects of these solutes at their pre-HD mean and maximum serum concentrations on reactive oxygen species (ROS) production in human umbilical vein endothelial cells (HUVEC) were measured with a ROS probe. Serum levels of 11 of the solutes (all except 4-ethylphenyl sulfate) were significantly increased in HD patients compared to healthy subjects. All 12 solutes showed changes in their protein-binding ratios. In particular, indoxyl sulfate, p-cresyl sulfate, CMPF, and 4-ethylphenyl sulfate showed high protein-binding ratios (>95 %) and low reduction rates by HD (<35 %). Indoxyl sulfate at its mean and maximum pre-HD serum concentrations-even with 4 % albumin-stimulated ROS production in HUVEC most intensely, followed by CMPF. In conclusion, the serum levels of 11 protein-bound uremic toxins were increased in HD patients. Indoxyl sulfate, p-cresyl sulfate, and CMPF could not be removed efficiently by HD due to their high protein-binding ratios. Indoxyl sulfate most intensely induced endothelial ROS production, followed by CMPF.

On-line solid-phase extraction LC-MS/MS for the determination of Ac-SDKP peptide in human plasma from hemodialysis patients.

We developed a high-throughput method based on on-line solid-phase extraction liquid chromatography tandem mass spectrometry (SPE-LC-MS/MS) to determine N-terminal thymosin-ß fragment peptide (N-acetyl-seryl-aspartyl-lysyl-proline, Ac-SDKP) in human plasma samples. Quantification of Ac-SDKP was performed using direct injection for on-line SPE based on C(18), reversed-phase LC separation and stable isotope dilution electrospray ionization-MS/MS in multiple reaction-monitoring (MRM) mode. The Ac-SDKP-(13)C(6), (15)N(2) (m/z 496 → 137) was synthesized for the internal standard. The MRM ion for Ac-SDKP was m/z 488 → 129 (quantitative ion)/226. The limit of detection and lower limit of quantitation were 0.05 and 0.1 ng/mL in standard solution, respectively. Recovery values were 98.3-100.4% with inter-day (relative standard deviation, RSD, 0.4-14.1%) and intra-day (RSD, 0.8-19.7%) assays. This method was applied to the measurement of Ac-SDKP levels in plasma from hemodialyzed subjects. Concentrations were 0.59 ± 0.23 ng/mL (pre-hemodialyzed subjects, n = 9) and 0.44 ± 0.19 ng/mL (post-hemodialyzed subjects, n = 9). All plasma Ac-SDKP levels were decreased by dialysis. Thus, plasma Ac-SDKP was decreased through dialysis in chronic kidney disease. The findings in this study will be useful for the treatment of anemia in chronic kidney disease with dialysis.

Coronary artery calcification score is associated with mortality in Japanese hemodialysis patients.

OBJECTIVE: Coronary artery calcification has been associated with higher mortality in coronary artery disease and chronic kidney disease. This study aimed to correlate coronary artery calcification score (CACS) with all-cause and cardiovascular mortalities in hemodialysis (HD) patients. DESIGN, SETTING, SUBJECTS: A survival analysis was conducted in 200 HD patients. CACS was assessed by multidetector-row computed tomography and stratified as tertiles: group 1 (0∼105 U), group 2 (110∼1067 U), and group 3 (1094∼15481 U). The duration of follow-up was 7 years and 4 months. Kaplan-Meier method and Cox proportional hazard analysis adjusted for age and HD duration were performed to examine the impact of CACS on survival. MAIN OUTCOME MEASURE: All-cause and cardiovascular mortalities were measured. RESULTS: The cumulative all-cause and cardiovascular mortalities of group 1 were significantly lower than those of groups 2 and 3 (all-cause mortality: 7.6% vs. 43.3% and 52.2%, respectively, cardiovascular mortality: 3.0% vs. 22.4% and 26.9%, respectively). Cox proportional hazard analysis adjusted for age and HD duration revealed that all-cause and cardiovascular mortalities of group 1 were significantly lower than those of groups 2 and 3. CONCLUSION: CACS is helpful to predict prognosis of HD patients independently of age and HD duration.

SIRTUIN 1 gene polymorphisms are associated with cholesterol metabolism and coronary artery calcification in Japanese hemodialysis patients.

OBJECTIVES: Sirtuin 1 (SIRT1), a longevity gene, protects cells against oxidative and genotoxic stress. This study aimed to investigate the association of SIRT 1 gene single-nucleotide polymorphisms, namely, rs7895833, rs7069102, and rs2273773 with lipid profiles and coronary artery calcification score in 219 Japanese hemodialysis (HD) patients. METHODS: Genotyping of these polymorphisms was performed using polymerase chain reaction with confronting two-pair primers assay. RESULTS: The A allele frequency of rs7895833 and G allele frequency of rs7069102 were significantly lower in HD patients (0.228 and 0.131, respectively) than those in 803 control subjects (general population) (0.289 and 0.181, respectively) (P = .010 and P = .012, respectively). However, the allele frequency of rs2273773 was not significantly different from that in the control subjects. Multivariate analysis adjusted for age and duration on HD demonstrated that the serum levels of total and low-density lipoprotein cholesterol were significantly high in G allele carriers of rs7069102 compared with CC genotype in male HD patients. Coronary artery calcification score was significantly high in C allele carriers of rs2273773 in all and male HD patients. CONCLUSIONS: SIRT 1 polymorphisms, rs7069102 and rs2273773, are associated with abnormal cholesterol metabolism and coronary artery calcification, respectively, in Japanese HD patients, especially in males.

A Prospective, Randomized Clinical Trial of Etelcalcetide in Patients Receiving Hemodialysis With Secondary Hyperparathyroidism (the DUET Trial).

INTRODUCTION: The clinical trial on the Development of a treatment strategy for chronic kidney disease‒mineral and bone disorder by a mUltilateral mechanism of ETelcalcetide hydrochloride, or the DUET trial, was designed to determine the efficacy of etelcalcetide, an intravenous calcimimetic, for control of secondary hyperparathyroidism (SHPT). METHODS: Eligible SHPT maintenance hemodialysis patients (n = 124) were randomized (1:1:1) for inclusion in the DUET trial, a 12-week, multicenter, open-label, parallel-group study (jRCTs041180108), and assigned to either an etelcalcetide + active vitamin D group (group E+D), an etelcalcetide + oral calcium preparation group (group E+Ca), or a control group (group C). The primary endpoint was number of patients with a 50% reduction from baseline of intact parathyroid hormone (iPTH) levels, and iPTH levels ≤ 240 pg/mL at 12 weeks after start of the trial. RESULTS: The proportion of patients reaching the primary endpoint (95% confidence interval [CI]) was 90.0% (76.3%-97.2%) in group E+D, 56.8% (39.5%-72.9%) in group E+Ca, and 19.5% (8.8%-34.9%) in group C. Etelcalcetide treatment led to a significant increase in the number of patients achieving the endpoint (odds ratio, 13.4; 95% CI, 5.10-35.3) on logistic regression analysis, with iPTH, corrected serum calcium, and phosphate at baseline as covariates. Significantly more patients achieved the endpoint in group E+D compared with group E+Ca (odds ratio, 6.35; 95% CI, 1.79-22.48). There were fewer hypocalcemic visits in group E+D compared with group E+Ca (P = 0.018), yet the former group was prone to hyperphosphatemia. CONCLUSION: Etelcalcetide showed good control of iPTH for maintenance hemodialysis patients with SHPT. Active vitamin D was useful in correcting hypocalcemia, but the oral calcium preparation was superior for suppression of hyperphosphatemia.

KLOTHO gene polymorphisms G-395A and C1818T are associated with low-density lipoprotein cholesterol and uric acid in Japanese hemodialysis patients.

BACKGROUND/AIMS: This study aimed to investigate the association of the KLOTHO gene single nucleotide polymorphisms (SNPs), G-395A and C1818T, with various laboratory data in 219 Japanese hemodialysis (HD) patients. METHODS: The genotyping of G-395A in the promoter region and C1818T in exon 4 was performed using polymerase chain reaction with confronting two-pair primers (PCR-CTPP) assay. RESULTS: In HD patients, the allele frequencies of G-395A were 0.847 for the G allele and 0.153 for the A allele and those of the C1818T were 0.829 for the C allele and 0.171 for the T allele. There were no significant differences in allele frequencies of G-395A and those of the C1818T between HD patients and healthy subjects. Multivariate analysis adjusted for age and duration on HD demonstrated that uric acid was significantly high in A allele carriers of G-395A compared with GG genotype in all and female patients. Low-density lipoprotein cholesterol was significantly low in T allele carriers of C1818T compared with CC genotype in all and male patients. CONCLUSION: KLOTHO gene SNPs G-395A and C1818T are associated with low-density lipoprotein cholesterol and uric acid in HD patients.

Cardiac troponin T and advanced glycation end-products in hemodialysis patients.

BACKGROUND: Cardiac troponin T (cTnT) is used as a biomarker of myocardial damage for the diagnosis of acute myocardial infarction and acute coronary syndrome. The aim was to investigate the association between advanced glycation end products (AGEs) and cTnT in hemodialysis (HD) patients. METHODS: The plasma level of cTnT in 224 HD patients was measured using the electrochemiluminescence immunoassay. The plasma levels of N(epsilon)-(carboxymethyl)lysine (CML) and pentosidine were measured using an enzyme-linked immunosorbent assay. RESULTS: The cTnT-positive group (>0.1 ng/ml) showed significantly high plasma levels of calcium, CML and pentosidine as compared with the cTnT-negative group. In multiple logistic regression analysis, the prevalence of patients with high plasma calcium (>median) was increased in the cTnT-positive group as compared with the cTnT-negative group (OR: 5.08, 95% CI: 1.62-15.92, p < 0.01). The prevalence of high plasma CML (>median) was increased in the cTnT-positive group (OR: 4.45, 95% CI: 1.41-14.03, p < 0.05). Further, the prevalence of high plasma pentosidine (>median) was also increased in the cTnT-positive group (OR: 4.94, 95% CI: 1.55-15.70, p < 0.01). CONCLUSION: In addition to calcium, AGEs such as CML and pentosidine were associated with cTnT, a marker of myocardial damage, in HD patients.

Comparison of sleep-disordered breathing and heart rate variability between hemodialysis and non-hemodialysis days in hemodialysis patients.

Sleep disturbances manifesting as insomnia, daytime sleepiness, fatigue, and other symptoms are frequently found in patients with end-stage renal disease that is being treated with dialysis. Many factors, including neurosis, uremic symptoms, dialysis drugs, and sleep-wake rhythms have been suggested as potential causes for these sleep disturbances. We examined sleep apnea/hypopnea and heart rate variability (HRV) reflecting autonomic activity in hemodialysis patients on their hemodialysis and non-hemodialysis days using a home medical care device (Morpheus C, TEIJIN). Eleven hemodialysis patients and 14 healthy adults were enrolled in this study. We calculated the number of apnea/hypopnea episodes per hour (apnea/hypopnea index: AHI) and HRV (percentage of R-R intervals that differ by at least 50 ms from the previous interval: pNN50, very low frequency: VLF, low frequency: LF, high frequency: HF and LF/ HF). There was no significant difference in the AHI between hemodialysis and non-hemodialysis days. The heart rate in hemodialysis patients on non-hemodialysis days was significantly higher than in the controls, whereas the pNN50 was significantly lower in hemodialysis patients on non-hemodialysis days than in the controls. Although VLF was significantly lower in hemodialysis patients on non-hemodialysis days compared to the controls, there were no significant differences in LF, HF or LF/HF between the two groups. Hemodialysis itself might not be an important contributing factor in sleep-related breathing disturbances. The simultaneous analysis of HRV reflecting autonomic activity and sleep-disordered breathing on both hemodialysis and non-hemodialysis days provides important information.

Indoxyl sulfate and atherosclerotic risk factors in hemodialysis patients.

BACKGROUND: Indoxyl sulfate is a uremic toxin that accelerates the progression of chronic kidney disease (CKD). Serum levels of indoxyl sulfate are increased in dialysis patients. It was reported that indoxyl sulfate plays a role in endothelial dysfunction in uremic patients, and stimulates proliferation of rat vascular smooth muscle cells (VSMC). We examined associations between indoxyl sulfate and several markers related to atherosclerosis. METHODS: The association between indoxyl sulfate and atherosclerotic risk factors was studied in 224 hemodialysis (HD) patients (123 male, 101 female). Serum levels of indoxyl sulfate were measured by using high-performance liquid chromatography (HPLC). RESULTS: There were significant differences in serum levels of creatinine, calcium x phosphate and pentosidine between high- and low-indoxyl sulfate level groups. Indoxyl sulfate showed significant positive correlations with pentosidine, creatinine, and protein catabolic rate, and a significant negative correlation with high-density lipoprotein (HDL) cholesterol. Further, pentosidine, creatinine, and HDL-cholesterol were independently associated with indoxyl sulfate by multiple linear regression analysis. CONCLUSION: In addition to creatinine, pentosidine and HDL-cholesterol, the risk factors of atherosclerosis, were associated with indoxyl sulfate in HD patients. Indoxyl sulfate may be involved in the pathogenesis of atherosclerosis.

Is the volume of the parathyroid gland a predictor of Maxacalcitol response in advanced secondary hyperparathyroidism?

We evaluated the relationship between the volume of parathyroid glands estimated by ultrasonography (US) and response of 22-oxa calcitriol (Maxacalcitol, OCT) in patients with secondary hyperparathyroidism (2HPT) to evaluate whether the volume can be a predictor of the OCT response. Eleven institutes participated in this study. Ninety-four patients with advanced 2HPT were enrolled. The volume of the parathyroid glands were estimated by US before and 6 months after OCT treatment. The response of OCT treatment was classified into three groups (Group A: i-PTH < 300 pg/mL; Group B: 300 pg/mL < or = i-PTH < 500 pg/mL; Group C: i-PTH > or = 500 pg/mL). Forty-eight patients were in Group A, 28 patients in Group B, and 18 patients in Group C. The PTH levels at the beginning and 6 months were 458.3-199.1 pg/mL (P < 0.0001) in Group A, 524.6-403.2 pg/mL (P = 0.007) in Group B and 736.7-613.6 pg/mL (ns) in Group C, respectively. The volume of the largest gland in Group B was significantly larger than that in Group A (96.2 vs. 343.2 mm3: P < 0.001). Clinical factors affecting response of OCT was evaluated by logistic regression analysis and only the volume of the largest gland was a significant factor. In the patients whose volume was less than 300 mm3, the OCT response was significantly effective. We conclude that the glandular volume of the largest parathyroid gland estimated by US can be a useful factor to predict the OCT response in patients with moderate or severe renal HPT.

Role of sevelamer hydrochloride in the coronary artery calcification score.

The coronary artery calcification score (CACS) is higher in hemodialysis (HD) patients than in non-HD patients for each age group from the fifth to the eighth decade of life. In order to clarify the relationship between the rate of change in the CACS and several factors related to calcium (Ca) and phosphate (P) metabolism in HD patients, we determined the CACS twice in 144 HD outpatients at an interval of approximately 12 months (2003 and 2004). The dosage of vitamin D formulations (alfacalcidol or maxacalcitol) was reduced or ceased if the serum Ca concentration exceeded 5.0 mEq/L, or the serum P concentration exceeded 6.0 mg/dL, and the dosage of combined sevelamer hydrochloride (SH) and calcium carbonate (CaCO3), as the phosphate binder, was adjusted to maintain the concentrations below these levels. The study parameters were: (1) the total dosage of alfacalcidol (microg), maxacalcitol (microg), SH (mg), and CaCO3 at the time of each CACS measurement; and (2) serum concentrations of Ca, P, alkaline phosphatase, high-sensitivity parathyroid hormone (HS-PTH), total protein, albumin, total cholesterol, triglycerides (TG). Regression analysis showed a significant correlation among the total SH dosage, TG, and alphaCACS. Future investigations will include the differences in alphaCACS between patients treated with SH who experience a rise in Ca and/or P and those with a decrease in Ca and/or P.

Validity of a checklist for hemodialysis patients based on the International Classification Of Functioning, Disability and Health.

In 2009, we reported a "100-category checklist" for hemodialysis (HD) patients based on the International Classification of Functioning, Disability and Health. The purpose of the present study is to evaluate the validity and reliability of this checklist. The present study included 100 participants who had been on HD for at least 5 years when they were interviewed using the checklist. Subjects were asked whether they had experienced problems in each category since starting HD treatment. Categories for which more than 25% of subjects answered "yes" were extracted as problem categories. Additionally, the Kidney Disease Quality of Life (KDQOL) instrument was administered to the study subjects. Content validity was evaluated using the frequency and percentage of subjects who had a problem in each category. Criterion validity was performed based on correlation of the findings from the "100-category checklist" categories with the findings of the KDQOL. Construct validity was assessed based on the number of problem categories extracted as external criteria in carpal tunnel syndrome (CTS), anemia, and secondary hyperparathyroidism (SHPT). For reliability evaluation, we used Cronbach's coefficient alpha. Content validity showed that 54 were identified as problem categories. Criterion validity showed that 45 categories in all components correlated significantly with each subscale of the KDQOL. Construct validity showed that CTS, anemia, and SHPT contributed to an increased number of problems associated with HD. Cronbach's coefficient alpha of the "100-category checklist" was 0.86. This study confirmed the validity and reliability of the "100-category checklist".

Correlation between Serum Levels of Protein-Bound Uremic Toxins in Hemodialysis Patients Measured by LC/MS/MS.

Uremic toxins are involved in a variety of symptoms in advanced chronic kidney disease. Especially, the accumulation of protein-bound uremic toxins in the blood of dialysis patients might play an important role in the development of cardiovascular disease. Serum concentration of protein-bound uremic toxins such as indoxyl sulfate, indoxyl glucuronide, indoleacetic acid, p-cresyl sulfate, p-cresyl glucuronide, phenyl sulfate, phenyl glucuronide, phenylacetic acid, phenylacetylglutamine, hippuric acid, 4-ethylphenyl sulfate, and 3-carboxy-4-methyl-5-propyl-2-furanpropionic acid (CMPF) in hemodialysis patients were simultaneously measured by liquid chromatography/tandem mass spectrometry. Serum levels of these protein-bound uremic toxins were increased in hemodialysis patients. Indoxyl sulfate, p-cresyl sulfate, and CMPF could not be removed efficiently by hemodialysis due to their high protein-binding ratios. Serum level of total indoxyl sulfate did not show any significant correlation with total p-cresyl sulfate. However, free indoxyl sulfate correlated with free p-cresyl sulfate, and reduction rate by hemodialysis of indoxyl sulfate correlated with that of p-cresyl sulfate. Serum levels of total and free indoxyl sulfate showed significantly positive correlation with those of indoxyl glucuronide, phenyl sulfate, and phenyl glucuronide. Serum levels of total and free p-cresyl sulfate showed significantly positive correlation with those of p-cresyl glucuronide, phenylacetylglutamine, and phenylacetic acid. Indoxyl sulfate and indoxyl glucuronide are produced from indole which is produced in the intestine from tryptophan by intestinal bacteria. p-Cresyl sulfate and p-cresyl glucuronide are produced from p-cresol which is produced in the intestine from tyrosine by intestinal bacteria. Thus, intestinal bacteria play an important role in the metabolism of protein-bound uremic toxins.

DNA hypermethylation and inflammatory markers in incident Japanese dialysis patients.

BACKGROUND/AIMS: Inflammation is an established mortality risk factor in chronic kidney disease (CKD) patients. Although a previous report showed that uremic Caucasian patients with inflammation had signs of global DNA hypermethylation, it is still unknown whether DNA hypermethylation is linked to inflammatory markers including a marker of bacterial infections in Japanese CKD patients. METHODS: In 44 consecutive incident dialysis patients (26 males, mean age 59 ± 12 years) without clinical signs of infection, global DNA methylation was evaluated in peripheral blood DNA using the HpaII/MspI ratio by the luminometric methylation assay method. A lower ratio of HpaII/MspI indicates global DNA hypermethylation. Procalcitonin (PCT), a marker of inflammation due to bacterial infections, was measured using an immunochromatographic assay. RESULTS: The patients were divided into hyper- and hypomethylation groups based on the median value of the HpaII/MspI ratio 0.31 (range 0.29-0.37). Whereas patients in the hypermethylation group had higher ferritin levels [133.0 (51.5-247.3) vs. 59.5 (40.0-119.0) ng/ml; p = 0.046], there were no significant differences in age, gender, diabetes, smoking, anemia or serum albumin levels. However, the HpaII/MspI ratio showed significant negative correlations with PCT (ρ = -0.32, p = 0.035) and ferritin (ρ = -0.33, p = 0.027) in Spearman's rank test. In a multiple linear regression analysis, PCT and ferritin were associated with a lower HpaII/MspI ratio (R(2) = 0.24, p = 0.013). CONCLUSION: In this study, global DNA hypermethylation was associated with ferritin and, most likely, PCT, suggesting that inflammation induced by subclinical bacterial infection promoted DNA methylation.

Quantification of N-acetyl-seryl-aspartyl-lysyl-proline in hemodialysis patients administered angiotensin-converting enzyme inhibitors by stable isotope dilution liquid chromatography-tandem mass spectrometry.

We developed a sensitive, selective and accurate method based on liquid chromatography with tandem mass spectrometry (LC-MS/MS) to determine N-terminal thymosin-ß peptides of Ac-SDKP and Ac-ADKP in human plasma samples. Quantification of Ac-SDKP and Ac-ADKP was performed using solid phase extraction (SPE) based on C(18), reversed phase LC separation, and stable isotope dilution electrospray ionization-MS/MS in multiple reaction-monitoring (MRM) mode. The Ac-SDKP-(13)C(6), (15)N(2) and Ac-ADKP-d(7) were synthesized for the internal standards. These MRM monitoring ions were m/z 488→129 (quantitative ion)/226 for Ac-SDKP, m/z 496→137 for Ac-SDKP-(13)C(6), (15)N(2), m/z 472→129 (quantitative ion)/226 for Ac-ADKP, and m/z 479→129 for Ac-ADKP-d(7), respectively. Lower limit of quantitation (LLOQ) of Ac-SDKP and Ac-ADKP was 0.1ng/mL in human plasma. Recovery values were ranged from 94.7% to 106.3% for inter- (RSD: 0.6-3.5%) and intra- (RSD: 0.4-4.9%) day assays. Plasma Ac-SDKP levels were significantly higher in hemodialyzed subjects treated with angiotensin-converting enzyme inhibitors of enalapril (27.3±24.6ng/mL, n=10) and trandolapril (12.3±16.9ng/mL, n=18) than healthy (0.4±0.2ng/mL, n=7) and hemodialyzed subjects (0.6±0.2ng/mL, n=34). This analytical method would be useful to measure N-terminal thymosin-ß peptides in human plasma for the clinical study.