Clinical effectiveness of molnupiravir in patients with COVID-19 undergoing haemodialysis.

BACKGROUND: Molnupiravir is an essential oral antiviral agent against coronavirus disease 2019 (COVID-19); however, its real-world effectiveness has not been evaluated in patients undergoing haemodialysis (HD). METHODS: This multi-centre retrospective study, involving 225 patients undergoing HD with initially mild or asymptomatic COVID-19, was conducted to compare the risks of 30-day COVID-19-related acute care visits between patients receiving and not receiving molnupiravir. Patients who received molnupiravir were stratified by rapid antigen detection (RAD) test results on day 7 after disease onset to assess whether rapid molnupiravir introduction accelerated viral clearance. RESULTS: Thirty-day COVID-19-related acute care visits were reported in 9.41% and 21.74% of the molnupiravir and control groups, respectively, and use of molnupiravir markedly reduced the risk of acute care visits after adjusting for baseline characteristics via propensity score weighting [hazard ratio 0.218, 95% confidence interval (CI) 0.074-0.642; P=0.006]. The tolerability of molnupiravir in the enrolled patients was generally acceptable, with only 11.88% of molnupiravir users reporting mild adverse events. Moreover, rapid initiation of molnupiravir within 1 day of COVID-19 onset was an independent predictor of conversion to a negative RAD test result on day 7 after disease onset (odds ratio 6.207, 95% CI 2.509-15.358; P<0.001). CONCLUSIONS: Molnupiravir is well tolerated and decreases the medical needs in patients with COVID-19 undergoing HD. Furthermore, the rapid initiation of molnupiravir accelerates viral clearance in patients with COVID-19 undergoing HD. These findings highlight the therapeutic role of molnupiravir for this vulnerable population.

Reference ranges for ultrasonographic renal dimensions as functions of age and body indices: A retrospective observational study in Taiwan.

An ethnicity-based reference range for normal renal size is fundamental for ultrasonographic assessment. Herein, we aimed to establish a Chinese renal reference by a large sample size, as well as to elucidate the relationship of renal dimension to age and body indices, with the aid of a comprehensive literature review. Records of 3707 healthy cases were obtained from health evaluation centers of Kaohsiung and Linkuo Chang Gung Memorial Hospitals. As a result, the mean right renal length was 10.62±0.69 cm, left renal length 10.76±0.70 cm, right renal width 4.78±0.75 cm, and left renal width 5.10±0.64 cm. Renal size was well-correlated curvilinearly to age, while linearly to body height, body weight, and body mass index. Renal size increases and then decreases with aging, and significant variations of renal size exist among different ethnicities. Our work provides a reliable reference range for renal size in the Chinese population, and valid relationships between renal dimensions and other parameters.

Longitudinal analysis of cardiac structure and function in incident-automated peritoneal dialysis: comparison between icodextrin solution and glucose-based solution.

BACKGROUND: This study aimed to evaluate the longitudinal changes in cardiac structure and function in incident-automated peritoneal dialysis (APD) patients. METHODS: We conducted a 2-year prospective, randomized, open-label, parallel-group study to compare the efficacy of icodextrin solution versus glucose-based solution. Echocardiography was performed at baseline, 1 and 2 years. Echocardiographic parameters over 2 years were evaluated for each group, using the Friedman test. Generalized linear regression analysis was used to test the associations between baseline clinical variables and echocardiographic changes, and a multivariate model was used to analyze cardiac function between the two groups. RESULTS: A total of 43 APD patients were enrolled in the beginning of this study. Twenty patients in the icodextrin group (ICO) and 18 patients in the glucose group (GLU) completed the study. In left ventricular (LV) systolic function measurements, ejection fraction (EF) increased significantly in the GLU group. Measurements of LV diastolic function and septal early mitral annulus velocity (EMV) increased significantly from baseline to 24-months in the ICO group (5.43-5.51 ms). The GLU group showed a significant decrease in peak early diastolic velocity (EDV) (70.67-68.25 cm/s), but a significant increase in septal EMV (5.94-7.57 ms) from baseline to 24-months. No significant association was found between the baseline clinical variables and echocardiographic changes within 24 months in the generalized linear regression analysis. Multivariate models were used to investigate changes in the four primary endpoints, namely, myocardial performance index (MPI), left ventricular ejection fraction (LVEF), deceleration time (DT), and E/e' ratio. These primary endpoints show no significant association with the baseline values in both the ICO and GLU groups. CONCLUSION: The present study demonstrates that long-dwell icodextrin solution can maintain reasonable cardiac structure and function in incident-APD patients. TRIAL REGISTRATION: ISRCTN14931270 (retrospectively registered on 23/03/2018).

Incidence and outcomes of encapsulating peritoneal sclerosis (EPS) and factors associated with severe EPS.

BACKGROUND: Encapsulating peritoneal sclerosis (EPS) is a rare but serious complication of long-term peritoneal dialysis (PD). However, previous studies reported large variations in its mortality rates that may associate with a different degree of EPS severity. This study reports the incidence and outcomes of EPS and identifies the risk factors associated with severe EPS. METHODS: We retrospectively analyzed clinical data of EPS patients from 3 medical centers in Taiwan from January 1982 to September 2015, and classified patients as having mild/moderate or severe EPS. Patients with intractable intestinal obstruction/gut-related sepsis that needed surgical intervention or resulted in mortality were in severe EPS group. Follow-up for outcome was through December 31, 2015. Clinical characteristics, peritoneal dialysis (PD)-related parameters, biochemical and imaging results were analyzed and compared between groups. RESULTS: Fifty-eight of 3202 patients undergoing PD during the study period had EPS (prevalence 1.8%). The incidence of EPS increased for patients on PD for >6-8 years (≤6 yrs. vs. >6-8 yrs., 0.0% vs. 1.8%, p = 0.001). Relative to those on PD for >6-8 years, the risk of EPS significantly increased with PD duration longer than 10 years (>10-12 years vs. >6-8 years: OR: 5.5, 95% CI: 1.7-17.1, p < 0.01). Twenty-three patients fulfilled the criteria for severe EPS. The overall mortality rate of EPS was 35% (20/58), and was 74% (17/23) in the severe EPS group. The average serum levels of C-reactive protein (CRP) and intact-parathyroid hormone (i-PTH), which were checked every 3~6 months within one year before diagnosis of EPS, were higher in severe EPS group than in mild/moderate group (p = 0.02, p = 0.08, respectively). Multivariate analysis revealed severe EPS was independently associated with bowel tethering (based on CT), presentation with bloody ascites, diagnosis of EPS after withdrawal from PD, and i-PTH ≥ 384 pg/mL. Receiver operating characteristic analysis indicated that presentation with 2 or more of the 5 risk factors (EPS diagnosis after PD withdrawal, bloody ascites, bowel tethering, CRP ≥ 29 mg/L, and i-PTH ≥ 384 pg/mL) had a good accuracy (AUC = 0.80, p = 0.001) for prediction of severe EPS. CONCLUSIONS: The incidence of EPS increases with PD duration. Severe EPS has high mortality rate and is associated with bowel tethering, presentation of bloody ascites, diagnosis after PD withdrawal, and higher serum levels of i-PTH before EPS diagnosis. Having 2 or more of the 5 risk factors can provide a good accuracy for prediction of severe EPS.

An association between time-varying serum alkaline phosphatase concentrations and mortality rate in patients undergoing peritoneal dialysis: a five-year cohort study.

The relationship between serum alkaline phosphatase (ALP) concentrations and mortality in peritoneal dialysis (PD) patients is rarely reported. We enrolled 667 PD patients in one PD centre in Taiwan to retrospectively examine the association between three ALP concentrations (baseline, time-averaged, time-dependent) and mortality over a 5-year period (2011-2015). Baseline data collection included demographics, clinical, and laboratory parameters. Multivariable-adjusted Cox models were used to analyse the association. Four ALP quartiles were defined at the baseline: ≤62, 63-82, 83-118, and ≥119 U/L. Of 667 patients, 65 patients died, of which 8 patients died due to cardiovascular disease. Females were predominant in the higher ALP quartiles, and 24-h urine volume was significantly proportionately decreased in the higher ALP quartiles. ALP quartiles expressed by the three models were not associated with all-cause or cardiovascular mortalities after adjusting for demographics, liver function, bone metabolism, mortality, hemoglobin, and 24-h urine volume. In conclusion, ALP concentrations were not associated with death risk in PD patients over the 5-year period.

Changes in Serum Concentrations of Fibroblast Growth Factor 23 and Soluble Klotho in Hemodialysis Patients after Total Parathyroidectomy.

Background. We examined the changes in circulating fibroblast growth factor 23 (FGF23) and Klotho concentrations in hemodialysis patients after parathyroidectomy (PTX). Methods. We enrolled a cohort of hemodialysis patients who received PTX. Postoperatively, patients received calcium supplements and/or vitamin D analogue (calcitriol) to maintain serum calcium within 7.0-8.0 mg/dL. Information on clinical parameters including bone-mineral metabolic variables was collected pre-PTX and on days 5 and 90 after PTX. Concomitantly, serum full-length FGF23 and α-Klotho levels were measured. The relationship between FGF23 and clinical parameters was analyzed by single linear regression. Results. Forty-six participants (33 women; 13 men) were enrolled in the study. Their mean age was 56.49 years. Serum FGF23 and α-Klotho concentrations were elevated on days 5 and 90 after PTX compared to baseline (p > 0.05). Serum FGF23 concentrations negatively correlated with serum calcium concentrations pre-PTX (Beta -0.31; R2 0.0949; p = 0.040), day 5 post-PTX (Beta -0.31; R2 0.0982; p = 0.036), and day 90 post-PTX (Beta -0.39; R2 0.1528; p = 0.008). Conclusions. There was no change in circulating FGF23 and Klotho concentrations after PTX in hemodialysis patients given postoperative calcium supplements and/or vitamin D analogue. Serum FGF23 concentrations pre-PTX and at days 5 and 90 after PTX were inversely related to serum calcium concentrations.

Switch From Epoetin Beta to Darbepoetin Alfa Treatment of Anemia in Taiwanese Hemodialysis Patients: Dose Equivalence by Hemoglobin Stratification.

This multicenter study was designed to assess the hemoglobin (Hb) stability and conversion ratio of the switch from epoetin beta to darbepoetin alfa in Taiwanese hemodialysis (HD) patients. A total of 135 HD patients were enrolled and randomized with intravenous darbepoetin alfa or epoetin beta. The study duration was 24 weeks. Equivalent doses and conversion ratios were assessed with respect to Hb stratification: low Hb (≥8.0 g/dL to ≤10.0 g/dL) and high Hb (>10.0 g/dL to ≤11.0 g/dL). The results showed stable Hb levels in the study period. At week 24, the conversion ratio was higher for high Hb than low Hb (296.4 IU/dose epoetin beta: 1 µg/dose darbepoetin alfa. vs. 277.2 IU/dose epoetin beta: 1 µg/dose darbepoetin alfa). In conclusion, the conversion ratio in the present study was higher than 1 µg: 200 IU for darbepoetin alfa: epoetin for treating anemia in Taiwanese HD patients.

Gelsolin and Progression of Aortic Arch Calcification in Chronic Hemodialysis Patients.

BACKGROUND: Vascular calcification (VC) is a key process associated with cardiovascular mortality in dialysis patients. Gelsolin is an actin-binding protein that can modulate inflammation, correlated inversely with hemodialysis (HD) mortality and involved in bone calcification homeostasis. In this report, we aim to characterize progression in aortic arch calcification (AAC) and investigate its association with gelsolin. METHODS: 184 HD patients were enrolled and their annual posterior-anterior chest X-ray films (CXR) in 2009 and 2013 were examined. The severity of AAC was classified as grade 0 to 3. Blood levels of gelsolin were measured by ELISA kits. Biographic and biochemical data at baseline were analyzed with status of AAC at baseline and changes after 4 years. RESULTS: At baseline, 60% of the patients had detectable AAC on CXR. After 4 years, 77% had AAC. Patients with grade 1 and 2 AAC had increased risk of progression (Odds ratio [OR] 2~3, P=0.001) compared to those with grade 0 at baseline. Compared to those with no AAC, patients with AAC progression had older age, lower gelsolin, higher waist circumference and prevalence of vascular disease. Regression analysis confirmed baseline gelsolin (odds ratio 0.845, 95% confidence interval [0.734-0.974]) and waist circumference as the independent factors associated with AAC progression. Gelsolin is positively correlated with serum albumin and negatively with tumor necrosis factor-alpha. CONCLUSION: Our study demonstrated that HD patients with grades 1 or 2 baseline AAC are at increased risk of further progression compared to those with grade 0. We also found lower blood levels of gelsolin associated with progressive AAC. Further investigation into the mechanistic roles of gelsolin in vascular calcification may provide new understanding of this key process.

Gelsolin and adipokines are associated with protein-energy wasting in hemodialysis patients.

Protein-energy wasting (PEW) contributes to mortality in hemodialysis (HD) patients. Adipokines regulate energy homeostasis and body weight. Circulating gelsolin can modulate inflammation and is correlated with HD mortality. Whether adipokines and gelsolin play important roles in PEW remains unclear. Based on the criteria proposed by the International Society of Renal Nutrition and Metabolism, we examined the associations between PEW and biomarkers (gelsolin, leptin, adiponectin, interleukin-6, tumor necrosis factor alpha [TNF-α]) in 188 stable HD patients. Patients with PEW had significantly lower serum leptin levels, and tended to have higher adiponectin, TNF-α, and lower gelsolin levels. Logistic regression analysis revealed that gelsolin, leptin, adiponectin, and blood urea nitrogen were independently associated with PEW score. Serum creatinine, TNF-α, gender, renin-angiotensin system (RAS) blockade, and lipid-lowering agents were not associated with PEW score. Patients on lipid-lowering agents had lower PEW scores and those with RAS blockade had higher PEW scores. Our study confirms that gelsolin, adiponectin, and leptin are significant associates with PEW in HD patients. Further understanding of how these factors contribute to PEW may help design novel therapeutic strategies for PEW in chronic kidney disease.

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.

Increasing high-sensitive C-reactive protein level predicts peritonitis risk in chronic peritoneal dialysis patients.

BACKGROUND: The aim of this study was to evaluate whether a high baseline level of high-sensitivity C-reactive protein (hs-CRP) or changes in the level predicts the risk of peritonitis in patients on continuous ambulatory peritoneal dialysis (CAPD). METHODS: A prospective, cross-sectional, case-control study was conducted in a single hospital-based PD unit. A total of 327 patients were included in the study. Serum hs-CRP was measured annually for 2 years. Patients were divided into 4 groups according to the changes in annual hs-CRP levels (at baseline and at 1 year intervals): group 1 (from <5 mg/L to <5 mg/L, n = 171), group 2 (from <5 mg/L to ≥5 mg/L, n = 45), group 3 (from ≥5 mg/L to <5 mg/L, n = 45), and group 4 (from ≥5 mg/L to ≥5 mg/L, n = 80). Demographics, biochemistry results, PD adequacy indices, and peritonitis risk were compared between the groups. RESULTS: The initial serum albumin level was similar in the 4 groups (p = 0.12). There was a negative linear correlation between the serial albumin change (∆alb) and serial hs-CRP change (∆hs-CRP; r = -0.154, p = 0.005). The hazard ratio (HR) for peritonitis was significantly higher in group 2 (HR = 1, reference) than in group 4 (HR = 0.401, 95% CI 0.209 - 0.769). Group 2 had a greater serum albumin decline rate (∆alb: -3% ± 9%) and hs-CRP elevation rate (∆hs-CRP: 835% ± 1232%) compared to those for the other groups. CONCLUSIONS: A progressive increase in the hs-CRP level was associated with a corresponding decline in the serum albumin level. Progressive rather than persistently high levels of serum hs-CRP predicted peritonitis risk in CAPD patients.

Adherence to phosphate binder therapy is the primary determinant of hyperphosphatemia incidence in patients receiving peritoneal dialysis.

We investigated the major determinant of hyperphosphatemia incidence among patients receiving peritoneal dialysis. Seventy-six patients aged 25-55 years who had received peritoneal dialysis for more than 3 months were recruited. The patients were divided into three groups according to their serum phosphorus levels (Group 1, ≥ 6 mg/dL; Group 2, 5.9-4.8 mg/dL; and Group 3, <4.8 mg/dL). Renal dietitians interviewed the patients to determine their phosphate intake and adherence to phosphate binder therapy. No statistical differences in demographics or phosphate intake were identified among the groups. However, adherence to phosphate binders was greater in Group 3 than in Groups 1 and 2 (96.3% vs. 21.4% and 52.4%, respectively; P < 0.001). Multivariate analysis showed that adherence to phosphate binder therapy was the only significant contributor to serum phosphorus levels (P= 0.0001). Adherence to diet was better than adherence to phosphate binder therapy among patients receiving peritoneal dialysis, and the latter determined the incidence of hyperphosphatemia.

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.

BACKGROUND: It 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. METHODS: It 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. RESULTS: Seventy-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. LIMITATIONS: A small cohort and a short observation period. CONCLUSIONS: The 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.

Association between interleukin-10 gene polymorphism -592 (A/C) and peritoneal transport in patients undergoing peritoneal dialysis.

AIM: The aim of this analysis was to know whether these three cytokine polymorphisms, including interleukin-6 (IL-6; -572 G/C), tumour necrosis factor-α (TNF-α; -308 G/A), and IL-10 (-592 A/C) have an effect on baseline peritoneal transport property and longitudinal evolution of peritoneal function. METHODS: A total of 141 stable peritoneal dialysis (PD) patients with mean treatment duration of 84.4 ± 34.2 months were enrolled. We genotyped these three cytokine polymorphisms, together with clinical parameters that were included as factors affecting longitudinal change of property of peritoneal transport over the first 3 year period after commencing therapy. RESULTS: There was no significant association between genotypes and baseline peritoneal transport property. The -592 A/C polymorphism of IL-10 was associated with longitudinal change of peritoneal transport. The ratio of D/P creatinine was significantly higher in patients with AA than those with CC/CA genotypes at 12 months (0.65 ± 0.11 vs 0.62 ± 0.09, P = 0.048) and 24 months (0.64 ± 0.12 vs 0.59 ± 0.09, P = 0.018). In addition, patients with increased peritoneal transport have greater frequency distribution of AA genotype and A allele. Logistic regression analysis revealed that -592 A allele was an independent predictor for the increase in D/P creatinine over the first 12 month period (odds ratio: 2.482, P = 0.017). There was no correlation between either polymorphism of IL-6 -572 (G/C) or TNF-α-308 (G/A) and longitudinal change of peritoneal function. CONCLUSIONS: Single nucleotide polymorphism of IL-10 -592 (A/C) was associated with longitudinal evolution of peritoneal transport rate in PD patients rather than the baseline peritoneal characteristics.

Mitochondrial DNA copy number correlates with oxidative stress and predicts mortality in nondiabetic hemodialysis patients.

BACKGROUND: Oxidative stress is highly prevalent in hemodialysis patients and may contribute to atherosclerosis and mortality. The copy number of mitochondrial DNA (mtDNA) is affected by oxidative stress in blood circulation. This study aimed to test whether mtDNA copy number correlates with oxidative stress and predicts all-cause mortality in nondiabetic hemodialysis patients. METHODS: Ninety-five nondiabetic hemodialysis patients and 95 healthy subjects were enrolled. Plasma thiobarbituric acid-reactive substances (TBARS) and plasma free thiol were used as indicators of oxidative stress and antioxidant defense, respectively. Mitochondrial DNA copy number in peripheral blood leukocytes was measured by determining relative amounts of mtDNA to nuclear DNA by quantitative real-time PCR. All-cause mortality of hemodialysis patient was recorded during a follow-up of 3 years. RESULTS: Nondiabetic hemodialysis patients showed higher TBARS levels, lower free thiol levels and higher mtDNA copy numbers compared with normal control subjects. The plasma TBARS level was a significant factor correlating positively to the mtDNA copy number (p=0.024). Patients with a mtDNA copy number higher than the median had a higher all-cause mortality than patients with a lower mtDNA copy number (17.0% vs. 4.2%; log-rank test: p=0.038). A 1-log increase in mtDNA copy number was independently related to an increase in the risk for mortality (hazard ratio 21.360; 95% confidence interval, 1.298-351.572). CONCLUSIONS: Nondiabetic hemodialysis patients had higher oxidative stress and mtDNA copy numbers than healthy subjects. The mtDNA copy number correlates with oxidative stress and predicts mortality in nondiabetic hemodialysis patients.

A longitudinal change of peritoneal equilibration test results in peritoneal dialysis patients aged 60 years and above: a 4-year observation study in comparison with a younger group.

BACKGROUND: The number of elderly people with end-stage renal disease has grown in developed countries and medical teams now face the choice of dialysis therapy in elderly patients. In the present study, we retrospectively analyzed two peritoneal dialysis (PD) patients, of different ages, who were treated at the same unit by the same PD team of doctors and nurses. Our purpose was to study peritoneal membrane changes in elderly and younger PD patients. METHODS: 108 patients above 60 years of age or younger at the start of dialysis, were separated into two cohorts. Diabetic patients were excluded. Peritoneal equilibration test (PET) results taken over 4 continuous years were compared between the two groups. RESULTS: No significant differences were seen between the two groups in peritoneal transport (D/P Cr, D/D0 glucose) during the 4-year observation. Total Kt/V and renal creatinine clearance (Ccr) values in the 4-year period were not significantly different between the two groups. Renal Ccr values showed a longitudinal decline in the two groups but the values of total Kt/V revealed a consistency over the 4-year period. CONCLUSION: Elderly PD patients demonstrated a similar peritoneal permeability to younger PD patients based on a 4-year PET.

Lack of association between mutations of gene-encoding mitochondrial D310 (displacement loop) mononucleotide repeat and oxidative stress in chronic dialysis patients in Taiwan.

BACKGROUND: Mitochondria (mt) are highly susceptible to reactive oxygen species (ROS). In this study, we investigated the association between a region within the displacement loop (D-loop) in mtDNA that is highly susceptible to ROS and oxidative stress markers in chronic dialysis patients. We enrolled 184 chronic dialysis patients and 213 age-matched healthy subjects for comparison. Blood levels of oxidative stress markers, such as thiobarbituric acid reactive substances (TBARS) and free thiol, and the mtDNA copy number were determined. A mononucleotide repeat sequence (CCCC...CCCTCCCCCC) between nucleotides 303 and 316-318 (D310) was identified in mtDNA. RESULTS: Depending on alterations in the D310 mononucleotide repeat, subjects were categorized into 4 subgroups: 7-C, 8-C, 9 or 10-C, and T-to-C transition. Oxidative stress was higher in chronic dialysis patients, evidenced by higher levels of TBARS and mtDNA copy number, and a lower level of free thiol. The distribution of 7-C, 8-C, and 9-10C in dialysis and control subjects was as follows: 7-C (38% vs. 31.5%), 8-C (35.3% vs. 43.2%), and 9-10C (24.5% vs. 22.1%). Although there were significant differences in levels of TBARS, free thiol, and the mtDNA copy number in the D310 repeat subgroups (except T-to-C transition) between dialysis patients and control subjects, post hoc analyses within the same study cohort revealed no significant differences. CONCLUSION: Although oxidative stress was elevated in chronic dialysis patients and resulted in a compensatory increase in the mtDNA copy number, homopolymeric C repeats in the mtDNA region (D310), susceptible to ROS, were not associated with oxidative stress markers in these patients.

Clinical interpretation of reticulocyte hemoglobin content, RET-Y, in chronic hemodialysis patients.

BACKGROUND: Iron deficiency is the most common factor associated with erythropoietin (EPO) hyporesponsiveness. Current iron indices are inadequate to demonstrate the status or utility of iron in erythropoiesis. The aims of this study are to investigate the value of the reticulocyte hemoglobin content, RET-Y, in hemodialysis (HD) patients and compare the levels with conventional iron indices. METHODS: HD patients (n = 289) were divided into 4 groups according to serum ferritin (cutoff value 100 ng/ml) and transferrin saturation (TSAT, cutoff value 20%). The RET-Y value, hemogram and biochemical data were determined and compared between groups. Factors associated with RET-Y were examined. RESULTS: The mean RET-Y value was 1,716 +/- 125 AU. Patients with absolute iron deficiency had lower RET-Y levels and mean corpuscular volume (MCV). Patients with functional iron deficiency had a lower reticulocyte production index and serum albumin levels. MCV, mean corpuscular hemoglobin concentration (MCHC) and albumin were independently correlated with the RET-Y level (all p < 0.001). EPO-independent patients had low iron indices and low RET-Y levels, but a higher reticulocyte production index and albumin levels were noted. CONCLUSION: RET-Y levels in HD patients were close to that of the normal population. Low RET-Y levels were observed in patients with absolute iron deficiency and also in EPO-independent patients with low ferritin and low TSAT. There was a strong association between the serum albumin and RET-Y levels in chronic HD patients.

Association between C-reactive protein and biomarkers of bone and mineral metabolism in chronic hemodialysis patients: a cross-sectional study.

OBJECTIVE: Both chronic inflammation and dysregulation of bone and mineral metabolism are closely related with long-term outcomes of dialysis patients. Our objective was to investigate the relationship between these two abnormalities. DESIGN: This was a cross-sectional study. SETTING: This study was performed at a hospital-based hemodialysis center. PATIENTS: We enrolled 448 (male, 198; female, 250) clinically stable hemodialysis patients. Patients with chronic inflammatory disease, malignancy, or viral hepatitis were excluded. Their age (mean +/- SD) was 57.4 +/- 12.5 years. MAIN OUTCOME MEASURES: Biomarkers, including high-sensitivity C-reactive protein (hsCRP), total calcium, phosphate, and intact parathyroid hormone levels, were measured and compared with the recommended range in the K/DOQI guidelines. Correlations between these parameters were analyzed, and factors independently associated with hsCRP and the calcium phosphate product (Ca x P) were identified by regression analysis. RESULTS: Most patients did not achieve the K/DOQI recommended therapeutic range in the four parameters, and only 50 patients (11%) met their treatment goals. The hsCRP level was directly related to calcium, phosphate, and Ca x P. Patients who achieved the guidelines' range had lower hsCRP levels (1.97 mg/L vs. 2.71 mg/L, P < .05). A high hsCRP level (> or = 10 mg/L) was associated with higher calcium, phosphate, and Ca x P levels, and lower albumin levels. Serum albumin, Ca x P, alkaline phosphatase, and diabetes independently predicted hsCRP levels. CONCLUSION: There is a strong association between chronic inflammation and the disturbance of bone mineral metabolism in chronic hemodialysis patients.