Effects of online hemodiafiltration on anemia and nutritional status in chronic hemodialysis patients

Background@#Online hemodiafiltration (OL-HDF) offers considerable advantages in clearance of molecules of various sizes. However, evidence of clinical effects of OL-HDF is scarce in Korea. In this study, we investigated changes in laboratory values over more than 12 months after switching to OL-HDF. @*Methods@#Adult patients with end-stage renal disease undergoing hemodialysis (HD) were prospectively enrolled in a K-cohort (CRIS no. KCT0003281) from 6 tertiary hospitals in South Korea. We recruited 435 patients, 339 of whom were on HD at enrollment. One hundred eighty-two patients were followed for more than 24 months. Among them, 44 were switched to OL-HDF for more than 12 months without conversion to HD. We used a paired t test to compare baseline and 24-month follow-up results. @*Results@#The mean age of the subjects was 61.2 ± 12.2 years, and 62.6% were male. The baseline hemoglobin level was not significantly different between HD and OL-HDF group (10.61 ± 1.15 vs. 10.46 ± 1.03 g/dL, P = 0.437). However, the baseline serum protein and albumin levels were significantly lower in the OL-HDF group (6.82 ± 0.49 vs. 6.59 ± 0.48 g/dL, P = 0.006; 3.93 ± 0.28 vs. 3.73 ± 0.29 g/dL, P < 0.001). In patients switched to OL-HDF, levels of hemoglobin and serum albumin significantly increased (10.46 ± 1.03 vs. 11.08 ± 0.82 g/dL, P = 0.001; 3.73 ± 0.29 vs.

Beneficial Effect of Chloroquine and Amodiaquine on Type 1 Diabetic Tubulopathy by Attenuating Mitochondrial Nox4 and Endoplasmic Reticulum Stress

Background@#Oxidative stress induced by chronic hyperglycemia is recognized as a significant mechanistic contributor to the development of diabetic kidney disease (DKD).Nonphagocytic nicotinamide adenine dinucleotide phosphate oxidase 4 (Nox4) is a major source of reactive oxygen species (ROS) in many cell types and in the kidney tissue of diabetic animals. We designed this study to explore the therapeutic potential of chloroquine (CQ) and amodiaquine (AQ) for inhibiting mitochondrial Nox4 and diabetic tubular injury. @*Methods@#Human renal proximal tubular epithelial cells (hRPTCs) were cultured in highglucose media (30 mM D-glucose), and diabetes was induced with streptozotocin (STZ, 50 mg/kg i.p. for 5 days) in male C57BL/6J mice. CQ and AQ were administered to the mice via intraperitoneal injection for 14 weeks. @*Results@#CQ and AQ inhibited mitochondrial Nox4 and increased mitochondrial mass in hRPTCs under high-glucose conditions. Reduced mitochondrial ROS production after treatment with the drugs resulted in decreased endoplasmic reticulum (ER) stress, suppressed inflammatory protein expression and reduced cell apoptosis in hRPTCs under high-glucose conditions. Notably, CQ and AQ treatment diminished Nox4 activation and ER stress in the kidneys of STZ-induced diabetic mice. In addition, we observed attenuated inflammatory protein expression and albuminuria in STZ-induced diabetic mice after CQ and AQ treatment. @*Conclusion@#We substantiated the protective actions of CQ and AQ in diabetic tubulopathy associated with reduced mitochondrial Nox4 activation and ER stress alleviation. Further studies exploring the roles of mitochondrial Nox4 in the pathogenesis of DKD could suggest new therapeutic targets for patients with DKD.

Diabetic kidney disease: seven questions

Diabetic kidney disease is a microvascular complication of diabetes mellitus and the leading cause of end-stage renal disease resulting in renal replacement therapy. Approximately 30% to 40% of diabetic patients have diabetic kidney disease, which contributes to a significant increase in morbidity and mortality. Microalbuminuria is considered the gold standard for diabetic kidney disease diagnosis; however, its predictive value is restricted. Although blood glucose control, blood pressure control, and angiotensin converting enzyme inhibitors have been the primary treatment strategies, there are no definitive treatment modalities capable of inhibiting the progression of kidney dysfunction in these patients. This study was undertaken to answer seven questions regarding the various aspects of diabetic kidney disease. Why does it develop? what kind of factors affect its development? How is it diagnosed? What are its possible biomarkers? When is a kidney biopsy necessary? What are the preventive and therapeutic options? And what are the novel treatments?

Diabetic kidney disease: seven questions

Diabetic kidney disease is a microvascular complication of diabetes mellitus and the leading cause of end-stage renal disease resulting in renal replacement therapy. Approximately 30% to 40% of diabetic patients have diabetic kidney disease, which contributes to a significant increase in morbidity and mortality. Microalbuminuria is considered the gold standard for diabetic kidney disease diagnosis; however, its predictive value is restricted. Although blood glucose control, blood pressure control, and angiotensin converting enzyme inhibitors have been the primary treatment strategies, there are no definitive treatment modalities capable of inhibiting the progression of kidney dysfunction in these patients. This study was undertaken to answer seven questions regarding the various aspects of diabetic kidney disease. Why does it develop? what kind of factors affect its development? How is it diagnosed? What are its possible biomarkers? When is a kidney biopsy necessary? What are the preventive and therapeutic options? And what are the novel treatments?

Diabetic kidney disease: seven questions

Diabetic kidney disease is a microvascular complication of diabetes mellitus and the leading cause of end-stage renal disease resulting in renal replacement therapy. Approximately 30% to 40% of diabetic patients have diabetic kidney disease, which contributes to a significant increase in morbidity and mortality. Microalbuminuria is considered the gold standard for diabetic kidney disease diagnosis; however, its predictive value is restricted. Although blood glucose control, blood pressure control, and angiotensin converting enzyme inhibitors have been the primary treatment strategies, there are no definitive treatment modalities capable of inhibiting the progression of kidney dysfunction in these patients. This study was undertaken to answer seven questions regarding the various aspects of diabetic kidney disease. Why does it develop? what kind of factors affect its development? How is it diagnosed? What are its possible biomarkers? When is a kidney biopsy necessary? What are the preventive and therapeutic options? And what are the novel treatments?

Stabilization of serum alkaline phosphatase in hemodialysis patients by implementation of local chronic kidney disease-mineral bone disorder management strategy: A quality improvement study

BACKGROUND: The aim of this study is to narrow the gap between global guidelines and local practices, we recently established domestic recommendations by adapting the international guidelines for management of chronic kidney disease-mineral bone disorder (CKD-MBD) in patients on maintenance hemodialysis (MHD). This study was undertaken to determine whether application of this guideline adaptation was associated with improved serum mineral profiles in patients with CKD-MBD. METHODS: A total of 355 patients on MHD were enrolled from seven dialysis units. After adhering to our strategy for one year, serum phosphorus, calcium, intact parathyroid hormone (iPTH), and alkaline phosphatase (AP) levels were compared with the baseline. The endpoint was improvement in the proportion of patients with serum mineral levels at target recommendations. RESULTS: The median serum phosphorus level and proportion of patients with serum phosphorus within the target range were not changed. Although the median serum calcium level was significantly increased, the proportion of patients with serum calcium within the target range was not significantly affected. The proportion of patients with serum iPTH at the target level was not altered, although the median serum iPTH was significantly decreased. However, both median serum AP and the proportion of patients with serum AP at the target level (70.4% vs. 89.6%, P < 0.001) were improved. CONCLUSION: In our patients with MHD, serum mineral profiles were altered and the serum AP level stabilized after implementing our recommendations. Long-term follow-up evaluations are necessary to determine whether uremic bone disease and cardiovascular calcifications are affected by these recommendations.

Erratum: Association of serum uric acid level with coronary artery stenosis severity in Korean end-stage renal disease patients Volume 36, Issue 3, September 2017, Pages 282–289

Hye Yun Jeong and Hye Jeong Cho contributed equally to the above study as co-first authors.

Association of serum uric acid level with coronary artery stenosis severity in Korean end-stage renal disease patients

BACKGROUND: Hyperuricemia is common in end-stage renal disease (ESRD) patients, and many previous studies have reported the associations between hyperuricemia and adverse cardiovascular outcomes, which are the major cause of death in such patients. We investigated the relationship between serum uric acid level and the severity of coronary stenosis in ESRD patients on maintenance hemodialysis (MHD). METHODS: Among 721 patients who started MHD treatment, 102 underwent coronary angiographic tests complaining of chest discomfort that was new at initiation of MHD. We collected data on uric acid level and coronary artery luminal diameter, defining luminal diameter narrowing of more than 50% in any major coronary artery as critical-stenosis. RESULTS: We detected critical coronary artery stenosis in 52 (57.8%) patients. The mean uric acid level was 6.6 ± 2.2 mg/dL, and that was significantly higher in the critical-stenosis group (4.9 ± 1.4 mg/dL vs. 7.8 ± 2.0 mg/dL, P < 0.001). The only independent predictor of critical-stenosis in multivariate analysis was serum uric acid level (P < 0.001). CONCLUSION: High serum uric acid was associated with severe coronary artery stenosis in Korean ESRD patients. Hyperuricemia is a readily modifiable factor, and appropriately preventing it could provide significant benefits in ESRD patients.

Vitamin D and Hypertension

Vitamin D has the pleiotropic effects in multiple organ systems, and vitamin D deficiency was suggested to be associated with high blood pressure according to previous reports. Several interventional studies have examined the effect of vitamin D supplementation on high blood pressure patients, but the results have been inconsistent. In this article, we examined the literature that have proposed a mechanism involving vitamin D in the regulation of blood pressure and review previous observational and interventional studies that have shown the relationship between vitamin D and hypertension among various populations.

Administration of a High-Dose Erythropoietin-Stimulating Agent in Hemodialysis Patients is Associated with Late Arteriovenous Fistula Failure

PURPOSE: Investigating the risk of vascular access failure is critical for maintenance hemodialysis (MHD) patients. Erythropoietin stimulating agents (ESA) typically used for anemia of chronic kidney disease (CKD) may also stimulate neointimal hyperplasia, which is the most important factor in late arteriovenous fistula (AVF) failure. The aim of this study was to investigate whether ESA treatment is associated with late AVF failure. MATERIALS AND METHODS: The late AVF failure group comprised 51 patients who underwent percutaneous intervention or surgery for fistula revision after successful use for at least three months. There were 51 controls whose AVF had been patent for at least 24 months. RESULTS: The mean time from the first cannulation to late loss of AVF patency was 8.4±4.2 months. The average weekly dose of ESA was significantly higher in patients with AVF failure (4782.2±2360.5 IU/mL/wk vs. 7161.8±2775.2 IU/mL/wk, p<0.001). The only independent predictor of late AVF failure in multivariate analysis was high average ESA dose (odds ratio=1.015, 95% confidence interval=1.002–1.028, p=0.022). CONCLUSION: Patients with late AVF patency loss exhibit an association with a higher dose of ESA, although causality is unproven. Further study to elucidate potential mechanisms is warranted.

25-hydroxyvitamin D Levels was not Associated with Blood Pressure and Arterial Stiffness in Patients with Chronic Kidney Disease

BACKGROUND: We investigated the effect of vitamin D deficiency on cardiovascular risk profiles in an Asian population with chronic kidney disease (CKD). METHODS: A total of 210 participants (62 non-dialysis CKD patients and 148 hemodialysis [HD] patients) were enrolled between December 2009 and February 2010. Vitamin D deficiency was determined using the serum 25-hydroxyvitamin D [25(OH)D] concentration. Blood pressure and arterial stiffness were measured. Subjects were divided into groups according to 25(OH)D concentration based on a cut-off of 13.5 ng/mL in non-dialysis CKD patients and 11.3 ng/mL in HD patients. RESULTS: The mean age was 61.7±12.3 years in non-dialysis CKD patients and 57.0±12.7 years in HD patients. In the non-dialysis CKD group, mean estimated glomerular filtration rate (eGFR) was 29.7±15.4 mL/min/1.73 m2. Mean 25(OH)D concentration was 13.6±7.8 ng/mL in non-dialysis CKD patients and 11.3±6.7 ng/mL in HD patients. More than half of the subjects had vitamin D deficiency (67.6% in non-dialysis CKD patients and 80.4% in HD patients). There were no significant differences in systolic blood pressure, pulse pressure, and arterial stiffness between higher and lower 25(OH)D groups among non-dialysis CKD and HD patients. Multivariate analysis revealed that female sex (odds ratio [OR]: 5.890; 95% confidence interval [CI]: 2.597–13.387; p<0.001) and presence of diabetes (OR: 2.434; 95% CI: 1.103–5.370; p=0.028) were significantly associated with lower serum 25(OH)D levels in HD patients. CONCLUSION: The prevalence of vitamin D deficiency was high in both nondialysis CKD patients and HD patients. Serum 25(OH)D concentration was not a significant factor associated with blood pressure and arterial stiffness among non-dialysis CKD and HD patients.

Effect of low-dose valsartan on proteinuria in normotensive immunoglobulin A nephropathy with minimal proteinuria: a randomized trial

BACKGROUND/AIMS: Immunoglobulin A nephropathy (IgAN) is a generally progressive disease, even in patients with favorable prognostic features. In this study, we aimed to investigate the antiproteinuric effect and tolerability of low-dose valsartan (an angiotensin II receptor blocker) therapy in normotensive IgAN patients with minimal proteinuria of less than 0.5 to 1.0 g/day. METHODS: Normotensive IgAN patients, who had persistent proteinuria with a spot urine protein-to-creatinine ratio of 0.3 to 1.0 mg/mg creatinine, were recruited from five hospitals and randomly assigned to either 40 mg of valsartan as the low-dose group or 80 mg of valsartan as the regular-dose group. Clinical and laboratory data were collected at baseline, and at 4, 8, 12, and 24 weeks after valsartan therapy. RESULTS: Forty-three patients (low-dose group, n = 23; regular-dose group, n = 20) were enrolled in the study. Proteinuria decreased significantly not only in the regular-dose group but also in the low-dose group. The change in urine protein-to-creatinine ratio at week 24 was -41.3% +/- 26.1% (p < 0.001) in the regular-dose group and -21.1% +/- 45.1% (p = 0.005) in the low-dose group. In the low-dose group, blood pressure was constant throughout the study period, and there was no symptomatic hypotension. In the regular-dose group, blood pressure decreased at weeks 8 and 12. No significant change in glomerular filtration rate, serum creatinine level, or serum potassium level was observed during the study period. CONCLUSIONS: Our results suggest that low-dose valsartan can significantly reduce proteinuria without causing any intolerability in normotensive IgAN patients with minimal proteinuria.

Serum 25-hydroxyvitamin D as a predictor of hospitalization-free survival in predialysis and dialysis patients with chronic kidney disease: a single-center prospective observational analysis

BACKGROUND: Vitamin D has pleiotropic effects important for the proper functioning of multiple organ systems. We investigated whether serum 25-hydroxyvitamin D [25(OH)D] levels influenced hospitalization-free survival in patients with chronic kidney disease (CKD). METHODS: In this prospective study, serum levels of 25(OH)D were measured in 210 patients with CKD in the winter of 2009. Data regarding hospitalizations were collected over the subsequent 3 years. RESULTS: Vitamin D deficiency, as defined by a serum 25(OH)D level below 15 ng/mL, was observed in 76.7% of the patients. The mean 25(OH)D serum level was 13.6 ± 7.8 ng/mL in predialysis patients (n = 62) and 11.3 ± 6.7 ng/mL in dialysis patients (n = 148). During the follow-up, 107 patients (28 predialysis and 79 dialysis) were hospitalized because of infectious (33.6%) or cardiovascular diseases (23.4%). Predialysis and dialysis groups were divided into 2 subgroups based on the median 25(OH)D serum level. Kaplan-Meier analysis revealed that the risk of hospitalization was significantly lower in both predialysis and dialysis patients with above-median serum 25(OH)D levels (log-rank test; P = 0.043 and 0.002, respectively). Multivariate Cox proportional hazards models also demonstrated that the risk of hospitalization was significantly lower for patients with higher serum 25(OH)D levels in both the predialysis (hazard ratio, 0.963; 95% confidence interval, 0.93-0.99) and dialysis groups (hazard ratio, 0.955; 95% confidence interval, 0.91-0.99). CONCLUSION: A lower serum 25(OH)D level predicted poorer hospitalization-free survival in both predialysis and dialysis CKD patients.

Spinning-induced Rhabdomyolysis: Eleven Case Reports and Review of the Literature

Non-traumatic exertional rhabdomyolysis (exRML) occurs in individuals with normal muscles when the energy supplied to the muscle is insufficient. Here, we report 11 cases of spinning-induced rhabdomyolysis and review related literature. Spinning is a kind of indoor bicycle sport. The 11 patients who were diagnosed with exRML and admitted to CHA Bundang Medical Center were female and their ages ranged from 15 to 46 years. Two to three days prior to the presentation, the patients had attended a spinning class for the first time. All the patients had been otherwise healthy without any known medical illnesses. They were successfully treated without any complications, except mild non-symptomatic hypocalcemia. However, in the literature, severe complications such as compartment syndrome or acute kidney injury had been reported in relation to exRML including spinning-induced rhabdomyolysis. This spinning exercise needs prior guidelines and specific warnings to prevent exertional rhabdomyolysis.

A randomized crossover study of single biweekly administration of epoetin-alpha compared with darbepoetin-alpha in chronic kidney disease patients not receiving dialysis

BACKGROUND: Recent evidence demonstrates that high doses of epoetin-alpha (EPO-alpha) can be administrated at extended intervals, despite its relatively short serum half-life. However, no prospective randomized trials on the effects of extended dosing intervals of EPO-alpha compared with darbepoetin-alpha (DA-alpha) have been performed. This study was designed to investigate whether a single biweekly (Q2W) administration of a high dose of EPO-alpha is as effective as DA-alpha for anemia in chronic kidney disease (CKD) patients not receiving dialysis. METHODS: Sixty non-dialysis CKD patients were equally randomized to either Q2W subcutaneous EPO-alpha (10,000 unit) or DA-alpha (50microg) therapy groups for the first 6 weeks. After a 6-week washout period, the participants of the EPO-alpha and DA-alpha treatment groups switched to the alternate regimen for 6 weeks. The mean hemoglobin (Hb) levels after erythropoiesis stimulating agent (ESA) therapy and percentage change in Hb levels from baseline to the end of the study were analyzed. RESULTS: The mean Hb levels of postESA therapy increased significantly compared with those of preESA therapy in both ESA regimens. The percentage increase in Hb levels and erythropoietin resistance index did not show a significant difference between the different ESA regimens. No difference was observed between the regimens regarding mean Hb levels after ESA therapy. Additionally, there were no serious adverse effects leading to withdrawal from treatment. CONCLUSION: Biweekly high doses of EPO-alpha therapy may be equally as effective as Q2W DA-alpha therapy in maintaining target Hb levels in non-dialysis CKD patients.

A Case of Renal-limited Lupus-like Nephritis

Systemic lupus erythematosus (SLE) is a systemic autoimmune disease that is clinically heterogeneous and affects multiple organs particularly the kidney. Lupus nephritis is a common and severe manifestation of SLE in which immune-mediated inflammation can lead to permanent damage within the kidney, resulting in end stage renal failure. Recently a renal biopsy showed lupus nephritis on a 40-year old female without any other features of SLE such as clinical symptoms and autoantibodies including antinuclear antibody and anti-dsDNA. The renal biopsy showed that histopathological change of global and segmental sclerosis of glomeluri, diffuse proliferative nephritis with crescent formation compatible with class IV lupus nephritis. She was treated with systemic corticosteroids and pulse cyclophosphamide, followed by mycofenolate mofetil. During two years of follow-up, there have been no clinical or laboratory findings to meet the diagnostic criteria of SLE, suggesting that isolated lupus nephritis could occur without SLE.

Prevalence of Occult Hepatitis B Virus Infection in Hemodialysis Patients / 대한소화기학회지

BACKGROUND/AIMS: The prevalence of occult HBV infection depends on the prevalence of HBV infection in the general population. Hemodialysis patients are at increased risk for HBV infection. The aim of this study was to determine the prevalence of occult HBV infection in hemodialysis patients. METHODS: Total of 98 patients undergoing hemodialysis in CHA Bundang Medical Center (Seongnam, Korea) were included. Liver function tests and analysis of HBsAg, anti-HBs, anti-HBc and anti-HCV were performed. HBV DNA testing was conducted by using two specific quantitative methods. RESULTS: HBsAg was detected in 4 of 98 patients (4.1%), and they were excluded. Among 94 patients with HBsAg negative and anti-HCV negative, one (1.1%) patient with the TaqMan PCR test and 3 (3.2%) patients with the COBAS Amplicor HBV test were positive for HBV DNA. One patient was positive in both methods. Two patients were positive for both anti-HBs and anti-HBc and one patient was negative for both anti-HBs and anti-HBc. CONCLUSIONS: The present study showed the prevalence of occult HBV infection in HBsAg negative and anti-HCV negative patients on hemodialysis at our center was 3.2%. Because there is possibility of HBV transmission in HBsAg negative patients on hemodialysis, more attention should be given to prevent HBV transmission.

MTHFR C677T Polymorphism as a Risk Factor for Vascular Calcification in Chronic Hemodialysis Patients

Polymorphism of 5,10-methylenetetrahydrofolate reductase (MTHFR) C677T is one of the suggested risk factors for atherosclerosis. However, few studies have reported on the relationship between MTHFR C677T polymorphism and vascular calcification (VC) in chronic hemodialysis patients. We investigated the relationship between the MTHFR C677T polymorphism and VC in 152 chronic hemodialysis patients. Patients with a TT genotype exhibited significantly higher VC scores than patients expressing CC and CT (P = 0.002). The prevalence of peripheral vascular disease increased with the incidence of MTHFR C677T mutations for all patients, and the incidence of cerebrovascular accidents also increased with the presence of mutations for young patients (< or = 60 yr) (P < 0.05). Patients with CT and TT genotypes had adjusted odds ratios for VC of 1.39 and 1.58, respectively (P < 0.05). In summary, these data suggest that the MTHFR C677T polymorphism affects the degree of VC in chronic hemodialysis patients.

Intra-Renal Arterial Pseudoaneurysm Associated with Acute Pyelonephritis / 대한신장학회지

Renal artery pseudoaneurysm is an uncommon disease. A 47-year-old man complained of recently developed gross hematuria and left flank pain. The initial laboratory study and radiographic evaluation revealed acute pyelonephritis. After the treatment with antibiotics, gross hematuria was resolved and the patient was discharged. However, he revisited with repeated gross hematuria and throbbing left flank pain. The renal angiography revealed left intra-renal arterial pseudoaneurysm. Angiographic embolization by glue injection was successfully performed. Thereafter, gross hematuria and flank pain were disappeared. We report a successful glue embolization of intra-renal artery pseudoaneurym associated with acute pyelonephritis.

A Case of Rhabdomyolysis Associated with Use of a Pneumatic Tourniquet during Arthroscopic Knee Surgery

The common causes of rhabdomyolysis include trauma, hypoxia, drugs, toxins, infections and hyperthermia. Operative insults, including direct trauma and ischemia, have the potential to cause the development of rhabdomyolysis. Pneumatic tourniquets used during arthroscopic knee surgery to prevent blood loss have led to many complications such as nerve paralysis and vascular injuries. Rhabdomyolysis can also be caused by prolonged pneumatic tourniquet application without a midapplication release, and also from an increased application pressure, but the actual incidence of this is low. In order to prevent rhabdomyolysis, the clinicians must be aware of such risks and follow strict guidelines for the application time, the midapplication release and also the inflation pressure. Vigorous hydration and postoperative patient surveillance are helpful to prevent rhabdomyolysis. We have recently experienced a case of rhabdomyolysis after the arthroscopic knee surgery, and the rhabdomyolysis could have been associated with the use of a pneumatic tourniquet.