IL-6/p-BTK/p-ERK signaling mediates calcium phosphate-induced pruritus.

Uremic pruritus with elevated levels of calcium phosphate (CaP) in skin is a common symptom in patients with chronic kidney disease (CKD). In this study, we demonstrate that intradermal injection of CaP into mice triggered scratching by up-regulating the IL-6 in skin and phosphorylation of ERKs in dorsal root ganglion (DRG) in a dose-dependent manner. IL-6 is essential because the CaP-induced up-regulation of phosphorylated (p)-ERK in DRG was considerably reduced in the IL-6 knockout mice. Microarray analysis in conjunction with real-time PCR revealed a higher mRNA expression of Bruton's tyrosine kinase (BTK) gene in DRG after CaP injection. The inhibition of BTK by ibrutinib noticeably diminish the CaP-induced up-regulation of IL-6 and p-ERK in mice. A high amount of IL-6 was detected in itchy skin and blood of patients with CKD. The expressions of p-BTK and p-ERK in DRG primary cells reached maximum levels at 1 and 10 min, respectively, after treatment of recombinant IL-6 and were significantly reduced by treatment of IL-6 along with ibrutinib. The mechanism by which the CaP-induced pruritus mediated by the IL-6/p-BTK/p-ERK signaling was revealed.-Keshari, S., Sipayung, A. D., Hsieh, C.-C., Su, L.-J., Chiang, Y.-R., Chang, H.-C., Yang, W.-C., Chuang, T.-H., Chen, C.-L., Huang, C.-M. IL-6/p-BTK/p-ERK signaling mediates calcium phosphate-induced pruritus.

Plasma miRNA profile is a biomarker associated with urothelial carcinoma in chronic hemodialysis patients.

The incidence of urothelial carcinoma (UC) is higher in patients undergoing chronic dialysis than in the general population. This study investigated plasma miRNA profiling as the ancillary diagnosis biomarker associated with UC in patients undergoing chronic hemodialysis. We successfully screened out and detected miRNA expression from plasma in eight patients undergoing dialysis through quantitative real-time PCR array analysis and identified eight candidate miRNAs. The candidate miRNAs were then validated using single quantitative RT-PCR assays from 52 plasma samples. The miRNA classifier for ancillary UC detection was developed by multiple logistic regression analyses. Moreover, we validated the classifier by testing another nine samples. Expression levels of miR-150-5p, miR-150-5p/miR-155-5p, miR-378a-3p/miR-150-5p, miR-636/miR-150-5p, miR-150-5p/miR-210-3p, and miR-19b-1-5p/miR-378a-3p were shown to be significantly different between UC and non-UC samples (P = 0.035, 0.0048, 0.016, 0.024, 0.038, and 0.048). Kaplan-Meier curve analysis also showed that low miR-19b-1-5p expression was associated with a worse prognosis (P = 0.0382). We also developed a miRNA classifier based on five miRNA expression levels to predict UC and found that the area under curve was 0.882. The classifier had a sensitivity of 80% (95% confidence interval: 0.5191% to 0.9567%) and a specificity of 83.7% (95% confidence interval: 0.6799% to 0.9381%). This classifier was tested by nine samples with 100% accuracy. The miRNA classifier offers higher sensitivity and specificity than the existing makers. Thus, this approach will improve the prospective diagnosis of UC in patients undergoing chronic hemodialysis.

Four-and-a-Half LIM Domains Protein 2 Is a Coactivator of Wnt Signaling in Diabetic Kidney Disease.

Diabetic kidney disease (DKD) is a microvascular complication that leads to kidney dysfunction and ESRD, but the underlying mechanisms remain unclear. Podocyte Wnt-pathway activation has been demonstrated to be a trigger mechanism for various proteinuric diseases. Notably, four-and-a-half LIM domains protein 2 (FHL2) is highly expressed in urogenital systems and has been implicated in Wnt/ß-catenin signaling. Here, we used in vitro podocyte culture experiments and a streptozotocin-induced DKD model in FHL2 gene-knockout mice to determine the possible role of FHL2 in DKD and to clarify its association with the Wnt pathway. In human and mouse kidney tissues, FHL2 protein was abundantly expressed in podocytes but not in renal tubular cells. Treatment with high glucose or diabetes-related cytokines, including angiotensin II and TGF-ß1, activated FHL2 protein and Wnt/ß-catenin signaling in cultured podocytes. This activation also upregulated FHL2 expression and promoted FHL2 translocation from cytosol to nucleus. Genetic deletion of the FHL2 gene mitigated the podocyte dedifferentiation caused by activated Wnt/ß-catenin signaling under Wnt-On, but not under Wnt-Off, conditions. Diabetic FHL2(+/+) mice developed markedly increased albuminuria and thickening of the glomerular basement membrane compared with nondiabetic FHL2(+/+) mice. However, FHL2 knockout significantly attenuated these DKD-induced changes. Furthermore, kidney samples from patients with diabetes had a higher degree of FHL2 podocyte nuclear translocation, which was positively associated with albuminuria and progressive renal function deterioration. Therefore, we conclude that FHL2 has both structural and functional protein-protein interactions with ß-catenin in the podocyte nucleus and that FHL2 protein inhibition can mitigate Wnt/ß-catenin-induced podocytopathy.

Genotype polymorphisms of genes regulating nitric oxide synthesis determine long-term arteriovenous fistula patency in male hemodialysis patients.

OBJECTIVES: Nitric oxide (NO) is a pivotal vasoactive substance modulating arteriovenous fistula (AVF) patency for hemodialysis (HD). Since genetic background could be the predicting factor of AVF malfunction, we aimed to investigate whether the NO-related genotype polymorphisms determine AVF survival rates. METHODS: This is a retrospective, observational, multi-center study involving eight HD units in Taiwan, enrolled 580 patients initiating maintenance HD via AVFs. Genotype polymorphisms of NO-biosynthesis regulating enzymes (DDAH-1, DDAH-2, eNOS and PRMT1) were compared between HD patients with (n = 161) and without (n = 419) history of AVF malfunction. Subgroup analyses by gender were performed to evaluate the genetic effect in difference sexes. RESULTS: In overall population, statistically significant associations were not found between AVF malfunction and the genetic polymorphisms. In the male subgroup (n = 313), a single nucleotide polymorphism (SNP) of PRMT1, rs10415880 (IVS9-193 A/G), showed a significant association with AVF malfunction. Male patients with AA/AG genotype had inferior AVF outcomes compared to GG genotype, regarding primary patency (70.6% vs. 40.9%, p = 0.001), assisted primary patency (81.0% vs. 58.4%, p < 0.001) and secondary patency (83.7% vs. 63.3%, p < 0.001) at a 5-year observation period. From multivariate Cox regression model, the AA/AG genotypes of PRMT1 were an independent risk factor for AVF malfunction in men (HR: 4.539, 95% CI 2.015-10.223; p < 0.001). However, such associations were not found in women. CONCLUSIONS: rs10415880, the SNP of PRMT1 could be a novel genetic marker associated with AVF malfunction risk in male HD patients. Those with AA and AG genotypes of rs10415880 may predict a poorer long-term patency of AVF.

Association of Genetic Polymorphisms of Renin-Angiotensin-Aldosterone System-Related Genes with Arterio-Venous Fistula Malfunction in Hemodialysis Patients.

Hemodialysis (HD) is the most commonly-used renal replacement therapy for patients with end-stage renal disease worldwide. Arterio-venous fistula (AVF) is the vascular access of choice for HD patients with lowest risk of infection and thrombosis. In addition to environmental factors, genetic factors may also contribute to malfunction of AVF. Previous studies have demonstrated the effect of genotype polymorphisms of angiotensin converting enzyme on vascular access malfunction. We conducted a multicenter, cross-sectional study to evaluate the association between genetic polymorphisms of renin-angiotensin-aldosterone system and AVF malfunction. Totally, 577 patients were enrolled. Their mean age was 60 years old and 53% were male. HD patients with AVF malfunction had longer duration of HD (92.5 ± 68.1 vs. 61.2 ± 51.9 months, p < 0.001), lower prevalence of hypertension (44.8% vs. 55.3%, p = 0.025), right-sided (31.8% vs. 18.4%, p = 0.002) and upper arm AVF (26.6% vs. 9.7%, p < 0.001), and higher mean dynamic venous pressure (DVP) (147.8 ± 28.3 vs. 139.8 ± 30.0, p = 0.021). In subgroup analysis of different genders, location of AVF and DVP remained significant clinical risk factors of AVF malfunction in univariate and multivariate binary logistic regression in female HD patients. Among male HD patients, univariate binary logistic regression analysis revealed that right-side AVF and upper arm location are two important clinical risk factors. In addition, two single nucleotide polymorphisms (SNPs), rs275653 (Odds ratio 1.90, p = 0.038) and rs1492099 (Odds ratio 2.29, p = 0.017) of angiotensin II receptor 1 (AGTR1), were associated with increased risk of AVF malfunction. After adjustment for age and other clinical factors, minor allele-containing genotype polymorphisms (AA and CA) of rs1492099 still remained to be a significant risk factor of AVF malfunction (Odds ratio 3.63, p = 0.005). In conclusion, we demonstrated that rs1492099, a SNP of AGTR1 gene, could be a potential genetic risk factor of AVF malfunction in male HD patients.

Long-term clinical outcome of major adverse cardiac events in survivors of infective endocarditis: a nationwide population-based study.

BACKGROUND: Substantial infective endocarditis (IE)-related morbidity and mortality may occur even after successful treatment. However, no previous study has explored long-term hard end points (ie, stroke, myocardial infarction, heart failure, cardiovascular death) in addition to all-cause mortality in IE survivors. METHODS AND RESULTS: A nationwide population-based cohort study was conducted among IE survivors identified with the use of the Taiwan National Health Insurance Research Database during 2000 to 2009. IE survivors were defined as those who survived after discharge from first hospitalization with a diagnosis of IE. A total of 10 116 IE survivors were identified. IE survivors were matched to control subjects without IE at a 1:1 ratio through the use of propensity scores. The primary outcomes were stroke, myocardial infarction, readmission for heart failure, and sudden cardiac death or ventricular arrhythmia. The secondary outcomes were repeat IE and all-cause mortality. Compared with the matched cohort, IE survivors had higher risks of ischemic stroke (adjusted hazard ratio [aHR], 1.59; 95% confidence interval [CI], 1.40-1.80), hemorrhagic stroke (aHR, 2.37; 95% CI, 1.90-2.96), myocardial infarction (aHR, 1.44; 95% CI, 1.17-1.79), readmission for heart failure (aHR, 2.24; 95% CI, 2.05-2.43), sudden death or ventricular arrhythmia (aHR, 1.69; 95% CI, 1.44-1.98), and all-cause death (aHR, 2.27; 95% CI, 2.14-2.40). Risk factors for repeat IE were older age, male sex, drug abuse, and valvular replacement after an initial episode of IE. CONCLUSION: Despite treatment, the risk of long-term major adverse cardiac events was substantially increased in IE survivors.

Circulating Wnt/ß-catenin signalling inhibitors and uraemic vascular calcifications.

BACKGROUND: The process of vascular calcification has been associated with the canonical Wnt/ß-catenin signalling pathway in cell cultures and animal studies. The relationship between circulating Wnt/ß-catenin inhibitors and vascular calcification in dialysis patients is unknown. The aim of this study was to investigate the associations between serum dickkopf-1 (Dkk-1) and sclerostin, two circulating inhibitors of the Wnt/ß-catenin signalling pathway, and the severity of aortic calcification (AoC) and cardiovascular outcomes in dialysis patients. METHODS: This was a prospective observational cohort study. One hundred and twenty-five patients on maintenance haemodialysis participated in the study. Serum levels of Dkk-1 and sclerostin were measured. AoC scores were calculated from plain films of both posterior-anterior and lateral views. The patients were followed up for 2 years or until death or withdrawal. RESULTS: The circulating sclerostin level was inversely associated with the severity of AoC (P = 0.035) and indicators of the bone turnover rate including serum alkaline phosphatase (ALP) (r = -0.235, P = 0.008) and intact parathyroid hormone (r = -0.523, P < 0.001). Furthermore, Cox regression analysis indicated that the patients with high circulating sclerostin levels were less likely to experience future cardiovascular events [1 pmol/L sclerostin increase, hazard ratio 0.982 (95% CI, 0.967-0.996), P = 0.015] after adjusting for a propensity score. In contrast, serum Dkk-1 was not associated with AoC and clinical outcomes. CONCLUSIONS: In long-term haemodialysis patients, circulating sclerostin but not Dkk-1 is inversely associated with AoCs and future cardiovascular events. Our findings suggest that sclerostin, as a bone-related protein, might act as a communicator between uraemic bone and vasculature.

Long-term Outcomes of Parathyroidectomy in Kidney Transplant Recipients with Persistent Hyperparathyroidism.

BACKGROUND/AIMS: Hyperparathyroidism (HPT) is a common complication of chronic kidney disease and contributes to hypertension and cardiovascular risks. Successful kidney transplantation corrects abnormal mineral metabolism, but persistent HPT is still observed in up to 25% of patients one year after transplantation despite renal function improvement. The purpose of this study was to examine the long-term effects of parathyroidectomy (PTX) on blood pressure (BP) and graft function in patients with persistent post-transplant HPT. METHODS: This is a retrospective study of renal allograft recipients at a single institute. Records from all the patients who received kidney transplantation at the Taipei Veterans General Hospital between 2004 and 2012 were reviewed and enrolled 19 patients who underwent PTX for persistent post-transplant HPT. Preoperative and postoperative clinical and biochemical data were compared. Matched controls (n = 19) in the corresponding time span were enrolled for graft function comparisons. RESULTS: The mean systolic BP (127.7 ± 14.3 to 119.5 ± 12.7 mmHg, p = 0.028, 1 year after PTX; 127.7 ± 14.3 to 117 ± 12.4 mmHg, p = 0.007, 2 years after PTX) and pulse pressure (PP) (51.3 ± 10.7 to 44.3 ± 11.6, p = 0.019 1 year after PTX; 51.3 ± 10.7 to 44.9 ± 12.5 mmHg, p = 0.028, 2 years after PTX) reduced significantly at 1 year and 2 years of follow-up. However, no significant change of diastolic BP was observed. The improvement of SBP, DBP and PP was not correlated with the reduction of serum calcium level 1 year after PTX. The estimated glomerular filtration rate decreased significantly from 74.0 ± 20.5 mL/min/1.73m(2) preoperatively to 68.2 ± 24.8 mL/min/1.73 m(2) 12 months after PTX but recovered at 15 months and lasted to 2 years after PTX. The all-cause hospitalization rate 1 year after PTX tended to be higher than that 1 year before PTX (105.3 versus 47.4 per 100 patient-years; RR, 2.22; 95 % CI: 0.97-5.54), but there was no significant difference between them. CONCLUSIONS: Our study demonstrated systolic BP and PP reduced 2 years after PTX and there was no significant difference between the peri-operative all-cause hospitalization rates. In addition, kidney allograft function impaired temporarily 12 months after PTX, but recovered 15 months after PTX.

Matrix metalloproteinase-9 deficiency attenuates diabetic nephropathy by modulation of podocyte functions and dedifferentiation.

Diabetic nephropathy is characterized by excessive deposition of extracellular matrix protein and disruption of the glomerular filtration barrier. Matrix metalloproteinases (MMPs) affect the breakdown and turnover of extracellular matrix protein, suggesting that altered expression of MMPs may contribute to diabetic nephropathy. Here we used an MMP-9 gene knockout mouse model, with in vitro experiments and clinical samples, to determine the possible role of MMP-9 in diabetic nephropathy. After 6 months of streptozotocin-induced diabetes, mice developed markedly increased albuminuria, glomerular and kidney hypertrophy, and thickening of the glomerular basement membrane. Gelatin zymographic analysis and western blotting showed that there was enhanced MMP-9 protein production and activity in the glomeruli. However, MMP-9 knockout in diabetic mice significantly attenuated these nephropathy changes. In cultured podocytes, various cytokines related to diabetic nephropathy including TGF-ß1, TNF-α, and VEGF stimulated MMP-9 secretion. Overexpression of endogenous MMP-9 induced podocyte dedifferentiation. MMP-9 also interrupted podocyte cell integrity, promoted podocyte monolayer permeability to albumin, and extracellular matrix protein synthesis. In diabetic patients, the upregulation of urinary MMP-9 concentrations occurred earlier than the onset of microalbuminuria. Thus, MMP-9 seems to play a role in the development of diabetic nephropathy.

The impact of dialysis therapy on older patients with advanced chronic kidney disease: a nationwide population-based study.

BACKGROUND: Older patients with advanced chronic kidney disease (CKD) face the decision of whether to undergo dialysis. Currently available data on this issue are limited because they were generated by small, short-term studies with statistical drawbacks. Further research is urgently needed to provide objective information for dialysis decision making in older patients with advanced CKD. METHODS: This nationwide population-based cohort study was conducted using Taiwan's National Health Insurance Research Database. Data from 2000 to 2010 were extracted. A total of 8,341 patients≥70 years old with advanced CKD and serum creatinine levels>6 mg/dl, who had been treated with erythropoiesis-stimulating agents were included. Cox proportional hazard models in which initiation of chronic dialysis was defined as the time-dependent covariate were used to calculate adjusted hazard ratios for mortality. The endpoint was all-cause mortality. RESULTS: During a median follow-up period of 2.7 years, 6,292 (75.4%) older patients chose dialysis therapy and 2,049 (24.6%) received conservative care. Dialysis was initiated to treat kidney failure a median of 6.4 months after enrollment. Dialysis was associated with a 1.4-fold increased risk of mortality compared with conservative care (adjusted hazard ratio 1.39, 95% confidence interval 1.30 to 1.49). In subgroup analyses, the risk of mortality remained consistently increased, independent of age, sex and comorbidities. CONCLUSIONS: In older patients, dialysis may be associated with increased mortality risk and healthcare cost compared with conservative care. For patients who are ≥70 years old with advanced CKD, decision making about whether to undergo dialysis should be weighted by consideration of risks and benefits.

Nonsteroidal anti-inflammatory drug use is associated with cancer risk reduction in chronic dialysis patients.

Previous studies have shown that nonsteroidal anti-inflammatory drug (NSAID) use might be associated with a lower risk of developing cancer in the general population. Patients on dialysis have increased risk for cancer, but there are no studies to determine the relationship between NSAID use and cancer risk in these patients. To identify any association between NSAID use and cancer risk in patients with end-stage renal disease on dialysis, we used Taiwan's National Health Insurance database to conduct a nationwide population-based, propensity score-matched cohort study. All cancers between groups were compared by Cox proportional hazards models. Compared to nonuse of NSAIDs, the use of non-COX-2-selective inhibitors (hazard ratio 0.81, 95% confidence interval 0.67-0.97) or COX-2-selective inhibitors (0.78, 0.62-0.98) was associated with a lower risk of developing cancer. NSAID use reduced the risk of respiratory (0.39, 0.19-0.79), breast (0.41, 0.19-0.89), kidney (0.58, 0.38-0.88), digestive tract (0.64, 0.49-0.85), and bladder cancers (0.73, 0.55-0.96). NSAID use, however, significantly increased risk for upper gastrointestinal bleeding (odds ratio, 1.15, 1.07-1.23) but not adverse cardiac or cerebrovascular events. Thus, NSAID use was associated with a lower risk of developing cancer in chronic dialysis patients; however, they should still be used with caution due to the side effects of gastrointestinal bleeding.

Expression of TNFRSF6B in kidneys is a novel predictor for progression of chronic kidney disease.

TNFRSF6B overexpression in tumors is a novel predictor for poor prognosis in various cancers; however, whether TNFRSF6B could be expressed in kidney tissues of patients with chronic kidney disease is unknown. Current established risk factors cannot fully predict the progression of chronic kidney disease, and, therefore, it is mandatory to develop a newer marker for predicting disease progression. We conducted a prospective cohort study comprised 167 patients with chronic kidney disease undergoing renal biopsy at a tertiary hospital with median follow-up of 30.5 months. Computer-assisted quantitative immunohistochemical staining analysis of TNFRSF6B in kidney tissues, the expression of α-smooth muscle actin and percentage of fibrosis in renal interstitium, estimated glomerular filtration rate, and urinary protein excretion rate were investigated. Study endpoint was a doubling of serum creatinine and/or end-stage renal failure requiring renal replacement therapy. We found that TNFRSF6B was predominantly expressed in the tubular epithelial cells of renal cortex. The higher the expression of TNFRSF6B, the more the expression of α-smooth muscle actin and fibrosis in interstitium (P<0.001). Forty patients reaching endpoint had lower baseline estimated glomerular filtration rate and higher expression of TNFRSF6B in renal tubular epithelial cells. Multivariate Cox regression analysis showed that high expression of TNFRSF6B independently predicted the risk toward the renal endpoint with a hazard ratio of 3.46 (95% confidence interval (CI) 1.76-6.80, P<0.001) by adjusting for clinical and pathologic variables. While added to a model of estimated glomerular filtration rate, proteinuria and other conventional risk factors, TNFRSF6B further significantly improved the model predictability for progression of chronic kidney disease (area under the curve, 0.82). In conclusion, TNFRSF6B is associated with renal fibrosis and high expression of TNFRSF6B is a novel biomarker for predicting the progression of chronic kidney disease.

Effect of far infrared therapy on arteriovenous fistula maturation: an open-label randomized controlled trial.

BACKGROUND: Malfunction of the arteriovenous fistula (AVF) is an important cause of morbidity and hospitalization in hemodialysis (HD) patients. The aim of this study is to evaluate the effect of far infrared therapy on the maturation and patency of newly created AVFs in patients with chronic kidney disease stage 4 or 5. STUDY DESIGN: Randomized controlled study. SETTING & PARTICIPANTS: Patients with estimated glomerular filtration rate of 5-20 mL/min/1.73 m². INTERVENTION: 40 minutes of far infrared therapy 3 times weekly for a year. OUTCOMES: The primary outcome is the rate of AVF malfunction within 12 months, with malfunction defined as either: (1) thrombosis without thrill for AVFs not undergoing HD or (2) receiving any type of interventional procedure due to a lower Kt/V (<1.2) for patients undergoing HD. Secondary outcomes include: (1) cumulative primary unassisted AVF patency, defined as time from creation of the AVF to the first episode of AVF malfunction; (2) physiologic maturation of the AVF by the definition of AVF access blood flow (Qa) ≥500 mL/min and AVF diameter ≥4 mm at 3 months; and (3) clinical maturation of the AVF suitable for HD at 1 year. MEASUREMENTS: AVF Qa was measured by Doppler ultrasonography at 2 days and 1, 2, 3, and 12 months. RESULTS: We enrolled 122 patients who were randomly allocated to the intervention (n = 60) and control (n = 62) groups. In comparison to controls, patients in the intervention group had higher Qa values at 1, 2, 3, and 12 months; a higher rate of physiologic maturation (90% vs 76%; P = 0.04) at 3 months; and a lower rate of AVF malfunction (12% vs 29%; P = 0.02) but higher rates of AVF cumulative unassisted patency (87% vs 70%; P = 0.01) and clinical maturation (82% vs 60%; P = 0.008) within 12 months. LIMITATIONS: This is a single-center nonblinded study. CONCLUSIONS: Far infrared therapy improves the access flow, maturation, and patency of newly created AVFs in patients with chronic kidney disease stages 4 and 5.

Gene polymorphisms of interleukin-10 and tumor necrosis factor-α are associated with contrast-induced nephropathy.

BACKGROUND/AIMS: Contrast-induced nephropathy (CIN) is the third most common cause of hospital-acquired acute renal failure. However, the pathogenesis of CIN remains unclear. This study evaluated the role of anti-inflammatory cytokine interleukin-10 (IL-10) and pro-inflammatory cytokine tumor necrosis factor-α (TNF-α) gene polymorphisms as CIN susceptibility markers after percutaneous coronary intervention (PCI). METHODS: Four IL-10 tag SNPs (rs1554286, rs3021094, rs3790622, rs1800896) and three TNF-α tag SNPs (rs1799964, rs1800630, rs1800629) were analyzed by MALDI-TOF mass spectrometry in 53 CIN patients and 455 control subjects. Serum IL-10 and TNF-α were detected using ELISA. RESULTS: When compared to controls, the CIN patients showed increased frequencies of CC (rs1554286) and AG+GG (rs1800896) genotypes in IL-10 and GA+AA (rs1800629) genotype in TNF-α (OR = 2.24 (1.13-4.44), p = 0.018; OR = 2.61 (1.30-5.26), p = 0.005, and OR = 2.11 (1.08-4.09), p = 0.025, respectively). Baseline serum IL-10 levels in CIN patients were significantly lower (1.02 ± 1.14 vs. 2.78 ± 4.73 pg/ml, p = 0.008). Patients with CIN had a higher rate of decline in renal function than those without CIN (0.89 ± 1.67 vs. 0.30 ± 0.95 ml/min/1.73 m(2) per month, p = 0.002). Significantly higher rates of decline in creatinine clearance were noted in patients with TNF-α (rs1800629) GA+AA than GG genotype (0.88 ± 1.83 vs. 0.36 ± 0.70, p = 0.03), and with IL-10 (rs1800896) AG+GG than AA genotype (1.28 ± 2.14 vs. 0.33 ± 0.90, p < 0.001). CONCLUSIONS: Gene polymorphisms of IL-10 and TNF-α are associated with CIN risk and long-term renal outcome after PCI. More prospective studies are needed to confirm our results.

Length polymorphisms of heme oxygenase-1 determine the effect of far-infrared therapy on the function of arteriovenous fistula in hemodialysis patients: a novel physicogenomic study.

BACKGROUND: The objective of this study was to evaluate the interaction between the length polymorphism of the guanosine thymidine repeat [(GT)n] in the heme oxygenase-1 (HO-1) gene and far-infrared (FIR) therapy on access flow (Qa) and arteriovenous fistula (AVF) patency in hemodialysis (HD) patients. METHODS: A total of 280 HD patients were randomized into a control group (n = 141) and the FIR group (n = 139) who received 40 min of FIR therapy three times weekly for a year during the study period from May 2005 to December 2007. Access flow was measured during HD. The [(GT)n] was determined with the definition of long (L) allele as [(GT)n] ≥ 30 and short (S) allele as [(GT)n] < 30. RESULTS: The Qa decreased from S/S to S/L and further to the L/L group but increased by FIR therapy with the highest Qa increase in the S/S group. The incidence of AVF malfunction decreased both from the L/L, S/L to S/S group (32.4 versus 17.2 versus 10.9%, P = 0.007) and from the control group to FIR group (27.5 versus 12.6%, P = 0.004). Significant associations were found between AVF malfunction and the following factors (hazard ratio, P-value): a past history of AVF malfunction (2.45, P = 0.044), FIR therapy (0.369, P = 0.03) and L/L genotypes of HO-1 (2.531 versus S/S + S/L genotypes). The 1-year unassisted patency decreased from 91.9 and 77.6% in S/S and S/L subgroups with and without FIR therapy to 75.8 and 60% for L/L subgroup with and without FIR therapy, respectively (P < 0.001). CONCLUSIONS: FIR therapy improves Qa and patency of AVF in HD patients, with the best protective effect in those with S/S genotype of HO-1.

Parathyroidectomy reduces intradialytic hypotension in hemodialysis patients with secondary hyperparathyroidism.

BACKGROUND: Secondary hyperparathyroidism is associated with vascular calcification and arterial stiffness in patients with end-stage renal disease. The aim of this study was to analyze the frequency of intradialytic hypotension (IDH) and cardiovascular function before and after parathyroidectomy (PTX) in maintenance hemodialysis patients. METHODS: We compared predialytic and intradialytic blood pressure, left and right ventricular ejection fraction (LVEF and RVEF), and cardiothoracic ratio 1 month before PTX, and 6 and 12 months after PTX. IDH was defined as a decrease in systolic blood pressure ≥ 20 mmHg or a decrease in mean arterial pressure ≥ 10 mmHg. RESULTS: At the time of PTX, the mean age of the patients was 57.4 ± 12.0 years, and the mean dialysis vintage was 12.2 ± 5.8 years. At baseline, 6 months, and 12 months after PTX, the average numbers of sessions disturbed by IDH during 13 dialysis sessions (1 month) were 6.4, 3.9 (p < 0.016 vs. baseline), and 4.0 sessions (p < 0.037 vs. baseline, p = 0.801 vs. 6 months), respectively. LVEF and RVEF were improved significantly after PTX. Furthermore, volume status was also improved, as evidenced by the significantly greater ultrafiltration volume and reduced cardiothoracic ratio. CONCLUSIONS: Hemodialysis patients with severe secondary hyperparathyroidism are more likely to achieve normotensive and euvolemic status after PTX, probably through improved heart function and reduced IDH episodes.

Mesenteric ischemia in patients with end-stage renal disease: a nationwide longitudinal study.

BACKGROUND AND AIMS: Mesenteric ischemia is an uncommon disorder associated with an extremely high mortality rate. Only limited studies have evaluated this lethal disease among patients with end-stage renal disease (ESRD). The objective of this study was to evaluate the risks of mesenteric ischemia among ESRD patients and compare the incidence between two dialysis modalities. METHODS: Records of all ESRD patients older than 20 years of age from 1998 to 2007 and a control group consisting of 1 million records were retrieved from the Taiwan National Health Insurance Research Database. Hospitalizations for mesenteric ischemic events were retrieved using ICD-9-CM diagnosis codes and ICD-9-CM operation codes from inpatient claims. RESULTS: Among 55,807 incident ESRD patients who received hemodialysis or peritoneal dialysis, there were 458 mesenteric ischemic events, corresponding to an incidence rate of 2.7 per 1,000 patient-years. Multivariate Cox regression analysis indicated that the independent risk factors were old age (HR 1.42 per 10 years), diabetes (HR 2.85), peripheral vascular disease (HR 2.66), atrial fibrillation (HR 2.15), heart failure (HR 1.65), chronic pulmonary disease (HR 1.41), neoplasm (HR 1.54), peptic ulcer disease (HR 1.86), and peritoneal dialysis (HR 1.51, all p < 0.05). There was no effect of dialysis modality on the mesenteric ischemia mortality rate. CONCLUSION: The risk of mesenteric ischemia for ESRD patients was 44.1 (95% confidence interval 13.4-106.2, p < 0.001) times higher than that of the general population. Compared to hemodialysis, peritoneal dialysis was associated with a higher risk of mesenteric ischemia.

Postdialysis blood pressure rise predicts long-term outcomes in chronic hemodialysis patients: a four-year prospective observational cohort study.

BACKGROUND: The blood pressure (BP) of a proportion of chronic hemodialysis (HD) patients rises after HD. We investigated the influence of postdialysis BP rise on long-term outcomes. METHODS: A total of 115 prevalent HD patients were enrolled. Because of the fluctuating nature of predialysis and postdialysis BP, systolic BP (SBP) and diastolic BP before and after HD were recorded from 25 consecutive HD sessions during a 2-month period. Patients were followed for 4 years or until death or withdrawal. RESULTS: Kaplan-Meier estimates revealed that patients with average postdialysis SBP rise of more than 5 mmHg were at the highest risk of both cardiovascular and all-cause mortality as compared to those with an average postdialysis SBP change between -5 to 5 mmHg and those with an average postdialysis SBP drop of more than 5 mmHg. Furthermore, multivariate Cox regression analysis indicated that both postdialysis SBP rise of more than 5 mmHg (HR, 3.925 [95% CI, 1.410-10.846], p = 0.008) and high cardiothoracic (CT) ratio of more than 50% (HR, 7.560 [95% CI, 2.048-27.912], p = 0.002) independently predicted all-cause mortality. We also found that patients with an average postdialysis SBP rise were associated with subclinical volume overload, as evidenced by the significantly higher CT ratio (p = 0.008). CONCLUSIONS: A postdialysis SBP rise in HD patients independently predicted 4-year cardiovascular and all-cause mortality. Considering postdialysis SBP rise was associated with higher CT ratio, intensive evaluation of cardiac and volume status should be performed in patients with postdialysis SBP rise.

Effect of add-on direct renin inhibitor aliskiren in patients with non-diabetes related chronic kidney disease.

BACKGROUND: The renin-angiotensin-aldosterone system (RAAS) plays an important role in the progression of chronic kidney disease (CKD). Although dual RAAS inhibition results in worse renal outcomes than monotherapy in high risk type 2 diabetes patients, the effect of dual RAAS inhibition in patients with non-DM CKD is unclear. The aim of this study was to evaluate the potential renoprotective effect of add-on direct renin inhibitor in non-DM CKD patients. METHODS: We retrospectively enrolled 189 non-DM CKD patients who had been taking angiotensin II receptor blockers (ARBs) for more than six months. Patients were divided into an add-on aliskiren group and an ARB monotherapy group. The primary outcomes were a decline in glomerular filtration rate (GFR) and a reduction in urinary protein-to-creatinine ratio at six months. RESULTS: The baseline characteristics of the two groups were similar. Aliskiren 150 mg daily reduced the urinary protein-to-creatinine ratio by 26% (95% confidence interval, 15 to 37%; p < 0.001). The decline in GFR was smaller in the add-on aliskiren group (-2.1 vs. -4.0 ml/min, p = 0.038). Add-on aliskiren had a neutral effect on serum potassium in the non-DM CKD patients. In subgroup analysis, the proteinuria-reducing effect of aliskiren was more prominent in patients with a GFR less than 60 ml/min, and in patients with a urinary protein-to-creatinine ratio greater than 1.8. The effect of aliskiren in retarding the decline in GFR was more prominent in patients with hypertensive nephropathy than in those with glomerulonephritis. CONCLUSION: Add-on direct renin inhibitor aliskiren (150 mg daily) safely reduced proteinuria and attenuated the decline in GFR in the non-DM CKD patients who were receiving ARBs.

Serum creatinine determined by Jaffe, enzymatic method, and isotope dilution-liquid chromatography-mass spectrometry in patients under hemodialysis.

OBJECTIVES: Serum creatinine is an important clinical marker for renal clearance. However, the Jaffe method had much interference and the accuracy had not been tested in patients under hemodialysis (HD) with standard isotope dilution-liquid chromatography-mass spectrometry (IDLCMS) method. The validity of enzymatic method is also unknown. METHODS: The predialysis serum creatinine levels of 126 patients under regular HD for 3 months were checked by Jaffe, enzymatic, and IDLCMS methods. We compared the value of the Jaffe and enzymatic to that of IDLCMS in linear regression model. And we also tried to find the clinical parameters that influence the difference between Jaffe vs. IDLCMS and enzymatic vs. IDLCMS method. RESULTS: We found significant underestimate serum creatinine in uremic patients by Jaffe and enzymatic methods. Serum glucose and globulin are positive biases, whereas albumin, potassium, and phosphorus are negative biases. Enzymatic method is less affected by serum glucose and serum protein. Albumin acts differently in uremic serum compared to the results of mixing them with normal serum. CONCLUSIONS: For uremic patients, in whom creatinine level is high and many of them suffered from diabetes mellitus, serum creatinine can be either under- or overestimated by Jaffe method. Enzymatic method is less affected and may be a better method.