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Purpose: Recent studies have reported that loss of bone mass is associated with renal function decline and increased fracture risks in chronic kidney disease (CKD) patients. The aim of this study was to investigate the best estimated glomerular filtration rate (eGFR) equation to detect osteopenia in CKD patients., Materials and Methods: This was a cross-sectional study, and 780 patients aged 50 years or above were classified into normal bone mass or osteopenia groups according to the -1.0 of T-scores at total hip and femur neck. Comparisons of area under the receiver operating characteristic (ROC) curves (AUC) were performed to investigate significant differences among three eGFR formulas: Modification of Diet in Renal Disease, CKD-Epidemiology Collaboration (EPI) creatinine, and CKD-EPI cystatin C (CKD-EPI-Cys)., Results: The mean age was 61 years old and the proportion of females was 37.3%. The total hip osteopenia group showed lower CKD-EPI-Cys eGFR levels (osteopenia group, 33.3±19.0 mL/min/1.73 m²; normal group, 48.1±26.2 mL/min/1.73 m², p<0.001). In multiple logistic regression analysis, CKD-EPI-Cys eGFR was independently associated with osteopenia at the total hip (per 1 mL/min/1.73 m² increase, odds ratio 0.98, 95% confidence interval 0.97-0.99, p=0.004) after adjusting for confounding variables. ROC curve analyses indicated that CKD-EPI-Cys shows the largest AUC for osteopenia at the total hip (AUC=0.678, all p<0.01) and the femur neck (AUC=0.665, all p<0.05)., Conclusion: Decreased renal function assessed by CKD-EPI-Cys equation correlates with osteopenia better than creatinine-based methods in CKD patients, and the CKD-EPI-Cys formula might be a useful tool to assess skeletal-related event risks., Competing Interests: The authors have no financial conflicts of interest.

Purpose: Smoking reportedly exerts deleterious effects on renal function; however, its effects on histology have not been clarified in patients with IgA nephropathy (IgAN)., Materials and Methods: Renal histology was evaluated in a cohort of 397 patients diagnosed with IgAN according to smoking status and dose in relation to renal function., Results: Among the study cohort, which was predominantly male (88.5%), 52 patients (13%) were current smokers. These current smokers demonstrated more frequent hypertension and higher serum creatinine levels than non/ex-smokers at the time of diagnosis, which was apparent with increased smoking dose. The percentages of global glomerulosclerosis and arteriolar hyalinosis increased with increased smoking dose, whereas tubulointerstitial fibrosis or arterial intimal thickening did not. Glomerular mesangial alpha-smooth muscle actin expression were similar between current and non/ex-smokers matched for age, gender, hypertension, and histologic severity, although the number of glomerular CD68+ cells was significantly fewer in smokers. Initial serum creatinine level, estimated glomerular filtration rate (eGFR), and global glomerulosclerosis were found to be risk factors of serum creatinine doubling in both smokers and non/ex-smokers by univariate analysis during a mean follow-up of 3.8 years., Conclusion: In addition to dose dependent renal functional decline and hypertension, smoking contributes to renal disease progression by eliciting microvascular injury in IgAN patients.

Purpose: The conventional trocar and cannula method in peritoneal dialysis (PD) catheter insertion has its limitation in clinical setting. The aim of this study was to compare a modified method for percutaneous PD catheter insertion with the conventional method, and demonstrate advantages of the modified method., Materials and Methods: Patients at a single center who had percutaneous PD catheters inserted by nephrologists from January 2006 until September 2012, using either a modified method (group M) or the conventional trocar and cannula method (group C), were retrospectively analyzed, in terms of baseline characteristics, complications experienced up to 3 months after the procedure, and the suitability of the procedure for patients., Results: Group M included 82 subjects, while group C included 66 cases. The overall early complication rate in group M (1.2%) was significantly lower than that in group C (19.7%) (p<0.001). The catheter revision rate during timeframe for early complications was significantly lower in group M (0%) than in group C (6.1%) (p=0.024). When comparing Procedure time (1 h 3 min±16 min vs. 1 h 36 min±19 min, p<0.01), immediate post-procedural pain (2.43±1.80 vs. 3.14±2.07, p<0.05), and post-procedure days until ambulation (3.95±1.13 days vs. 6.17±1.34 days, p<0.01), group M was significantly lower than group C. There was no significant difference in total hospitalization period (14.71±7.05 days vs. 13.86±3.7 days)., Conclusion: Our modified PD catheter insertion method shows its advantages in early complication rate, early complications revision rate, and the patients' conveniences.

Purpose: Continuous renal replacement therapy (CRRT) has been established for critically ill acute kidney injury (AKI) patients. In addition, some centers consist of a specialized CRRT team (SCT) with physicians and nurses. To our best knowledge, however, ona a few studies have yet been carried out on the superiority of SCT management., Materials and Methods: A total of 551 patients, who received CRRT between January 2008 and March 2009, were divided into two groups based on the controller of CRRT. The impact of the CRRT management on 28-day mortality was compared between two groups by Kaplan-Meier curve and Cox analysis., Results: During the study period, the number of filters used, down-time per day, and intensive care unit length of day were significantly higher in non-SCT group than in SCT group (6.2 hrs vs. 5.0 hrs, p=0.042; 5.0 hrs vs. 3.8 hrs, p<0.001; 27.5 days vs. 21.1 days, p=0.027, respectively), while net ultrafiltration rate was significantly lower in non-SCT group than SCT group (28.0 mL/kg/hr vs. 29.5 mL/kg/hr, p=0.043, respectively). In addition, 28-day mortality rate was significantly lower in SCT group than with non-SCT group (p=0.031). Moreover, Cox regression analysis showed that 28-day mortality rate was significantly lower in SCT control group, even after adjusting for age, gender, severity scores, biomarkers, risk, injury, failure, loss, and end-stage renal disease, and contributing factors (hazard ratio 0.91, p=0.046)., Conclusion: A well-trained CRRT team could be beneficial for mortality improvement of AKI patients requiring CRRT.

Purpose: The effect of different peritoneal dialysis (PD) modalities on the decline in residual renal function (RRF) is unclear due to inconsistencies among studies. In particular, the effect of automated peritoneal dialysis (APD) modalities [continuous cyclic peritoneal dialysis (CCPD) and nightly intermittent peritoneal dialysis (NIPD)] on RRF has not been examined in a large cohort., Materials and Methods: We conducted a single-center retrospective study to investigate the association between PD modalities and decline in RRF in 142 incident PD patients [34 on CCPD, 36 on NIPD, and 72 on continuous ambulatory peritoneal dialysis (CAPD)]. RRF was measured within 2 months from PD start and at 1 year after PD initiation., Results: The RRF at 1 year after PD initiation was 1.98±2.20 mL/min/1.73 m² in CCPD patients and 3.63±3.67 mL/min/1.73 m² in NIPD patients, which were moderately lower than 4.23±3.51 mL/min/1.73 m² in CAPD patients (p=0.064). Moreover, there was no significant difference in the 1-year rate of decline of RRF between CCPD and NIPD patients, although APD patients had a faster 1-year RRF decline rate than CAPD patients (CCPD and NIPD vs. CAPD: -45.68 and -36.69 vs. 1.17%/year, p=0.045). APD was associated with a more rapid decline in RRF in patients with end-stage renal disease undergoing PD, although multivariate analysis attenuated the significance of this finding (β=-31.50; 95% CI, -63.61 to 0.62; p=0.052)., Conclusion: Our results suggest that CAPD might be more helpful than APD for preserving RRF during the first year of dialysis therapy, although there was no significant difference in the 1-year rate of decline of RRF between the two APD modalities.

Purpose: We undertook an observational study to investigate the effects of immunosuppressive treatment on proteinuria and renal function in 179 Korean idiopathic membranous nephropathy patients with nephrotic syndrome., Materials and Methods: The primary outcome was regarded as the first appearance of remission and the secondary outcomes as a decline in estimated glomerular filtration rate (eGFR) >50% or initiation of dialysis, and all-cause mortality. Seventy-two (40.2%) and 50 (27.9%) patients were treated with corticosteroids alone (C) and corticosteroids plus cyclosporine (C+C), respectively, whereas 57 (31.8%) did not receive immunosuppressants (NTx). Cyclosporine was added if there was no reduction in proteinuria of >50% from baseline by corticosteroids alone within 3 months., Results: There were no differences in baseline renal function and the amount of proteinuria among the three groups. Overall, complete remission (CR) was achieved in 88 (72.1%) patients by immunosuppressants. In a multivariate analysis adjusted for covariates associated with adverse renal outcome, the probability of reaching CR was significantly higher in the C [hazard ratio (HR), 4.09; p<0.001] and C+C groups (HR, 2.57; p=0.003) than in the NTx group. Kaplan-Meier analysis revealed that 5-year CR rates of C, C+C, and NTx groups were 88.5%, 86.2%, and 56.7% (p<0.001). Ten-year event-free rates for the secondary endpoints in these three groups were 91.7%, 79.9%, and 57.2% (p=0.01)., Conclusion: Immunosuppressive treatment was effective in inducing remission and preserving renal function in these patients. Therefore, stepwise treatment using corticosteroids alone and in combination with cyclosporine is warranted in these patients.

Purpose: Cinacalcet is effective for treating refractory secondary hyperparathyroidism (SHPT), but little is known about the response rates and clinical factors influencing the response., Materials and Methods: A prospective, single-arm, multi-center study was performed for 24 weeks. Cinacalcet was administered to patients with intact parathyroid hormone (iPTH) level greater than 300 pg/mL. Cinacalcet was started at a dose of 25 mg daily and titrated until 100 mg to achieve a serum iPTH level<300 pg/mL (primary end point). Early response to cinacalcet was defined as a decrease of iPTH more than 50% within one month., Results: Fifty-seven patients were examined. Based on the magnitude of iPTH decrease, patients were divided into responder (n=47, 82.5%) and non-responder (n=10, 17.5%) groups. Among the responders, 38 achieved the primary end point, whereas 9 patients showed a reduction in serum iPTH of 30% or more, but did not reach the primary end point. Compared to non-responders, responders were significantly older (p=0.026), female (p=0.041), and diabetics (p<0.001). Additionally, early response was observed more frequently in the responders (30/47, 63.8%), of whom the majority (27/30, 90.0%) achieved the primary end point. Multivariate analysis showed that lower baseline iPTH levels [odds ratio (OR) 0.96, 95% confidence interval (CI) 0.93-0.99], the presence of diabetes (OR 46.45, CI 1.92-1125.6) and early response (OR 21.54, CI 2.94-157.7) were significant clinical factors affecting achievement of iPTH target., Conclusion: Cinacalcet was effective in most hemodialysis patients with refractory SHPT. The presence of an early response was closely associated with the achievement of target levels of iPTH.

Purpose: This study aimed to elucidate whether stone removal by extracorporeal shock wave lithotripsy (ESWL) is associated with delayed chronic kidney disease (CKD) progression., Materials and Methods: We conducted a retrospective analysis of 131 nephrolithiasis patients with stage 3 and 4 CKD. We collected baseline clinical and laboratory data, kidney stone characteristics, and history of receiving ESWL. We classified study patients into two groups according to whether they underwent ESWL or not (Non-ESWL group vs. ESWL group). We initially compared annual estimated glomerular filtration rate (eGFR) changes of Non-ESWL group with those of ESWL group before undergoing ESWL. In the next step, we sought to compare annual eGFR changes in the same patients before and after ESWL. Finally, we compared annual eGFR changes between success and failure groups among patients undergoing ESWL., Results: The mean age of the patients was 62 years and 72.5% were male. The mean observation period was 3.2 years. Non-ESWL group and ESWL group before undergoing ESWL showed similar annual eGFR changes (-1.75±6.5 vs. -1.63±7.2 mL/min/1.73 m²/year, p=0.425). However, eGFR declined slower after undergoing ESWL than before ESWL (annual eGFR changes, -0.29±6.1 vs. -1.63±7.2 mL/min/1.73 m²/year, p<0.05). In addition, among patients in ESWL group, eGFR declined faster in the failure group than in the success group (annual eGFR change, -1.01±4.7 vs. -0.05±5.2 mL/min/1.73 m²/year, p<0.05)., Conclusion: Our results suggest that stone removal by ESWL is associated with delayed deterioration of renal function in CKD patients with nephrolithiasis.

Purpose: In patients with diabetic end stage renal disease (ESRD), glycated albumin (GA) reflects recent glycemic control more accurately than glycated hemoglobin (HbA1c). We evaluated the relationship between GA and average blood glucose (AG) level and developed an estimating equation for translating GA values into easier-to-understand AG levels., Materials and Methods: A total of 185 ESRD patients, including 154 diabetic and 31 non-diabetic participants, were enrolled (108 hemodialysis, 77 peritoneal dialysis). Patients were asked to perform four-point daily self-monitoring of capillary blood glucose (SMBG) at least three consecutive days each week for four weeks. Serum levels of GA, HbA1c and other biochemical parameters were checked at baseline, as well as at 4 and 8 weeks., Results: Approximately 74.3±7.0 SMBG readings were obtained from each participant and mean AG was 169.1±48.2 mg/dL. The correlation coefficient between serum GA and AG levels (r=0.70, p<0.001) was higher than that of HbA1c and AG (r=0.54, p<0.001). Linear regression analysis yielded the following equation: estimated AG (eAG) (mg/dL)=4.71×GA%+73.35, and with this formula, serum GA levels could be easily translated to eAG levels. Multivariate analysis revealed significant contributions of postprandial hyperglycemia (β=0.25, p=0.03) and serum albumin (β=0.17, p=0.04) in determining serum GA level, independent to other clinical parameters., Conclusion: Compared to HbA1c, serum GA levels were better correlated with AG levels. Using the estimating equation, an average blood glucose level of 155-160 mg/dL could be matched to a GA value of 18-19% in patients with ESRD.

Idiopathic retroperitoneal fibrosis (IRPF) is a rare disease characterized by a retroperitoneal inflammatory proliferative fibrosing process. Hashimoto's thyroiditis is the most common inflammatory condition of the thyroid gland; and is a frequently-occurring autoimmune disorder manifesting predominantly in middle-aged women. We report a rare association of IRPF with Hashimoto's thyroiditis in a 67-year-old man demonstrating good response to steroid therapy.

Puromycin aminonucleoside (PAN)-induced nephrosis is a well-described model of human idiopathic nephrotic syndrome, but the mechanism of PAN's effect is not completely understood. To investigate whether proteinuria in the PAN model is associated with an alteration of zonula occludens-1 (ZO-1) expression within the glomeruli, and whether cyclosporin A (CsA) has an effect on proteinuria and ZO-1 expression in this model, eighteen Sprague Dawley (SD) rats were assigned into three groups. Twelve rats received a single intraperitoneal injection of PAN (15 mg/100 g). The other six rats received an equal volume of saline (normal control group; control). CsA solution was administered intraperitoneally once a day for 20 days after the PAN injection (n=6, PAN+CsA). The remaining six rats received PAN, but they didn't receive CsA (n=6, PAN). Compared to control rats (35.1+/-5.4 mg/day), the 24-hour urinary protein excretion on day 18 was significantly higher in the PAN rats (1021.9+/-128.9 mg/day, p<0.01), and the CsA treatment partly reversed the increase in proteinuria in the PAN rats (556.4+/-102.3 mg/day, p<0.05). Glomerular ZO-1 protein expressions were significantly increased in the PAN rats as compared to the control group on day 20 (176%, p<0.01). CsA treatment for 20 days in the PAN rats inhibited the increase in ZO-1 protein expression by 71.1% (p<0.05). CsA treatment significantly diminished the glomerular ZO-1 expression in the PAN rats as assessed by immunohistochemistry. CsA treatment significantly reduced proteinuria and the diminished glomerular ZO-1 expression in a PAN nephrosis rat model. These findings suggest the potential role of the slit diaphragm associated proteins in the development of the nephrotic syndrome, and CsA decreased the proteinuria probably by a direct action on the expression of these proteins in podocytes. Further investigations are needed to clarify the role of slit diaphragm associated proteins in the development of PAN nephrosis.

Sclerosing encapsulating peritonitis (SEP) is a rare but serious complication in patients with continuous ambulatory peritoneal dialysis (CAPD), and is characterized by a progressive, intra-abdominal, inflammatory process resulting in the formation of sheets of new fibrous tissue, which cover, bind, and constrict the viscera, thereby compromising the motility of the bowel. No satisfactory estimate is available on the comparative incidence of dialysis related SEP and the pathogenesis of SEP still remains uncertain. Although recent therapeutic approaches have reported varying degrees of success, an efficient measure to detect, at an early stage, patients at risk for SEP would be beneficial and a standardized treatment regimen to prevent the illness is urgently needed. This study aimed to evaluate the clinical features of SEP and to identify the possible risk factors for the development of SEP in CAPD patients. We retrospectively reviewed by questionnaire SEP cases among CAPD patients from 7 university hospital dialysis centers in Korea, including Yonsei University, Ajou University, Catholic University, Inha University, Kyungpook University, Seoul National University and Soonchunhyang University, from January 1981 to December 2002. Out of a total of 4,290 CAPD patients in these centers, 34 cases developed SEP with an overall prevalence of 0.79%. The male to female ratio was 17:17. The median age of these patients was 44.5 years (range 19-66). The median duration of CAPD before SEP was 64 months (9-144) and 68% of patients (23/34) had been on CAPD for more than 4 years. Peritonitis (including two fungal cases) was the main cause of catheter removal in SEP (27 cases, 79%). Seventy-five percent of the cases (15/20) were administered beta-blocker for a mean duration of 85 months (26-130). Among 10 cases with available peritoneal equilibration test (PET) data, 8 showed high transporter characteristics, and the remaining 2 were high average. Eighteen cases were diagnosed by clinical and radiologic methods, and 16 were surgically diagnosed. Eleven cases were surgically treated and the others were treated conservatively with intermittent total parenteral nutrition (TPN). The overall mortality rate was 24%. SEP is a serious, life threatening complication of CAPD. Most cases had a PD duration of more than 4 years, a history of severe peritonitis, and high transporter characteristics in PET. Therefore, to reduce the incidence of SEP, careful monitoring and treatment, including early catheter removal in patients with severe peritonitis, should be considered for long-term CAPD patients with the above characteristics.

The aim of this study was to evaluate the evolution of lupus activity in end-stage renal disease (ESRD) patients due to lupus nephritis and to determine the long-term prognosis. We reviewed the clinical courses of 45 patients with ESRD due to systemic lupus erythematosus (SLE). We analyzed the course of SLE following the onset of ESRD, with special attention to the clinical and serological manifestations, survival time on dialysis, and renal transplantation outcome. Disease activity was measured using the SLE Disease Activity Index (SLEDAI). Of the 45 patients, 21 patients were being treated with hemodialysis (HD), 11 were undergoing peritoneal dialysis (PD), and 13 underwent transplantation. Duration of follow- up was 53 +/- 29 months. The SLEDAI score on commencement of renal replacement therapy was not significantly different among the 3 groups (HD: 4.2 +/- 4.2, PD: 4.3 +/- 2.3, Transplant: 3.2 +/- 1.9). However, disease activity scored by follow-up maximal SLEDAI during dialysis or transplantation showed a significant increase after peritoneal dialysis (HD: 5.0 +/- 3.6, PD: 7.4 +/- 3.7, Transplant: 2.2 +/- 1.7, p < 0.05). When the individual changes in the maximal SLEDAI score were considered, a significant increase was apparent after peritoneal dialysis (p < 0.05), but not after either hemodialysis or renal transplantation. There was no significant difference in cumulative survival rate, and also in technique or graft survival rates of the 3 groups. Among the variables tested, follow-up maximal SLEDAI score was the only significant factor associated with patient survival (odds ratio: 1.15, p < 0.05). The incidence (36% versus 19%) of high disease activity was greater, but not significantly, in the peritoneal dialysis group, as compared to the hemodialysis group. Clinical activity of SLE was apparent in 65% of patients in the first year of dialysis, but none showed any activity after the third year of dialysis. We found that although lupus disease activity declined after patients progressed to ESRD, lupus disease activity still affected patients' survival. An incremental increase in postdialysis lupus activity was not uncommon, especially during the first one year of dialysis. During the follow-up period, maximal SLEDAI score increased significantly after peritoneal dialysis. However, the long-term prognosis was not significantly different according to the treatment modality.

The number of diabetic ESRD patients has increased and death rates of diabetic patients on hemodialysis (HD), peritoneal dialysis (PD) and renal transplantation (RT) have remained higher than the death rate of non-diabetic patients. An attempt was made to compare the clinical characteristics, patients' cumulative survival, and technical survival among the three groups retrospectively according to the mode of renal replacement therapy(RRT), and to analyze the risk factors associated with mortality. A total of 229 diabetic ESRD patients diagnosed between 1986 and 1995 at the Severance Hospital who began dialysis or who underwent a kidney transplant were included and their medical charts were reviewed. Hypertension was the most common co-morbid disease in all study groups. The prevalence of cardiovascular disease was the only co-morbid condition that was significantly different among the three groups, which was highest in the PD group (24.4%) and lowest in the RT group (8%). In the analysis of a patient's cumulative survival rate not adjusted for age and sex, the RT group had the highest survival rate, and the cumulative survival rate of the HD and PD group were similar. The 5-year survival rate of the patients treated with HD, PD and RT was 28.8%, 19.8%, and 72.0%, respectively. No differences were observed in the patient's cumulative survival rate between the HD and PD patients even when it was adjusted for age. When adjusted for age, sex and risk factors, the relative death rate of the RT group was significantly lower in male patients younger than 60 years of age. With the exception of male patients younger than 60 years of age, the PD group showed a slightly lower relative death rate although it was not significant. The multiple Cox regression analysis of patient survival showed that age, serum albumin, BUN, mean hospital days, the presence of cardiovascular disease at the initiation of RRT were associated with mortality. The analysis of the technique survival rate revealed a better result in the HD group compared to PD group, but a limitation in being able to investigate the AVF function disturbed the accuracy of the analysis of technical survival rate. In conclusion, the survival rate between the PD and HD patients was not different and the RT group had the best survival rate. Therefore, kidney transplantation in diabetic ESRD patients should be considered positively if no other contraindicated condition for RT exit.

Previously, we reported that high glucose enhanced cytokine-induced nitric oxide (NO) production by rat mesangial cells (MCs), and that the enhanced expression of the iNOS pathway may promote extracellular matrix accumulation by MCs. The present study was designed to examine whether the iNOS pathway is pathologically altered in experimental diabetic nephropathy, and whether therapy with angiotensin converting enzyme (ACE) inhibitor (imidapril: I) or angiotensin II type I receptor (AT1) blocker (L-158,809: L), ameliorates these changes. Male Sprague-Dawley rats were injected with diluent (control: C) or streptozotocin. At sacrifice after 4, 8 and 12 weeks, rats underwent either a 4 hour placebo or an intraperitoneal lipopolysaccharide (LPS, 2 mg/kg) challenge. Systolic blood pressure (SBP) and urinary protein excretion (UPE) increased significantly in diabetic (D) rats compared with C. The basal expression of glomerular iNOS mRNA was increased in D rats compared with that of C rats, by reverse- transcription (RT)-polymerase chain reaction (PCR), whereas there was no significant difference in the level of protein by Western blot analysis. Upon LPS stimulation, the iNOS mRNA and protein expression was significantly elevated in D rats. In D rats, this up-regulation, of LPS-stimulated iNOS expression, was equally ameliorated both by I and L in mRNA and protein levels. From immunohistochemistry (IHC), there was a negative staining for the iNOS within the glomeruli of five C rats without LPS treatment, but one of four rats, with LPS treatment, showed minimal iNOS staining in the glomeruli. In D rats, the glomerular mesangium and podocytes were positive for iNOS in each of three out of five rats with, and without, LPS treatment. In conclusion, LPS-stimulated glomerular iNOS expression was enhanced in diabetic pnephropathy, and the activation of angiotensin II may play a role in this enhancement.