Suhnggwon Kim

Benefits of biocompatible PD fluid for preservation of residual renal function in incident CAPD patients: a 1-year study

BACKGROUND In vitro studies of peritoneal dialysis (PD) solutions demonstrated that a biocompatible fluid with neutral-pH and low glucose degradation products (LF) has better biocompatibility than a conventional acidic lactate-buffered fluid (CF). However, few clinical trials have investigated the effects of the biocompatible solution on residual renal function (RRF). We performed a prospective, randomized trial with patients starting continuous ambulatory peritoneal dialysis (CAPD). METHODS Ninety-one incident patients started CAPD for 12-month treatment with either LF (Balance, Fresenius, n = 48) or CF (CAPD/DPCA, Fresenius, n = 43). RRF, peritoneal solute transport rate and solute clearance were measured every 6 months. RESULTS LF had a significant effect on the change of glomerular filtration rate (GFR) (P = 0.048 by the mixed model). In per-protocol analysis, GFR in the LF group did not decrease over a 12-month period, while GFR in the control group significantly decreased (0.13 +/- 33.4 L/ week/1.73 m(2) for LF versus -13.6 +/- 19.4 L/week/1.73 m(2) for CF, P = 0.049). Subgroup analysis for patients with initial GFR of 2 mL/min/1.73 m(2) or above showed a significantly higher GFR for the LF group over the 12-month period. At Month 13, serum total CO(2) levels were higher and serum albumin levels were lower in the LF group. No differences between the two groups were observed for the C-reactive protein. Over the 12-month period, effluent cancer antigen-125 levels significantly increased in the LF group, compared with those of the CF group, while effluent interleukin-6 levels were not different between the two groups. CONCLUSION Our study suggests that LF may better preserve RRF over the 12-month treatment period in incident CAPD patients.

Ethnic Coefficients for Glomerular Filtration Rate Estimation by the Modification of Diet in Renal Disease Study Equations in the Korean Population

Race and ethnicity are influential in estimating glomerular filtration rate (GFR). We aimed to find the Korean coefficients for the Modification of Diet in Renal Disease (MDRD) study equations and to obtain novel proper estimation equations. Reference GFR was measured by systemic inulin clearance. Serum creatinine (SCr) values were measured by the alkaline picrate Jaffé kinetic method, then, recalibrated to CX3 analyzer and to isotope dilution mass spectrometry (IDMS). The Korean coefficients for the 4 and 6 variable MDRD and IDMS MDRD study equations based on the SCr recalibrated to CX3 and to IDMS were 0.73989/0.74254 and 0.99096/0.9554, respectively. Coefficients for the 4 and 6 variable MDRD equations based on the SCr measured by Jaffé method were 1.09825 and 1.04334, respectively. The modified equations showed better performances than the original equations. The novel 4 variable equations for Korean based on the SCr measured and recalibrated to IDMS were 107.904×SCr-1.009×age-0.02 (×0.667, if woman) and 87.832×SCr-0.882×age0.01 (×0.653, if woman), respectively. Modified estimations of the MDRD and IDMS MDRD study equations with ethnic coefficients and the novel equations improve the performance of GFR estimation for the overall renal function.

Incidence and Outcomes of Contrast-Induced Nephropathy After Computed Tomography in Patients With CKD: A Quality Improvement Report

BACKGROUND Although there has been considerable investigation of the general characteristics of contrast-induced nephropathy (CIN), it has not been studied adequately in a computed tomography (CT) population. We assessed the incidence and outcomes of CIN after contrast-enhanced CT in patients with chronic kidney disease pretreated with saline and N-acetylcysteine (NAC). DESIGN Quality improvement report. SETTING & PARTICIPANTS 520 patients registered in a CIN prevention program. QUALITY IMPROVEMENT PLAN We initiated the CIN prevention program in January 2007. In this program, patients with chronic kidney disease undergoing contrast-enhanced CT in an outpatient setting were automatically referred to nephrologists, and patients received saline and NAC before and after CT. The development of CIN was assessed 48-96 hours after CT. OUTCOMES Incidence of CIN and time to renal replacement therapy. MEASUREMENTS Baseline serum creatinine, hemoglobin, and serum albumin levels; type and volume of contrast agents; and post-CT serum creatinine level. RESULTS Overall, CIN occurred in 13 (2.5%) patients. Incidences of CIN were 0.0%, 2.9%, and 12.1% in patients with an estimated glomerular filtration rate of 45-59, 30-44, and <30 mL/min/1.73 m(2), respectively. The risk of CIN was increased in patients with severely decreased kidney function and diabetes. The development of CIN consequently increased the risk of renal replacement therapy (P < 0.001 by log-rank), and the risk was significantly accentuated in patients with estimated glomerular filtration rate <30 mL/min/1.73 m(2). LIMITATIONS A single-center study and comparison with previous studies. CONCLUSIONS The incidence of CIN was relatively low in patients treated with saline and NAC. The development of CIN predisposed to poor kidney survival in the long term.

The Prevalence of Chronic Kidney Disease (CKD) and the Associated Factors to CKD in Urban Korea: A Population-based Cross-sectional Epidemiologic Study

Chronic kidney disease (CKD) is a worldwide problem. This study was designed to survey the prevalence and risk factors for CKD in Korea. The 2,356 subjects were selected in proportion to age, gender, and city. Subjects 35 yr of age or older were selected from 7 cities. Estimated glomerular filtration rate (eGFR) was calculated using the Modification of Diet in Renal Disease (MDRD) Study equation, with albuminuria defined as a urine albumin to creatinine ratio of 30 mg/g or more. The overall prevalence of CKD was 13.7%. The prevalences of CKD according to stage were 2.0% stage 1, 6.7% stage 2, 4.8% stage 3, 0.2% stage 4, and 0.0% stage 5. The prevalences of microalbuminuria and macroalbuminuria were 8.6% and 1.6%, respectively. The prevalence of eGFR less than 60 mL/min/1.73 m2 was 5.0%. Age, body mass index (BMI), hypertension, diabetes mellitus, systolic blood pressure (SBP), diastolic blood pressure (DBP), and fasting blood glucose were independent factors related to the presence of CKD. In conclusions, Korea, in which the prevalence of CKD is increasing, should prepare a policy for early detection and appropriate treatment of CKD. The present data will be helpful in taking those actions.

Lean Mass Index: A Better Predictor of Mortality than Body Mass Index in Elderly Asians

OBJECTIVES: To evaluate the correlation between body mass index (BMI), body composition, and all‐cause mortality in an elderly Asian population.

Clinical implications of pathologic diagnosis and classification for diabetic nephropathy

AIM The usefulness of renal pathologic diagnosis in type II DM (diabetes mellitus) remains debate. METHODS We grouped the pathologic diagnoses as pure DN (diabetic nephropathy), NDRD (non-diabetic renal disease), and NDRD mixed with DN (Mixed). We classified pure DN as the criteria suggested by Tervaert. We compared the accuracy of clinical parameters to predict DN and usefulness of pathology to predict renal prognosis. RESULTS Among 126 enrolled patients, there were 50 pure DN, 65 NDRN, and 11 Mixed. The sensitivity and specificity for predicting DN with the presence of retinopathy were 77.8-73.6% and, with a cut-off value of 7.5 years of diabetic duration, the sensitivity and specificity were 64.5-67.2%. ESRD (end stage renal disease) occurred in 44.0% of DN, 18.2% of Mixed, and 12.3% of NDRD (p<0.001). Among pure DN, Class IV showed the lowest estimated glomerular filtration rate (eGFR). We estimated the 5-year renal survival rate as 100.0% in Classes I and IIa, 75.0% in Class IIb, 66.7% in Class III, and 38.1% in Class IV (p=0.002). CONCLUSIONS Nephropathy of type II DM was diverse and could not be completely predicted by clinical parameters. The renal pathologic diagnosis was a good predictor for renal prognosis in type II DM.

Hemorrhagic Fever with Renal Syndrome Caused by the Seoul Virus

The Seoul virus is an important etiologic agent in hemorrhagic fever with renal syndrome (HFRS), and infections with the Seoul virus are less severe than those with the Hantaan virus. However, the information on HFRS caused by the Seoul virus is limited in Korea. Retrospective clinical analysis was done on 30 patients with Seoul virus infection who had been diagnosed as having HFRS by clinical features and serologic testing by the plaque reduction neutralization test from 1986 to 1991 at the Seoul National University Hospital. They were compared with 69 patients with Hantaan virus infection. The Seoul virus was the etiologic agent in 25% of Korean HFRS and the major cause of HFRS during the summer season although infections occurred throughout the year. The Seoul virus infection had a milder degree of bleeding and renal derangement but had severer liver dysfunction than the Hantaan virus infection. Renal histopathologic findings revealed a milder degree of hemorrhage and vascular changes than cases involving Hantaan virus infection. The precise mechanisms of vascular dysfunction and organ involvement in Seoul virus infection, however, still remain to be explored.

Mutational analysis of idiopathic renal hypouricemia in Korea

Idiopathic renal hypouricemia is a hereditary disease characterized by abnormally high renal uric acid clearance. Most patients are clinically silent, but acute renal failure (ARF), urolithiasis, or hematuria may develop. A defect in the SLC22A12 gene, which encodes the renal uric acid transporter, URAT1, is the known major cause of this disorder. We performed a mutational analysis of the SLC22A12 gene in five Korean patients with idiopathic renal hypouricemia in this study. Two patients presented with microscopic hematuria, one with uric acid urolithiasis, and one with exercise-induced ARF. One patient was asymptomatic. Three different mutations, W258X, R90H and R477H, were detected in four of the patients. However, no mutation was found in the fifth ARF patient. This is the first study of SLC22A12 mutations in a country other than Japan. W258X was found to be the predominant SLC22A12 mutation in Korean renal hypouricemia patients, as has been reported in Japan.

Decreased acetylation of isoniazid in chronic renal failure

Pharmacokinetic parameters of isoniazid obtained from 37 normal subjects were compared with parameters obtained from 14 patients with chronic renal failure. In the 29 normal rapid acetylators and eight normal slow acetylators, the mean plasma half‐life values of isoniazid were 1.54 ± 0.31 and 3.68 ± 0.59 hours, respectively. The plasma half‐life values of isoniazid in patients with chronic renal failure varied widely from 1.30 to 10.13 hours, but the values were significantly longer than those of normal subjects. Because isoniazid clearance is governed mainly by hepatic metabolism, such a significant prolongation of plasma half‐life of isoniazid was unexpected; thus the pharmacokinetics of isoniazid were reevaluated in the same patients with chronic renal failure after the kidney transplantation. After successful kidney transplantation, the shortening of isoniazid half‐life was pronounced and the nonrenal clearance was markedly increased. These findings indicate that decreased isoniazid clearance in chronic renal failure is caused in minor part by the decreased renal excretion of isoniazid and in major part by the depressed hepatic N‐acetylation of isoniazid.

Asian chronic kidney disease best practice recommendations: Positional statements for early detection of chronic kidney disease from Asian Forum for Chronic Kidney Disease Initiatives (AFCKDI)

1. Targets