Il Ha - Academia.edu (original) (raw)

Papers by Il Ha

PloS one, 2018

Vancomycin is known to be unintentionally eliminated by continuous renal replacement therapy, and... more Vancomycin is known to be unintentionally eliminated by continuous renal replacement therapy, and the protein bound fraction of vancomycin is also known to be different in adults and children. However, there are only a few studies investigating the relationship between the dose of continuous venovenous hemodiafiltration (CVVHDF) parameters and serum concentration of vancomycin in pediatric patients. The aim of this study was to determine clinical and demographic parameters that significantly affect serum vancomycin concentrations. This retrospective cohort study was conducted at a pediatric intensive care unit in a tertiary university children's hospital. Data from oliguric patients who underwent CVVHDF and vancomycin therapeutic drug monitoring were collected. The correlation between factors affecting serum concentration of vancomycin was analyzed using mixed effect model. A total of 177 serum samples undergoing vancomycin therapeutic drug monitoring were analyzed. The median a...

Kidney and Blood Pressure Research, 2017

Background/Aims: Renovascular hypertension (RVHT) is an important cause of childhood hypertension... more Background/Aims: Renovascular hypertension (RVHT) is an important cause of childhood hypertension. This study evaluated the clinical characteristics and outcomes of Korean children with RVHT. Methods: Children treated for RVHT between 2000 and 2015 at our center were retrospectively reviewed. Results: Forty-six children were followed for a median of 6.5 (0.66-27.23) years. Forty-five percutaneous transluminal angioplasties (PTAs) were performed in 32 children. At the last visit, clinical benefit was observed in 53.3% of children. Patients with comorbid cerebrovascular disease (CVD) showed less favorable long-term outcomes after PTA (clinical benefit in 41.7% vs. 61.1% in others) and higher restenosis rates (50% vs. 31.6% in others). Surgical procedures (bypass or nephrectomy) were performed in 8 patients. After surgery, blood pressure was normalized in 2 patients, improved in 3 patients, and unchanged in the remaining patients. Between PTA group (n=21) and medication group (n=14), p...

Journal of the Korean Society of Pediatric Nephrology, 2010

Purpose : Genetic and clinical factors can influence the permeability of the peritoneal membrane.... more Purpose : Genetic and clinical factors can influence the permeability of the peritoneal membrane. The peritoneal equilibration test (PET) is helpful in measuring peritoneal permeability in peritoneal dialysis (PD). We investigated the influence of genetic polymorphism of vascular endothelial growth factor (VEGF) on the PET parameters. Methods : Pediatric patients who underwent PET within 12 months of initiating PD at Seoul National University Children s Hospital and Samsung Medical Center were selected. The ' patients with positive history of peritonitis before PET were excluded. The VEGF-2578C/ A,-14978T/C,-1154G/A,-634G/C, and +936C/T single-nucleotide polymorphisms were genotyped. Results : The mean 4-hour dialysate-to-plasma ratio for creatinine (D/P creatinine) and the mean 4-hour dialysate glucose to baseline dialysate glucose ratio (D/D0 glucose) were 0.56 0.13 and 0.43 0.11, respectively. The patients with haplotype CTGGC showed higher ± ± 4-hour D/P creatinine (0.67 0.12 vs 0.50 0.09, ± ± P =0.007) and lower 4-hour D/D0 glucose (0.35 0.12 vs 0.47 0.08, ± ± P =0.037) than those without haplotype CTGGC. Conclusion : The VEGF genetic polymorphism may influence the peritoneal solute transport.

Kidney Research and Clinical Practice, 2014

Conclusion: In CAMR, RIT could be proposed as a promising regimen in terms of delaying the progre... more Conclusion: In CAMR, RIT could be proposed as a promising regimen in terms of delaying the progression of CAMR and better allograft survival rate compared to HC group.

Pediatric Nephrology, 1999

Several cases of hereditary glomerulopathy associated with an A to G transition at position 3243 ... more Several cases of hereditary glomerulopathy associated with an A to G transition at position 3243 in mitochondrial DNA, which is known to be associated with most cases of MELAS syndrome (myopathy, encephalopathy, lactic acidosis, and stroke-like episodes), have been recently reported. These patients share the characteristics of hereditary progressive glomerular disease and hearing loss with Alport syndrome. We therefore screened 27 patients with kidney disease clinically mimicking Alport syndrome for the presence of the 3243 mitochondrial mutation, and found one girl with the mutation and a positive family history. Her clinical features were very similar to those of all cases reported to date. An absence of hematuria, severe kidney involvement in a female, pathological changes of focal segmental glomerulosclerosis with no basket-weave change of the glomerular capillary wall, and the frequent association of steroid-induced diabetes are the major features that distinguish this condition from Alport syndrome. Careful neurological examination may detect neuromuscular symptoms compatible with mitochondrial cytopathies. In conclusion, progressive glomerulopathy should be included in the broad spectrum of mitochondrial cytopathies, especially in cases of MELAS syndrome. This mutation should also be included in the etiologies of secondary focal segmental glomerulosclerosis and in the differential diagnosis of Alport syndrome.

Journal of the Korean Society of Pediatric Nephrology, 2007

Purpose Urinary lithiasis is uncommon in children, however, it may lead to chronic renal insuffic... more Purpose Urinary lithiasis is uncommon in children, however, it may lead to chronic renal insufficiency and even end stage renal disease. The etiology of stone formation in children is largely unknown; although the most common causes are known to be associated with ...

Korean Journal of Pediatrics, 2009

Purpose : Idiopathic nephrotic syndrome (NS) can be clinically classified as steroid-sensitive an... more Purpose : Idiopathic nephrotic syndrome (NS) can be clinically classified as steroid-sensitive and steroid-resistant. The detailed mechanism of glucocorticoid action in NS is currently unknown. Methods : In this study, we investigated 3 known single nucleotide polymorphisms (SNPs) (ER22/23EK, N363S, and BclI) of the glucocorticoid receptor gene (the NR3C1 gene) in 190 children with NS using polymerase chain reaction-restriction fragment length polymorphism and analyzed the correlation between the genotypes and clinicopathologic features of the patients. Results : Eighty patients (42.1%) were initial steroid nonresponders, of which 31 (16.3% of the total) developed end-stage renal disease during follow-up. Renal biopsy findings of 133 patients were available, of which 36 (31.9%) showed minimal changes in NS and 77 (68.1%) had focal segmental glomerulosclerosis. The distribution of the BclI genotypes was comparable between the patient and control groups, and the G allele frequencies in both the groups were almost the same. The ER22/23EK and N363S genotypes were homogenous as ER/ER and NN, respectively, in all the patients and in 100 control subjects. The BclI genotype showed no correlation with the NS onset age, initial steroid responsiveness, renal pathologic findings, or progression to end-stage renal disease. Conclusion : These data suggested that the ER22/23EK, N363S, and BclI SNPs in the NR3C1 gene do not affect the development of NS, initial steroid responsiveness, renal pathologic lesion, and progression to end-stage renal disease in Korean children with NS.

Journal of the Korean Society of Pediatric Nephrology, 2010

Purpose : Glomerulonephropathy (GN) often manifests as proteinuria and progresses to chronic rena... more Purpose : Glomerulonephropathy (GN) often manifests as proteinuria and progresses to chronic renal failure without specific therapy. Mesenchymal stem cell (MSC) has been tried as a therapeutic agent in experimental GN, and previous studies showed that administration of MSC concomitantly to the insult inducing GN or via intra-renal administration ameliorated proteinuria. The purpose of this study was to test the therapeutic potential of MSC administered via intravenous route at the time of clinically evident proteinuria. Methods : MSCs were administered intravenously via tail vain into the mice with adriamycin (ADR) induced nephropathy (ADR-GN), two weeks after ADR injection when massive proteinuria was evident. To test the capacity of MSC modulate the cytokine production in the inflammatory milieu, the concentrations of IFN-and IL-10 were measured in the su γ pernatant of in vitro mixed lymphocyte culture (MLC) with or without additional MSC. Results : MSCs administered intravenously into the proteinuric mice with ADR-GN accelerated the recovery of this experimental GN with disappearance of proteinuria in two weeks when the saline treated (control) mice still showed significant proteinuria. The mice treated with MSC also had a tendency of better survival. Addition of MSC decreased IFNand increased IL-10 in the supernatant of MLC. γ Conclusion : This study showed that MSC had a therapeutic potential even when administered in a more clinically relevant setting into a proteinuric glomerulonephropathy model. Further study to verify the mechanism and long-term safety of this phenomenon is required. (

Journal of the Korean Society of Pediatric Nephrology, 2010

Korean journal of pediatrics, 2011

To validate the Dinamap ProCare 200 blood pressure (BP) monitor against a mercury sphygmomanomete... more To validate the Dinamap ProCare 200 blood pressure (BP) monitor against a mercury sphygmomanometer in children 7 to 18 years old in accordance with the 2010 International Protocol of European Society of Hypertension (ESH-IP2) and the British Hypertension Society (BHS) protocol. Forty-five children were recruited for the study. A validation procedure was performed following the protocol based on the ESH-IP2 and BHS protocols for children and adolescents. Each subject underwent 7 sequential BP measurements alternatively with a mercury sphygmomanometer and the test device by trained nurses. The results were analyzed according to the validation criteria of ESH-IP2. The mean (±SD) difference in the absolute BP values between test device and mercury sphygmomanometer readings was 1.85±1.65 mmHg for systolic BP (SBP) and 4.41±3.53 mmHg for diastolic BP (DBP). These results fulfilled the Association for the Advancement of Medical Instrumentation criterion of a mean±SD below 5±8 mmHg for both...

Kidney Research and Clinical Practice, 2012

The Korean Society of Nephrology (KSN) launched the official End-Stage Renal Disease (ESRD) Patie... more The Korean Society of Nephrology (KSN) launched the official End-Stage Renal Disease (ESRD) Patient Registry in 1985 and the Internet online registry program was opened in 2001. The ESRD Registry Committee of KSN has collected data on dialysis therapy in Korea through the online registry program in the KSN Internet website. The increasing number of elderly people and diabetic patients in Korea has resulted in a very rapid increase in the number of ESRD patients. The total number of ESRD patients was 58,860 (hemodialysis [HD], 39,509; peritoneal dialysis [PD], 7309; and functioning kidney transplant [KT], 12,042). The prevalence of ESRD was 1144.4 patients per million population (PMP), and the proportion of renal replacement therapy was HD, 67.1%; PD, 12.4%; and KT, 20.5%. The number of new ESRD patients in 2010 was 9335 (HD, 7204; PD, 867; and KT, 1264; the incidence rate was 181.5 PMP). The primary causes of ESRD were diabetic nephropathy (45.2%), hypertensive nephrosclerosis (19.2%), and chronic glomerulonephritis (11.3%). The mean urea reduction ratio was 67.9% in male HD patients and 73.9% in female HD patients. The mean Kt/V was 1.394 in male patients and 1.659 in female patients. Five-year survival rates of male and female dialysis patients were 64.9% and 67.3%, respectively.

Peritoneal dialysis international : journal of the International Society for Peritoneal Dialysis

BACKGROUND, OBJECTIVES, AND METHODS: Hospitalization and mortality rates in pediatric dialysis pa... more BACKGROUND, OBJECTIVES, AND METHODS: Hospitalization and mortality rates in pediatric dialysis patients remain unacceptably high. Although studies have associated the presence of comorbidities with an increased risk for death in a relatively small number of pediatric dialysis patients, no large-scale study had set out to describe the comorbidities seen in pediatric dialysis patients or to evaluate the impact of those comorbidities on outcomes beyond the newborn period. In the present study, we evaluated the prevalence of comorbidities in a large international cohort of pediatric chronic peritoneal dialysis (CPD) patients from the International Pediatric Peritoneal Dialysis Network registry and began to assess potential associations between those comorbidities and hospitalization rates and mortality. Information on comorbidities was available for 1830 patients 0 - 19 years of age at dialysis initiation. Median age at dialysis initiation was 9.1 years [interquartile range (IQR): 10.9]...

Journal of Korean Medical Science, 2009

Nephron, 1997

X-linked nephrogenic diabetes insipidus (NDI) is a rare disease caused by mutations in the vasopr... more X-linked nephrogenic diabetes insipidus (NDI) is a rare disease caused by mutations in the vasopressin V2 receptor (AVPR2) gene. We analyzed the AVPR2 gene in 6 unrelated Korean families with X-linked NDI, and found 6 novel mutations. Two of them were missense point mutations, 2 were short deletions causing frameshifts, 1 was a duplication of 9 bases, and 1 was a compound gene rearrangement. Four mutations cosegregated with the clinical phenotype in corresponding family members, and one was a de novo mutation. In 1 family, prenatal diagnosis was made by amniocentesis. In conclusion, we found 6 novel mutations in the AVPR2 gene causing X-linked NDI in 6 families, and direct mutational analysis is now applicable for carrier detection and early (prenatal) diagnosis.

Pediatric Research, 2005

X-linked hypophosphatemic rickets (XLH), autosomal dominant hypophosphatemic rickets, hereditary ... more X-linked hypophosphatemic rickets (XLH), autosomal dominant hypophosphatemic rickets, hereditary hypophosphatemic rickets with hypercalciuria, and tumor-induced osteomalacia share clinical and biochemical features, and are collectively referred to as hypophosphatemic rickets (HR). Recently, the molecular bases of HR were elucidated. A review of medical records and mutational analyses of the PHEX and FGF23 genes were performed on 17 unrelated Korean children with HR. The male-to-female ratio was 3:14, and 5 patients were familial. Initial laboratory tests revealed typical features of HR. Seven different PHEX mutations were detected in 8 patients: 2 missense mutations, 2 nonsense mutations, and 3 short deletions. No functional FGF23 mutation was detected in any patient. Patients with the PHEX mutation tended to have more severe skeletal disease than those without. Of the patients with this mutation, no genotype-phenotype correlation and no gene dosage effect were noted. Treatment with vitamin D and phosphate resulted in only a partial growth improvement in most cases, and was frequently complicated by hypercalciuria, hypercalcemia, nephrocalcinosis, or hyperparathyroidism. Renal glycosuria was detected in six

Pediatric Nephrology, 2010

Reactive AA amyloidosis is caused by the accumulation of the acute phase reactant, serum amyloid ... more Reactive AA amyloidosis is caused by the accumulation of the acute phase reactant, serum amyloid A (SAA), as a complication of chronic inflammatory conditions. Cyclic neutropenia is a rare hereditary disorder characterized by repeated episodes of neutropenia at regular intervals, with or without concurrent infection, and is known to be a rare cause of AA amyloidosis. Here, we report a case of a patient who developed systemic AA amyloidosis following a prolonged course of undiagnosed cyclic neutropenia. The patient had a history of recurrent infections since infancy and developed goiter, proteinuria, and azotemia at age 14 years. Her SAA level was markedly increased (601.8 μg/mL, normal range <8 μg/mL), and a thyroid and kidney biopsy revealed typical lesions of AA amyloidosis. Amyloid deposits were also detected in the myocardium, colon, and gallbladder. She had repeated episodes of neutropenia regularly at 3-week intervals and a pathogenic mutation in the ELA2 gene. After 10 months of treatment with recombinant human granulocyte colony-stimulating factor, her SAA level normalized (<2.5 μg/mL), but her renal function did not recover. This case clearly shows that cyclic neutropenia can be complicated by AA amyloidosis unless it is detected early and treated adequately.

Pediatric Nephrology, 2011

MYH9-related disorders are a group of autosomal, dominantly inherited disorders caused by mutatio... more MYH9-related disorders are a group of autosomal, dominantly inherited disorders caused by mutations of the MYH9 gene, which encodes the non-muscle myosin heavy chain IIA (NMMHC-IIA). May-Hegglin anomaly and Sebastian, Fechtner, and Epstein syndromes belong to this group. Macrothrombocytopenia is a common characteristic associated with MYH9-related disorders, and basophilic cytoplasmic inclusion bodies in leukocytes (Döhle-like bodies), deafness, cataracts, and glomerulopathy are also found in some patients. In this study, renal manifestations of 7 unrelated Korean patients with MYH9-related disorders were analyzed. Of a total of 7 patients, 4 had disease-related family histories. One familial case had a mutation in the tail domain of NMMHC-IIA and showed milder renal involvement with preserved renal function by his 30s. Among the 3 familial cases without renal involvement, 2 had mutations in the tail domain of NMMHC-IIA and 1 had a mutation in the motor domain. The remaining 3 sporadic cases had severe renal involvement with rapid progression to end-stage renal disease and mutations located in the motor domain. In summary, mutations in the motor domain of NMMHC-IIA and negative family history were associated with severe renal involvement in patients with MYH9-related disorders. These results are in agreement with those of previous reports.

Kidney International, 2007

Peritonitis is the most common cause of dialysis failure in children on chronic peritoneal dialys... more Peritonitis is the most common cause of dialysis failure in children on chronic peritoneal dialysis. We performed a prospective study of 501 peritonitis episodes in 44 pediatric dialysis centers located in 14 countries that examined peritonitis etiology, efficiency of opinion-based management guidelines, and final outcomes. Culture-negative incidence varied significantly from 11% in North America to 67% in Mexico. Argentina and North America had the highest rate of Gram-negative episodes. Pseudomonas-based peritonitis was eightfold more common in the United States than in Europe, and correlated with the frequency of exit site cleansing and topical mupirocin administration. Significant regional variation in antibiotic susceptibility was noted for the first generation cephalosporins and aminoglycosides. Initial response rates to standardized empiric antibiotic treatment did not differ between regions; however, final outcomes were significantly less favorable in Eastern Europe. The wide regional variation in culture-negative peritonitis, and the distribution and antibiotic susceptibilities of causative bacteria needs to be taken into consideration when the guidelines for empiric therapy of pediatric dialysis-associated peritonitis are revised.

Kidney International, 2010

The mineral and bone disorder of chronic kidney disease remains a challenging complication in ped... more The mineral and bone disorder of chronic kidney disease remains a challenging complication in pediatric end-stage renal disease. Here, we assessed symptoms, risk factors and management of this disorder in 890 children and adolescents from 24 countries reported to the International Pediatric Peritoneal Dialysis Network Registry. Signs of this disease were most common in North American patients. The prevalence of hyperphosphatemia increased with age from 6% in young infants to 81% in adolescents. Serum parathyroid hormone (PTH) was outside the guideline targets in the majority of patients and associated with low calcium, high phosphorus, acidosis, dialysis vintage and female gender. Serum calcium was associated with dialytic calcium exposure, serum phosphorus with low residual renal function and pubertal status. PTH levels were highest in Latin America and lowest in Europe. Vitamin D and its active analogs were most frequently administered in Europe; calcium-free phosphate binders and cinacalcet in North America. Clinical and radiological symptoms markedly increased when PTH exceeded 300 pg/ml, the risk of hypercalcemia increased with levels below 100 pg/ml, and time-averaged PTH concentrations above 500 pg/ml were associated with impaired longitudinal growth. Hence, the symptoms and management of the mineral and bone disorder of chronic kidney disease in children on peritoneal dialysis showed substantial regional variation. Our findings support a PTH target range of 100-300 pg/ml in the pediatric age group.

Journal of the American Society of Nephrology, 2013

PloS one, 2018

Vancomycin is known to be unintentionally eliminated by continuous renal replacement therapy, and... more Vancomycin is known to be unintentionally eliminated by continuous renal replacement therapy, and the protein bound fraction of vancomycin is also known to be different in adults and children. However, there are only a few studies investigating the relationship between the dose of continuous venovenous hemodiafiltration (CVVHDF) parameters and serum concentration of vancomycin in pediatric patients. The aim of this study was to determine clinical and demographic parameters that significantly affect serum vancomycin concentrations. This retrospective cohort study was conducted at a pediatric intensive care unit in a tertiary university children's hospital. Data from oliguric patients who underwent CVVHDF and vancomycin therapeutic drug monitoring were collected. The correlation between factors affecting serum concentration of vancomycin was analyzed using mixed effect model. A total of 177 serum samples undergoing vancomycin therapeutic drug monitoring were analyzed. The median a...

Kidney and Blood Pressure Research, 2017

Background/Aims: Renovascular hypertension (RVHT) is an important cause of childhood hypertension... more Background/Aims: Renovascular hypertension (RVHT) is an important cause of childhood hypertension. This study evaluated the clinical characteristics and outcomes of Korean children with RVHT. Methods: Children treated for RVHT between 2000 and 2015 at our center were retrospectively reviewed. Results: Forty-six children were followed for a median of 6.5 (0.66-27.23) years. Forty-five percutaneous transluminal angioplasties (PTAs) were performed in 32 children. At the last visit, clinical benefit was observed in 53.3% of children. Patients with comorbid cerebrovascular disease (CVD) showed less favorable long-term outcomes after PTA (clinical benefit in 41.7% vs. 61.1% in others) and higher restenosis rates (50% vs. 31.6% in others). Surgical procedures (bypass or nephrectomy) were performed in 8 patients. After surgery, blood pressure was normalized in 2 patients, improved in 3 patients, and unchanged in the remaining patients. Between PTA group (n=21) and medication group (n=14), p...

Journal of the Korean Society of Pediatric Nephrology, 2010

Purpose : Genetic and clinical factors can influence the permeability of the peritoneal membrane.... more Purpose : Genetic and clinical factors can influence the permeability of the peritoneal membrane. The peritoneal equilibration test (PET) is helpful in measuring peritoneal permeability in peritoneal dialysis (PD). We investigated the influence of genetic polymorphism of vascular endothelial growth factor (VEGF) on the PET parameters. Methods : Pediatric patients who underwent PET within 12 months of initiating PD at Seoul National University Children s Hospital and Samsung Medical Center were selected. The ' patients with positive history of peritonitis before PET were excluded. The VEGF-2578C/ A,-14978T/C,-1154G/A,-634G/C, and +936C/T single-nucleotide polymorphisms were genotyped. Results : The mean 4-hour dialysate-to-plasma ratio for creatinine (D/P creatinine) and the mean 4-hour dialysate glucose to baseline dialysate glucose ratio (D/D0 glucose) were 0.56 0.13 and 0.43 0.11, respectively. The patients with haplotype CTGGC showed higher ± ± 4-hour D/P creatinine (0.67 0.12 vs 0.50 0.09, ± ± P =0.007) and lower 4-hour D/D0 glucose (0.35 0.12 vs 0.47 0.08, ± ± P =0.037) than those without haplotype CTGGC. Conclusion : The VEGF genetic polymorphism may influence the peritoneal solute transport.

Kidney Research and Clinical Practice, 2014

Conclusion: In CAMR, RIT could be proposed as a promising regimen in terms of delaying the progre... more Conclusion: In CAMR, RIT could be proposed as a promising regimen in terms of delaying the progression of CAMR and better allograft survival rate compared to HC group.

Pediatric Nephrology, 1999

Several cases of hereditary glomerulopathy associated with an A to G transition at position 3243 ... more Several cases of hereditary glomerulopathy associated with an A to G transition at position 3243 in mitochondrial DNA, which is known to be associated with most cases of MELAS syndrome (myopathy, encephalopathy, lactic acidosis, and stroke-like episodes), have been recently reported. These patients share the characteristics of hereditary progressive glomerular disease and hearing loss with Alport syndrome. We therefore screened 27 patients with kidney disease clinically mimicking Alport syndrome for the presence of the 3243 mitochondrial mutation, and found one girl with the mutation and a positive family history. Her clinical features were very similar to those of all cases reported to date. An absence of hematuria, severe kidney involvement in a female, pathological changes of focal segmental glomerulosclerosis with no basket-weave change of the glomerular capillary wall, and the frequent association of steroid-induced diabetes are the major features that distinguish this condition from Alport syndrome. Careful neurological examination may detect neuromuscular symptoms compatible with mitochondrial cytopathies. In conclusion, progressive glomerulopathy should be included in the broad spectrum of mitochondrial cytopathies, especially in cases of MELAS syndrome. This mutation should also be included in the etiologies of secondary focal segmental glomerulosclerosis and in the differential diagnosis of Alport syndrome.

Journal of the Korean Society of Pediatric Nephrology, 2007

Purpose Urinary lithiasis is uncommon in children, however, it may lead to chronic renal insuffic... more Purpose Urinary lithiasis is uncommon in children, however, it may lead to chronic renal insufficiency and even end stage renal disease. The etiology of stone formation in children is largely unknown; although the most common causes are known to be associated with ...

Korean Journal of Pediatrics, 2009

Purpose : Idiopathic nephrotic syndrome (NS) can be clinically classified as steroid-sensitive an... more Purpose : Idiopathic nephrotic syndrome (NS) can be clinically classified as steroid-sensitive and steroid-resistant. The detailed mechanism of glucocorticoid action in NS is currently unknown. Methods : In this study, we investigated 3 known single nucleotide polymorphisms (SNPs) (ER22/23EK, N363S, and BclI) of the glucocorticoid receptor gene (the NR3C1 gene) in 190 children with NS using polymerase chain reaction-restriction fragment length polymorphism and analyzed the correlation between the genotypes and clinicopathologic features of the patients. Results : Eighty patients (42.1%) were initial steroid nonresponders, of which 31 (16.3% of the total) developed end-stage renal disease during follow-up. Renal biopsy findings of 133 patients were available, of which 36 (31.9%) showed minimal changes in NS and 77 (68.1%) had focal segmental glomerulosclerosis. The distribution of the BclI genotypes was comparable between the patient and control groups, and the G allele frequencies in both the groups were almost the same. The ER22/23EK and N363S genotypes were homogenous as ER/ER and NN, respectively, in all the patients and in 100 control subjects. The BclI genotype showed no correlation with the NS onset age, initial steroid responsiveness, renal pathologic findings, or progression to end-stage renal disease. Conclusion : These data suggested that the ER22/23EK, N363S, and BclI SNPs in the NR3C1 gene do not affect the development of NS, initial steroid responsiveness, renal pathologic lesion, and progression to end-stage renal disease in Korean children with NS.

Journal of the Korean Society of Pediatric Nephrology, 2010

Purpose : Glomerulonephropathy (GN) often manifests as proteinuria and progresses to chronic rena... more Purpose : Glomerulonephropathy (GN) often manifests as proteinuria and progresses to chronic renal failure without specific therapy. Mesenchymal stem cell (MSC) has been tried as a therapeutic agent in experimental GN, and previous studies showed that administration of MSC concomitantly to the insult inducing GN or via intra-renal administration ameliorated proteinuria. The purpose of this study was to test the therapeutic potential of MSC administered via intravenous route at the time of clinically evident proteinuria. Methods : MSCs were administered intravenously via tail vain into the mice with adriamycin (ADR) induced nephropathy (ADR-GN), two weeks after ADR injection when massive proteinuria was evident. To test the capacity of MSC modulate the cytokine production in the inflammatory milieu, the concentrations of IFN-and IL-10 were measured in the su γ pernatant of in vitro mixed lymphocyte culture (MLC) with or without additional MSC. Results : MSCs administered intravenously into the proteinuric mice with ADR-GN accelerated the recovery of this experimental GN with disappearance of proteinuria in two weeks when the saline treated (control) mice still showed significant proteinuria. The mice treated with MSC also had a tendency of better survival. Addition of MSC decreased IFNand increased IL-10 in the supernatant of MLC. γ Conclusion : This study showed that MSC had a therapeutic potential even when administered in a more clinically relevant setting into a proteinuric glomerulonephropathy model. Further study to verify the mechanism and long-term safety of this phenomenon is required. (

Journal of the Korean Society of Pediatric Nephrology, 2010

Korean journal of pediatrics, 2011

To validate the Dinamap ProCare 200 blood pressure (BP) monitor against a mercury sphygmomanomete... more To validate the Dinamap ProCare 200 blood pressure (BP) monitor against a mercury sphygmomanometer in children 7 to 18 years old in accordance with the 2010 International Protocol of European Society of Hypertension (ESH-IP2) and the British Hypertension Society (BHS) protocol. Forty-five children were recruited for the study. A validation procedure was performed following the protocol based on the ESH-IP2 and BHS protocols for children and adolescents. Each subject underwent 7 sequential BP measurements alternatively with a mercury sphygmomanometer and the test device by trained nurses. The results were analyzed according to the validation criteria of ESH-IP2. The mean (±SD) difference in the absolute BP values between test device and mercury sphygmomanometer readings was 1.85±1.65 mmHg for systolic BP (SBP) and 4.41±3.53 mmHg for diastolic BP (DBP). These results fulfilled the Association for the Advancement of Medical Instrumentation criterion of a mean±SD below 5±8 mmHg for both...

Kidney Research and Clinical Practice, 2012

The Korean Society of Nephrology (KSN) launched the official End-Stage Renal Disease (ESRD) Patie... more The Korean Society of Nephrology (KSN) launched the official End-Stage Renal Disease (ESRD) Patient Registry in 1985 and the Internet online registry program was opened in 2001. The ESRD Registry Committee of KSN has collected data on dialysis therapy in Korea through the online registry program in the KSN Internet website. The increasing number of elderly people and diabetic patients in Korea has resulted in a very rapid increase in the number of ESRD patients. The total number of ESRD patients was 58,860 (hemodialysis [HD], 39,509; peritoneal dialysis [PD], 7309; and functioning kidney transplant [KT], 12,042). The prevalence of ESRD was 1144.4 patients per million population (PMP), and the proportion of renal replacement therapy was HD, 67.1%; PD, 12.4%; and KT, 20.5%. The number of new ESRD patients in 2010 was 9335 (HD, 7204; PD, 867; and KT, 1264; the incidence rate was 181.5 PMP). The primary causes of ESRD were diabetic nephropathy (45.2%), hypertensive nephrosclerosis (19.2%), and chronic glomerulonephritis (11.3%). The mean urea reduction ratio was 67.9% in male HD patients and 73.9% in female HD patients. The mean Kt/V was 1.394 in male patients and 1.659 in female patients. Five-year survival rates of male and female dialysis patients were 64.9% and 67.3%, respectively.

Peritoneal dialysis international : journal of the International Society for Peritoneal Dialysis

BACKGROUND, OBJECTIVES, AND METHODS: Hospitalization and mortality rates in pediatric dialysis pa... more BACKGROUND, OBJECTIVES, AND METHODS: Hospitalization and mortality rates in pediatric dialysis patients remain unacceptably high. Although studies have associated the presence of comorbidities with an increased risk for death in a relatively small number of pediatric dialysis patients, no large-scale study had set out to describe the comorbidities seen in pediatric dialysis patients or to evaluate the impact of those comorbidities on outcomes beyond the newborn period. In the present study, we evaluated the prevalence of comorbidities in a large international cohort of pediatric chronic peritoneal dialysis (CPD) patients from the International Pediatric Peritoneal Dialysis Network registry and began to assess potential associations between those comorbidities and hospitalization rates and mortality. Information on comorbidities was available for 1830 patients 0 - 19 years of age at dialysis initiation. Median age at dialysis initiation was 9.1 years [interquartile range (IQR): 10.9]...

Journal of Korean Medical Science, 2009

Nephron, 1997

X-linked nephrogenic diabetes insipidus (NDI) is a rare disease caused by mutations in the vasopr... more X-linked nephrogenic diabetes insipidus (NDI) is a rare disease caused by mutations in the vasopressin V2 receptor (AVPR2) gene. We analyzed the AVPR2 gene in 6 unrelated Korean families with X-linked NDI, and found 6 novel mutations. Two of them were missense point mutations, 2 were short deletions causing frameshifts, 1 was a duplication of 9 bases, and 1 was a compound gene rearrangement. Four mutations cosegregated with the clinical phenotype in corresponding family members, and one was a de novo mutation. In 1 family, prenatal diagnosis was made by amniocentesis. In conclusion, we found 6 novel mutations in the AVPR2 gene causing X-linked NDI in 6 families, and direct mutational analysis is now applicable for carrier detection and early (prenatal) diagnosis.

Pediatric Research, 2005

X-linked hypophosphatemic rickets (XLH), autosomal dominant hypophosphatemic rickets, hereditary ... more X-linked hypophosphatemic rickets (XLH), autosomal dominant hypophosphatemic rickets, hereditary hypophosphatemic rickets with hypercalciuria, and tumor-induced osteomalacia share clinical and biochemical features, and are collectively referred to as hypophosphatemic rickets (HR). Recently, the molecular bases of HR were elucidated. A review of medical records and mutational analyses of the PHEX and FGF23 genes were performed on 17 unrelated Korean children with HR. The male-to-female ratio was 3:14, and 5 patients were familial. Initial laboratory tests revealed typical features of HR. Seven different PHEX mutations were detected in 8 patients: 2 missense mutations, 2 nonsense mutations, and 3 short deletions. No functional FGF23 mutation was detected in any patient. Patients with the PHEX mutation tended to have more severe skeletal disease than those without. Of the patients with this mutation, no genotype-phenotype correlation and no gene dosage effect were noted. Treatment with vitamin D and phosphate resulted in only a partial growth improvement in most cases, and was frequently complicated by hypercalciuria, hypercalcemia, nephrocalcinosis, or hyperparathyroidism. Renal glycosuria was detected in six

Pediatric Nephrology, 2010

Reactive AA amyloidosis is caused by the accumulation of the acute phase reactant, serum amyloid ... more Reactive AA amyloidosis is caused by the accumulation of the acute phase reactant, serum amyloid A (SAA), as a complication of chronic inflammatory conditions. Cyclic neutropenia is a rare hereditary disorder characterized by repeated episodes of neutropenia at regular intervals, with or without concurrent infection, and is known to be a rare cause of AA amyloidosis. Here, we report a case of a patient who developed systemic AA amyloidosis following a prolonged course of undiagnosed cyclic neutropenia. The patient had a history of recurrent infections since infancy and developed goiter, proteinuria, and azotemia at age 14 years. Her SAA level was markedly increased (601.8 μg/mL, normal range <8 μg/mL), and a thyroid and kidney biopsy revealed typical lesions of AA amyloidosis. Amyloid deposits were also detected in the myocardium, colon, and gallbladder. She had repeated episodes of neutropenia regularly at 3-week intervals and a pathogenic mutation in the ELA2 gene. After 10 months of treatment with recombinant human granulocyte colony-stimulating factor, her SAA level normalized (<2.5 μg/mL), but her renal function did not recover. This case clearly shows that cyclic neutropenia can be complicated by AA amyloidosis unless it is detected early and treated adequately.

Pediatric Nephrology, 2011

MYH9-related disorders are a group of autosomal, dominantly inherited disorders caused by mutatio... more MYH9-related disorders are a group of autosomal, dominantly inherited disorders caused by mutations of the MYH9 gene, which encodes the non-muscle myosin heavy chain IIA (NMMHC-IIA). May-Hegglin anomaly and Sebastian, Fechtner, and Epstein syndromes belong to this group. Macrothrombocytopenia is a common characteristic associated with MYH9-related disorders, and basophilic cytoplasmic inclusion bodies in leukocytes (Döhle-like bodies), deafness, cataracts, and glomerulopathy are also found in some patients. In this study, renal manifestations of 7 unrelated Korean patients with MYH9-related disorders were analyzed. Of a total of 7 patients, 4 had disease-related family histories. One familial case had a mutation in the tail domain of NMMHC-IIA and showed milder renal involvement with preserved renal function by his 30s. Among the 3 familial cases without renal involvement, 2 had mutations in the tail domain of NMMHC-IIA and 1 had a mutation in the motor domain. The remaining 3 sporadic cases had severe renal involvement with rapid progression to end-stage renal disease and mutations located in the motor domain. In summary, mutations in the motor domain of NMMHC-IIA and negative family history were associated with severe renal involvement in patients with MYH9-related disorders. These results are in agreement with those of previous reports.

Kidney International, 2007

Peritonitis is the most common cause of dialysis failure in children on chronic peritoneal dialys... more Peritonitis is the most common cause of dialysis failure in children on chronic peritoneal dialysis. We performed a prospective study of 501 peritonitis episodes in 44 pediatric dialysis centers located in 14 countries that examined peritonitis etiology, efficiency of opinion-based management guidelines, and final outcomes. Culture-negative incidence varied significantly from 11% in North America to 67% in Mexico. Argentina and North America had the highest rate of Gram-negative episodes. Pseudomonas-based peritonitis was eightfold more common in the United States than in Europe, and correlated with the frequency of exit site cleansing and topical mupirocin administration. Significant regional variation in antibiotic susceptibility was noted for the first generation cephalosporins and aminoglycosides. Initial response rates to standardized empiric antibiotic treatment did not differ between regions; however, final outcomes were significantly less favorable in Eastern Europe. The wide regional variation in culture-negative peritonitis, and the distribution and antibiotic susceptibilities of causative bacteria needs to be taken into consideration when the guidelines for empiric therapy of pediatric dialysis-associated peritonitis are revised.

Kidney International, 2010

The mineral and bone disorder of chronic kidney disease remains a challenging complication in ped... more The mineral and bone disorder of chronic kidney disease remains a challenging complication in pediatric end-stage renal disease. Here, we assessed symptoms, risk factors and management of this disorder in 890 children and adolescents from 24 countries reported to the International Pediatric Peritoneal Dialysis Network Registry. Signs of this disease were most common in North American patients. The prevalence of hyperphosphatemia increased with age from 6% in young infants to 81% in adolescents. Serum parathyroid hormone (PTH) was outside the guideline targets in the majority of patients and associated with low calcium, high phosphorus, acidosis, dialysis vintage and female gender. Serum calcium was associated with dialytic calcium exposure, serum phosphorus with low residual renal function and pubertal status. PTH levels were highest in Latin America and lowest in Europe. Vitamin D and its active analogs were most frequently administered in Europe; calcium-free phosphate binders and cinacalcet in North America. Clinical and radiological symptoms markedly increased when PTH exceeded 300 pg/ml, the risk of hypercalcemia increased with levels below 100 pg/ml, and time-averaged PTH concentrations above 500 pg/ml were associated with impaired longitudinal growth. Hence, the symptoms and management of the mineral and bone disorder of chronic kidney disease in children on peritoneal dialysis showed substantial regional variation. Our findings support a PTH target range of 100-300 pg/ml in the pediatric age group.

Journal of the American Society of Nephrology, 2013