Cheol Woo Ko

Long-term therapeutic efficacy of lamivudine compared with interferon-α in children with chronic hepatitis B : The younger the better

Objectives: To assess and compare the long-term therapeutic response to lamivudine compared with interferon-α (IFN-α) in children with chronic hepatitis B. Methods: A total of 40 children (27 male; age, 1.3–18 y, mean, 7.7 y) with chronic hepatitis B who received lamivudine for at least 12 months were followed for a mean period of 39 (24–76) months. Their treatment efficacy was historically compared with that of 19 children (14 male; age, 2.1–17 y; mean, 10 y) who had been treated with IFN-α and were followed for a mean period of 39 (24–104) months. Therapeutic responses were compared at 2 y after the initiation of either of the treatment methods. Results: Two years after the initiation of treatment, the results for children treated with lamivudine versus IFN-α were as follows: hepatitis B e antigen (HBeAg) seroconversion occurred in 26 (65%) of the 40 children versus 7 (37%) of the 19 children, P < 0.05. In the lamivudine-treated group, the results for children treated before the age of 7 versus age >7 were as follows: HBeAg seroconversion occurred in 17 (89%) of the 19 children versus 9 (43%) of the 21 children, P < 0.01, and loss of hepatitis B surface antigen (HBsAg) occurred in 8 (42%) versus 0%, P < 0.001. Conclusions: Long-term treatment of lamivudine led to significant improvement in the seroconversion rate of HBeAg in children with chronic hepatitis B compared with IFN-α therapy. Furthermore, in preschool-age children, it led to significant improvement in the seroconversion rate of HBeAg and HBsAg compared with school-age children.

Quality of life in children with end-stage renal disease based on a PedsQL ESRD module.

BackgroundHealth-related quality of life (HRQOL) is an essential subject for children with end-stage renal disease (ESRD) and their families.MethodsWe performed a cross-sectional investigation of HRQOL in children undergoing renal replacement therapies, such as dialysis and renal transplantation, using the 34-item Pediatric Quality of Life Inventory 3.0 End-Stage Renal Disease (PedsQL 3.0 ESRD) module. We assessed 92 ESRD patients aged 2–18 from four Korean university hospitals.ResultsThe male:female ratio was 44:48, and the most common cause of ESRD was chronic glomerulonephritis. Fifty-five children were treated by dialysis, and 37 received renal transplantation. Transplant patients had better HRQOL than dialysis patients in two domains in parent proxy reports: “About my kidney disease” and “Worry.” In child self-reports, transplant patients had better HRQOL than dialysis patients in one domain: Treatment problems. However, there were no significant differences in total QOL scores between peritoneal dialysis (PD) and transplant patients in child self-reports. In addition, there were differences in the ESRD module scores between child self- and parent proxy reports. Children usually reported better QOL than their parents. Child self-reports showed significantly higher QOL scores than parent proxy reports in the domains of General fatigue, Family & peer interaction, and Worry. Children on PD self-reported a significantly higher QOL than children on hemodialysis (HD).ConclusionsThe PedsQL 3.0 ESRD module may be useful as an ESRD-specific instrument to evaluate HRQOL in children; however, a larger, longitudinal prospective study is warranted.

Molecular Analysis of HLA Class ll-Associated Susceptibility to Neuroinflammatory Diseases in Korean Children

The work was done to study immunogenetic peculiarities of neuroinflammatory diseases among Korean children. A total of 13 children with neuroinflammatory diseases (8 males and 5 females; mean age 4.6±2.6 yr) were consecutively recruited. Genomic typing was performed on their HLA DRB/HLA DQB genes using PCR-SSOP/SSP techniques with gel immunoelectrophoresis. The frequencies of HLA-DR1*15 in children with acute disseminated encephalomyelitis (ADEM) (31%) and DQB1*06 in other neuroinflammatory diseases (38%) were significantly increased compared with control subjects. The frequencies of HLA-DRB3*0202 (100%), HLA-DRB1*1302 (67%), HLA-DRB3*0301 (67%), and HLA-DQB1*0301 (67%) were significantly increased in children with multiple sclerosis and the frequencies of HLA-DRB1*1501 (40%) and HLA-DRB5*0101 (40%) were significantly increased in children with ADEM. HLA-DRB1*1401, HLA-DRB3*0202, and HLA-DQB1*0502 were found in children with acute necrotizing encephalopathy. In conclusion, HLA-DR1*15 and DQB1*06 may be involved in susceptibility to inflammation in Korean children. The frequencies of HLA-DRB1*1501, HLA-DRB5*0101, HLA-DRB3*0301, and HLA-DQB1*0602 were not as high in Korean children with multiple sclerosis as in western children. However, HLA-DRB3*0202 was seen in all children with multiple sclerosis. Our data may provide further evidence that the immunogenetic background of neuroinflammatory diseases in Korean is distinctly different from the ones in western countries. Further studies are necessary to confirm this finding.

Reference values for serum levels of insulin-like growth factor-I and insulin-like growth factor binding protein-3 in Korean children and adolescents.

OBJECTIVE Measurements of serum insulin-like growth factor-I (IGF-I) and IGF binding protein-3 (IGFBP-3) are utilized in the diagnostic work-up and clinical management of children with growth disorders. We designed this study to establish the reference values of serum IGF-I and IGFBP-3 levels according to age, sex and pubertal stage in Korean children and adolescents. METHODS For the study, 1378 healthy Korean children and adolescents aged 0 to 17 years (722 boys, 656 girls) were randomly selected. Blood samples were collected, and the stored sera were assayed for IGF-I and IGFBP-3 using immunoradiometric assay (IRMA, Immunotech). The R 2.8.1 program (Bell Laboratories) was used to generate reference percentile curves for IGF-I and IGFBP-3 according to age, sex, and pubertal stage RESULTS Serum IGFBP-3 level was higher in girls compared to that in boys of the same ages throughout the pubertal period, whereas IGF-I was only higher for girls younger than 13 years of age. Serum levels of IGF-I and IGFBP-3 increased steadily with age in the prepubertal stage, followed by a progressive decline thereafter. Peak levels of serum IGF-I and IGFBP-3 were observed two years earlier in girls compared to those in boys (13 vs. 15 years of age, respectively). Serum IGF-I and IGFBP-3 concentrations were highest at Tanner stage IV in boys and girls, with a subsequent decline. CONCLUSIONS Our reference value model based on age, sex, and pubertal stage can improve the diagnostic utility of IGF-1 and IGFBP-3 levels in the evaluation and management of Korean children and adolescents with growth disorders.

Pathophysiology of minimal change nephrotic syndrome and focal segmental glomerulosclerosis

SUMMARY:  Minimal change nephrotic syndrome (MCNS) is the most common cause of the nephrotic syndrome in children, accounting for 90% of cases under the age of 10 years and more than 50% in older children. It has been proposed that MCNS reflects a disorder of T‐lymphocytes. These T cells are thought to release a cytokine – so‐called permeability factor – that injures the glomerular epithelial cells. The identity of this permeability factor is still uncertain. Epithelial cell damage may lead to albuminuria in MCNS by altering the metabolism of polyanions, such as heparan sulphates, that constitute most of the normal charge barrier to the glomerular filtration of macromolecules such as albumin. In contrast, in focal segmental glomerulosclerosis (FSGS) the proteinuria is primarily due to an increased number of large pores in the glomerular basement membrane, leading to an impairment in size selectivity. It has been documented by repeated renal biopsies that some patients with apparent MCNS at the initial biopsy progress to FSGS. Morphological signs which have been proposed to identify the high‐risk subset of MCNS include widespread IgM deposits (IgM nephropathy) and diffuse mesangial hypercellularity. It has been also documented that the initial biopsy of paediatric patients who subsequently showed FSGS had larger glomeruli from children with MCNS and healthy controls. Therefore, the presence of glomerular hypertrophy in biopsies of apparent MCNS appeared to be a high specific indicator of increased risk for progression to FSGS. In comparison with MCNS, a higher proportion of patients with mild mesangial hypercellularity are initial non‐responder. More severe degree of mesangial hypercellularity, as seen in patients with diffuse mesangial hypercellularity, was associated with an even poorer initial response to steroid. Accordingly, it appears that mesangial proliferative glomerulonephritis is a more severe form of MCNS in which the initial injury is greater, leading to mesangial dysfunction and a slower rate of recovery, and this disorder is a part of the MCNS‐FSGS spectrum. In this viewpoint, it can also be said that FSGS is the most severe form of MCNS in which the initial injury is the greatest, so the majority of patients with FSGS are non‐responders to steroid and progress to chronic renal failure. In summary, documents define the risk for progressive renal disease based on the presence of mesangial hypercellularity and glomerular hypertrophy in renal biopsies of patients with MCNS, thus directing vigilant follow up and more aggressive treatment of high‐risk patients.

Clinical characterization and identification of two novel mutations of the GNAS gene in patients with pseudohypoparathyroidism and pseudopseudohypoparathyroidism

Objective  Pseudohypoparathyroidism (PHP) and pseudopseudohypoparathyroidism (PPHP) are rare disorders resulting from genetic and epigenetic aberrations in the GNAS locus.

Interleukin-8 and Tumor Necrosis Factor-Alpha Are Increased in Minimal Change Disease but Do Not Alter Albumin Permeability

Aims: Minimal change disease (MCD) is the most common primary nephrotic syndrome in children. Some suggested that interleukin-8 (IL-8) and tumor necrosis factor-α (TNF-α) are involved in the pathogenesis of MCD. This study was done to see changes of plasma and urinary IL-8, TNF-α, and their effects on determination of permeability of glomerular basement membrane (BM) contributed by heparan sulfate proteoglycan (HSPG). Methods: Study patients consisted of 19 biopsy-proven MCD children aged 2–15 years old. Both plasma, urinary IL-8 and TNF-α were measured. Employing the Millicell system, IL-8 and TNF-α were screened for the permeability factors. We examined whether IL-8 and TNF-α regulated BM HSPG gene expression and HS synthesis in the glomerular epithelial cells (GECs). Results: Urinary IL-8 during relapse was significantly increased when compared with that of during remission or controls (13,996 ± 2,811 vs. 2,941 ± 373, 5,331 ± 640 ng/mg·cr) (p < 0.05). Urinary TNF-α during relapse was also significantly increased (364.4 ± 51.2 vs. 155.3 ± 20.8, 36.0 ± 4.5 ng/mg·cr) (p < 0.05). Plasma IL-8 during relapse was significantly increased compared to that during remission(1.19 ± 0.62 vs. 0.51 ± 0.42 ng/ml) (p < 0.05). However, the negative results were obtained in the permeability assay using the Millicell system. No difference was seen in BM HSPG gene expression and HS synthesis in the GECs. Conclusion: Therefore, it seems that both IL-8 and TNF-α may not play a disease-specific role in the pathogenesis of MCD.

Recombinant human growth hormone and Gitelman's syndrome.

Gitelmans syndrome is a primary renal tubular disorder with hypokalemic metabolic alkalosis, hypocalciuria, and magnesium deficiency. Short stature is one of clinical manifestations in children. The pathogenesis of short stature in Gitelmans syndrome is not known. To evaluate whether growth hormone (GH) is deficient and whether recombinant human GH (rhGH) improves growth rate, rhGH therapy was tried in a child with Gitelmans syndrome. Both height and body weight were less than the third percentile. Laboratory and radiologic findings suggested GH deficiency. During the first 6 months, rhGH therapy with potassium supplement markedly elevated growth rate from 3.8 cm/yr to 12.0 cm/yr. After cessation of rhGH, height increment markedly decreased to the pretreatment level of 3.6 cm/yr during the second 6 months. Additionally, hypomagnesemia was corrected after rhGH therapy. Accordingly, GH deficiency may contribute to short stature in children with Gitelmans syndrome, and rhGH therapy would be an excellent adjunctive treatment for short children with Gitelmans syndrome whose condition is resistant to conventional therapies in terms of growth.

Identification of Candidate Gene Variants in Korean MODY Families by Whole-Exome Sequencing

Aims: To date, 13 genes causing maturity-onset diabetes of the young (MODY) have been identified. However, there is a big discrepancy in the genetic locus between Asian and Caucasian patients with MODY. Thus, we conducted whole-exome sequencing in Korean MODY families to identify causative gene variants. Methods: Six MODY probands and their family members were included. Variants in the dbSNP135 and TIARA databases for Koreans and the variants with minor allele frequencies >0.5% of the 1000 Genomes database were excluded. We selected only the functional variants (gain of stop codon, frameshifts and nonsynonymous single-nucleotide variants) and conducted a case-control comparison in the family members. The selected variants were scanned for the previously introduced gene set implicated in glucose metabolism. Results: Three variants c.620C>T:p.Thr207Ile in PTPRD, c.559C>G:p.Gln187Glu in SYT9, and c.1526T>G:p.Val509Gly in WFS1 were respectively identified in 3 families. We could not find any disease-causative alleles of known MODY 1-13 genes. Based on the predictive program, Thr207Ile in PTPRD was considered pathogenic. Conclusions: Whole-exome sequencing is a valuable method for the genetic diagnosis of MODY. Further evaluation is necessary about the role of PTPRD, SYT9 and WFS1 in normal insulin release from pancreatic beta cells.

Efficacy of Short-Term Growth Hormone Treatment in Prepubertal Children with Idiopathic Short Stature

Purpose It has been reported that daily recombinant human growth hormone (GH) treatment showed beneficial effects on growth in prepubertal children with idiopathic short stature (ISS). The present study aimed to validate the GH (Eutropin®) effect on growth promotion and safety after short-term GH treatment. Materials and Methods This study was an open-label, multicenter, interventional study conducted at nine university hospitals in Korea between 2008 and 2009. Thirty six prepubertal children with ISS were enrolled in this study to receive 6-month GH treatment. Yearly growth rate, height standard deviation score (SDS), and adverse events were investigated during treatment. Results After 26 weeks of GH treatment, the height velocity significantly increased by 6.36±3.36 cm/year (p<0.001). The lower end of one-sided 95% confidence interval was 5.22 cm/year, far greater than the predefined effect size. The gain in height SDS at week 26 was 0.57±0.27 (p<0.0001). Bone age significantly increased after GH treatment, however, bone maturation rate (bone age for chronological age) showed limited advancement. This 26-week GH treatment was effective in increasing serum levels of insulin-like growth factor (IGF)-I and IGF binding protein (IGFBP)-3 from baseline (p<0.0001). Eutropin was well tolerated and there were no withdrawals due to adverse events. No clinically significant changes in laboratory values were observed. Conclusion This 6-month daily GH treatment in children with ISS demonstrated increased height velocity, improved height SDS, and increased IGF-I and IGFBP-3 levels with a favorable safety profile.