• Childhood Kidney Diseases
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• v.21 no.2
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• pp.41-46
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• 2017

Purpose: Thin glomerular basement membrane nephropathy (TBMN) is, along with the IgA nephropathy, the most common cause of asymptomatic hematuria in Korean children. TBMN is usually a benign renal disease not requiring treatment and is associated with a good prognosis, but some cases hematuria is indicative of a state of progressive renal insufficiency. We aimed to retrospectively evaluate clinical manifestations and renal prognosis of patients with TBMN. Methods: Among the 428 renal biopsies performed on children at Yeungnam University Hospital between January 2000 and February 2017, 167 patients were diagnosed as having TBMN. We retrospectively investigated 167 pediatric patients and identified 59 children with follow-up duration >3 years. Results: Among 59 patients, there were 33 boys and 26 girls. Mean age of onset of hematuria was $7.18{\pm}2.64$ years, and mean time from onset of disease until a renal biopsy was performed was $2.48{\pm}2.10$ years. There were no clinical features or laboratory findings among studied children to indicate decreased renal function during follow-up; however, one case progressed to chronic kidney disease (CKD) due to an unknown cause. There were seven patients among these related a positive family history of hematuria or renal insufficiency. Concluson: Although almost all patients had normal renal functions during follow-up, there were one patient who progressed to CKD and seven patients with family history of hematuria or renal insufficiency. Moreover, four among the 428 patients over 17 years underwent repeat renal biopsies, which showed results different from their earlier biopsies.Thus, large-scales studies may be required to determine long-term prognosis of TBMN in children, and further evaluation for Alport syndrome in TBMN cases is essential.

• Clinical and Experimental Pediatrics
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• v.54 no.1
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• pp.36-39
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• 2011

Bartter syndrome (BS) is a clinically and genetically heterogeneous inherited renal tubular disorder characterized by renal salt wasting, hypokalemic metabolic alkalosis and normotensive hyperreninemic hyperaldosteronism. There have been several case reports of BS complicated by focal segmental glomerulosclerosis (FSGS). Here, we have reported the case of a BS patient who developed FSGS and subsequent end-stage renal disease (ESRD) and provided a brief literature review. The patient presented with classic BS at 3 months of age and developed proteinuria at 7 years. Renal biopsy performed at 11 years of age revealed a FSGS perihilar variant. Hemodialysis was initiated at 11 years of age, and kidney transplantation was performed at 16 years of age. The post-transplantation course has been uneventful for more than 3 years with complete disappearance of BS without the recurrence of FSGS. Genetic study revealed a homozygous p.Trp(TGG)610Stop(TGA) mutation in the CLCNKB gene. In summary, BS may be complicated by secondary FSGS due to the adaptive response to chronic salt-losing nephropathy, and FSGS may progress to ESRD in some patients. Renal transplantation in patients with BS and ESRD results in complete remission of BS.

• Childhood Kidney Diseases
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• v.11 no.2
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• pp.299-305
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• 2007

Herlyn-Werner-Wunderlich syndrome(HWWs) is a rare variant of Mullerian ductal anomalies characterized by the presence of a hemivaginal septum, a didelphic uterus, and ipsilateral renal agenesis. It usually presents after menarche with progressive pelvic pain, and palpable mass due to hemihematocolpos. If a cystic mass is detected behind the urinary bladder in children, in association with the absence of a kidney, the diagnosis of uterus didelphys with imperforate vagina and hydrocolpos should be considered. When renal agenesis is found in asymptomatic children, the small size and the tubular shape of the uterus makes it almost impossible to evaluate uterine anomalies, so follow-up should be performed until the end of puberty. Appropriate preoperative diagnosis and treatment will prevent unnecessary procedures and offer relief of symptoms. We report one case of didelphic uterus with blind hemivagina and ipsilateral renal agenesis with biopsy- proven thin glomerular basement membrane disease which is not related to the above syndrome.

• Childhood Kidney Diseases
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• v.12 no.2
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• pp.250-255
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• 2008

Diabetes mellitus(DM) is a metabolic syndrome caused by deficiency of insulin secretion and a consequence of insulin resistance. Poor glycemic control is a common finding in children with Type 1 DM(T1DM). Approximately 60% of the young patients with T1DM develop abnormalities in the eyes and 15-20% in the kidney. Diabetic nephropathy (DN) is a serious metabolic complication of T1DM that leads to renal failure. Some clinical studies report that the duration of prepubertal diabetes may contribute less to the development of microvascular complications than pubertal and postpubertal duration. There have been few cases of DN in prepubertal patients with T1DM in Korea. Thus we report a case of a 12-year-old female with T1DM who had poor glycemic control and was diagnosed as DN in a prepubertal period. It was proven by renal biopsy after microscopic hematuria and proteinuria were detected through the mass school urinary screening program.

• Childhood Kidney Diseases
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• v.10 no.1
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• pp.83-88
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• 2006

Orthostatic or postural proteinuria is a benign condition characterized by the presence of protein in urine samples collected in the upright position during the day and its absence in the supine position. Recently, nutcracker phenomenon has been documented as the source of postural proteinuria. The nutcracker phenomenon refers to compression of the left renal vein between the aorta and superior mesenteric artery, resulting in elevation of pressure in the left renal vein, leading to congestion of the left kidney and occasionally to collateral veins formation. Entrapment of the left renal vein is a cause of left-sided gross hematuria, ureteral and peripelvic varices, unexplained left flank pain and variable degrees of orthostatic proteinuria. We report the case of a 14-year-old girl with orthostatic proteinuria, diagnosed as having nutcracker syndrome by doppler sonography and MR angiography. Because daily protein excretion was more than 1.5 grams over 3 years of follow up, we decided to perform a renal biopsy which revealed moderate mesangial cell proliferation in all glomeruli.

• Childhood Kidney Diseases
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• v.14 no.1
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• pp.94-99
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• 2010

Obesity-related glomerulopathy (ORG) is a secondary form of focal and segmental glomerulosclerosis (FSGS) manifesting as proteinuria and progressive renal dysfunction that results from maladaptive glomerular response to increasing adiposity. Reports of ORG progressing to end stage renal diseases in rare in the pediatric population. We report a 9-year-old boy with obesity (body mass index $35\;kg/m^2$) who was diagnosed with ORG presenting with proteinuria. He was diagnosed with obesity-related glomerulopathy based on the laboratory, urinary, and kidney biopsy finding. In spite of treatment with angiotensin- converting enzyme (ACE) inhibitor and/or, angiotensin-receptor blocking agent, the degree or amount of proteinuria increased and renal function declined continuously. His BMI did not decrease and eventually progressed to chronic renal failure. Consequently, obese patients should be monitored for proteinuria, which may be the first manifestation of FSGS, a lesion that may be associated with serious renal sequelae.

• Childhood Kidney Diseases
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• v.24 no.2
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• pp.120-125
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• 2020

Gorham-Stout syndrome is a rare bone disorder characterized by progressive massive osteolysis and proliferation of vascular and lymphatic vessels. A 15-year-old boy was initially diagnosed with Gorham-Stout at the age of 8 years based on clinical and radiological findings. Following diagnosis, he was treated with pamidronate, interferon alfa, propranolol, oral corticosteroids, and sirolimus. He developed proteinuria at the age of 15 and progressed into the nephrotic range 2 years later. A renal biopsy revealed focal segmental glomerulosclerosis, not otherwise specified variant. The sequential increase in proteinuria associated with medications suggested that the focal segmental glomerulosclerosis may be caused by pamidronate and sirolimus, but cannot completely rule out the possibility of kidney involvement of GSS itself.

• Childhood Kidney Diseases
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• v.10 no.2
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• pp.152-161
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• 2006

Purpose : In Korea, the school urine screening program is a useful tool for screening urine abnormalities. It is particularly useful in early detection of membranoproliferative glomerulonephritis(MPGN) I, which frequently progresses to chronic renal failure. In this study, we studied the medical history, laboratory findings, and histologic findings of MPGN to gain helpful information on early detection and treatment. Methods : The subjects were 19 children, who were diagnosed with MPGN from kidney biopsies that were performed in ten nationwide university hospitals because of abnormal urine findings from school urine screening programs conducted from July 1999 to April 2004. We divided the patients into 2 groups, a nephrotic range proteinuria group(n=8) and a non-nephrotic proteinuria group(n=11), and retrospectively analyzed the clinical features, laboratory findings, histologic findings, treatment, and clinical course. Results : The mean age at the first abnormal urinalysis was $10.6{\pm}2.2$ years in the nephrotic proteinuria group and $9.6{\pm}3.2$ years in the non-nephrotic proteinuria group. The mean age at the time of kidney biopsy was $11.3{\pm}2.3$ years in the nephrotic range proteinuria group and $10.4{\pm}3.2$ years in the non-nephrotic proteinuria group respectively. There was no significant difference in the mean age and sex between the two groups. In the nephrotic proteinuria group, 6 children had a low plasma C3 level and in the non-nephrotic proteinuria group, 8 children had a low plasma C3 level, but there was no significant difference between the 2 groups. There was no significant difference in the laboratory test results(including WBC count, RBC count, platelet count and other serologic tests) between the 2 groups except for 24 hour urine protein secretion. There was no difference between the 2 groups with regard to the acute and chronic changes in the glomerulus on light microscopic findings, IgG, IgA, Ig M, C1q, C3, C4, fibrogen deposition on immunofluoroscence findings, and mesangial deposits, subendothelial deposits, and subepithelial deposits on electron microscopic findings. The children were treated with corticosteroids, ACE(angiotensin-converting enzyme) inhibitors, dipyridamole and other immunosuppressive agents. During the course of treatment, there were no children whose clinical condition worsened. Among 19 children, 3 children went into remission(2 in the nephrotic proteinuria group, 1 in the non-nephrotic proteinuria group) and 9 children went into a partial remission(4 in the nephrotic proteinuria group, 5 in the non-nephrotic proteinuria group) on urinalysis. There was no significant difference in the treatment results between the two groups. Conclusion : The 73.7% of children who were incidentally diagnosed with MPGN by the school urine screening program had reduced C3. 42.1% of the children had nephrotic range proteinuria. There were no significant differences in clinical features, laboratory test results, light microscopic, immunofluorescence microscopic, and electron microscopic findings between the nephrotic proteinuria group and the non-nephrotic proteinuria group except for the 24 hour urine protein secretion. Therefore, for early detection of MPGN during the school urine screening program, we strongly recommend a kidney biopsy if children have abnormal urine findings such as persistent proteinuria and persistent hematuria, or if the serum C3 is reduced.

• Childhood Kidney Diseases
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• v.4 no.2
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• pp.154-160
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• 2000

The pathogenesis of IgA nephropathy and acute poststreptococcal glomerulonephritis is not fully understood. In the past, acute poststreptococcal glumerulonephritis was the most common cause of gross hematuria in children, but now IgA nephropathy is the most common one. We experienced two cases of acute poststreptococcal glomerulonephritis superimposing to IgA nephropathy in boys Case 1 had upper respiratory infection before elevation of anti-streptolysin O, generalized edema, gross hematuria and proteinuria. The complement levels were normal. Electron microscopic findings of renal biopsy at ten days after onset showed a few big subepithelial 'humps' and localized heavy subendothelial and mesangial deposits. Immunofluoroscopic findings revealed predominant IgA deposition in the mesangium. The electron microscopic findings were diagnostic of acute poststreptococcal glomerulonephritis On the other hand, immunoflorescence microscopic findings were compatible to IgA nephropathy. In case 2, the renal biopsy which was done 2 years after onset showed only finding of IgA nephropathy. To our knowledges, there has been kw reports of acute poststreptococcal glomerulonephritis superimposing to IgA nephropathy which was confirmed by renal biopsy. We report two cases of acute poststreptococcal glomerulonephritis superimposing: to IgA nephropathy with a brief review of the literatures.

• Childhood Kidney Diseases
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• v.12 no.1
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• pp.93-98
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• 2008

Rare cases of IgG associated mesangial glomerulonephritis(IgG GN) defined by exclusive or predominant mesangial IgG deposits were reported first by Sato et al.(1993). and subsequently 10 pediatric cases were reported by Yoshikawa et al.(1994). Previous reports suggested that the prognosis of IgG GN is relatively benign course but recent report suggested that prognosis of IgG GN is highly variable. Also the recurrence of IgG GN in a renal transplant was reported by Fakhouri et al. (2002). Such a recurrence highlights the specificity of this type of glomerulonephritis. We experienced two pediatric cases of IgG GN proven by renal biopsy. Case 1. 4-year-old girl with nephrotic syndrome admitted because of general edema. The patient's urinalysis showed proteinuria and microscopic hematuria. Renal biopsy was performed because of relapsed nephritic syndrome. Light microscopic finding was nonspecific with almost normal histology. Immunofluorescent findings showed diffuse segmental IgG(+) and IgM(+) deposits in the capillary walls, and focal segmental spotty C4(trace), C1q(trace) deposits. Electron microscopic findings showed focal portion of mesangial electron dense deposits without mesangial widening. Case 2. 11-year-old girl admitted for evaluation of microsopic hematuria detected through mass school urinary screening program. Renal biopsy was performed for exact diagnosis. Immunofluorescent findings showed focal segmental IgG(+), IgM(+/-) and C3(+/-) deposits. Electron microscopic findings showed focal portion of mesangial electron dense deposits without mesangial widening.